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Background: The diagnostic criteria for lateral lymph node metastasis in rectal cancer have not been established. This research aimed to investigate the risk factors for lateral lymph node metastasis and develop machine learning models combining these risk factors to improve the diagnostic performance of standard imaging., Method: This multicentre prospective study included patients who underwent lateral lymph node dissection without preoperative treatment for rectal cancer between 2017 and 2019 in 15 Japanese institutions. First, preoperative clinicopathological factors and magnetic resonance imaging findings were evaluated using multivariable analyses for their correlation with lateral lymph node metastasis. Next, machine learning diagnostic models for lateral lymph node metastasis were developed combining these risk factors. The models were tested in a training set and in an internal validation cohort and their diagnostic performance was tested using receiver operating characteristic curve analyses., Results: Of 212 rectal cancers, 122 patients were selected, including 232 lateral pelvic sides, 30 sides of which had pathological lateral lymph node metastasis. Multivariable analysis revealed that poorly differentiated/mucinous adenocarcinoma, extramural vascular invasion, tumour deposit and a short-axis diameter of lateral lymph node ≥ 6.0 mm were independent risk factors for lateral lymph node metastasis. Patients were randomly divided into a training cohort (139 sides) and a test cohort (93 sides) and machine learning models were computed on the basis of a combination of significant features (including: histological type, extramural vascular invasion, tumour deposit, short- and long-axis diameter of lateral lymph node, body mass index, serum carcinoembryonic antigen level, cT, cN, cM, irregular border and mixed signal intensity). The top three models with the highest sensitivity in the training cohort were as follows: support vector machine (sensitivity, 1.000; specificity, 0.773), light gradient boosting machine (sensitivity, 0.950; specificity, 0.918) and ensemble learning (sensitivity, 0.950; specificity, 0.917). The diagnostic performances of these models in the test cohort were as follows: support vector machine (sensitivity, 0.750; specificity, 0.667), light gradient boosting machine (sensitivity, 0.500; specificity, 0.852) and ensemble learning (sensitivity, 0.667; specificity, 0.864)., Conclusion: Machine learning models combining multiple risk factors can contribute to improving diagnostic performance of lateral lymph node metastasis., (© The Author(s) 2024. Published by Oxford University Press on behalf of BJS Foundation Ltd.)

Aim: The significance of lymphadenectomy and its indications in patients with inguinal lymph node metastasis (ILNM) of anorectal adenocarcinoma is unclear. This study aimed to clarify the surgical outcomes and prognostic factors of inguinal lymphadenectomy for ILNM., Method: This study included patients who underwent surgical resection for ILNM of rectal or anal canal adenocarcinoma with pathologically positive metastases between 1997 and 2011 at 20 participating centres in the Study Group for Inguinal Lymph Node Metastasis from Colorectal Cancer organized by the Japanese Society for Cancer of the Colon and Rectum. Clinicopathological characteristics and short- and long-term postoperative outcomes were retrospectively analysed., Results: In total, 107 patients were included. The primary tumour was in the rectum in 57 patients (53.3%) and in the anal canal in 50 (46.7%). The median number of ILNMs was 2.34. Postoperative complications of Clavien-Dindo Grade III or higher were observed in five patients. The 5-year overall survival rate was 38.8%. Multivariate analysis identified undifferentiated histological type (P < 0.001), pathological venous invasion (P = 0.01) and pathological primary tumour depth T0-2 (P = 0.01) as independent prognostic factors for poor overall survival., Conclusion: The 5-year overall survival after inguinal lymph node dissection was acceptable, and it warrants consideration in more patients. Further larger-scale studies are needed in order to clarify the surgical indications., (© 2024 Association of Coloproctology of Great Britain and Ireland.)

Background: The neoadjuvant rectal score (NAR score) has recently been proposed as a better prognostic model than the conventional TNM classification for rectal cancer patients that have undergone neoadjuvant chemoradiotherapy. We recently developed an apoptosis-detection technique for assessing the viability of residual tumors in resected specimens after chemoradiotherapy. This study aimed to establish an improved prognostic classification by combining the NAR score and the assessment of the apoptosis of residual cancer cells., Methods: We retrospectively enrolled 319 rectal cancer patients who underwent chemoradiotherapy followed by radical surgery. The recurrence-free survival and overall survival of the four models were compared: TNM stage, NAR score, modified TNM stage by re-staging according to cancer cell viability, and modified NAR score also by re-staging., Results: Downstaging of the ypT stage was observed in 15.5% of cases, whereas only 4.5% showed downstaging of ypN stage. C-index was highest for the modified NAR score (0.715), followed by the modified TNM, TNM, and NAR score. Similarly, Akaike's information criterion was smallest in the modified NAR score (926.2), followed by modified TNM, TNM, and NAR score, suggesting that the modified NAR score was the best among these four models. The overall survival results were similar: C-index was the highest (0.767) and Akaike's information criterion was the smallest (383.9) for the modified NAR score among the four models tested., Conclusion: We established a novel prognostic model, for rectal cancer patients that have undergone neoadjuvant chemoradiotherapy, using a combination of apoptosis-detecting immunohistochemistry and neoadjuvant rectal scores., (© 2024. The Author(s) under exclusive licence to Japan Society of Clinical Oncology.)

Purpose: Although lateral lymph node dissection has been performed to prevent lateral pelvic recurrence in locally advanced lower rectal cancer, the incidence of lateral pelvic recurrence after this procedure has not been investigated. Therefore, this study aimed to investigate the long-term outcomes of patients who underwent lateral pelvic lymph node dissection, with a particular focus on recurrence patterns., Methods: This was a retrospective study conducted at a single high-volume cancer center in Japan. A total of 493 consecutive patients with stage II-III rectal cancer who underwent lateral lymph node dissection between January 2005 and August 2022 were included. The primary outcome measures included patterns of recurrence, overall survival, and relapse-free survival. Patterns of recurrence were categorized as lateral or central pelvic., Results: Among patients who underwent lateral lymph node dissection, 18.1% had pathologically positive lateral lymph node metastasis. Lateral pelvic recurrence occurred in 5.5% of patients after surgery. Multivariate analysis identified age > 75 years, lateral lymph node metastasis, and adjuvant chemotherapy as independent risk factors for lateral pelvic recurrence. Evaluation of the recurrence rate by dissection area revealed approximately 1% of recurrences in each area after dissection., Conclusion: We demonstrated the prognostic outcome and limitations of lateral lymph node dissection for patients with advanced lower rectal cancer, focusing on the incidence of recurrence in the lateral area after the dissection. Our study emphasizes the clinical importance of lateral lymph node dissection, which is an essential technique that surgeons should acquire., (© 2024. The Author(s).)

A 50s female was diagnosed as rectal cancer with multiple liver metastases after fecal occult blood scrutiny. Liver metastases were multiple in both lobes and involved the right Glisson's capsule. We determined that the liver metastases were unresectable and initiated FOLFOXIRI plus panitumumab treatment. After 6 courses of chemotherapy, rectal cancer resection was performed. After 12 courses of chemotherapy, the liver metastases which had extensively involved the right Glisson on imaging, shrank until the P7 root was visible. If S7 Glisson could be preserved, the radical resection was planned. If not, associated liver partition and portal vein ligation for staged hepatectomy(ALPPS)was planned. Intraoperatively, it was determined that preservation of S7 Glisson was possible and blood flow preservation in the S7 region was feasible, and an anterior segment hepatic resection(S5-6-8)and lateral segment hepatic partial resection(S2/3)were performed. She was discharged on the 18th day and has been under outpatient observation 12 months after hepatectomy.

Background: Metastatic lateral lymph node dissection can improve survival in patients with rectal adenocarcinoma, with or without chemoradiotherapy. However, the optimal imaging diagnostic criteria for lateral lymph node metastases remain undetermined., Objective: To develop a lateral lymph node metastasis diagnostic artificial intelligence tool using deep learning, for patients with rectal adenocarcinoma who underwent radical surgery and lateral lymph node dissection., Design: Retrospective study., Settings: Multicenter study., Patients: A total of 209 patients with rectal adenocarcinoma, who underwent radical surgery and lateral lymph node dissection at 15 participating hospitals, were enrolled in the study and allocated to training (n = 139), test (n = 17), or validation (n = 53) cohorts., Main Outcome Measures: In the neoadjuvant treatment group, images taken before pretreatment were classified as baseline images and those taken after pretreatment as presurgery images. In the upfront surgery group, presurgery images were classified as both baseline and presurgery images. We constructed 2 types of artificial intelligence, using baseline and presurgery images, by inputting the patches from these images into ResNet-18, and we assessed their diagnostic accuracy., Results: Overall, 124 patients underwent surgery alone, 52 received neoadjuvant chemotherapy, and 33 received chemoradiotherapy. The number of resected lateral lymph nodes in the training, test, and validation cohorts was 2418, 279, and 850, respectively. The metastatic rates were 2.8%, 0.7%, and 3.7%, respectively. In the validation cohort, the precision-recall area under the curve was 0.870 and 0.963 for the baseline and presurgery images, respectively. Although both baseline and presurgery images provided good accuracy for diagnosing lateral lymph node metastases, the accuracy of presurgery images was better than that of baseline images., Limitations: The number of cases is small., Conclusions: An artificial intelligence tool is a promising tool for diagnosing lateral lymph node metastasis with high accuracy., Desarrollo De Una Herramienta De Inteligencia Artificial Para El Diagnstico De Metstasis En Ganglios Linfticos Laterales En Cncer De Recto Avanzado: ANTECEDENTES:Disección de nódulos linfáticos laterales metastásicos puede mejorar la supervivencia en pacientes con adenocarcinoma del recto, con o sin quimiorradioterapia. Sin embargo, aún no se han determinado los criterios óptimos de diagnóstico por imágenes de los nódulos linfáticos laterales metastásicos.OBJETIVO:Nuestro objetivo fue desarrollar una herramienta de inteligencia artificial para el diagnóstico de metástasis en nódulos linfáticos laterales mediante el aprendizaje profundo, para pacientes con adenocarcinoma del recto que se sometieron a cirugía radical y disección de nódulos linfáticos laterales.DISEÑO:Estudio retrospectivo.AJUSTES:Estudio multicéntrico.PACIENTES:Un total de 209 pacientes con adenocarcinoma del recto, que se sometieron a cirugía radical y disección de nódulos linfáticos laterales en 15 hospitales participantes, se inscribieron en el estudio y se asignaron a cohortes de entrenamiento (n = 139), prueba (n = 17) o validación (n = 53).PRINCIPALES MEDIDAS DE RESULTADO:En el grupo de tratamiento neoadyuvante, las imágenes tomadas antes del tratamiento se clasificaron como imágenes de referencia y las posteriores al tratamiento, como imágenes previas a la cirugía. En el grupo de cirugía inicial, las imágenes previas a la cirugía se clasificaron como imágenes de referencia y previas a la cirugía. Construimos dos tipos de inteligencia artificial, utilizando imágenes de referencia y previas a la cirugía, ingresando los parches de estas imágenes en ResNet-18. Evaluamos la precisión diagnóstica de los dos tipos de inteligencia artificial.RESULTADOS:En general, 124 pacientes se sometieron a cirugía solamente, 52 recibieron quimioterapia neoadyuvante y 33 recibieron quimiorradioterapia. El número de nódulos linfáticos laterales removidos en los cohortes de entrenamiento, prueba y validación fue de 2,418; 279 y 850, respectivamente. Las tasas metastásicas fueron 2.8%, 0.7%, y 3.7%, respectivamente. En el cohorte de validación, el área de recuperación de precisión bajo la curva fue de 0.870 y 0.963 para las imágenes de referencia y antes de la cirugía, respectivamente. Aunque tanto las imágenes previas a la cirugía como las iniciales proporcionaron una buena precisión para diagnosticar metástasis en los nódulos linfáticos laterales, la precisión de las imágenes previas a la cirugía fue mejor que la de las imágenes iniciales.LIMITACIONES:El número de casos es pequeño.CONCLUSIÓN:La inteligencia artificial es una herramienta prometedora para diagnosticar metástasis en los nódulos linfáticos laterales con alta precisión. (Traducción-Dr. Aurian Garcia Gonzalez )., (Copyright © The ASCRS 2023.)

A 66-year-old man with a history of frequent diarrhea was diagnosed with rectal cancer with obstruction and a pelvic abscess. Following a transverse colostomy, he was referred to our hospital. The initial diagnosis was rectal cancer(cT4a N1bM0, cStage Ⅲb)and a pelvic abscess due to tumor perforation. To address this condition, we performed neoadjuvant chemotherapy using a combination of 5-fluorouracil, Leucovorin, oxaliplatin, and irinotecan(FOLFOXIRI). Following 6 courses of FOLFOXIRI, the abscess disappeared and no signs of tumor progression and distant metastases were detected. Subsequently, we performed radical resection with D3LD2 lymph node dissection, leading to a pathological diagnosis of ypT3N1aM0, ypStage Ⅲb. The patient then underwent adjuvant chemotherapy with capecitabine and oxaliplatin(CAPOX). No recurrence was observed after 9 months of follow-up.

Aim: The preoperative prediction of lymph node metastasis of well-differentiated rectal neuroendocrine tumours is highly desirable and useful in defining surgical indication more accurately. We aimed to evaluate lymph node metastasis in rectal neuroendocrine neoplasms using multiple imaging modalities., Methods: The clinical records and radiological images of 70 patients with well-differentiated rectal neuroendocrine tumours who received treatment at the University of Tokyo Hospital between 2010 and 2022 were retrospectively analysed. The relationship between evaluation by multiple imaging modalities and pathological lymph node metastasis was analysed., Results: The receiver operating characteristic curves showed that a maximum lymph node diameter ≥4 mm on computed tomography and ≥8 mm on magnetic resonance imaging were the optimal predictive factors for lymph node metastasis. Accumulation in the lymph nodes on somatostatin receptor scintigraphy (P = 0.058) and Delle's findings on colonoscopy (P = 0.014) were also significant predictors of pathological lymph node positivity, and combination of multiple modalities was useful. Pathologically, lymphatic (P = 0.0030)/venous (P = 0.0007) invasion were risk factors for lymph node metastasis., Conclusions: In addition to pathological risk factors, a combination of multiple radiological imaging modalities is useful for predicting lymph node metastasis in well-differentiated rectal neuroendocrine tumours., (© 2023 The Authors. Colorectal Disease published by John Wiley & Sons Ltd on behalf of Association of Coloproctology of Great Britain and Ireland.)

Background: Total neoadjuvant therapy (TNT) is a novel treatment strategy that is an alternative to preoperative chemoradiotherapy (CRT) for locally advanced rectal cancer (LARC). However, an optimal protocol for TNT has not yet been established. The present study will be an open-label, single-arm, single-center trial to develop a new protocol., Methods: Thirty LARC patients at high risk of distant metastasis will receive CRT consisting of long-course radiation, concurrent with tegafur/uracil, oral leucovorin, irinotecan (TEGAFIRI), followed by mFOLFOX-6 or CAPOX before undergoing surgery., Discussion: Since previous findings showed a high percentage of grade 3-4 adverse events with the TEGAFIRI regimen for CRT and TNT, the primary outcome of this study will be safety and feasibility. Our regimen for CRT consists of the biweekly administration of irinotecan for good patient compliance. The novel combination approach of this treatment may improve the long-term outcomes of LARC., Trial Registration: Japan Registry of Clinical Trials jRCTs031210660., (© 2023. The Author(s).)

We report a case of a 73-year-old man who underwent endoscopic mucosal resection (EMR) for early rectal cancer(i ntramucosal cancer)at other hospital 17 years ago. Ten years later, he underwent a total colonoscopy, which showed no recurrence of the tumor. Twelve years later, a mass with calcification was incidentally detected in front of the sacrum, which was diagnosed as a benign tumor at that time. Seventeen years later, he presented with constipation and diarrhea, and was detected of a sub-circumferential tumor in the rectum by a total colonoscopy. Biopsy revealed that the tumor was malignancy. CT showed a mass in the left lateral liver lobe. The mass was suspected of metastasis. Laparoscopic super lower anterior resection was performed for rectal cancer, and pathological examination showed that the tumor was pT4a, N3, M1(H), Stage Ⅳa. One month after surgery, laparoscopic hepatectomy was performed for liver metastasis. Six months after surgery, CT showed multiple lung metastases. He continues to undergo chemotherapy. Although this case was treated with EMR for intramucosal carcinoma, clinical history and pathological findings suggested local recurrence.

A 98-year-old woman presented with hematochezia and a circumferential type 2 tumor in the rectum Rb identified on fiberoscopy. We a performed laparoscopic Hartmann's operation and D2 lymphadenectomy for advanced rectal cancer. A sigmoid colostomy was created via the intraperitoneal route. On the postoperative day 12, the patient experienced abdominal pain. Computed tomography showed that the small intestine formed a closed loop in the pelvic space. The patient was diagnosed with a strangulated bowel obstruction of the small intestine for which an emergency exploratory laparotomy was performed. The small intestine, which had passed through a defect between the lifted sigmoid colon and the left abdominal wall, was strangulated by the lifted sigmoid colon. We performed partial resection of the small intestine. The patient died on postoperative day 32 of acute deterioration of aortic valve stenosis. There have been few reports of strangulated bowel obstruction resulting from internal hernia associated with colostomy. These findings demonstrate that it is important to select the appropriate route for colostomy creation in each case.

Total mesorectal excision (TME) for rectal cancer is often technically challenging. We aimed to develop a method for three-dimensional (3D) visualization of the TME dissection plane and to evaluate its ability to predict surgical difficulty. Sixty-six patients with lower rectal cancer who underwent robot-assisted surgery were retrospectively analyzed. A 3D TME dissection plane image for each case was reconstructed using Ziostation2. Subsequently, a novel index that reflects accessibility to the deep pelvis during TME, namely, the TME difficulty index, was defined and measured. Representative bony pelvimetry parameters and clinicopathological factors were also analyzed. The operative time for TME was used as an indicator of surgical difficulty. Univariate regression analysis revealed that sex, body mass index, mesorectal fat area, and TME difficulty index were associated with the operative time for TME, whereas bony pelvimetry parameters were not. Multivariate regression analysis found that TME difficulty index (β = - 0.398, P = 0.0025) and mesorectal fat area (β = 0.223, P = 0.045) had significant predictability for the operative time for TME. Compared with conventional bony pelvimetry parameters, the TME difficulty index and mesorectal fat area might be more useful in predicting the difficulty of rectal cancer surgery., (© 2023. The Author(s).)

The patient was a 68-year-old woman without history of surgery. She presented with abdominal pain and leg edema. Ultrasound scan revealed hepatic masses. Colonoscopy and abdominal CT scan revealed unresectable rectal carcinoma with massive multiple liver metastases suspected of invasion of the inferior vena cava. After a transverse colon bi-pore colostomy, 10 courses of FOLFOX plus panitumumab therapy were administered, and the liver tumor was markedly reduced in size and determined to be PR by CT. Considering the possibility of unresectability due to the liver metastases re-growth, surgery was planned with liver-first approach(LFA). First, open resection of the right caudate lobe of the liver, combined resection of the IVC, combined resection of the diaphragm, partial hepatic S2 resection(2 sites), and cholecystectomy were performed, followed by laparoscopic anterior resection(D3)1 month later(R0). Postoperatively, the colostomy was closed after 8 courses of CapeOX(capecitabine alone from the middle of the course). Now the patient is alive and recurrence-free 4 years after the initial diagnosis. Conversion surgery with LFA after chemotherapy can be an effective treatment strategy for colorectal cancer with advanced liver metastases.

A 70s-year-old man visited the gastroenterologist with a complaint of bloody stool. Lower gastrointestinal endoscopy revealed a 50 mm type 0-Ⅰs+Ⅱa lesion in the center of the anterior wall of Rb in 4 cm from anal verge, and he was diagnosed with rectal cancer in cT1bcN0cM0, cStage Ⅰ. Endoscopic submucosal dissection was performed, but it was discontinued due to muscular traction, and was referred to our department at a later date for surgical purposes. Robot-assisted laparoscopic Hartmann's surgery(D2 dissection, sigmoid colon colostomy)was performed, and the pathological result was pT2pN0cM0, pStage Ⅰ with negative resection margins. Three months after the operation, a tumor was found on the left side of the stoma, and he visited us. Biopsy revealed the recurrence of skin metastasis of rectal cancer, and surgical procedure including colostomy and skin tumor resection, ileostomy, and colonic mucus fistula was performed. The patient was transferred to the hospital 3 months after the operation, but 2 months after the transfer, an increasing CEA was observed and CT revealed a local recurrence in the pelvis. Irradiation(45 Gy/15 times)was performed for the pain relief, but the general condition deteriorated thereafter and he died 8 months after the second operation.

Background: LLND in cases with suspected lateral lymph node (LLN) metastasis has been focused on as a novel treatment strategy in recent years. However, the optimal indication for LLND in rectal cancer patients has not been determined. This study aimed to establish the optimal indication for lateral lymph node dissection (LLND) in patients with rectal cancer using magnetic resonance imaging (MRI)., Methods: A total of 209 patients with rectal adenocarcinoma who underwent total mesorectal excision and LLND in 13 hospitals were prospectively registered. By matching the sizes of the harvested LNs and those in magnetic resonance imaging (MRI), the pathological outcome of each LN was confirmed one-by-one. Using parameters of the LLNs in MRI, the optimal diagnostic criteria for LLND were established., Results: Of 3241 harvested LLNs, including 83 metastatic nodes, 1010 (31.1%) were visualized on MRI. Although all parameters assessed showed strong correlations with the presence of metastasis, none of these parameters could discriminate metastatic LLNs from non-metastatic nodes with sufficient sensitivity. However, by using the combination of long axis and short/long ratio in pretreatment MRI, we could establish optimal criteria for LLND. The sensitivity and specificity of the criteria for LLN metastasis were 94.3% and 40.2%, respectively., Conclusions: In conclusion, we established novel criteria for LLND in rectal cancer patients using MRI. Our criteria will be of great clinical use in determining indications for LLND., (© 2022 Royal Australasian College of Surgeons.)

Introduction: We previously developed risk models for mortality and morbidity after low anterior resection using a nationwide Japanese database. However, the milieu of low anterior resection in Japan has undergone drastic changes since then. This study aimed to construct risk models for 6 short-term postoperative outcomes after low anterior resection, i.e., in-hospital mortality, 30-day mortality, anastomotic leakage, surgical site infection except for anastomotic leakage, overall postoperative complication rate, and 30-day reoperation rate., Methods: This study enrolled 120,912 patients registered with the National Clinical Database, who underwent low anterior resection between 2014 and 2019. Multiple logistic regression analyses were performed to generate predictive models of mortality and morbidity using preoperative information, including the TNM stage., Results: We developed new risk prediction models for the overall postoperative complication and 30-day reoperation rates for low anterior resection, which were absent from the previous version. The concordance indices for each endpoint were 0.82 for in-hospital mortality, 0.79 for 30-day mortality, 0.64 for anastomotic leakage, 0.62 for surgical site infection besides anastomotic leakage, 0.63 for complications, and 0.62 for reoperation. The concordance indices of all four models included in the previous version showed improvement., Conclusion: This study successfully updated the risk calculators for predicting mortality and morbidity after low anterior resection using a model based on vast nationwide Japanese data., (© 2023 S. Karger AG, Basel.)

Purpose: We investigated the surgical outcomes of robotic low anterior resection (LAR) for lower rectal cancer after preoperative chemoradiotherapy (pCRT)., Methods: A total of 175 patients with lower rectal cancer who underwent LAR after pCRT between 2005 and 2020 were stratified into open (OS, n = 65), laparoscopic (LS, n = 64), and robotic surgery (RS, n = 46) groups. We compared the clinical, surgical, and pathological results among the three groups., Results: The RS and LS groups had less blood loss than the OS group (p < 0.0001). The operating time in the RS group was longer than in the LS and OS groups (p < 0.0001). The RS group had a significantly longer mean distal margin than the LS and OS groups (25.4 mm vs. 20.7 mm and 20.3 mm, respectively; p = 0.026). There was no significant difference in the postoperative complication rate among the groups. The local recurrence rate in the RS group was comparable to those in the LS and OS groups., Conclusion: Robotic LAR after pCRT was performed safely for patients with advanced lower rectal cancer. It provided a longer distal margin and equivalent local control rates., (© 2022. The Author(s) under exclusive licence to Springer Nature Singapore Pte Ltd.)

The patient was a 70s man, whose chief complaint of Hematochezia. He visited neighborhood hospital and was diagnosed with lower rectal cancer by colonoscopy. Preoperative CT showed a mass in the bladder, which led to a diagnosis of multiple early stage bladder cancer after a thorough urological examination. We diagnosed that very low anterior resection was necessary for rectal cancer and total bladder resection was necessary for bladder cancer. The patient underwent robotic- assisted total pelvic exenteration with anal preservation. One year and three months have passed since the surgery, and no signs of recurrence have been observed.

Background: We carried out robot-assisted lateral pelvic lymph node dissection (LPLND) for rectal cancer with a stereotactic navigation system. The purpose of this study was to evaluate the accuracy and feasibility of the system., Methods: We constructed a navigation system based on the Polaris Spectra optical tracking device (Northern Digital Inc., Canada) and the open-source software 3D Slicer (version 3.8.1; http://www.slicer.org ). We used the landmark-based registration method for patient-to-image registration. Body surface landmarks and intra-abdominal landmarks were used. We evaluated the time required for registration and target registration error (TRE; the distance between corresponding points after registration) for the root of the superior gluteal artery the root of the obturator or superior vesical artery, and the obturator foramen during minimally invasive LPLND for rectal cancer. Five patients who had LPLND for rectal cancer at the University of Tokyo Hospital between September 2020 and May 2021 were enrolled., Results: The mean time required for registration was 49 s with the body surface landmarks and 88 s with the intra-abdominal landmarks. The mean TRE improved markedly when the registration was performed using intra-abdominal landmarks. The mean TRE of the root of the superior gluteal artery, the root of the obturator or superior vesical artery, and the obturator foramen were 55.8 mm, 53.4 mm, and 55.2 mm with the body surface landmarks and 11.8 mm, 10.0 mm, and 12.6 mm with the intra-abdominal landmarks, respectively. There were no adverse events related to the registration process., Conclusions: When stereotactic navigation systems are used for minimally invasive LPLND, the use of intra-abdominal landmarks for registration is feasible and may allow simpler and more accurate navigation than the use of body surface landmarks., (© 2022. Springer Nature Switzerland AG.)

Background: Persistent descending mesocolon (PDM) is a fetal abnormality in which the left-sided colon is not fused to the retroperitoneum, and it is often accompanied by the adhesion between the mesocolon and small bowel mesentery. Due to its rarity, whether PDM exhibits anatomical characteristics of the inferior mesenteric artery (IMA) and left colic artery (LCA), and how the anomaly affects laparoscopic surgery are largely unknown. We investigated the branches of these arteries and outcomes of patients who underwent laparoscopic surgery., Methods: Based on computed tomography (CT) and three-dimensional CT angiography, branching patterns of the IMA, LCA and branches originating from the LCA were analysed in 954 patients with left-sided colon or rectal cancer. PDM was diagnosed by preoperative CT colonography, and confirmed at time of surgery. The anatomical features of the vessels and short-term outcomes of laparoscopic surgery were compared between patient groups stratified by PDM., Results: Twelve patients (1.3%) were diagnosed with PDM. No branching pattern of the IMA specific to PDM was noted. On the other hand, patients with PDM had fewer branches (mean: 1.0) from the LCA than those without PDM (mean: 1.8, p = 0.009). In patients undergoing laparoscopic surgery, outcomes such as operative time, intraoperative blood loss, and number of harvested nodes were comparable between the two patient groups., Conclusion: Few branches of the LCA characterize PDM. PDM does not complicate laparoscopic surgery of the left-sided colon and rectum. However, the above anatomical feature increases the risk of poor colonic perfusion when dividing the LCA., (© 2022 Royal Australasian College of Surgeons.)

Purpose: We investigated whether or not computed tomographic colonography (CTC) is a viable alternative to double-contrast barium enema (BE) for a preoperative rectal cancer evaluation., Methods: The size and distance from the anal canal to the lower or upper tumor borders were laterally measured in 147 patients who underwent CTC and BE. Measurements were grouped into early cancer, advanced, and after chemoradiation therapy (CRT)., Results: In the early and advanced cancer groups, all lesions were visualized by BE. In contrast, 3 (7.8%) early and 8 (7.3%) advanced cases, located at the anterior wall near the anal canal, were not visualized by CTC because of liquid level formation. In the CRT group, 16 (23.5%) and 4 (5.8%) cases were not visualized by CTC and BE, respectively. The BE and CTC size measurements were similar among cohorts. However, the distance from the anal canal's superior margin tended to be longer with BE, especially in early cancer. The differences in distance from the anal canal were significantly larger in the early cancer group than in the other two groups (p = 0.0024)., Conclusion: CTC may be a viable alternative imaging modality in some cases. However, BE should be employed in anterior wall cases near the anal canal and CRT cases., (© 2021. The Author(s) under exclusive licence to Springer Nature Singapore Pte Ltd.)

Background: Lateral pelvic lymph node dissection for rectal cancer is challenging due to the complexity of the pelvic wall anatomy, and incomplete lateral pelvic lymph node dissection may result in local recurrence in the lateral pelvis. Although 3-dimensional printed organ models are useful for understanding spatial anatomy, it is currently unclear whether they improve surgical outcomes., Objective: We aimed to assess whether the surgical effectiveness of lateral pelvic lymph node dissection is increased by the use of individualized 3-dimensional printed pelvic models., Design: This was a retrospective study using a propensity matching analysis., Settings: This study was conducted at a university hospital in Japan., Patients: In total, 115 patients comprising 184 pelvic sides (right, 85 sides; left, 99 sides) who underwent lateral pelvic lymph node dissection for colorectal adenocarcinoma between January 2012 and December 2019 were enrolled., Interventions: We compared surgical outcomes using 3-dimensional printed pelvic models with control outcomes., Main Outcome Measures: The primary outcome was the number of harvested lateral pelvic lymph nodes on 1 pelvic side after the propensity matching analysis., Results: After matching, 35 pelvic sides each were allocated to the 3-dimensional model and control groups, and no significant differences were observed in patient characteristics between the 2 groups. The number of harvested lateral pelvic lymph nodes was significantly higher in the 3-dimensional model group (median, 9; range, 3-16) than in the control group (median, 6; range, 0-22; p = 0.047)., Limitations: This was a retrospective study using propensity score matching. However, historical backgrounds were not matched, and the majority of lateral pelvic lymph node dissection procedures in the 3-dimensional model group were recently performed. This limitation may have influenced surgical outcomes., Conclusion: The present study demonstrated that, by referring to individualized 3-dimensional printed pelvic models, colorectal surgeons harvested a larger number of lateral pelvic lymph nodes during lateral pelvic lymph node dissection. This result suggests that 3-dimensional printed models help surgeons to complete more detailed procedures. See Video Abstract at http://links.lww.com/DCR/B776., Mejora De Los Resultados Quirrgicos Mediante El Uso De Modelos Impresos En D Para La Diseccin Lateral De Los Ganglios Linfticos Plvicos En El Cncer De Recto: ANTECEDENTES:La disección lateral de los ganglios linfáticos de la pelvis en el cáncer de recto es un desafío debido a la complejidad de la anatomía de la pared pélvica; la disección incompleta de las mismas puede resultar en una recidiva local en dicha zona. Aunque la impresión tridimensional de modelos de órganos es útil para comprender la estructura anatómica espacial, actualmente no está claro si mejoran los resultados quirúrgicos.OBJETIVO:Nuestro objetivo fue evaluar si la efectividad quirúrgica de la disección de los ganglios linfáticos laterales de la pelvis aumenta mediante el uso individualizado de modelos pélvicos impresos en 3D.DISEÑO:Este fue un estudio retrospectivo que utilizó un análisis de coincidencia de propensión.AJUSTE:Este estudio se realizó en un hospital universitario de Japón.PACIENTES:En total, se enrolaron 115 pacientes que comprendían 184 lados pélvicos (85 de lado derecho; 99 de lado izquierdo) que fueron sometidas a disección lateral de ganglios linfáticos de la pelvis por adenocarcinoma colorrectal entre enero de 2012 y diciembre de 2019.INTERVENCIONES:Comparamos los resultados quirúrgicos mediante modelos pélvicos tridimensionales impresos con los resultados de control.PRINCIPALES MEDIDAS DE RESULTADO:El resultado primario fue el número de ganglios linfáticos laterales pélvicos extraídos en un lado pélvico después del análisis de coincidencia de propensión.RESULTADOS:Después del emparejamiento, se asignaron 35 lados pélvicos cada uno, tanto al modelo tridimensional como al grupo de control; no se observaron diferencias significativas con respecto a las características de los pacientes entre los dos grupos. El número de ganglios linfáticos pélvicos laterales extraídos fue significativamente mayor en el grupo del modelo tridimensional (mediana, 9; rango 3-16) que en el grupo de control (mediana, 6; rango, 0-22) (p = 0.047).LIMITACIONES:Este fue un estudio retrospectivo que utilizó el emparejamiento por puntuación de propensión. Sin embargo, antecedentes históricos no fueron encontrados y la mayoría de los procedimientos de disección de los ganglios linfáticos laterales pélvicos en el grupo del modelo tridimensional se realizaron recientemente. Esta limitación pudo haber influido en los resultados quirúrgicos.CONCLUSIONES:El presente estudio demostró que al referirse a modelos pélvicos individualizados impresos en 3D, los cirujanos colorrectales recolectaron un mayor número de ganglios linfáticos laterales de la pelvis durante la disección lateral. Este resultado sugiere que los modelos tridimensionales impresos ayudan a los cirujanos a completar procedimientos más detallados. Consulte Video Resumen en http://links.lww.com/DCR/B776., (Copyright © The ASCRS 2021.)

Background/aim: CD133 and hypoxia-inducible factor 1α (HIF-1α) have been reported to be affected by chemoradiotherapy (CRT), but the combinatorial assessment of these markers for prognosis after CRT has not been fully investigated. Therefore, we aimed to predict recurrence and prognosis in patients with rectal cancer by assessing changes in the expression of both CD133 and HIF-1α after CRT., Materials and Methods: CD133 and HIF-1α expression was evaluated by immunohistochemistry in surgical specimens from 243 patients with advanced low rectal cancer who received CRT followed by curative resection., Results: The positivity rate of CD133 expression showed increase with increased HIF-1α expression. The combination of these two markers showed that the CD133(+)HIF-1α(-) group exhibited a markedly shorter relapse-free survival (p=0.007), higher liver recurrence (p=0.004), and higher local recurrence (p=0.006)., Conclusion: CD133(+)HIF-1α(-) expression after CRT is a promising marker to predict recurrence in rectal cancer., (Copyright © 2022 International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

Background: Para-aortic lymph node (PALN) metastasis is an ominous manifestation indicating a poor prognosis in colorectal cancer (CRC) patients; however, some treatments prolong survival. In this study, we investigated predictors of prolonged survival in CRC patients after PALN metastasis., Methods: We examined 141 patients with CRC that metastasized to the PALNs from CRC with or without extra-PALN metastasis. Among clinicopathological parameters, factors associated with survival after PALN metastasis were identified by multivariate analyses using Cox's proportional hazard models., Results: The mean hemoglobin and albumin values at diagnosis were 12.3 g/dL and 3.7 g/dL, respectively. Rectal cancer was predominant (n = 81). Mutated RAS was detected in 43%. One hundred and four patients had differentiated adenocarcinoma. Patients underwent PALN dissection (n = 11), radiotherapy (n = 6), and systemic therapy (n = 120). Biologics were administered to 95 patients. The median survival time was 29.1 months. On multivariate analysis, independent factors associated with reduced survival after PALN metastasis were low albumin (hazard ratio [HR] 2.33 per -1 g/dL), mutated RAS (HR 2.55), other than differentiated adenocarcinoma (HR 2.75), rectal cancer (HR 3.38 against right-sided colon, and 3.48 against left-sided colon), the presence of extra-PALN metastasis (HR 6.56), and no use of biologics (HR 3.04)., Conclusions: This study revealed that hypoalbuminemia as well as RAS mutation, undifferentiated histology, rectal cancer, other site metastasis, and no use of biologics contribute to poor prognosis in CRC patients with PALN metastasis. Nutritional management may be important for improving survival of these patients., (© 2021. The Author(s) under exclusive licence to Japan Society of Clinical Oncology.)

Purpose: Preoperative chemoradiotherapy (CRT) followed by total mesorectal excision (TME) without lateral lymph node (LLN) dissection is widely performed for lower advanced rectal cancer. However, it is unclear whether residual cancer cells in the LLNs undergo apoptosis, disappear, or regrow if unresected., Methods: Overall, 293 consecutive patients with T3/4 rectal cancer who underwent CRT followed by radical surgery between September 2003 and December 2018 were retrospectively reviewed. We assessed apoptosis of the residual primary tumor, mesorectum lymph nodes (MLN), and LLN using M30 cytoDEATH immunostaining and evaluated the degree of apoptosis. The difference in the prognosis of the lateral lymph node metastasis positive (LLNM +) and lateral lymph node metastasis negative (LLNM-) groups was assessed., Results: There were 31 patients (10.6%) who were diagnosed with a complete response by hematoxylin and eosin (HE) staining. The residual cancer cells showed complete apoptosis in the primary lesion in 28 patients, in the metastatic MLN in only two patients, and in the metastatic LLN in one patient. The LLNM + group had a significantly poorer distant recurrence, recurrence-free survival, and overall survival than the LLNM- group., Conclusion: The majority of the residual cancer tissue in LNs observed by HE staining was found to be non-apoptotic. If LLN metastasis is suspected on pretreatment imaging, performing LLN dissection together with TME should be considered., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Background: This study aimed to investigate the effect of sarcopenia on the prognosis of advanced lower rectal cancer patients receiving neoadjuvant chemoradiotherapy (CRT). Sarcopenia has been recognized as an adverse factor for surgical outcomes in several malignancies. However, the impact of preoperative sarcopenia on rectal cancer patients receiving CRT is still unknown., Methods: This retrospective study included cT3-T4 anyN M0 lower rectal cancer patients who underwent CRT followed by R0 resection at our institution between October 2003 and December 2016. CRT consisted of 5-fluorouracil-based oral chemotherapy and long course radiation (50.4 Gy/28 fr). The psoas muscle area at the third lumbar vertebra level was evaluated by computed tomography before and after CRT, and was adjusted by the square of the height to obtain the psoas muscle mass index (PMI). Sarcopenia was defined as the sex-specific lowest quartile of the PMI. We assessed the association between pre- and post-CRT sarcopenia and postoperative prognosis., Results: Among 234 patients, 55 and 179 patients were categorized as sarcopenia and non-sarcopenia patients, respectively. Although post-CRT sarcopenia correlated with residual tumor size, it had no association with other pathological features. The median follow-up period was 72.9 months, and the 5-year DFS and OS were 67.0% and 85.8%, respectively. Multivariate analysis showed that post-CRT sarcopenia was independently associated with poor DFS (HR: 1.76; P = 0.036), OS (HR: 2.01; P = 0.049), and recurrence in the liver (HR: 3.01; P = 0.025)., Conclusions: Sarcopenia is a poor prognostic indicator in lower advanced rectal cancer patients treated with CRT., (© 2021. The Author(s) under exclusive licence to Japan Society of Clinical Oncology.)

Background/aim: This study aimed to determine the effectiveness of surgical site infection (SSI) prevention approaches in rectal cancer surgery., Patients and Methods: A total of 1,408 patients who underwent elective rectal cancer surgery between 1995 and 2017 were reviewed. Patients were divided into three groups: control group (group A, n=245), SSI prevention intervention group (group B, n=516), and laparoscopic or robotic surgery group (group C, n=647). The groups were compared in terms of SSI and anastomotic leakage (AL) incidences, and risk factors for SSI were investigated., Results: The overall SSI and AL rates were 19.4% and 3.6%, respectively. These rates were significantly lower in Group C (9.3%, 1.7%), compared to Groups A (40.0%, 6.1%) and B (22.5%, 3.5%). Abdominoperineal resection, open surgery, operation time, intraoperative bleeding, lack of absorbable sutures, lack of mechanical bowel preparation, and lack of oral antibiotics were independently associated with SSI., Conclusion: SSI reduction after rectal cancer surgery was achieved through various intervention strategies., (Copyright © 2022 International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

Background: Preoperative chemoradiotherapy (CRT) is the standard therapy for locally advanced rectal cancer (LARC). However, the changes that the patient's physical status during CRT, such as host systemic inflammatory response, nutritional status, and muscle depletion, are still unclear. We evaluated the clinical significance of malnutrition and sarcopenia for patients with LARC undergoing CRT., Patients and Methods: Patients with LARC treated with CRT following radical surgery at our institution between 2006 and 2016 (N = 225) were retrospectively analyzed. A new prognostic score (PNSI) was devised based on the prognostic nutritional index (PNI) and the psoas muscle mass index (PMI): patients with malnutrition/sarcopenia were scored 2; patients with one and neither abnormality were scored 1 and 0, respectively., Results: Neutrophil/lymphocyte ratio, monocyte/lymphocyte ratio, and platelet/lymphocyte ratio increased, whereas PNI and PMI decreased after CRT. There were 130, 73, and 22 patients in the PNSI 0, 1, and 2 groups, respectively. Patients with higher PNSI had higher residual tumor size (p = 0.003), yT stage (p = 0.007), ypStage (p < 0.001), post-CRT platelet/lymphocyte ratio (p = 0.027), and post-CRT C-reactive protein/albumin ratio (p < 0.001). Post-CRT PNSI was associated with overall survival and was an independent poor prognosis factor (PNSI 1 to 0, hazard ratio 2.40, p = 0.034, PNSI 2 to 0, hazard ratio 2.66, p = 0.043) together with mesenteric lymph node metastasis, lateral lymph node metastasis, and histology., Conclusion: A combined score of post-CRT malnutrition/sarcopenia is promising for predicting overall survival in LARC., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Background: Analysis of long-term clinical outcomes of patients with familial adenomatous polyposis is critical in reducing or preventing the incidence of extracolonic malignancies after initial surgery. The aim of the present study was to clarify the long-term outcomes, and establish a surveillance strategy for surgically treated familial adenomatous polyposis patients., Methods: Between January 1967 and March 2020, retrospective data were collected from 37 patients with familial adenomatous polyposis treated or monitored in our department. Occurrence of metachronous cancers, including rectal cancers and extracolonic malignancies, and other diseases was analyzed., Results: The median follow-up duration after the first surgery was 13.8 years. Initially, 16 patients underwent total proctocolectomy with ileal pouch-anal anastomosis, 18 underwent total colectomy with ileorectal anastomosis, and three underwent other procedures. A secondary proctectomy was performed for 9 of the 18 patients who underwent ileorectal anastomosis. Rectal cancer was diagnosed in 6 patients who underwent ileorectal anastomosis. In addition, 5 gastric cancer, 2 duodenal cancer, 1 gallbladder cancer, and 1 thyroid cancer cases were diagnosed. The age at which the extracolonic malignancies were diagnosed was >50 years. 4 patients died due to metachronous rectal cancer, gastric cancer, or gallbladder cancer., Conclusion: Careful consideration should be paid before choosing ileorectal anastomosis as the treatment procedure for familial adenomatous polyposis patients because completion proctectomy was eventually necessary for half of the patients. Long-term surveillance, with more frequent gastric surveillance for patients over 50 years, is important for the prevention and treatment of extracolonic malignancies in familial adenomatous polyposis patients., Competing Interests: Declaration of competing interest The authors have no conflicts to disclose., (Copyright © 2021. Published by Elsevier Taiwan LLC.)

Introduction: Preoperative chemoradiotherapy (CRT) is the standard therapy for downstaging in locally advanced lower rectal cancer. However, it remains unclear whether rectal cancers downstaged by preoperative therapy show similar prognoses to those of the same stage without preoperative therapy. We previously demonstrated that preoperative CRT did not affect prognosis of rectal cancer with pathological T1N0 (pT1N0) stage in a single institute. Here, using a larger dataset, we compared prognoses of (y)pT1 rectal cancer stratified by the use of preoperative therapy and analyzed prognostic factors., Methods: Cases of pT1N0 rectal cancer, registered between 2004 and 2016, were extracted from the Surveillance, Epidemiology, and End Results database. Patients were categorized as the "ypT1 group" if they had undergone preoperative therapy before surgery or as the "pT1 group" if they had undergone surgery alone. Overall survival (OS) and cancer-specific survival (CSS) between these groups of patients were compared. Factors associated with CSS and OS were identified by univariate and multivariate analyses., Results: Among 3,757 eligible patients, ypT1 and pT1 groups comprised 720 and 3,037 patients, respectively. While ypT1 patients showed poorer CSS than ypT1 patients, there was no significant difference in OS. Preoperative therapy was not an independent prognostic factor for CSS or OS. Multivariate analysis identified age and histological type as significant factors associated with CSS. Sex, age, race, and number of lymph nodes dissected were identified as significant factors associated with OS., Conclusions: Prognosis among patients with (y)p T1N0 rectal cancer was similar irrespective of whether they underwent preoperative therapy, which is consistent with our previous observations., (© 2021 The Author(s). Published by S. Karger AG, Basel.)

We report the case of a patient who underwent additional surgical resection of a rectal neuroendocrine tumor(NET)G1 with a tumor diameter of 5 mm after endoscopic resection, and lymph node metastasis was observed. The patient was a 33- year-old woman. A lower gastrointestinal endoscopy was performed to examine the blood in the stool. A submucosal tumor of 5 mm in size was found in the rectum Ra, and endoscopic mucosal resection was performed. Pathological examination of the resected tissue revealed NET G1; HE staining revealed negative margins and no vascular invasion, but additional immunostaining revealed lymphatic invasion(Ly1a). Additional surgical resection was decided, and a laparoscopy-assisted low anterior resection D3 were performed. The surgical resection specimen showed no residual NET component in the rectum, but metastasis was found in one lymph node. The postoperative course of the patient has been uneventful, and the patient is currently undergoing without recurrence 6 months after the surgery. In the case of NET G1, it is important to search for detailed vascular invasion by immunostaining even in small lesions, and if vascular invasion is found, additional surgical resection should be considered.

A woman in her 30s visited our hospital complaining primarily of melena. Colonoscopy revealed the presence of a type 1 tumor in 2 cm from anal verge. Contrast-enhanced CT showed an unresectable massive liver metastasis in the left lobe of the liver and another metastasis in the right lobe. The patient received front-line chemotherapy with Leucovorin, fluorouracil, oxaliplatin, and irinotecan(FOLFOXIRI)plus bevacizumab(BEV). A year later, a marked reduction of liver metastases and primary lesions was confirmed by CT scan imaging. A multidisciplinary team recommended resection of the liver metastases followed by laparoscopic intersphincteric resection for primary lesions. However, after 1 year, a recurrence was diagnosed in the liver; hence, FOLFOXIRI plus BEV was reintroduced for volume reduction. The patient underwent a repeat hepatectomy since enough volume reduction was confirmed. One year later, she experienced a re-relapse of the metastasis in the liver. Currently, she is still undergoing chemotherapy following 7 years since the first visit. Long-term survival can be expected following surgical treatment during chemotherapy.

The presence of extramural tumor deposits without lymph node structure (EX) is an important prognostic factor in patients with colorectal carcinoma. However, there is no English literature on neuroendocrine tumor (NET) with EX. We report a patient with rectal NET with extracapsular metastasis of a regional lymph node that was considered to be EX. A 51-year-old Japanese woman with diabetes was referred to our hospital for further examination of a submucosal tumor in the lower rectum. She was diagnosed as having rectal NET by immunohistochemical analysis of a biopsy, and underwent laparoscopic low anterior resection with lymph node dissection and covering ileostomy. Pathological findings of the resected specimen showed that the primary tumor was NET-G1 without any lymphatic or venous invasion. A single metastatic deposit was found near the capsule of a NET-negative regional lymph node. She has been free from recurrence for nine months without adjuvant treatments. Extracapsular metastasis of NET on a dissected lymph node in our case was considered to correspond to EX as defined for colorectal carcinoma. This rare case suggests that NET can disseminate to form EX in a similar manner to colorectal carcinoma., (© 2021. Japanese Society of Gastroenterology.)

Purpose: This study aimed to elucidate the benefits and limitations of preoperative chemoradiotherapy (CRT) in rectal cancer treatment, specifically in T4b rectal cancer., Methods: This retrospective cohort study reviewed 1014 consecutive patients with clinical T3/4a/T4b adenocarcinomas of the lower rectum, who underwent total mesorectal excision at the Department of Surgical Oncology of the University of Tokyo Hospital and 22 referral institutions affiliated with the Japanese Study Group for Postoperative Follow-up of Colorectal Cancer. Patients were divided into two cohorts: cohort 1 comprised 298 consecutive patients who underwent CRT followed by radical surgery and cohort 2 comprised 716 consecutive patients who underwent curative surgery without preoperative therapy. We assessed the prognostic differences between the two cohorts, focusing particularly on T stages., Results: In T3/4a patients, cohort 1 showed a significantly lower local recurrence rate than cohort 2 (4.8% vs. 9.4%, p=0.024), but not in T4b patients (23.5% vs. 16.0%, p=0.383). In contrast, no significant differences in survival were observed between T3/4a and T4b patients. T4b classification was found to be an independent predictive factor of local recurrence in cohort 1, but not in cohort 2., Conclusion: In T4b rectal cancer, preoperative CRT demonstrated a limited benefit for local control and survival. In cases of suspected T4b rectal tumors, additional therapies such as induction chemotherapy to conventional CRT may contribute to better outcomes.

Purpose: D3 dissection is the standard treatment modality for locally advanced low rectal cancer in Japan. The benefit of lateral pelvic lymph node (LPLN) dissection (LPLND) and lymph nodes along the root of inferior mesenteric artery (253 LN) dissection (253 LND) for low rectal cancer has often been studied separately, and few studies have investigated their benefit in the same cohort. This study aimed to clarify the therapeutic significance of dissection of the LPLN in comparison to that of dissection of the 253 LN for low rectal cancer., Methods: We retrospectively evaluated 3508 patients with treatment-naïve stage I-III low rectal cancer who underwent mesorectal excision between 1997 and 2012. They were identified from the Japanese Study Group for Postoperative Follow-Up of Colorectal Cancer database. The rates of metastasis, survival, and therapeutic value index (5-year overall survival (OS) rate multiplied by metastatic rate for lymph node metastasis) were compared between LPLN and 253 LN., Results: The rates of LPLN metastasis and 253 LN metastasis were 17.9% and 1.5%, respectively. The 5-year OS was significantly different between patients with and without LPLN metastasis (55.0% vs 85.5%, P < 0.0001) and between patients with and without 253 LN metastasis (36.2% vs 83.3%, P < 0.0001). The therapeutic value indexes of LPLN and 253 LN were 9.85 and 0.54, respectively., Conclusions: LPLND may have more therapeutic value than 253 LND for patients with treatment-naïve low rectal cancer, although both the patients with LPLN metastasis and those with 253 LN metastasis remained to have poor prognosis.

Background: Although chemoradiotherapy followed by radical surgery without lateral lymph node dissection is the current standard treatment in patients with rectal cancer, recent studies have demonstrated the benefits of adding lateral lymph node dissection to total mesorectal excision in patients with suspected lateral lymph node metastasis. However, the optimal indication for lateral lymph node dissection after chemoradiotherapy has not been determined., Objective: This study aimed to establish the optimal indication for lateral lymph node dissection after chemoradiotherapy in patients with rectal cancer., Design: This is a retrospective study., Settings: This study was conducted at a single referral hospital., Patients: A total of 279 patients with rectal cancer who underwent chemoradiotherapy followed by radical surgery between 2007 and 2018 were retrospectively enrolled., Main Outcome Measures: The largest lateral lymph nodes on CT were retrospectively assessed and compared with the pathologic results of dissected lateral lymph nodes and recurrences in lateral lymph node areas., Results: The incidence of lateral lymph node metastasis after chemoradiotherapy was estimated to be 9.3%. Although patients with lateral lymph node metastasis frequently developed distant recurrence, 40.4% survived for >5 years without recurrence. An analysis of the lateral lymph node sizes showed that lateral lymph node size ≥8 mm before chemoradiotherapy was the optimal criterion for lateral lymph node dissection, with a sensitivity and specificity of 92.3% and 78.7%. Using this criterion, 72.0% of the patients could be spared lateral lymph node dissection., Limitations: Because of the retrospective nature of the present study, the selection of patients who underwent lateral lymph node dissection was biased., Conclusions: The optimal indication for lateral lymph node dissection was lateral lymph node size ≥8 mm before chemoradiotherapy. Cancer could be eradicated in >30% of patients with lateral lymph node metastasis by dissecting metastatic lateral lymph nodes. See Video Abstract at http://links.lww.com/DCR/B428., Criterios De Tamao Ptimo Para La Diseccin De Ganglios Linfticos Laterales Despus De La Quimiorradioterapia Neoadyuvante Para El Cncer De Recto: ANTECEDENTES:Aunque la quimiorradioterapia seguida por cirugía radical sin disección de ganglios linfáticos laterales es el tratamiento estándar actual en pacientes con cáncer de recto, estudios recientes han demostrado beneficios de agregar disección de ganglios linfáticos laterales a la escisión mesorrectal total en pacientes con sospecha de metástasis de ganglios linfáticos laterales. Sin embargo, no se ha determinado la indicación óptima para la disección de los ganglios linfáticos laterales después de la quimiorradioterapia.OBJETIVO:Este estudio tuvo como objetivo establecer la indicación óptima para la disección de los ganglios linfáticos laterales después de la quimiorradioterapia en pacientes con cáncer de recto.DISEÑO:Estudio retrospectivo.ENTORNO CLINICO:Este estudio se realizó en un solo hospital de referencia.PACIENTES:Se inscribieron retrospectivamente un total de 279 pacientes con cáncer de recto que se sometieron a quimiorradioterapia seguida por cirugía radical entre 2007 y 2018.PRINCIPALES MEDIDAS DE VALORACION:Los ganglios linfáticos laterales más grandes en la tomografía computarizada se evaluaron retrospectivamente y se compararon con los resultados patológicos de los ganglios linfáticos laterales disecados y recidivas en las áreas de los ganglios linfáticos laterales.RESULTADOS:Se estimó que la incidencia de metástasis en los ganglios linfáticos laterales después de la quimiorradioterapia fue del 9,3%. Aunque los pacientes con metástasis en los ganglios linfáticos laterales con frecuencia desarrollaron recurrencia a distancia, el 40,4% sobrevivió durante más de 5 años sin recurrencia. Un análisis de los tamaños de los ganglios linfáticos laterales mostró que la mayor dimensión de los ganglios linfáticos laterales ≥ 8 mm antes de la quimiorradioterapia eran el criterio óptimo para la disección de los ganglios linfáticos laterales, con una sensibilidad y especificidad del 92,3% y 78,7%, respectivamente. Utilizando este criterio, el 72,0% de los pacientes podría evitarse la disección de los ganglios linfáticos laterales.LIMITACIONES:Debido a la naturaleza retrospectiva del presente estudio, la selección de pacientes que fueron sometidos a disección de ganglios linfáticos laterales fue sesgada.CONCLUSIÓN:La indicación óptima para la disección de los ganglios linfáticos laterales fue la dimensión mayor de los ganglios linfáticos laterales ≥ 8 mm antes de la quimiorradioterapia. El cáncer se podría erradicar en más del 30% de los pacientes con metástasis en los ganglios linfáticos laterales disecando los ganglios linfáticos laterales metastásicos. Consulte Video Resumen en http://links.lww.com/DCR/B428., (Copyright © The ASCRS 2020.)

Purpose: A diverting stoma is created to prevent anastomotic leakage and related complications impairing sphincteric function in rectal surgery. However, diverting stoma may be left unclosed. This study is aimed to analyze preoperative factors including anorectal manometric data associated with diverting stoma non-reversal before rectal surgery. We also addressed complications related to diverting stoma in patients undergoing surgery for rectal malignant tumor., Methods: A total of 203 patients with rectal malignant tumor who underwent sphincter-preserving surgery with diverting stoma were retrospectively evaluated. The risk factors for non-reversal of diverting stoma were identified by univariate and multivariate analyses. For these analyses, anorectal manometric data were measured before rectal surgery. The association between stoma-related complications and other clinicopathological features was also analyzed., Results: During the median follow-up of 46.4 months, 24% (49 patients) did not undergo stoma reversal. Among parameters that were available before rectal surgery, age ≥ 75 years, albumin < 3.5 g/dl, tumor size ≥ 30 mm, tumor distance from the anal verge < 4 cm, and maximum squeezing pressure (MSP) < 130 mmHg measured by anorectal manometry (ARM) were independent factors associated with stoma non-reversal. The most common stoma-related complication was peristomal skin irritation (25%). Ileostomy was the only factor associated with peristomal skin irritation., Conclusion: The current study demonstrated that low preoperative MSP evaluated by ARM, old age, hypoalbuminemia, and a large tumor close to the anus were predictive of diverting stoma non-reversal. Stoma site should be well deliberated when patients have the aforementioned risk factors for diverting stoma non-reversal.

We present a case of locally advanced rectal cancer(LARC)treated by robot assisted intersphincteric resection(ISR)and lateral lymph node dissection(LLND)after neoadjuvant chemotherapy(NAC). The patient was a 69-year-old female with the diagnosis of adenocarcinoma of the rectum Rb. The clinical stage diagnosis was cT3N0M0, cStage Ⅱ. NAC with FOLFOXIRI(5-fluorouracil/oxaliplatin/leucovorin/irinotecan)plus bevacizumab(BEV)was inisiated as NAC. Tumor volume reduction of primary lesion was evaluated by CT scan and colonoscopy after 6 courses of FOLFOXIRI plus BEV including omit of BEV on last course and were judged as partial response(PR)and no distant metastasis. With maintenance of tolerability for surgery even after NAC, robot assisted ISR and LLND were safely performed with curative resection. The histopathological treatment effect of post NAC was diagnosed as Grade 1b and the final pathological stage was ypT3pN0cM0, ypStage ⅡA. We experienced a case of LARC was performed FOLFOXIRI plus BEV as NAC followed by robotic ISR and LLND with anal preservation.

Background/aim: It remains unclear whether rectal cancers down-staged by preoperative chemoradiotherapy (CRT) have similar prognoses to those of the same stage without preoperative CRT. We compared prognoses of pT1 rectal cancer patients stratified by preoperative CRT., Patients and Methods: We retrieved data of patients with pathological T1 rectal cancer between 2003 and 2020. Patients were divided into the "ypT1 group" who received preoperative CRT following surgery and the "pT1 group" who underwent surgery alone. Factors associated with relapse-free survival (RFS) were investigated., Results: Among 86 patients, ypT1 and pT1 groups comprised 18 and 68 patients, respectively. There was no significant difference in RFS between the groups (p=0.19). Tumor location within 5 cm from the anal verge was associated with recurrence (hazard ratio: 0.13, p=0.034)., Conclusion: The prognosis of patients with ypT1 rectal cancer was similar to that of patients with pT1. Low tumor location was a poor prognostic factor., (Copyright© 2020, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

Aim: Endoscopic treatment for rectal cancer, such as endoscopic mucosal resection and endoscopic submucosal dissection, causes inflammation, oedema and fibrosis in the surrounding tissue. However, little is known about the effect of these endoscopic therapies on salvage laparoscopic rectal surgery. The objective of this retrospective cohort study was to analyse the effect of preceding endoscopic treatment on the outcomes of laparoscopic surgery for rectal cancer., Method: We analysed 53 patients who underwent laparoscopic surgery for rectal cancer with clinical Tis or T1 at our department between May 2011 and June 2019. Data from 30 patients who underwent laparoscopic surgery after preceding endoscopic treatment (Group E + S) were compared with those of 23 patients who underwent laparoscopic surgery alone (Group S)., Results: There was no significant difference between the groups with respect to preoperative details. The mean operative time tended to be longer in Group E + S, and the volume of intra-operative blood loss was greater in Group E + S than in Group S (median 63 ml vs 10 ml, P = 0.049). There were no significant differences between the groups in other surgical parameters or oncological outcomes., Conclusion: Laparoscopic surgery after endoscopic treatment for rectal cancer may be difficult due to an increased risk of intra-operative bleeding. Long-term prognosis after surgery was not affected by preceding endoscopic treatment in rectal cancer., (Colorectal Disease © 2020 The Association of Coloproctology of Great Britain and Ireland.)

Background: Several previous studies have shown that laparoscopic resection of rectal cancer is a feasible option. However, its safety and efficacy in patients receiving long-term anti-thrombotic therapy (AT) remain unclear. Material and methods: We retrospectively reviewed 364 patients who underwent elective resection for rectal cancer via a laparoscopic approach between 2007 and 2018 in our institute. Patients were classified according to the long-term use of AT. AT was interrupted perioperatively with or without heparin bridging therapy in all anti-thrombotic users. Clinicopathological factors and surgical outcomes were analyzed between patient groups. Results: Thirty-two patients (9%) receiving AT were older and had lower albumin and hemoglobin levels than those not receiving AT (the non-AT group), and were predominantly male. Estimated blood loss and operative time in the AT group (median: 50 mL and 294 min) did not differ from those in the non-AT group (median: 20 mL and 295 min). There were no intergroup differences in the frequencies of other postoperative complications and oncological outcomes. Conclusions: Our results at the very least can support that laparoscopic surgery for rectal cancer is a safe and feasible option for patients taking long-term AT discontinued perioperatively.

Purpose: This study aimed to clarify predictors and therapeutic significance of inguinal lymph node metastasis (ILNM) in patients with rectal cancer., Methods: Patients with rectal adenocarcinoma invading the anal canal who underwent curative surgery between 2003 and 2019 were retrospectively reviewed. Synchronous and metachronous lymph node (LN) metastasis were collectively defined as final nodal metastasis (f-LNM). Factors associated with f-LNM were analyzed. Moreover, the "modified therapeutic value index," defined by multiplication of the frequency of f-LNM by the 5-year overall survival rate for patients who received treatment for f-LNM, was calculated for each LN area., Results: A total of 145 patients were enrolled (16 patients with f-ILNM). To predict f-ILNM, the cutoff of the inguinal lymph node (ILN) diameter of 8.5 mm gave an area under the curve of 0.889. Dentate line involvement (odds ratio 33.4) and ILN larger than the cutoff of 8 mm (odds ratio 11.9) were independently associated with f-ILNM. The modified therapeutic value indices of the inguinal, lateral pelvic, and mesorectal LNs in the entire population were 6.1, 8.2, and 20.3 points, respectively. In patients with dentate line invasion by cancer, the index of the ILN increased to 11.7 points. In patients with an ILN > 8 mm, the index further increased to 21.1 points., Conclusion: Dentate line involvement and ILN > 8 mm predicted the development of ILNM in patients with rectal cancer invading the anal canal. Treatment of the ILN should be considered for patients with the above predictors given the significant therapeutic outcomes.

Background/aim: To date, there is no clear understanding whether preoperative long-course chemoradiotherapy combined with surgery for rectal cancer is detrimental to anorectal function. The purpose of this study was to clarify the influence of preoperative chemoradiotherapy and surgery for middle and lower rectal cancer on postoperative anorectal function., Patients and Methods: Data of 113 patients with middle or lower rectal cancer treated with preoperative chemoradiotherapy plus surgery or surgery alone between January 2013 and December 2016 were analyzed. A total of 84 and 29 patients underwent low anterior resection and intersphincteric resection, respectively. In patients with T3 or deeper and with any N stage cancer below peritoneal reflection, surgery plus lateral lymph node dissection or preoperative radiation (total: 50.4 Gy/28 fractions) to the pelvis with chemoradiotherapy plus surgery was treated. Anorectal function was assessed prior to treatment and 6 and 12 months postoperatively. Specifically, maximum resting pressure and maximum squeezing pressures were measured. The Wexner score was recorded prior to treatment and 12 months postoperatively., Results: maximum resting pressure and maximum squeezing pressure decreased post-surgery in both groups. Maximum resting pressure and maximum squeezing pressure at 12 months and the Wexner score at 12 months post-surgery were comparable among patients treated with chemoradiotherapy plus surgery and those treated with surgery alone., Conclusion: Preoperative chemoradiotherapy did not clearly impair postoperative anorectal function in patients who underwent low anterior resection and intersphincteric resection., (Copyright© 2020, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

Postoperative distant metastasis dramatically affects rectal cancer patients who have undergone neoadjuvant chemoradiotherapy (NACRT). Here, we clarified the association between NACRT-mediated mammalian target of rapamycin (mTOR) signaling pathway activation and rectal cancer metastatic potential. We performed immunohistochemistry for phosphorylated mTOR (p-mTOR) and phosphorylated S6 (p-S6) on surgical specimen blocks from 98 rectal cancer patients after NACRT (cohort 1) and 80 colorectal cancer patients without NACRT (cohort 2). In addition, we investigated the association between mTOR pathway activity, affected by irradiation, and the migration ability of colorectal cancer cells in vitro. Based on the results of the clinical study, p-mTOR was significantly overexpressed in cohort 1 (with NACRT) as compared to levels in cohort 2 (without NACRT) (P < .001). High p-mTOR and p-S6 levels correlated with the development of distant metastasis only in cohort 1. Specifically, high p-S6 expression (HR 4.51, P = .002) and high pathological T-stage (HR 3.73, P = .020) after NACRT were independent predictors of the development of distant metastasis. In vitro, p-S6 levels and migration ability increased after irradiation in SW480 cells (TP53 mutation-type) but decreased in LoVo cells (TP53 wild-type), suggesting that irradiation modulates mTOR signaling and migration through cell type-dependent mechanisms. We next assessed the expression level of p53 by immunostaining in cohort 1 and demonstrated that p-S6 was overexpressed in samples with high p53 expression as compared to levels in samples with low p53 expression (P = .008). In conclusion, p-S6 levels after NACRT correlate with postoperative distant metastasis in rectal cancer patients, suggesting that chemoradiotherapy might modulate the mTOR signaling pathway, promoting metastasis., (© 2020 The Authors. Cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese Cancer Association.)

The patient was a 70s woman who was referred to our hospital with a complaint of bloody stool. Colonoscopy revealed type 2 tumor at a distance of 1 cm from the dentate line, without obstruction. The pathological diagnosis was adenocarcinoma. Enhanced CT revealed a tumor at the rectum below peritoneal reflection as well as swelling of the mesorectal lymph nodes. Multiple liver and lung metastases were also observed. The diagnosis was lower rectal cancer cT4aN2M1b(H2, PUL2), cStage Ⅳ. Chemotherapy was performed for disease control because of unresectable metastases. She received 7 courses of mFOLFOX plus bevacizumab. Further, as the metastatic lesion was inhibited, the primary lesion was excised for the purpose of symptom control. We judged that sphincter preservation was impossible because it was 1 cm away from the dentate line. She underwent robot-assisted abdominoperineal resection with D3 lymphadenectomy and sigmoid colostomy.

Aim: Pelvic lymphocele is a common complication that develops after pelvic lymph node dissection. The incidence of pelvic lymphocele formation has been reported to be 10.5-51% after gynaecological or urological procedures. However, no evidence has been reported thus far with regard to the development of pelvic lymphocele following lateral pelvic lymph node dissection (LPND) for low rectal cancer. The aim of this study was to investigate the incidence of and risk factors for lymphocele formation after LPND for low rectal cancer and to examine its clinical management., Method: We retrospectively analysed the incidence of and risk factors for pelvic lymphocele formation after LPND for rectal cancer in our hospital between January 2012 and December 2017. We also compared the size of the lymphocele between asymptomatic and symptomatic patients by using CT volumetry and examined its clinical management., Results: A total of 30 out of 98 patients (30.8%) developed pelvic lymphocele after rectal LPND. The number of resected nodes was significantly higher in patients with a pelvic lymphocele (P < 0.01). The median volume was significantly higher in patients with symptomatic pelvic lymphocele (P = 0.011). Among the nine symptomatic patients, two underwent CT-guided drainage, one underwent transurethral ureteral stent placement and one underwent laparoscopic marsupialization., Conclusion: It is essential to keep in mind the possibility of pelvic lymphocele formation during follow-up of patients who undergo LPND, and to consider an appropriate treatment when these patients are symptomatic., (Colorectal Disease © 2019 The Association of Coloproctology of Great Britain and Ireland.)

A 67-year-old man without a history of surgery presented with bloody stool and anal pain. Colonoscopy and abdominal CT revealed locally advanced rectal cancer with right lateral lymph node metastasis. We administered 6courses of neoadjuvant therapy with capecitabine, oxaliplatin, and irinotecan(XELOXIRI)to the patient. After neoadjuvant chemotherapy, remarkable tumor shrinkage was observed. The patient underwent safety intrasphincteric resection(ISR)and lateral lymph node dissection with anal preservation. The postoperative course was uneventful, and he was discharged 17 days postoperatively. Pathologically, no residual cancer cells were observed in the rectum and lymph nodes(pathological CR). This case of locally advanced rectal cancer was successfully treated with laparoscopic ISR after XELOXIRI chemotherapy, and showed pathological CR. ISR after neoadjuvant XELOXIRI chemotherapy was safely performed and might be a good option for locally advanced rectal cancer.

Background: It is unclear whether neoadjuvant chemoradiation for lower rectal cancer causes a deterioration in urinary function. This study aimed to prospectively compare the postoperative urinary function of patients with lower rectal cancer treated by surgery after neoadjuvant chemoradiation with that of patients treated with surgery alone., Method: Urinary function was assessed before treatment and 1, 3, and 6 months after surgery by calculating the changes in the scores of the seven items of the International Prostatic Symptom Score (incomplete emptying, frequency, intermittency, urgency, weak stream, straining, and nocturia) and Quality of life index., Results: Among 123 patients with lower rectal cancer treated with chemoradiotherapy plus surgery and surgery alone between 2014 and 2016, 29 eligible patients in the surgery after neoadjuvant chemoradiation group and 34 eligible patients in the surgery alone group were analyzed. The changes in each item score at 1, 3, and 6 months after surgery were similar between the two treatment groups. The scores of all items were already recovered at 6 months after surgery, except for weak stream and straining in the Surgery + chemoradiotherapy group and nocturia in the Surgery-alone group., Conclusion: Neoadjuvant chemoradiotherapy for lower rectal cancer did not affect postoperative urinary function., (Copyright © 2019. Published by Elsevier Taiwan LLC.)

Rectal gastrointestinal stromal tumor (GIST) is a rare entity. Thus, its clinical features have not been well documented, and optimal treatment strategies have not been established. Surgery for rectal GISTs may be difficult because they are often large in size. In addition, rectal GISTs were found to be associated with high rates of local recurrence, regardless of the surgical procedure, before imatinib was introduced in the early 2000s. Since the introduction of imatinib therapy, accumulating evidence suggests that neoadjuvant imatinib therapy may improve the outcomes of rectal GIST treatment. Neoadjuvant imatinib therapy for rectal GISTs offers a number of potential benefits, including tumor downsizing, reduction in mitotic activity, reduced morbidity, and a reduced risk of recurrence. Less radical procedures may allow for the preservation of the anal sphincter and avoidance of a permanent colostomy. This review summarizes the current status and future perspectives of neoadjuvant imatinib therapy for the treatment of rectal GISTs.