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Abstract Background The nuclear factor E2‐related factor 2–Kelch‐like Ech‐associated protein (NRF2–KEAP1) pathway is a major cellular defense mechanism against oxidative stress. However, the role of NRF2–KEAP1 signaling in the development of chronic liver disease remains unclear. Methods Clinical liver specimens from 50 hepatocellular carcinoma (HCC) developed from non‐alcoholic steatohepatitis (NASH), 49 HCCs developed from chronic viral hepatitis C (CHc), and 48 liver metastases of colorectal cancer (CRC) from both tumorous and non‐tumorous areas were collected during hepatic resection surgery. They were evaluated by immunohistochemical analyses of hematoxylin–eosin, Masson's trichrome, NRF2, and KEAP1, and compared with clinicopathological information. Results Hepatic inflammation and fibrosis were more severe in the low‐intensity NRF2 group than in the high‐intensity NRF2 group both between CRC and NASH (Low vs. High: inflammation; p = 0.003, fibrosis; p = 0.014), and between CRC and CHc (Low vs. High: inflammation; p = 0.031, fibrosis; p = 0.011), which could indicate that NRF2 expression in cytosol of hepatocytes was inversely correlated with liver inflammation and fibrosis in non‐tumorous areas. The dense staining of NRF2 in the nuclei of non‐tumor hepatocytes positively correlated with liver inflammation (CRC and NASH; R = 0.451, p

Abstract Aim This study aimed to investigate the effect of the coronavirus disease pandemic on the number of surgeries for gastroenterological cancer cases in Japan. Methods The data recorded in the National Clinical Database of Japan between 2018 and 2020 were utilized for this study. Five specific surgeries for primary cancers and surgery for acute diffuse peritonitis were considered the primary endpoints. We divided the study period into the prepandemic and postpandemic (after April 2020) periods and examined the number of surgeries in relation to clinical factors. Results Overall, 228 860 surgeries were analyzed. Among the five primary cancer surgeries, the number of distal gastrectomies for gastric cancer decreased the most (to 81.0% of the monthly number in the prepandemic period), followed by that of low anterior resections for rectal cancer (91.4%). In contrast, the number of pancreaticoduodenectomies for pancreatic cancer increased by 7.1%, while that of surgeries for peritonitis remained stable. This trend was observed nationwide. We also noted a marked reduction in the number of distal gastrectomy (to 72.5%), low anterior resection (84.0%), and esophagectomy (88.8%) procedures for T1 tumors. The noncurative resection rate and mortalities were low despite the increased proportion of T4 tumors and older patients. Conclusion A marked reduction in surgeries for gastric and rectal cancers with early T factors may reflect prioritization of surgeries and reduction in cancer screenings. Although the quality of the surgery was maintained in terms of reduced mortalities and morbidities, the long‐term effects of this pandemic should be monitored.

Background: Biopsies of suspected gastrointestinal stromal tumors in submucosal locations, which were once a challenge, are now easily performed with endoscopic ultrasound-guided fine-needle aspiration. However, fine-needle aspiration biopsy (FNAB) specimens may be inadequate for the diagnosis of malignancy using quantification of histological mitotic count. Methods: We devised a procedure for rapid analysis with an algorithm for clinical use. DNA ploidy analysis conducted using flow cytometry determined the mitotic rate, which correlated with clinical prognostic factors (mitotic count and the Ki-67 labeling index). We then developed a risk classification system for gastrointestinal stromal tumors using flow cytometry parameters and tumor size. Results: The combined flow cytometry and tumor size parameters correlated with the modified-Fletcher risk classification of gastrointestinal stromal tumors. Conclusion: Rapid flow cytometry of endoscopic ultrasound-guided FNAB specimens can be used to diagnose gastrointestinal stromal tumors and assign a modified-Fletcher risk classification.

Background: Analysis of operative data using convolutional neural networks (CNN) is expected to improve surgeon knowledge and professional skill. Further, the identification of bleeding on surgical videos can lead to improved surgical assessment and navigation. In this study, we performed bleed detection modeling, which had been previously used in surgical videos taken during colorectal procedures, and evaluated the detection accuracy. Methods: A total of 250 objects were annotated in 140 images extracted from five colorectal surgical videos for model training, with 100 images clipped from other videos for validation. The images were annotated and segmented individually for modeling. IBM Visual Insights, including the most popular open-source deep learning framework, Detectron, was used for the CNN. Results: In total, 142/162 bleeds were correctly identified (87.7%) in 100 test images, with a precision of 98.6%. The bleeds were correctly identified in the videos, and graphs indicated the accurate time and duration of the bleed. Conclusions: We evaluated the identification of bleeds using a CNN, which resulted in accurate detection. Real-time high-quality assessment of bleed identification suggests the possibility of clinical application during surgery with simultaneous bleed detection and technical evaluation.

Abstract Background Curative surgery is the most effective treatment for intrahepatic cholangiocarcinoma (ICC). When an ICC involves the suprahepatic inferior vena cava (IVC), hepatectomy with suprahepatic IVC resection and reconstruction is challenging. For reconstruction of the suprahepatic IVC, total hepatic vascular exclusion (THVE), veno-venous bypass, and/or in situ hypothermic portal perfusion are required, but mortality and morbidity remain high. Case presentation We present a 73-year-old woman with mass-forming ICC which invaded the suprahepatic IVC and middle hepatic vein. Left hepatectomy, suprahepatic IVC resection, and reconstruction with an artificial graft were successfully performed during veno-arterial extracorporeal membrane oxygenation (V-A ECMO) to maintain blood pressure. While clamping the IVC diagonally, the right hepatic vein confluence could be preserved. No congestion in the right liver was seen; therefore, there was no requirement for the Pringle maneuver or THVE during reconstruction. No morbidity or mortality was seen after surgery. Conclusions Hepatectomy with suprahepatic IVC resection and reconstruction under V-A ECMO can be performed safely. When an ICC invades the suprahepatic IVC, V-A ECMO during resection and reconstruction of the suprahepatic IVC with an artificial graft is recommended as one of the options.

Summary: Background: Gallbladder cancer (GBC) is rare but aggressive. The extent of surgical intervention for different GBC stages is non-uniform, ranging from cholecystectomy alone to extended resections including major hepatectomy, resection of adjacent organs and routine extrahepatic bile duct resection (EBDR). Robust evidence here is lacking, however, and survival benefit poorly defined. This study assesses factors associated with recurrence-free survival (RFS), overall survival (OS) and morbidity and mortality following GBC surgery in high income countries (HIC) and low and middle income countries (LMIC). Methods: The multicentre, retrospective Operative Management of Gallbladder Cancer (OMEGA) cohort study included all patients who underwent GBC resection across 133 centres between 1st January 2010 and 31st December 2020. Regression analyses assessed factors associated with OS, RFS and morbidity. Findings: On multivariable analysis of all 3676 patients, wedge resection and segment IVb/V resection failed to improve RFS (HR 1.04 [0.84–1.29], p = 0.711 and HR 1.18 [0.95–1.46], p = 0.13 respectively) or OS (HR 0.96 [0.79–1.17], p = 0.67 and HR 1.48 [1.16–1.88], p = 0.49 respectively), while major hepatectomy was associated with worse RFS (HR 1.33 [1.02–1.74], p = 0.037) and OS (HR 1.26 [1.03–1.53], p = 0.022). Furthermore, EBDR (OR 2.86 [2.3–3.52], p

Introduction: In regenerative medicine, cell sheet engineering has various advantages, including the retention of cells at the transplantation site for a longer period and the local delivery of growth factors and cytokines. Adipose-derived stem cell (ASC) is widely used owing to their various functions such as wound healing, immunomodulation, and nerve regeneration, in addition to their ability to differentiate into adipocytes, chondrocytes, and osteoblasts. ASC sheet generated using cell sheet engineering is considered effective in preventing anastomotic leakage, a serious postoperative complication in gastrointestinal surgery. However, the ASC sheet is too soft, thin, and brittle to handle with laparoscopic forceps during the operation. Therefore, we considered using the peritoneum, which is stiff and easy to collect while operating, as an alternative support. In this study, we explored the feasibility of using the peritoneum as a support for the precise transplantation of ASC sheets during surgery. Methods: ASCs were isolated from the subcutaneous fat of the inguinal region of Sprague-Dawley (SD) transgenic rats expressing green fluorescent protein. ASCs were cultured until passage 3, seeded in temperature-responsive culture dishes, and the resulting ASC sheet was harvested at more than 80% confluency. Non-transgenic SD rats were used for transplant experiments. The wall peritoneum was harvested from SD rats following laparotomy, and hybrid adipose-derived stem cell (HASC) sheet was prepared by laminating the peritoneum with ASC sheet. The cell sheets were transplanted on the backs of SD rats following the incision. On post-transplantation days 3 and 7, the specimens were extracted. ASC and HASC sheets were then compared macroscopically and histopathologically. Results: HASC sheet transplantation was macroscopically and histopathologically more effective than ASC sheet transplantation. The peritoneum provided sufficient stiffness as a support for precise transplantation. Conclusion: The newly developed HASC sheet, which combine the advantages of ASC sheet with those of the peritoneum, could be more useful for clinical application than the ASC sheet alone.

Abstract Background Gallbladder cancer (GBC) with liver metastasis is considered unresectable. However, there have been infrequent reports of long-term survival in patients with GBC and liver metastases. Therefore, we examined the characteristics of long-term survivors of gallbladder cancer with liver metastasis. Methods A retrospective multicenter study of 462 patients with GBC (mean age, 71 years; female, 51%) was performed. Although patients with pre-operatively diagnosed GBC and liver metastasis were generally excluded from resection, some cases identified during surgery were resected. Result In patients with resected stage III/IV GBC (n = 193), the period 2007–2013 (vs. 2000–2006, hazard ratio 0.63), pre-operative jaundice (hazard ratio 1.70), ≥ 2 liver metastases (vs. no liver metastasis, hazard ratio 2.11), and metastasis to the peritoneum (vs. no peritoneal metastasis, hazard ratio 2.08) were independent prognostic factors for overall survival, whereas one liver metastasis (vs. no liver metastasis) was not. When examining the 5-year overall survival and median survival times by liver metastasis in patients without peritoneal metastasis or pre-operative jaundice, those with one liver metastasis (63.5%, not reached) were comparable to those without liver metastasis (40.4%, 33.0 months), and was better than those with ≥ 2 liver metastases although there was no statistical difference (16.7%, 9.0 months). According to the univariate analysis of resected patients with GBC and liver metastases (n = 26), minor hepatectomy, less blood loss, less surgery time, papillary adenocarcinoma, and T2 were significantly associated with longer survival. Morbidity of Clavien–Dindo classification ≤ 2 and received adjuvant chemotherapy were marginally not significant. Long-term survivors (n = 5) had a high frequency of T2 tumors (4/5), had small liver metastases near the gallbladder during or after surgery, underwent minor hepatectomy without postoperative complications, and received postoperative adjuvant chemotherapy. Conclusions Although there is no surgical indication for GBC with liver metastasis diagnosed pre-operatively, minor hepatectomy and postoperative chemotherapy may be an option for selected patients with T2 GBC and liver metastasis identified during or after surgery who do not have other poor prognostic factors.

Abstract Analysis of operative data with convolutional neural networks (CNNs) is expected to improve the knowledge and professional skills of surgeons. Identification of objects in videos recorded during surgery can be used for surgical skill assessment and surgical navigation. The objectives of this study were to recognize objects and types of forceps in surgical videos acquired during colorectal surgeries and evaluate detection accuracy. Images (n = 1818) were extracted from 11 surgical videos for model training, and another 500 images were extracted from 6 additional videos for validation. The following 5 types of forceps were selected for annotation: ultrasonic scalpel, grasping, clip, angled (Maryland and right-angled), and spatula. IBM Visual Insights software was used, which incorporates the most popular open-source deep-learning CNN frameworks. In total, 1039/1062 (97.8%) forceps were correctly identified among 500 test images. Calculated recall and precision values were as follows: grasping forceps, 98.1% and 98.0%; ultrasonic scalpel, 99.4% and 93.9%; clip forceps, 96.2% and 92.7%; angled forceps, 94.9% and 100%; and spatula forceps, 98.1% and 94.5%, respectively. Forceps recognition can be achieved with high accuracy using deep-learning models, providing the opportunity to evaluate how forceps are used in various operations.

Introduction: This study aimed to compare the prognostic impact of laparoscopic left hepatectomy (LLH) with that of open left hepatectomy (OLH) on patient survival after resection of left hepatocellular carcinoma (HCC). Methods: Among the 953 patients who received initial treatment for primary HCC that was resectable by either LLH or OLH from 2013 to 2017 in Japan and Korea, 146 patients underwent LLH and 807 underwent OLH. The inverse probability of treatment weighting approach based on propensity scoring was used to address the potential selection bias inherent in the recurrence and survival outcomes between the LLH and OLH groups. Results: The occurrence rate of postoperative complications and hepatic decompensation was significantly lower in the LLH group than in the OLH group. Recurrence-free survival (RFS) was better in the LLH group than in the OLH group (hazard ratio, 1.33; 95% confidence interval, 1.03–1.71; p = 0.029), whereas overall survival (OS) were not significantly different. Subgroup analyses of RFS and OS revealed an almost consistent trend in favor of LLH over OLH. In patients with tumor sizes of ≥4.0 cm or those with single tumors, both RFS and OS were significantly better in the LLH group than in the OLH group. Conclusions: LLH decreases the risk of tumor recurrence and improves OS in patients with primary HCC located in the left liver.

Abstract Aim We aimed to investigate whether later weekdays are related to worse short‐term outcomes after elective right hemicolectomy for colon cancer. Methods We retrospectively analyzed adult patients who underwent elective right hemicolectomy for colon cancer between 2012 and 2017. Records lacking details about surgical mortality were excluded, and multiple imputation was performed for other missing data (variables). The primary endpoint was surgical mortality, defined as the sum of 30‐day mortality and in‐hospital deaths within 90 days postoperatively. Using 22 clinical variables, hierarchal logistic regression modeling with clustering of patients from the same institutes was performed. Results Of the 112 658 patients undergoing elective right hemicolectomy for colon cancer, the 30‐day mortality and surgical mortality were 0.6% and 1.1%, respectively. Surgery on Friday was less frequent, accounting for 17.1% of all cases. The occurrence of severe postoperative complications, anastomotic leakage, or unadjusted odds ratio for surgical mortality did not show significant differences between weekdays. A hierarchal logistic regression model identified 19 independent factors for surgical mortality. Adjusted odds ratios for surgical mortality were 1.01 (95% confidence interval: 0.83‐1.22, P = .915), 0.86 (95% confidence interval: 0.71‐1.05, P = .144), 0.86 (95% confidence interval: 0.71‐1.05, P = .408), and 0.83 (95% confidence interval: 0.68‐1.03, P = .176) for Tuesday, Wednesday, Thursday, and Friday, respectively, showing no significant differences. Conclusion This study did not identify an evident difference in surgical mortality between weekdays; a safe elective right hemicolectomy for colon cancer is being offered throughout the week in Japan.

Abstract Background Chronic myeloid leukemia is a hematologic malignancy associated with the fusion of two genes: BCR and ABL1. This fusion results from a translocation between chromosomes 9 and 22, which is called the Philadelphia chromosome. Although the Philadelphia chromosome is present in more than 90% of patients with chronic myeloid leukemia, 5–8% of patients with chronic myeloid leukemia show complex variant translocations. Herein, we report a unique case of a three-way translocation variant in chronic phase chronic myeloid leukemia. Case presentation A 40-year-old Asian male who presented with leukocytosis was diagnosed with chronic phase chronic myeloid leukemia. Cytogenetic karyotyping analysis showed 46,XY,t(4;9;22)(q21;q34;q11.2). He was treated with bosutinib and then changed to dasatinib because of intolerance, and MR4.5 (BCR-ABL/ABL ≦ 0.0032%, international scale) was achieved after 17 months of continuous treatment. Conclusion This was the 14th case of t(4;9;22), in particular, a new variant Ph translocation involved in chromosome 4q21 and the first successful case treated with tyrosine kinase inhibitors in the world. We summarize previous case reports regarding three-way variant chromosome translocation, t(4;9;22) and discuss how this rare translocation is linked to prognosis.

Background: Photodynamic diagnosis (PDD) using 5-aminolevulinic acid (5-ALA) is useful for detecting microperitoneal dissemination in gastric cancer. However, reports on its use in colorectal cancer are sparse. In this study, we performed PDD with 5-ALA to diagnose peritoneal dissemination in colorectal cancer during laparoscopic surgery. Methods: Between January 2018 and March 2019, we examined six patients scheduled laparoscopic surgery for colorectal cancer (cT3 or deeper) with suspected peritoneal dissemination. A solution of 5-ALA (20 mg/kg) in water was orally administered 3 to 4 hours before surgery. Intraoperatively, the peritoneal cavity was observed with white and fluorescent lights. Nodules suspected as dissemination lesions were resected and the presence or absence of seeding was confirmed histopathologically. Results: The median time from oral 5-ALA administration to observation was 226 minutes. Peritoneal nodules found in four of six cases using white light were collected. In Case 5, white nodules were observed in white light and luminescence in fluorescent light. Of the nodules collected, only that of Case 5 was pathologically diagnosed as disseminating. No adverse events were observed. Conclusions: We attempted PDD using 5-ALA during laparoscopic surgery for colorectal cancer. Observing more cases and optimizing observation conditions are required to improve accuracy. This study was registered at the University Hospital Medical Information Network (UMIN) Clinical Trials Registry (UMIN Exam ID: UMIN000030531).

Background: The utility of endoscopic transplantation of epithelial cell sheets to ulcer sites after endoscopic submucosal dissection (ESD) has been shown to prevent scar stenosis after ESD of early esophageal cancer. Previously, our group reported use of an endoscopic transplantation device fabricated with a 3-dimensional printer. Cell sheets are transplanted to the esophageal wound site with the following procedure: first, a cell sheet harvested from temperature-responsive culture dishes is placed on the device's deflated balloon surface and transported to the wound site with endoscopic forceps; second, by applying pressure from inflating the balloon locally at the wound site, the cell sheet is successfully transferred and adhered to the wound tissue; third, the balloon is deflated, and the device is removed. By repeating the procedure, several cell sheets can be safely transplanted to a wider ESD area. Nonetheless, possible damage to cell sheets using this procedure has not yet been assessed. Objective: Effects of endoscopic transplantation balloon inflation on cell viability and damage of normal human epidermal keratinocyte sheets resident on the device's balloon surface were evaluated by histology after sheet placement onto lumenal surfaces in the ex vivo porcine submucosal dissection esophagus model. Endoscopic transplantation of these same cell sheets with conventional methods using a polyvinylidene fluoride (PVDF) cell sheet support membrane, balloon device transfer, and also using a novel modified balloon transfer procedure was also examined. Cell sheet transfer results obtained with these three procedures were compared. Method: Normal human epidermal keratinocyte sheets were fabricated on temperature-responsive culture inserts. By temperature reduction to 20 °C, all cells were harvested as a single contiguous cell sheet. Freshly excised porcine esophagi purchased in a slaughter house were turned inside-out, and the exposed lumenal mucosa and submucosal layers were removed by Cooper scissors. This luminal surface was then utilized as a transplantation bed in ex vivo cell sheet experiments. Cell sheets were adhered to the endoscopic transfer device balloon, expanded by balloon inflation and resulting cell viability was evaluated by trypan blue exclusion test after cell sheet trypsinization and dispersion. Cell sheets were transferred onto the esophagus lumen ex vivo using forceps and the balloon device, and also using a modified balloon transfer method. The obtained results were compared with those without balloon expansion, and evaluated for sheet thickness and lumenal histology. Finally, TUNEL staining was performed to examine cell apoptosis. Result: Cell sheets thinned after cell sheet balloon expansion, but no apoptosis was observed after these procedures. Conclusion: Expanding keratinocyte cell sheets on a balloon endoscopic transfer device did not damage the cell sheets. This sheet transplantation method using the endoscopic balloon transfer device may be considered as a future standard cell sheet endoscopic transplantation procedure for repairing the esophagus.

This paper presents the first version of clinical practice guidelines for intrahepatic cholangiocarcinoma (ICC) established by the Liver Cancer Study Group of Japan. These guidelines consist of 1 treatment algorithm, 5 background statements, 16 clinical questions, and 1 clinical topic, including etiology, staging, pathology, diagnosis, and treatments. Globally, high incidence of ICC has been reported in East and Southeast Asian countries and the incidence has been gradually increasing in Japan and also in Western countries. Reported risk factors for ICC include cirrhosis, hepatitis B/C, alcohol consumption, diabetes, obesity, smoking, nonalcoholic steatohepatitis, and liver fluke infestation, as well as biliary diseases, such as primary sclerosing cholangitis, hepatolithiasis, congenital cholangiectasis, and Caroli disease. Chemical risk factors include thorium-232, 1,2-dichloropropane, and dichloromethane. CA19-9 and CEA are recommended as tumor markers for early detection and diagnostic of ICC. Abdominal ultrasonography (US), CT, and MRI are effective imaging modalities for diagnosing ICC. If bile duct invasion is suspected, imaging modalities for examining the bile ducts may be useful. In unresectable cases, tumor biopsy should be considered when deemed necessary for the differential diagnosis and drug therapy selection. The mainstay of treatment for patients with Child-Pugh class A or B liver function is surgical resection and drug therapy. If the patient has no regional lymph node metastasis and has a single tumor, resection is the treatment of choice. If both regional lymph node metastasis and multiple tumors are present, drug therapy is the first treatment of choice. If the patient has either regional lymph node metastasis or multiple tumors, resection or drug therapy is selected depending on the extent of metastasis or the number of tumors. If distant metastasis is present, drug therapy is the treatment of choice. Percutaneous ablation therapy may be considered for patients who are ineligible for surgical resection or drug therapy due to decreased hepatic functional reserve or comorbidities. For unresectable ICC without extrahepatic metastasis, stereotactic radiotherapy (tumor size ≤5 cm) or particle radiotherapy (no size restriction) may be considered. ICC is generally not indicated for liver transplantation, and palliative care is recommended for patients with Child-Pugh class C liver function.

Abstract Background Pouch volvulus after proctocolectomy for ulcerative colitis is a very rare postoperative complication. The common site of pouch volvulus has been reported to be the ileal pouch–anal anastomosis and the middle part of the pouch, but no reports on pouch volvulus in the afferent limb of the pouch have been observed. Here, we report the case of a patient with afferent limb volvulus who underwent afferent limbpexy, but required reoperation 7 months later. Case presentation A 38-year-old man with refractory ulcerative colitis had undergone open proctocolectomy 10 years ago at another hospital. He had been aware of lower abdominal pain and bowel movement difficulty for 2 years. After repeated bowel obstruction, he was referred to our hospital for surgery. Based on the radiographic findings, we diagnosed a pouch volvulus and performed an operation. Laparoscopically, counterclockwise rotation of the afferent limb of the pouch was recognized. Moreover, the ileal mesentery was adhered and fixed to the presacral space 20 cm from the oral side of the pouch. The antimesenteric side of the afferent limb was fixed using interrupted stiches on the left peritoneal wall of the pelvis. He was discharged uneventfully 18 days after surgery, and defecation improved immediately. However, he was readmitted 7 months after surgery with the same abdominal pain and defecation difficulty. A similar finding was found and diagnosed as recurrent volvulus. Therefore, we performed a laparoscopic surgery. The same volvulus as in the previous surgery was confirmed. The site fixed during the previous surgery showed scars, but the afferent limb was free. The dilated ileum that contained the volvulus was excised only on the oral side of the pouch and an intraluminal anastomosis was performed on the anterior wall of the pouch. He had a good postoperative course and was discharged. Conclusion Proper diagnosis of volvulus based on the characteristic imaging findings is important. In principle, bilateral row fixation of the rotated ileum is the basic procedure for volvulus. However, fixation with this technique is sometimes difficult. Therefore, this procedure is one of the useful options for the fixation of difficult or recurrent cases.

Abstract Background There are no previous reports of debulking of giant liver hemangioma. This report describes our experience with debulking surgery for a patient with bilateral giant liver hemangiomas with severe symptoms. Case presentation We present a case of symptomatic giant liver hemangioma in a 41-year-old woman. She presented with abdominal pain and fullness at a local hospital and underwent trans-arterial embolization (TAE). TAE was not effective, and she was not able to walk a long distance. Giant liver hemangiomas, 30 cm and 15 cm in diameter, were located in the right liver and in the left lateral section, respectively, and normal liver parenchyma with tiny liver hemangiomas was present in segment 4. The liver function was normal. However, right hemi-hepatectomy with left lateral sectionectomy was considered to be risky according to the 3DCT volumetry. Therefore, we performed right hemi-hepatectomy in order to reduce her symptoms. The postoperative course was uneventful, and she was discharged on the 14th day after surgery. The abdominal fullness and abdominal pain disappeared immediately after surgery. The hemangiomas in the remnant liver, 15 cm in diameter, showed no change, and she is well without symptoms 7 years after surgery. Conclusions Debulking surgery is one of the options for bilateral giant liver hemangiomas with severe symptoms.

Abstract Background Ring calcification in hepatocellular carcinoma is extremely rare. Untreated hepatocellular carcinoma occasionally includes calcified lesions. Here, we report a case of ring-calcified hepatocellular carcinoma. Case presentation A 60-year-old man with a hepatic tumor was referred to Tokyo Women’s Medical University Hospital. He had a history of chronic hepatitis C. Computed tomography showed a liver tumor 20 mm in diameter in segment 6 of the Couinaud classification, with ring calcification. Based on this uncommon imaging presentation and the patient’s past exposure to the definitive hosts of Echinococcus multilocularis, he was preoperatively diagnosed with echinococcosis. Partial hepatectomy was performed as a radical treatment for echinococcosis. A final diagnosis of hepatocellular carcinoma was confirmed based on pathological findings. The patient was discharged uneventfully. Conclusion The presentation of an extremely rare hepatocellular carcinoma with ring calcification may be disguised as hydatid disease.

Abstract Background The Fontan procedure has been widely accepted for children with single ventricle physiology and guarantees survival rates of approximately 80% at age 20 years. However, there have been cases of Fontan-associated liver disease (FALD) caused due to congestion, along with recent reports of the development of hepatocellular carcinoma (HCC) in younger patients with FALD. The literature consists of only five previous case reports of patients who underwent hepatectomy for HCC due to poorer cardiac function and liver cirrhosis caused due to congestion. Case presentation The patient was a 37-year-old woman who presented with epigastralgia. Computed tomography (CT) revealed a liver tumor, 8 cm in diameter, in the caudate lobe. Liver damage was A, with an indocyanine green retention rate of 6% at 15 min. The levels of alpha-fetoprotein (AFP) and protein induced by vitamin K antagonists-II (PIVKA-II) were elevated to 81,663 ng/ml (normal < 10 ng/ml) and 238 mAU/ml (normal < 40 mAU/ml), respectively. Left ventricular ejection fraction was 56%, and central venous pressure (CVP) was 12 mmHg. Left hepatectomy and caudate lobe resection were successfully performed in the reverse Trendelenburg position which reduced the CVP. The total operation duration was 450 min, with a total blood loss of 3200 ml. The patient’s postoperative course was uneventful, and she is still alive 16 months after surgery. Conclusions First left hepatectomy with caudate lobectomy during reverse Trendelenburg position which reduced the CVP was performed in a patient with HCC and FALD.

Abstract Background Ulcerative colitis (UC) is one of the major types of inflammatory bowel diseases and is associated with a significantly increased risk of not only lymphoproliferative disorders but also lymphomas, of which most cases are related to the long-term usage of immunosuppressants. Here, we demonstrate a very rare case of other iatrogenic immunodeficiency-associated colonic diffuse large B-cell lymphoma (Oii-DLBCL) complicating UC and rectal perforation. In addition, we reviewed the clinicopathological features of previous cases of DLBCL related to UC. Case presentation A 68-year-old man was diagnosed with left-sided UC 26 months prior. Although he was followed by immunosuppressive therapy with azathioprine and infliximab, an emergency total proctocolectomy was performed due to rectal perforation. The resected specimen exhibited irregular wall thickening and elevated multinodular lesions extending from the mid-transverse colon to the rectum, measuring up to 52 cm in length. Histologically, the lesion was diagnosed as Oii-DLBCL and crypt abscess surrounded by mixed inflammatory cell was remained. Conclusion Oii-DLBCL complicating UC with rectal perforation is extremely rare. Macro- and microscopic findings are important for early diagnosis of the lesion.

Purpose: Carbon ion beams have several physical and biological advantages compared with conventional radiation for cancer therapy. The objective of this study is to evaluate the safety and effectiveness of 2-fraction carbon ion radiation therapy (CIRT) in patients with hepatocellular carcinoma (HCC). Methods and Materials: Between December 2008 and March 2013, 57 patients with localized HCC were treated with CIRT at a total dose of 45 Gy (relative biological effectiveness) in 2 fractions and retrospectively analyzed after long-term observation. The main endpoints of this study were treatment-related toxicity and local tumor control. Toxicity was assessed using the National Cancer Institute Common Terminology Criteria for Adverse Events, version 4.0. Changes in the Child-Pugh score from before to after CIRT were also examined to evaluate hepatic toxicity. Local control was defined as no progression of the irradiated lesion according to the modified Response Evaluation Criteria in Solid Tumors. Results: The median age of the patients was 75 years (range, 49-89 years). Of these patients, 41 had a newly diagnosed lesion, and 16 had residual or recurrent lesions after previous treatments. The median follow-up duration was 54 months (range, 7-103 months). All surviving patients were followed for more than 51 months. Two patients experienced grade 3 acute skin reactions, but no other grade 3 or higher toxicities were observed in any organ. No patient exhibited an increase in the Child-Pugh score of 2 or more points after CIRT. The local tumor control rates at 1, 3, and 5 years were 98%, 91%, and 91% after CIRT, respectively. All lesions that failed to respond to previous treatments were successfully controlled by CIRT. The 1-, 3-, and 5-year overall survival rates were 97%, 67%, and 45%, respectively. Conclusions: Two-fraction CIRT was a well-tolerated and effective treatment for patients with HCC.

Purposes: Whether hepatectomy is justified in patients with hepatocellular carcinoma (HCC) on hemodialysis (HD) for end-stage renal disease (ESRD) is unclear. This study evaluated clinical characteristics and outcomes in patients with HCC on HD for ESRD who underwent hepatectomy.Methods: Hepatectomy was performed in 17 patients in an ESRD group and 181 in a non-ESRD group. We compared clinical characteristics and outcomes between these groups.Results: Compared with the non-ESRD group, the ESRD group had a significantly higher rate of diabetes mellitus, higher serum creatinine levels, lower levels of hemoglobin, aspartate aminotransferase, and alanine aminotransferase, and a lower indocyanine green retention rate at 15 min. There were no significant differences between the 2 groups in other clinical characteristics, laboratory data, surgical outcomes, pathological findings, or overall postoperative morbidity or mortality. However, the incidence of postoperative pneumonia, gastrointestinal bleeding, and intra-abdominal bleeding was significantly higher in the ESRD group. The 5-year disease-free survival rate was 44.3% in the ESRD group and 24.0% in the non-ESRD group (p=0.4483), and the 5-year survival rates were 76.4% and 65.1% (p=0.2291), respectively. HD and serum creatinine levels were not significant prognostic factors for survival and recurrence.Conclusion: Hepatectomy for HCC in patients with ESRD on HD may be associated with increased risk of postoperative pneumonia, gastrointestinal bleeding, and intra-abdominal bleeding, but is feasible if careful surgical and perioperative management are provided.

Abstract Background The use of laparoscopic surgery has become widespread, and many surgeons are striving to acquire the necessary techniques for it. The Endoscopic Surgical Skill Qualification System (ESSQS), established by the Japan Society for Endoscopic Surgery, serves to maintain and improve the quality of laparoscopic surgery in Japan. In this study, we aimed to determine whether ESSQS certification is useful in maintaining and improving the quality of surgical techniques and in standardization of laparoscopic surgery in Japan. Methods This retrospective study used data from the Institute for Integrated Medical Sciences, Tokyo Women’s Medical University, Japan. From January 2016 to October 2017, 241 patients with colorectal cancer underwent laparoscopic surgery. Of them, 220 patients were selected and divided into two groups on the basis of surgery performed by an ESSQS-qualified surgeon (QS group) (n = 170) and a non-ESSQS-QS (NQS) (n = 50). We compared the short-term results in the two groups and examined those before and after propensity score matching (PSM). Results Mean operation time was longer in the NQS group than in the QS group. Furthermore, mean blood loss was significantly less in the QS group. These were similar before and after PSM. The rate of conversion to open surgery was significantly higher in the NQS group before PSM. However, the rate of postoperative complications was not different between the two groups. Conclusions A laparoscopic procedure performed by ESSQS-QS often leads to good short-term outcomes. Thus, the ESSQS system works and is potentially useful in maintaining and improving the quality of surgical techniques and in standardization of laparoscopic surgery in Japan.

Background: Gastric leiomyomas are usually solitary, rounded, and demarcated masses, and multiple leiomyomas (more than three) are extremely rare. We report a case of a 30-year-old woman who was referred to our hospital for further treatment of an enlarging gastric submucosal tumour (SMT).Case Presentation: She underwent laparoscopic gastric partial resection with oesophagogastroduodenoscopy (OGD), which revealed a multinodular gastric SMT (10 cm in diameter) located in the upper body of the stomach. Endoscopic ultrasonography (EUS) revealed a hypoechoic mass located in the fourth layer and multiple nodules approximately 1 cm in diameter. We subsequently performed EUS-guided fine-needle aspiration biopsy. The patient underwent laparoscopic gastric partial resection with EGD. Because the tumour was extensive on the lesser curvature of the stomach and was located near the oesophagogastric junction, we preserved the gastric function with minimal resection of the stomach. No intraoperative or postoperative complications were observed. The tumour was pathologically diagnosed as gastric leiomyoma. Laparoscopic minimized resection used by endoscope, can avoid gastric deformity and preserve gastric function, especially when the gastric SMTs are located near the oesophagogastric junction.Conclusion: Laparoscopic gastric partial resection with EGD is an effective treatment option for complete resection of extensive gastric SMT.

Abstract Background Hepatocellular carcinoma (HCC) with tumor thrombus (TT) in the right atrium is a critical condition. The general consensus is to perform hepatectomy prior to cavo-atrial thrombectomy because of the risk of uncontrollable bleeding during the liver transection after heparinization. However, sudden cardiac arrest due to the ball-valve effect and pulmonary embolism have been reported in cases of TT. Cavo-atrial thrombectomy prior to hepatectomy for HCC with TT in the right atrium was successfully performed to prevent sudden cardiac arrest and pulmonary embolism. Case presentation Tumor thrombectomy under cardiopulmonary bypass with heparin and electrical ventricular fibrillation prior to hepatectomy was successfully performed to prevent sudden cardiac arrest or pulmonary embolism in a 75-year-old woman with a huge HCC and TT in the right atrium. After the neutralization of heparin, right hepatectomy with tumor thrombectomy in the inferior vena cava was performed. The total operation time was 9 h, and the total blood loss was 8200 mL. The patient’s postoperative course was uneventful, and she was discharged 14 days after surgery. One year after surgery, she is alive with HCC recurrence in the lung. Conclusions Cavo-atrial thrombectomy prior to hepatectomy for HCC with TT in the right atrium can be performed safely to prevent sudden cardiac arrest and pulmonary embolism by collaboration of cardiovascular surgeons and gastroenterological surgeons.

Abstract Background Chemotherapy with or without surgery is the first-line treatment for stage III/IV gastric cancer, while surgery is the first-line treatment for stage I/II gastric cancer. Accordingly, it is important to distinguish between stage III/IV and stage I/II gastric cancer, but clinical staging is less accurate than pathological staging. This study was performed to develop a clinical score that could distinguish stage III/IV gastric cancer from stage I/II gastric cancer. Methods We reviewed 2722 patients who underwent gastrectomy at our hospital from January 1996 to December 2015. As pretreatment factors potentially related to tumor stage, we assessed age, sex, tumor markers, tumor diameter, tumor location, tumor histology, and macroscopic type. Factors showing significance on multivariate analysis were used to develop the Clinical Stage Prediction score (CSP score), and a cutoff value for the score was determined by receiver operating characteristics analysis. Results According to multivariate analysis, clinical factors associated with stage III/IV disease were elevation of the carcinoembryonic antigen level, tumor diameter ≥ 60 mm, circumferential gastric involvement, esophageal infiltration, mucinous adenocarcinoma, and macroscopic types 2–4. The CSP score was obtained by weighting these factors according to the non-standardized β-coefficient. Receiver operating characteristics analysis indicated that the optimum cutoff value of the CSP score was 17 points. Among 1042 patients with a CSP score ≥ 17 points, 820 patients (78.7%) had stage III/IV gastric cancer. Conversely, among 1680 patients with a CSP score

Abstract Background Pneumothorax during surgery under general anesthesia is a life-threatening situation for the patient because it can progress easily to the tension pneumothorax due to positive pressure ventilation unless appropriate treatments such as inserting a drainage tube in the thoracic cavity are initiated. The authors experienced a case of intraoperative pneumothorax and the diffuse dissection of visceral pleura during liver transplantation surgery, and achieved successful repair by a trans-diaphragmatic approach without changing patient’s body position. Case presentation A 66-year-old male with multiple liver and renal cysts caused by autosomal dominant polycystic kidney disease (ADPKD) was admitted to the authors’ hospital for treating the infection of the liver cysts. The infection was unable to be controlled by conservative treatments. Therefore, the patient was planned to undergo living-donor liver transplantation. Intraoperatively, the liver was found to swell markedly and to firmly adhere to the right diaphragm. After the extraction of the liver, because the right diaphragm swelled markedly, pneumothorax was suspected. Chest tube was inserted immediately, and the small incision was made in the right diaphragm. Thoracoscopic observation revealed that (1) the visceral pleura of the bottom of the right lung widely expanded like a giant cyst due to the dissection from the lung parenchyma and (2) a large air leakage from a pin hole appeared in the dissected pleura. After the completion of the liver transplantation, the thoracoscopic leakage-closing operation was performed through the right diaphragm incision. Because the dissection of visceral pleura was too wide to perform plication or cystectomy by a stapler or sutures, the dissected pleura was opened, and absorbable fibrin sealant patches and fibrin glue were put or injected between the lung parenchyma and the pleura. Although, after being observed postoperatively, prolonged minor air leakage disappeared by a conservative drainage treatment, and the cyst on the bottom of the right lung disappeared on chest computed tomography (CT). Conclusions Although intraoperative pneumothorax and broad dissection of visceral pleura during laparotomy is a complicated situation, the authors successfully repaired air leakage via a trans-diaphragmatic approach without changing the patient’s body position.

Introduction Familial hypercholesterolaemia (FH) is an autosomal-dominant inherited genetic disease. It carries an extremely high cardiovascular risk associated with significantly elevated low-density lipoprotein (LDL) cholesterol. The diagnostic rate of this disease in some European nations is quite high, due to the presence of multiple prospective registries. On the other hand, few data—and in particular multicentre data—exist regarding this issue among Japanese subjects. Therefore, this study intends to assemble a multicentre registry that aims to comprehensively assess cardiovascular risk among Japanese FH patients while taking into account their genetic backgrounds.Methods and analysis The Hokuriku-plus FH registry is a prospective, observational, multicentre cohort study, enrolling consecutive FH patients who fulfil the clinical criteria of FH in Japan from 37 participating hospitals mostly in Hokuriku region of Japan from April 2020 to March 2024. A total of 1000 patients will be enrolled into the study, and we plan to follow-up participants over 5 years. We will collect clinical parameters, including lipids, physical findings, genetic backgrounds and clinical events covering atherosclerotic and other important events, such as malignancies. The primary endpoint of this study is new atherosclerotic cardiovascular disease (ASCVD) events. The secondary endpoints are as follows: LDL cholesterol, secondary ASCVD events and the occurrence of other diseases including hypertension, diabetes and malignancies.Ethics and dissemination This study is being conducted in compliance with the Declaration of Helsinki, the Ethical Guidelines for Medical and Health Research Involving Human Subjects, and all other applicable laws and guidelines in Japan. This study protocol has been approved by the Institutional Review Board at Kanazawa University. We will disseminate the final results at international conferences and in a peer-reviewed journal.Trial registration number UMIN000038210.

Abstract Background Although patients with stage IV gastric cancer who respond well to systemic chemotherapy can be treated with gastrectomy, the prognosis of patients with unresectable gastric cancer with para-aortic lymph node metastasis is poor. We herein report a case of remnant gastric cancer with para-aortic lymph node metastasis that was treated with potentially curative conversion surgery after showing a complete response to chemotherapy with S-1 and oxaliplatin (SOX). Case presentation An 81-year-old man was diagnosed with type 3 remnant gastric cancer with giant para-aortic lymph node metastasis, and he received SOX chemotherapy. After three courses of SOX chemotherapy, the primary tumor and para-aortic lymph node metastases markedly reduced in size, indicating a partial response. Because conversion surgery was possible, the patient underwent total remnant gastrectomy with D2 and para-aortic lymph node dissection. Histological examination revealed no residual cancer cells in the resected stomach and lymph nodes. The patient was diagnosed with a complete pathological response and was discharged on postoperative day 24. Currently, 1 year after surgery, the patient is alive and has not shown any tumor recurrence. Conclusion To the best of our knowledge, this is the first case of advanced remnant gastric cancer with giant para-aortic lymph node metastasis that showed a pathological complete response and favorable outcome after SOX chemotherapy.

Abstract Background Clostridium ramosum is a generally non-pathogenic enteric anaerobe, and Fournier’s gangrene is a rare necrotizing soft tissue infection with male predisposition affecting the perineum and the genital area. We report, to our knowledge, the first case of Fournier’s gangrene caused by C. ramosum in a female patient with multiple underlying conditions. Case presentation A 44-year-old woman with a 6-year history of insulin-dependent diabetes mellitus after total pancreatectomy and an 11-year history of central diabetes insipidus developed a pain in the genital area after a month of urinary catheter use. The lower abdominal pain worsened gradually over 2 weeks, and the pain, general fatigue, and loss of appetite prompted the patient’s hospital admission. As she had severe edema in her pelvic and bilateral femoral areas, ceftriaxone was started empirically after collecting two sets of blood cultures. On hospital day 2, CT examination revealed the presence of necrotizing faciitis in the genital and pelvic areas, and the antibiotics were changed to a combination of meropenem, vancomycin, and clindamycin. Gram-positive cocci and gram-positive rods were isolated from blood cultures, which were finally identified as Streptococcus constellatus and C. ramosum using superoxide dismutase and 16S rDNA sequencing. An emergent surgery was performed on hospital day 2 to remove the affected tissue. Despite undergoing debridement and receiving combined antimicrobial chemotherapies, the patient’s clinical improvement remained limited. The patient’s condition continued to deteriorate, and she eventually died on hospital day 8. In the present case, the underlying diabetes mellitus, urinary incontinence due to central diabetes insipidus, undernutrition, and edema served as the predisposing conditions. Conclusions C. ramosum is a potentially opportunistic pathogen among immunosuppressed persons and a rare cause of necrotizing fasciitis.

Introduction: Islet transplantation is one of the most promising therapeutic approaches for patients with severe type 1 diabetes mellitus (T1DM). Transplantation of engineered islet cell sheets holds great potential for treating T1DM as it enables the creation of stable neo-islet tissues. However, a large mass of islet cell sheets is required for the subcutaneous transplantation to reverse hyperglycemia in diabetic mice. Here, we investigated whether the liver surface could serve as an alternative site for islet cell sheet transplantation. Methods: Dispersed rat islet cells (0.8 × 106 cells) were cultured on laminin-332-coated thermoresponsive culture dishes. After 2 days of cultivation, we harvested the islet cell sheets by lowering the culture temperature using a support membrane with a gelatin gel. We transplanted two recovered islet cell sheets into the subcutaneous space or onto the liver surface of severe combined immunodeficiency (SCID) mice with streptozocin-induced diabetes. Results: In the liver surface group, the non-fasting blood glucose level decreased rapidly within several days after transplantation. In marked contrast, the hyperglycemia state was maintained in the subcutaneous space transplantation group. The levels of rat C-peptide and insulin in the liver surface group were significantly higher than those in the subcutaneous space group. An immunohistological analysis confirmed that most of the islet cells engrafted on the liver surface were insulin-positive. The CD31-positive endothelial cells formed vascular networks within the neo-islets and in the surrounding tissues. In contrast, viable islet cells were not found in the subcutaneous space group. Conclusions: Compared with the subcutaneous space, a relatively small mass of islet cell sheets was enough to achieve normoglycemia in diabetic mice when the liver surface was selected as the transplantation site. Our results demonstrate that the optimization of the transplantation site for islet cell sheets leads to significant improvements in the therapeutic efficiency for T1DM. Keywords: Cell sheet, Islet cells, Type 1 diabetes mellitus, Transplantation site, Cellular therapy

Abstract Mutations in genes of the breast cancer susceptibility gene (BRCA) pathway, namely, BRCA1, BRCA2, and PALB2, can provide useful information for the efficacy of platinum-based or poly ADP-ribose polymerase inhibitors chemotherapeutic regimens. Pancreatic ductal adenocarcinoma (PDAC) is an important target for such precision chemotherapies because of its dismal prognosis. We analyzed mutations in the entire coding regions of the BRCA pathway genes, expression of breast cancer 2 (BRCA2), and mutations in hotspots of 50 cancer-associated genes in 42 surgically resected PDACs, and evaluated their associations with clinicopathological features. We identified 13 rare germline mutations in the BRCA pathway genes; 68 somatic mutations in KRAS, TP53, SMAD4, CDKN2A, GNAS, SMARCB1, and RB1; and 2 germline variations in MLH1. Among them, BRCA2 S2148fs was known to be pathogenic. BRCA2 R18H and BRCA2 G2044V were enriched in tumor tissues. BRCA2 K799R and BRCA2 R2964T were novel germline variations. Patients harboring potentially deleterious mutations in the BRCA pathway genes showed significantly better prognosis than those with benign mutations or no mutation. These results indicate that rare germline variations in BRCA pathway genes could be found more frequently than previously anticipated and, more importantly, potentially deleterious mutations of them could be a favorable prognostic factor in patients with resectable PDACs.

Summary: MyoD and Myf5 are fundamental regulators of skeletal muscle lineage determination in the embryo, and their expression is induced in satellite cells following muscle injury. MyoD and Myf5 are also expressed by satellite cell precursors developmentally, although the relative contribution of historical and injury-induced expression to satellite cell function is unknown. We show that satellite cells lacking both MyoD and Myf5 (double knockout [dKO]) are maintained with aging in uninjured muscle. However, injured muscle fails to regenerate and dKO satellite cell progeny accumulate in damaged muscle but do not undergo muscle differentiation. dKO satellite cell progeny continue to express markers of myoblast identity, although their myogenic programming is labile, as demonstrated by dramatic morphological changes and increased propensity for non-myogenic differentiation. These data demonstrate an absolute requirement for either MyoD or Myf5 in muscle regeneration and indicate that their expression after injury stabilizes myogenic identity and confers the capacity for muscle differentiation. : In this article, Goldhamer and colleagues show that loss of both MyoD and Myf5 in skeletal muscle satellite cells results in regenerative failure following injury. Satellite cell progeny accumulate in injured muscle and continue to express markers of myoblast identity, but do not undergo muscle differentiation, and exhibit a propensity for non-myogenic differentiation. Keywords: skeletal muscle regeneration, muscle stem cell programming, muscle differentiation, satellite cell, MyoD, Myf5, adipogenesis, fibrosis, conditional knockout, Cre/loxP

Fibrodysplasia ossificans progressiva is a severe disorder characterized by heterotopic ossification, and is caused by mutations in ACVR1. Here, the authors show that expression of mutant ACVR1 in fibro/adipogenic progenitors recapitulates disease progression, and that this can be halted by systemic inhibition of activin A in mice.

We report a case of appendiceal mucinous cystadenoma that was successfully diagnosed preoperatively and treated by laparoscopic resection. We could find volcano sign on colonoscopy and cystic lesion without any nodules at the appendix on computed tomography (CT). Without any malignant factors in preoperative examinations, we performed laparoscopic appendectomy including the cecal wall. We could avoid performing excessive operation for cystadenoma with accurate preoperative diagnosis and intraoperative finding and pathological diagnosis during surgery. Appendiceal mucocele is a rare disease that is divided into 3 pathological types: hyperplasia, cystadenoma, and cystadenocarcinoma. The surgical approaches for it remain controversial and oversurgery is sometimes done for benign tumor, because preoperative diagnosis is difficult and rupturing an appendiceal tumor results in dissemination. Based on our study, volcano sign on colonoscopy and CT findings were important for the preoperative diagnosis of appendiceal mucocele. Furthermore, we think that laparoscopic resection will become a surgical option for the treatment of appendiceal mucocele.

Abstract Background The molecular profiles of tumors may inform the selection of appropriate targeted therapies. Circulating tumor cells (CTCs) reflect the real-time status of tumor genotypes. CTCs exhibit high genetic heterogeneity within a patient; accordingly, the analysis of individual CTCs, including their heterogeneity, may enable more precise treatments. We analyzed KRAS mutations in single CTCs from patients with metastatic colorectal cancer (mCRC) using a new single-cell picking system. Methods Blood samples were obtained from 61 patients with mCRC. CTCs were enriched and fluorescently labeled using the CellSearch® System. They were recovered using the single-cell picking system based on the fluorescence intensity of marker dyes. Single CTCs and tumor tissue samples were examined for mutations in codons 12 and 13 of the KRAS gene. Results CTCs were detected in 27 of 61 patients with mCRC. We isolated at least two CTCs from 15 of 27 patients. KRAS genotype was evaluated in a total of 284 CTCs from 11 patients, and 15 cells with mutations were identified in four patients. In 10 of 11 patients, the KRAS status was the same in the primary tumor and CTCs. In one patient, the KRAS status was discordant between the primary tumor and CTCs. In two patients, different KRAS mutations were found among individual CTCs. Conclusions We successfully isolated single CTCs and detected KRAS mutations in individual cells from clinical samples using a novel application of single-cell isolation system. Using the system, we detected CTC heterozygosity and heterogeneity in KRAS status among CTCs within a patient and between CTCs and tumor tissues.

Abstract Background Various types of preoperative chemoradiotherapy (CRT) have been established for rectal cancer; thus,Physicians will need to refine the selection of appropriate preoperative CRT for different patients since there are various treatment regimens. Oral tegafur-uracil (UFT) plus leucovorin (LV) is commonly used to treat rectal cancer in Japan. Oral chemotherapy offers patients many potential advantages. Since 2008, we have been performing preoperative CRT with intermittent oral UFT plus LV in locally advanced rectal cancer patients to prevent postoperative local recurrence. Here, in a retrospective analysis, we evaluated the efficacy and short-term outcomes of preoperative CRT with intermittent oral UFT plus LV. Methods We analyzed data from 62 patients with locally advanced rectal cancer, including 31 patients who underwent preoperative CRT between 2009 and 2013 (the CRT group) and 31 patients who were treated with surgery alone between 2001 and 2008 (the non-CRT group). Clinicopathologically, both groups included patients with rectal cancer at clinical tumor stages 3-4 or clinical node stages 0-3. In the CRT group, curative operations were performed ≥8 weeks after CRT. Patients were concomitantly treated with 2 cycles of oral UFT (300 mg/m2/day, days 1–14 and 29–42) plus LV (75 mg/day, days 1–14 and 29–42) and 45 Gy of radiotherapy. Chemotherapy was repeated every 28 days, followed by a 2-week break. Results The completion rate of CRT was high at 94% (n = 29/31). The downstaging rate of CRT was 61% (n = 19/31). The pathological complete response rate was 6.5% (n = 2/31). Significant differences were observed in the 3-year local recurrence rate between the two groups (P < 0.05). Conclusions Preoperative CRT with intermittent oral UFT plus LV appears to be a tolerable and effective treatment for Japanese patients with rectal cancer. A further investigation of a diversification of preoperative CRT for Japanese rectal cancer patients is required.