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Abstract Adjuvant oxaliplatin plus capecitabine (XELOX) therapy is recommended for patients with curatively resected colon cancer. However, prospective data on its practical application in Japanese patients are limited. Therefore, we aimed to conduct a long-term clinical evaluation of the efficacy and safety of adjuvant XELOX in patients with curatively resected stage III colon cancer (MCSCO-1024). This prospective, multi-center, open-label, single-arm, phase II study enrolled patients with curatively resected stage III colon cancer. The treatment protocol consisted of a 120-minute intravenous infusion of oxaliplatin (130 mg/m2) on day 1 and two divided doses oral capecitabine (2000 mg/m2/day) for 14 days in a 3-week cycle, totaling eight cycles (24 weeks). The primary endpoint was 3-year disease-free survival (DFS), and the secondary endpoints were 5-year overall survival and long-term prognosis of peripheral sensory neuropathy. A total of 196 patients were enrolled between November 2011 and August 2014 (34 months). The 3-year DFS rate was 73%, and the 5-year overall survival rate was 87%. The overall incidence of peripheral sensory neuropathy was 17%, with a 1% rate of grade 3 neuropathy after 5 years. Adjuvant XELOX demonstrated utility and safety in the clinical management of Japanese patients with stage III colon cancer.

Abstract Background Advanced hepatobiliary–pancreatic cancer often invades critical blood vessels, including the portal vein (PV) and hepatic artery. Resection with tumor-free resection margins is crucial to achieving a favorable prognosis in these patients. Herein, we present our cases and surgical techniques for PV wedge resection with patch venoplasty using autologous vein grafts during surgery for pancreatic ductal adenocarcinoma (PDAC) and perihilar cholangiocarcinoma (PhCC). Case presentation Case 1: 73-year-old female patient with PDAC; underwent subtotal stomach-preserving pancreatoduodenectomy, with superior mesenteric vein wedge resection and venoplasty with the right gonadal vein. Case 2: 67-year-old male patient with PDAC; underwent distal pancreatectomy and celiac axis resection, with PV wedge resection and venoplasty with the middle colic vein. Case 3: 51-year-old female patient with type IV PhCC; underwent left hepatectomy with caudate lobectomy and bile duct resection, with hilar PV wedge resection and venoplasty with the inferior mesenteric vein (IMV). Case 4: 69-year-old male patient with type IIIA PhCC; underwent right hepatopancreatoduodenectomy, with hilar PV resection and patch venoplasty with the IMV. All patients survived for over 12 months after the surgery, without local recurrence. Conclusions PV wedge resection and patch venoplasty is a useful technique for obtaining tumor-free margins in surgeries for hepatobiliary–pancreatic cancer.

Abstract Background In Japan, there are no substantial reports on robotic‐assisted colectomy because few institutions performed the procedure, as it was not covered by national insurance until March 2022. Aim This study aimed to evaluate the safety and feasibility of robotic‐assisted colectomy for patients with curatively resectable colon cancer in Japan. Methods This multi‐institutional, prospective, single‐arm, observational study enrolled patients diagnosed with curatively resectable clinical stage I–IIIC colon adenocarcinoma with D2 or D3 lymph node dissection and treated with robotic‐assisted colectomy. The primary endpoint was the conversion rate to laparotomy. The non‐inferiority of outcomes for robotic‐assisted colectomy versus laparoscopic colectomy, which was determined from historical data, was verified. Results One hundred patients were registered between July 2019 and March 2022 and underwent robotic‐assisted colectomy performed by seven expert surgeons at six institutions. Thirteen patients were excluded because their surgeons had insufficient experience performing robotic‐assisted colectomy; therefore, 87 patients were eligible for the primary endpoint analysis. There was no conversion in these 87 patients, and robotic‐assisted colectomy was non‐inferior to laparoscopic colectomy in terms of conversion rate (90% confidence interval 0–3.38, p = 0.0006). No intraoperative adverse events occurred, and no mortality was observed in a total of 100 patients. The rate of patients with Clavien–Dindo complications grade III or higher was 4%. Conclusion This study showed the non‐inferiority of the conversion rates between robotic‐assisted colectomy and laparoscopic colectomy. Favorable perioperative outcomes also suggest the safety and feasibility of robotic‐assisted colectomy.

Abstract Circulating tumor cells (CTCs) play an important role in metastasis and recurrence. However, which cells comprise the complex tumor lineages in recurrence and are key in metastasis are unknown in colorectal cancer (CRC). CRC with high expression of POU5F1 has a poor prognosis with a high incidence of liver metastatic recurrence. We aim to reveal the key cells promoting metastasis and identify treatment-resistant lineages with established EGFP-expressing organoids in two-dimensional culture (2DOs) under the POU5F1 promotor. POU5F1-expressing cells are highly present in relapsed clinical patients’ blood as CTCs. Sorted POU5F1-expressing cells from 2DOs have cancer stem cell abilities and abundantly form liver metastases in vivo. Single-cell RNA sequencing of 2DOs identifies heterogeneous populations derived from POU5F1-expressing cells and the Wnt signaling pathway is enriched in POU5F1-expressing cells. Characteristic high expression of CTLA4 is observed in POU5F1-expressing cells and immunocytochemistry confirms the co-expression of POU5F1 and CTLA4. Demethylation in some CpG islands at the transcriptional start sites of POU5F1 and CTLA4 is observed. The Wnt/β-catenin pathway inhibitor, XAV939, prevents the adhesion and survival of POU5F1-expressing cells in vitro. Early administration of XAV939 also completely inhibits liver metastasis induced by POU5F1-positive cells.

Objectives: Preoperative deep venous thrombosis (DVT) can cause potentially life-threatening postoperative venous thromboembolism (VTE). Lower limb venous ultrasound (LLVU) is a modality that can detect DVT. However, the threshold for performing preoperative LLVU in the population undergoing colorectal resection is controversial. In this context, we evaluated whether a preoperative D-dimer value can identify patients who benefit from LLVU from the perspective of preventing postoperative symptomatic VTE. Methods: Patients undergoing colorectal resection in our institute from 2013 to 2020 were retrospectively enrolled (n=2071). We divided the patients into two groups: the clinical indication group (CG: including patients from 2013 to 2016, n=875) and the D-dimer-orientated group (DG: including patients from 2017 to 2020, n=1196). In the CG, LLVU was performed when DVT was clinically suspected; in the DG, preoperative LLVU was performed in patients with a preoperative D-dimer>1.0 μg/ml. Results: In the surveyed period, 277 LLVUs were performed, among which DVT was detected in 34 cases (12.3%). In the CG, DVT was detected in 0.7% of patients, whereas in the DG, it was detected in 2.3% of patients. Postoperative symptomatic VTE was significantly reduced in the DG at both 3 and 6 months after surgery (p=0.041 and 0.020, respectively). Moreover, Multivariate analysis showed that a past medical history of PE and treatment following the CG protocol were independent risk factors for postoperative symptomatic VTE within 6 months of surgery (p1.0 μg/ml is a useful method to prevent postoperative symptomatic VTE.

Abstract Regorafenib has shown significant survival benefit as a salvage therapy for colorectal cancer; however, its starting dose has been controversial in recent studies. Therefore, we conducted a prospective study on the efficacy and safety of the dose reduction of regorafenib to 120 mg. Patients received 120 mg regorafenib once per day for 3 weeks, followed by a 1-week off-treatment period. The primary endpoint was the investigator-assessed disease control rate (DCR). Sixty patients were registered, and the DCR was 38.3% with a median progression-free survival of 2.5 months (95% confidence interval [CI] 1.9–3.7) and median overall survival of 10.0 months (95% CI 6.9–15.2). Common grade 3–4 adverse events were hand-foot skin reaction and hypertension (20.0% each). The results of administration of 120 mg regorafenib as the starting dose are consistent with reports from prior phase III trials, which used starting doses of 160 mg. This lower initiating dose of regorafenib may be beneficial to certain patient populations. This clinical trial was registered in the UMIN Clinical Trials Registry (UMIN-CTR number UMIN000018968, registration date: 10/09/2015).

Abstract Background Duke pancreatic mono-clonal antigen type 2 (DUPAN-II) is a famous tumour maker for pancreatic cancer (PC) as well as carbohydrate antigen 19–9 (CA19-9). We evaluated the clinical implications of DUPAN-II levels as a biological indicator for PC during preoperative chemoradiation therapy (CRT). Methods This retrospective analysis included data from 221 consecutive patients with resectable and borderline resectable PC at diagnosis who underwent preoperative CRT between 2008 and 2017. We focused on 73 patients with elevated pre-CRT DUPAN-II levels (> 230 U/mL; more than 1.5 times the cut-off value for the normal range). Pre- and post-CRT DUPAN-II levels and the changes in DUPAN-II ratio were measured. Results Univariate analysis identified normalisation of DUPAN-II levels after CRT as a significant prognostic factor (hazard ratio [HR] = 2.06, confidence interval [CI] = 1.03–4.24, p = 0.042). Total normalisation ratio was 49% (n = 36). Overall survival (OS) in patients with normalised DUPAN-II levels was significantly longer than that in 73 patients with elevated levels (5-year survival, 55% vs. 21%, p = 0.032) and in 60 patients who underwent tumour resection (5-year survival, 59% vs. 26%, p = 0.039). Conclusion Normalisation of DUPAN-II levels during preoperative CRT was a significant prognostic factor and could be an indicator to monitor treatment efficacy and predict patient prognosis.

Abstract Purpose Addition of perioperative multi‐agent chemotherapy to the treatment strategy for locally advanced rectal cancer (LARC) may be a promising option. We conducted a phase II study to evaluate the safety and efficacy of capecitabine combined with oxaliplatin and irinotecan (XELOXIRI) as triplet neoadjuvant chemotherapy in patients with LARC. Methods Patients received neoadjuvant irinotecan and oxaliplatin and capecitabine and then underwent total mesorectal excision. The primary study endpoint was the pathological complete response (pCR) rate. Results Between June 2013 and December 2016, 55 patients were enrolled in the study. Forty‐two (77.8%) of 54 completed the study protocol. The pCR rate was 7.7% (95% CI 3.0% to 18.2%). The 3‐year local recurrence rate was 3.9%, the 3‐year disease‐free survival (DFS) rate was 77.3, and the 3‐year overall survival rate was 96.0%. Conclusion XELOXIRI neoadjuvant chemotherapy appears to be feasible and efficacious for patients with LARC. Although neoadjuvant XELOXIRI alone did not yield our expected pCR rate, the local recurrence rate, 3‐year DFS, and measures of safety met current standards.

Abstract Background Gastric cancer with portal vein tumor thrombus (PVTT) is poor prognosis, and the treatment remains challenging. Regarding surgery, there are only reports of highly invasive laparotomy. We report some techniques of the completely robotic total gastrectomy with thrombectomy and portal vein reconstruction for the patient with gastric cancer and PVTT for the first time. Case presentation A 79-year-old man was diagnosed with a 5-cm gastric cancer on the side of the lesser curvature from the middle of the gastric body to the cardia. Computed tomography revealed a massive PVTT extending from the left gastric vein to the portal trunk (28 x 16 mm). There were no other distant metastases. After 3 cycles of the chemotherapy, the PVTT shrank to 19 x 12 mm. After obtaining informed consent from the patient, robotic total gastrectomy with regional lymphadenectomy and thrombectomy were performed. We used the da Vinci Xi Surgical System. A 3-cm incision was made at the umbilicus, and a wound retractor was placed. Five additional ports were placed. The right side suprapancreatic lymph nodes were performed at the time of the thrombectomy. It was important to identify the precise extent of the PVTT with intraoperative ultrasonography before the thrombectomy. After PVTT identification, the portal trunk was clamped above and below the tumor thrombus with vascular clips. The membrane on the anterior wall of the portal trunk around the PVTT was carefully incised with da Vinci Scissors. The tumor thrombus was completely enucleated without separation. The incised part of the portal trunk was reconstructed with continuous 5-0 synthetic monofilament nonabsorbable polypropylene sutures. After removing the vascular clamps, we made sure there was no leakage from the portal vein and no tumor thrombus remnants with intraoperative ultrasonography. Robotic total gastrectomy with lymphadenectomy and Roux-en-Y reconstruction were performed. The patient was discharged without complications. The patient has remained alive for 30 months after surgery. Conclusions Robotic total gastrectomy with thrombectomy and portal vein reconstruction is a safe, minimally invasive, and precise surgery. It may contribute to improved prognosis of gastric cancer with PVTT when combined with chemotherapy.

Abstract Purpose Pathological extramural venous invasion (EMVI) is defined as the active invasion of malignant cells into veins beyond the muscularis propria in colorectal cancer. It is associated with poor prognosis and increases the risk of disease recurrence. Specific findings on MRI (termed MRI-EMVI) are reportedly associated with pathological EMVI. In this study, we aimed to identify risk factors for lateral lymph node (LLN) metastasis related to rectal cancer and to evaluate whether MRI-EMVI could be a new and useful imaging biomarker to help LLN metastasis diagnosis besides LLN size. Methods We investigated 67 patients who underwent rectal resection and LLN dissection for rectal cancer. We evaluated MRI-EMVI grading score and examined the relationship between MRI-EMVI and LLN metastasis. Results Pathological LLN metastasis was detected in 18 cases (26.9%), and MRI-EMVI was observed in 32 cases (47.8%). Patients were divided into two cohorts, according to LLN metastasis. Multivariate analyses demonstrated that higher risk of LLN metastasis was significantly associated with MRI-EMVI (P = 0.0112) and a short lateral lymph node axis (≥ 5 mm) (P = 0.0002). The positive likelihood ratios of MRI-EMVI alone, LLN size alone, and the combination of both factors were 2.12, 4.84, and 16.33, respectively. Patients negative for both showed better 2-year relapse-free survival compared to other patients (84.4% vs. 62.1%, P = 0.0374). Conclusions MRI-EMVI was a useful imaging biomarker for identifying LLN metastasis in patients with rectal cancer. The combination of MRI-EMVI and LLN size can improve diagnostic accuracy.

Abstract Background Total mesorectal excision (TME) and lateral lymph node dissection (LLND) without radiotherapy (RT) are standard treatment for lower cT3/4 rectal cancers in Eastern countries. In comparative studies, both TME + LLND and RT + TME yield good local control. Although Japanese guidelines recommend LLND for locally advanced rectal cancers below the peritoneal reflection, LLND dissection of clinically negative lateral pelvic lymph nodes (LPLN) is controversial, and laparoscopic TME + LLND is technically challenging and time-consuming. New optical instruments for laparoscopy allow easy perioperative sentinel lymph node (SLN) identification using ICG. The SLN concept may facilitate accurate diagnosis of LPLN involvement, and thus reduce LLND in laparoscopic rectal cancer surgery. Here we investigated lateral pelvic SLN navigation surgery for SLN detection during laparoscopic rectal cancer surgery. Methods This study included 21 patients with clinical StageII/III lower rectal cancer without LPLN enlargement, who underwent curative laparoscopic surgery. All patients underwent TME, followed by lateral SLN identification and biopsy using ICG, and then laparoscopic LLND. ICG fluorescence imaging was conducted using the laparoscopic near-infrared camera system. Results Lateral SLNs were successfully identified in 16 (76.2%) of the 21 patients. Among the 15 patients without SLN tumor metastasis, the dissected lateral non-SLNs were all negative. Conclusions A lack of metastasis in the lateral pelvic SLN seems to reflect a lack of metastases to all lateral LNs. Our present results suggest that this laparoscopic ICG-guided SLN strategy may be a low-risk and time-saving method to prevent laparoscopic LLND in cases with negative lateral pelvic lymph nodes.

Abstract Background Although chemotherapy for metastatic colorectal cancer (mCRC) has improved, the standard chemotherapy regimens for patients with RAS wild-type mCRC remain debated. This study aimed to compare S-1 and oxaliplatin (SOX) + bevacizumab (B-mab) with SOX + cetuximab (C-mab) in patients with previously untreated recurrent advanced CRC with wild-type KRAS. Methods This randomized phase II, open-label, multicenter study compared the efficacy and safety of SOX+B-mab with SOX+C-mab in patients with previously untreated advanced CRC with wild-type KRAS. Between February 2012 and October 2016, 45 patients were enrolled. Results Overall response rates were 59.1 and 43.5% (p = 0.29) and disease control rates were 90.9 and 91.3% (p = 0.96) in the SOX+B-mab and SOX+C-mab groups, respectively. Median overall survival (OS) was 25.3 and 15.5 months (HR = 0.607, p = 0.167) and median progression-free survival (PFS) were 11.7 and 5.5 months (HR = 0.558, p = 0.077) in the SOX+B-mab and SOX+C-mab groups, respectively. The OS and PFS of patients with early tumor shrinkage (ETS) were not significantly different in the SOX+B-mab group. However, they were significantly better when ETS was ≥20 in the SOX+C-mab group (p = 0.032 and p = 0.003, respectively). Conclusions The efficacy and safety of SOX+B-mab and SOX+C-mab for wild-type KRAS recurrent advanced CRC as first-line chemotherapy were almost the same. Consideration of the treatment strategy based on ETS may improve patient prognosis, especially in patients receiving the SOX+C-mab regimen. Trial registration UMIN Clinical Trials Registry ( UMIN000006706 ). Date of registration: NOV/11/2011. URL of trial registry record: https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000007920

Abstract Aim The management of diabetes mellitus (DM) after pancreatic surgery is a long‐standing issue. We aimed to investigate DM concerning pancreatic surgery, including new onset diabetes mellitus (NODM), DM resolution, and the change in insulin excretion before/after pancreatic surgery. Methods We retrospectively investigated three different cohorts (total 403 patients) undergoing pancreatectomy. Of those, 275 patients without preoperative DM were investigated for the risk factors of NODM. Fifty‐four patients without preoperative DM of the other cohort were assessed for pre/postoperative 24‐hour urinary C‐peptide excretion (24‐hr CPR). To evaluate the influence of pancreatic surgery on DM treatment in patients with preoperative DM, 74 patients were investigated. In all those patients, the pancreatic volume in pre/postoperative images was assessed to estimate the resected pancreatic volume. Results NODM was observed in 60 patients (21%), and a lower ratio of remnant pancreatic volume (RRPV) was the only significant risk factor for NODM. Postoperative 24‐hr CPR was significantly associated with two factors, RRPV and preoperative 24‐hr CPR. Nine of 74 patients with preoperative DM achieved DM resolution after pancreatic surgery, and the presence of gastrointestinal anastomosis was a significant preferable factor for DM resolution. Conclusions Considering the management of DM after surgery, both predicting the postoperative pancreatic volume and the presence of gastrointestinal reconstruction are significant. We concluded that the combined assessment of the predicted remnant pancreatic volume and the preoperative 24‐hr CPR value is useful to predict the postoperative pancreatic function.

Objectives: Anastomotic leakage is one of the most severe complications of rectal cancer surgery. A diverting ileostomy was constructed for the purpose of reducing anastomotic failure risk. Outlet obstruction (OO) is one of the complications of diverting stoma that results in a lack of fecal discharge from the stoma. Detailed etiologies and preventive measures for outlet obstruction have not yet been identified. Methods: We studied 125 patients who underwent rectal resection, anastomosis, and elective ileostomy. We evaluated the incidence of outlet obstruction and looked for any relationship between perioperative factors and outlet obstruction. Results: Outlet obstruction was detected in 20 cases (16.0%). Outlet obstruction occurred 9 days after surgery in most cases. Inserting a decompressing tube improved obstructive symptoms in 4 days. Patients were divided into two cohorts according to the occurrence of outlet obstruction. Postoperative hospital stay was longer in the outlet obstruction group (19 vs. 15 days; p = 0.0003). A multivariate analysis identified that younger patients, a postoperative thicker rectus abdominis muscle at the stoma passage and high output syndrome were independent risk factors for outlet obstruction. Conclusions: Younger patients, a postoperative thicker rectus abdominis muscle at stoma passage and high output syndrome were independent risk factors for outlet obstruction.

Abstract POU5F1-expressing cells can self-renew and differentiate, contributing to metastasis formation in colorectal cancer (CRC), but it plays an important role in normal pluripotent stem cells. Here, we identified the CRC-specific gene, HNF1A, which is the downstream of POU5F1. HNF1A associates with fatty acid and glucose metabolism, and CRC cells highly expressed it. In 198 CRC patients, high HNF1A expression was an independent predictor of disease-free (P = 0.031) and overall (P = 0.007) survival. HNF1A-knockdown showed significantly reduced cell growth, increased apoptosis, and improved anticancer drug sensitivity. We revealed that HNF1A regulated controlled GLUT1 expression via HIF1A and multidrug resistance protein function to suppress SRI. HNF1A expression was elevated in persister cells after exposure to anticancer drugs, and anticancer drug sensitivity was also improved in persister cells via the inhibition of HNF1A. In conclusion, HNF1A expression can reflect resistance to anticancer drug treatment, and its suppression improves anticancer drug sensitivity as a new therapeutic target.

Abstract Olanzapine has exhibited efficacy as an antiemetic agent when used with 5-HT3 receptor antagonists, dexamethasone, and NK1 receptor antagonists for patients receiving highly emetogenic chemotherapy. In addition, several studies have reported the efficacy or safety of olanzapine in patients receiving moderately emetogenic chemotherapy, including carboplatin, irinotecan, and oxaliplatin. However, no reports of olanzapine use have focused on patients receiving oxaliplatin-based chemotherapy. Therefore, we analyzed the safety of antiemetic therapy using olanzapine, palonosetron, aprepitant, and dexamethasone in colorectal cancer patients undergoing oxaliplatin-based chemotherapy. This study was a prospective phase II single-institution study of 40 patients (median age 60 years, 23 patients were male). The primary endpoint was the incidence of adverse events, and the exploratory endpoints were the rate of chemotherapy-induced nausea and vomiting. Almost all patients (90%) had a performance status of 0. All patients received the scheduled antiemetic therapy. The most common adverse event was somnolence (n = 7 patients, 17.5%). All adverse events were grade 1. Thirty-six patients were included in the exploratory analysis of efficacy. No patients experienced vomiting during the first 120 h after chemotherapy, and complete response and complete control were both 86.1%. The rate of total control was 55.6% during the same time period. Olanzapine use with 5-HT3 receptor antagonists, dexamethasone, and NK1 receptor antagonists was safe for colorectal cancer patients receiving oxaliplatin-based chemotherapy.

Abstract Background Peutz–Jeghers syndrome (PJS) is a very rare autosomal dominant genetic disorder characterized by hamartomatous polyps in the gastrointestinal tract and hyperpigmentation of the lips, hands, and feet. The hamartomatous polyps in the small intestine often cause intussusception and bleeding. Case presentation A 62-year-old male was hospitalized for treatment of deep vein thrombosis and pulmonary embolism. In the small intestine, computed tomography showed three small polyps with intussusceptions. Since the patient had gastrointestinal polyposis and pigmentation of his lips, fingers, and toes, he was diagnosed with PJS. After an inferior vena cava filter was placed, he underwent laparoscopic-assisted surgery. The polyps causing intussusception were resected as far as possible without intestinal resection, since they had caused progressive anemia and might cause intestinal obstruction in the future. The patient was discharged from the hospital on postoperative day 9 without complications. Conclusions Laparoscopic-assisted disinvagination and polypectomy is a useful, minimally invasive treatment for multiple intussusceptions caused by small intestinal polyps in patients with PJS.

Abstract Malnutrition has been considered to be associated with the prognosis of cancer. The Geriatric Nutritional Risk Index (GNRI), based on serum albumin levels, present body weight, and ideal body weight, is a simple screening tool to predict the risk of nutrition-related morbidity and mortality in elderly patients. We aimed to evaluate whether preoperative GNRI was associated with postoperative complications and prognosis in elderly patients with colorectal cancer (CRC). We retrospectively enrolled 313 CRC patients aged ≥65 years after curative surgery and classified them into an all-risk GNRI (≤98) group and a no-risk GNRI (>98) group. Kaplan-Meier analysis showed overall survival was significantly worse in the all-risk GNRI group than in the no-risk GNRI group (P = 0.009). Multivariable analyses showed low GNRI (≤98) was an independent risk factor for postoperative complications (P = 0.048) and overall survival (P = 0.001) in the patients. Among the complications, the incidence of surgical site infection, in particular, was significantly higher in the all-risk GNRI group (P = 0.008). In conclusion, low preoperative GNRI (≤98) was associated with increased postoperative complications and poor prognosis. Preoperative GNRI can be used as an identifier for potential high-risk group of morbidity and mortality in elderly CRC patients.

Objectives: We previously reported the feasibility of neoadjuvant capecitabine and oxaliplatin plus bevacizumab as a treatment for locally advanced rectal cancer (UMIN000003219). The aim of this study is to investigate the prognostic relevance of neoadjuvant chemotherapy followed by total mesorectal resection (TME). Methods: Twenty-five patients of our prior multicenter prospective study of neoadjuvant chemotherapy followed by TME enrolled to this study. We analyzed the adjuvant chemotherapy regimen, and the duration between surgery and initial chemotherapy treatment. Five-year progression-free survival and overall survival were estimated using the Kaplan-Meier method. Results: Among survivors, the median follow-up time was 66 months. Recurrence occurred in six patients, all of whom had suboptimal tumor regression after neoadjuvant chemotherapy. Five patients died from other causes. The rate of local recurrence and distant metastasis was 17.4% and 8.7%, respectively. Five-year progression-free survival was 70.0%, and 5 year overall survival was 84.0%. Conclusions: We report the long-term survival of patients who received neoadjuvant chemotherapy without radiation followed by TME, revealing a generally favorable prognosis.

Objectives: The efficacy of negative pressure wound therapy (NPWT) and its application to severely contaminated wounds sustained during surgery remain to be established. Here, we evaluated the efficacy of utilizing NPWT until delayed primary closure (DPC) by assessing the infection rates in patients with lower gastrointestinal perforations. Methods: This prospective multicenter cohort study included 56 patients that underwent abdominal surgery for lower gastrointestinal perforations in eight institutions, from February 2016 to May 2017. All patients received NPWT after surgery before attempting DPC. The extent of peritonitis was categorized according to Hinchey's classification. Patients in stages II-IV were included. Results: Five patients had surgical site infections (SSIs) during NPWT and did not receive a DPC (9%). Of the 51 patients that received DPCs, 44 had no infection (91%) and 7 developed SSIs after the DPC (13.7%). For stages II, III, and IV, the SSI rates were 0%, 22.6%, and 35.7%, respectively; the median (range) times to wound healing were 15 (10-36), 19 (11-99), and 19 (10-53) days, respectively. There were no significant differences between the stages. Conclusions: NPWT followed by DPC resulted in low infection rates in each peritonitis stage. This approach appears promising as an alternative to traditional DPC alone for treating lower gastrointestinal perforations.

Abstract This review outlines current topics on the surgical treatment of benign colorectal diseases, with a focus on inflammatory bowel disease (IBD) and diverticulitis. Treatment options for IBD and diverticulitis have evolved in the last few years as a result of medical advances in technology and new clinical trials. Therefore, treatment options and strategies need to be updated to provide optimal care for patients. The purpose of this review is to elucidate recent global trends and update the surgical treatment strategy for IBD and diverticulitis based on literature published in the past 2 years. Prevalence of IBD, including ulcerative colitis and Crohn's disease, has increased over the last few decades. During this period, many new medical therapies were introduced for the treatment of IBD, including biological therapy, immunomodulators, and leukocyte apheresis therapy. As a result, new surgical strategies for IBD are required. In order to improve surgical outcomes in IBD patients, the influence of preoperative treatment on postoperative complications needs to be considered. The incidence of diverticulitis is also increasing with lifestyle changes and increasing numbers of older people. For diverticulitis with perforation and generalized peritonitis, surgery is the gold standard. Elective surgery after conservative treatment of diverticulitis is also an option because of high recurrence rates. With an increase in diverticulitis, systematic strategies are essential for an appropriate approach to diverticulitis, taking into account various factors, including the patient's background.

Abstract Aim Visceral obesity (VO) reportedly has a stronger association with complications after colorectal surgery than does body mass index. Here, we retrospectively assessed VO as a risk factor for postoperative ileus (POI) after colorectal resection in patients with colorectal cancer. Methods This study included 417 consecutive patients with colorectal cancer who underwent elective surgery at our institute from January 2010 to December 2012. Visceral fat area (VFA) was calculated by image analysis software. VO was defined as VFA ≥100 cm2. We assessed 49 factors, including VO, comorbidities, surgical procedure, and postoperative complications. Data were analyzed using a propensity score‐matching strategy. Results Postoperative ileus occurred in 18 patients (4.3%) from the entire cohort, and in 14 (5.5%) of the 256 matched patients. Multivariate analysis (n = 417 patients) showed that significant risk factors for POI included VO (OR 7.9, 95% confidence interval [CI] 1.9‐32.1, P = .004), open surgery (OR 6.4, 95% CI 1.6‐26.7, P = .010), and pelvic/intra‐abdominal abscess (OR 11.0, 95% CI 1.1‐110.2, P = .041). Propensity score matching showed two independent risk factors in the multivariate analysis: VO (OR 6.2, 95% CI 1.3‐30.4, P = .025) and open surgery (OR 9.1, 95% CI 2.0‐40.5, P = .004). Conclusion Visceral obesity may be an independent risk factor for POI in patients with colorectal cancer.

Abstract Aim To investigate the efficacy and safety of anticoagulant prophylaxis to prevent postoperative venous thromboembolism (VTE) during laparoscopic colorectal cancer (CRC) surgery, which is unknown in Japanese patients. Methods We conducted this randomized controlled trial at nine institutions in Japan from 2011 to 2015. It included 302 eligible patients aged 20 years or older who underwent elective laparoscopic surgery for CRC. Patients were randomly assigned to an intermittent pneumatic compression (IPC) therapy group or to an IPC + anticoagulation therapy group. Anticoagulation therapy comprised fondaparinux or enoxaparin for postoperative VTE prophylaxis. Postoperative VTE was diagnosed based on enhanced multi‐detector helical computed tomography. The primary endpoint was VTE incidence, including asymptomatic cases, the secondary endpoint was incidence of major bleeding, and we conducted an intention‐to‐treat analysis. This study is registered in UMINCTR (UMIN000008435). Results Postoperative VTE incidence was 5.10% with IPC therapy (n = 157) and 2.76% with IPC + anticoagulant therapy (n = 145; P = .293). We identified no symptomatic VTE cases. The major bleeding rates were 1.27% with IPC alone and 1.38% with the combination (P = .936). The overall bleeding rates were 7.69% for enoxaparin and 13.6% for fondaparinux (P = .500), and there were no bleeding‐related deaths. Conclusion Anticoagulant prophylaxis did not reduce the incidence of VTE and the incidence of major bleeding was comparable between the two groups. Usefulness of perioperative anticoagulation was not demonstrated in this study. Pharmacological prophylaxis must be restricted in Japanese patients with higher risk of VTE.

Abstract Background Preoperative 5-FU-based chemoradiation is currently a standard treatment for advanced rectal cancer, particularly in Western countries. Although it reduced the local recurrence, it could not necessarily improve overall survival. Furthermore, it can also produce adverse effects and long-term sphincter function deficiency. Adjuvant oxaliplatin plus capecitabine (XELOX) is a recommended regimen for patients with curatively resected colon cancer. However, the efficacy of postoperative adjuvant therapy for rectal cancer patients who have not undergone preoperative chemoradiation remains unknown. We aimed to evaluate the efficacy of surgery and postoperative XELOX without preoperative chemoradiation for treating rectal cancer. Methods We performed a prospective, multicenter, open-label, single arm phase II study. Patients with curatively resected high-risk stage II and stage III rectal cancer who had not undergone preoperative therapy were treated with a 120 min intravenous infusion of oxaliplatin (130 mg/m2) on day 1 and capecitabine (2000 mg/m2/day) in 2 divided doses for 14 days of a 3-week cycle, for a total of 8 cycles (24 weeks). The primary endpoint was 3-year disease-free survival (DFS). Results Between August 2012 and June 2015, 60 men and 47 women with a median age was 63 years (range: 29–77 years) were enrolled. Ninety-three patients had Eastern Cooperative Oncology Group performance status scores of ‘0’ and 14 had scores of ‘1’. Tumors were located in the upper and lower rectums in 54 and 48 patients, respectively; 8 patients had stage II disease and 99 had stage III. The 3-year DFS was 70.1% (95% confidence interval, 60.8–78.0%) and 33 patients (31%) experienced recurrence, most commonly in the lung (16 patients) followed by local recurrence (9) and hepatic recurrence (7). Conclusions Postoperative XELOX without preoperative chemoradiation is effective for rectal cancer and provides adequate 3-year DFS prospects. Trial registration This clinical trial was registered in the University Hospital Medical Information Network registry system as UMIN000008634 at Aug 06, 2012.

Objectives: It has been reported that there is an association between the nutritional condition and the prognosis of cancer. Here, we evaluated the relation between the prognostic nutritional index (PNI) and colorectal cancer (CRC). Methods: A total of 184 patients with CRC who underwent curative surgery from October 2011 to December 2012 at the Osaka University Hospital were investigated. According to the median PNI value of our data set, patients were classified into a high-PNI (46) group and a low-PNI (

Abstract Aim Appendiceal mucinous neoplasms are rare, and thus the literature is sparse with regard to histological types, staging, and prognosis. In particular, it is unclear how long‐term outcome may differ between mucinous adenocarcinomas and other adenocarcinomas. In the present study, we aimed to investigate the histological types and stages of appendiceal neoplasms, and to evaluate the prognostic impacts of these factors in patients with mucinous adenocarcinomas and non‐mucinous adenocarcinomas. Methods Patients with appendiceal tumors diagnosed between 2007 and 2016 were retrospectively identified from the databases of 19 institutions in the Clinical Study Group of Osaka University, Colorectal Group. Results A total of 266 patients with appendiceal tumors were identified, of whom 130 had pathologically diagnosed adenocarcinomas, including 57 with mucinous adenocarcinomas and 73 with non‐mucinous adenocarcinomas. Five‐year overall survival (OS) rates were 64.5% for mucinous adenocarcinomas, and 49.0% for non‐mucinous adenocarcinomas. OS was significantly shorter among patients with non‐mucinous adenocarcinomas compared to mucinous adenocarcinomas. Among patients with mucinous adenocarcinomas, 5‐year OS rates were 53.6% for stage 0/I, 82.6% for II/III, and 48.4% for IV. Among patients with non‐mucinous adenocarcinomas, 5‐year OS rates were 90.9% for stage 0/I, 68.8% for II/III, and 7.1% for IV. Analysis of patients with stage IV disease revealed significantly shorter OS among patients with non‐mucinous adenocarcinomas compared to mucinous adenocarcinomas. Conclusion Our present findings showed a better prognosis in patients with mucinous adenocarcinomas compared to non‐mucinous adenocarcinomas. In this setting, Union for International Cancer Control staging was associated with prognosis for non‐mucinous adenocarcinomas, but not for mucinous adenocarcinomas.

The incidence of inflammatory bowel disease (IBD) is increasing. Nucleic acid-based medicine has potential as a next-generation treatment, but it is rarely successful with IBD. The aim of this study was to establish a microRNA-based therapy in an IBD model. For this purpose, we used microRNA-29 (miR-29) and a supercarbonate apatite (sCA) nanoparticle as a drug delivery system. Injection of sCA-miR-29a-3p or sCA-miR-29b-3p into mouse tail veins markedly prevented and restored inflammation because of dextran sulfate sodium (DSS)-induced colitis. RNA sequencing analysis revealed that miR-29a and miR-29b could inhibit the interferon-associated inflammatory cascade. Subcutaneous injection of sCA-miR-29b also potently inhibited inflammation, and it efficiently targeted CD11c+ dendritic cells (DCs) among various types of immune cells in the inflamed mucosa. RT-PCR analysis indicated that the miR-29 RNAs in CD11c+ DCs suppressed the production of interleukin-6 (IL-6), transforming growth factor β (TGF-β), and IL-23 subunits in DSS-treated mice. This may inhibit Th17 differentiation and subsequent activation, which is critical in IBD pathogenesis. In vivo experiments using a non-natural artificial microRNA sequence revealed that targeting of DCs in the inflamed colon is an exceptional feature of sCA. This study suggests that sCA-miR-29s may open a new avenue in nucleic acid-based medicine for IBD treatment. Keywords: microRNA-29a, microRNA-29b, DSS colitis, supercarbonate apatite, dendritic cells

Objectives: The aim of this study was to evaluate the feasibility of a protocol for enhanced recovery after surgery (ERAS) for colon cancer in older patients. Methods: One hundred and fifty-nine patients enrolled in the ERAS group of our previous clinical study were divided according to age into an older group (n = 31; ≥80 years old) and a younger group (n = 128;