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It is occasionally difficult to diagnose cT3 or cT4b using imaging examinations for esophageal cancer. The optimal treatment strategy for borderline resectable esophageal squamous cell carcinoma (BR-ESCC) is unclear.We included 131 patients with cT3 ESCC who received neoadjuvant chemoradiotherapy (NCRT) followed by surgery. The patients were classified as having definitive cT3 (D-cT3) or borderline resectable cT3 (BR-cT3), based on presence of undeniable adjacent organ invasion on pretreatment CT. Surgical outcomes and prognoses were compared among patients with D-cT3 and BR-cT3 tumors, and the risk factors for non-R0 resection were assessed.Ninety and 41 patients were classified as D-cT3 and BR-cT3, respectively. Although BR-cT3 had a significantly higher non-R0 resection rate than D-cT3 (D-cT3 3.7%; BR-cT3 14.6%), BR-cT3 was not correlated with shorter overall survival (OS) (D-cT3 5-year OS, 50.8%; BR-cT3 5-year OS 38.4%; p = 0.234). Conversely, non-R0 resection was significantly associated with poor OS (R0 resection 5-year OS 48.8%; non-R0 resection 5-year OS 22.2%; p = 0.031). Cox regression analysis of OS demonstrated that BR-cT3 was not a prognostic factor. In the analysis of risk factors for non-R0 resection, BR-cT3 (p = 0.027), suspected invasion of the trachea or bronchus (p = 0.046), and high SUVmax of the primary lesion after NCRT (p = 0.002) were risk factors.NCRT followed by surgery achieved a relatively high R0 resection rate and an almost equal overall survival rate for BR-cT3 compared with D-cT3 ESCC. Thus, NCRT followed by surgery is an effective treatment strategy for patients with BR-cT3 ESCC.

Morgagni hernia is a rare form of diaphragmatic hernia. It is located at the anterior edge of the diaphragm and does not have an anterior rim. It is difficult to achieve a secure closure and maintain the tension of closure with laparoscopic surgery. We have performed laparoscopic resection of colorectal cancer and hernia repair simultaneously. An 89-year-old woman underwent laparoscopic hernia repair and ileocecal resection simultaneously. Regarding hernia repair, we considered that it would be difficult to use a mesh from the viewpoint of infection due to the colectomy. Therefore, we have done the extra-abdominal suture method. After laparoscopic ileocecal resection, a small incision was made in the epigastric region, and Morgagni hernia repair was performed with extra-abdominal sutures. She had no recurrence of either colon cancer or hernia for 22 months post-operatively. The extra-abdominal suture method can provide secure closure of the hernia orifice for Morgagni hernia.

Patients with peritoneal dissemination of gastric cancer have poor oral intake caused by malignant bowel obstruction (MBO). Palliative surgery has often been undertaken to improve quality of life (QOL), but few prospective studies on palliative surgery in this patient population have been published. We prospectively investigated the significance of palliative surgery using patient-reported QOL measures. Patients underwent palliative surgery by small intestine/colon resection or small intestine/colon bypass or ileostomy/colostomy for MBO. The primary endpoint was change in QOL assessed at baseline, 14 days, 1 month, and 3 months following palliative surgery using the Euro QoL Five Dimensions (EQ-5D™) questionnaire and the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire gastric cancer module (QLQ-STO22). Secondary endpoints were postoperative improvement in oral intake and surgical complications. Between April 2013 and March 2018, 63 patients were enrolled from 14 institutions. The mean EQ-5D™ utility index baseline score of 0.6 remained consistent. Gastric-specific symptoms mostly showed statistically significant improvement from baseline. Forty-two patients (67%) were able to eat solid food 2 weeks after palliative surgery and 36 patients (57%) tolerated it for 3 months. The rate of overall morbidity of ≥ grade III according to the Clavien–Dindo classification was 16% (10 patients) and the 30-day postoperative mortality rate was 3.2% (2 patients). In patients with MBO caused by peritoneal dissemination of gastric cancer, palliative surgery did not improve QOL while improving solid food intake, with an acceptable postoperative morbidity and mortality rate.

348 Background: CapeOX is a standard regimen for treating advanced gastric cancer (AGC). However, limited data are available for its use in the elderly patients. Geriatric assessment (GA) assessment is also considered important other than the age. Therefore, we conducted a multicenter, single-arm, phase II study to evaluate the efficacy and safety of CapeOX as a first-line therapy for AGC in elderly patients. We performed GA assessments using the G8, and the MINI-COG. Methods: The inclusion criteria were: HER2-negative or unknown status, age 70 years or older, PS 0 or 1, no history of chemotherapy or radiotherapy, and an evaluable lesion based on the RECIST v1.1 guidelines. The initial treatment plan consisted of capecitabine (1,000 mg/m2, b.i.d., on days 1–14), and oxaliplatin (130 mg/m2, on day 1) every three weeks. After the initial feasibility assessment, the treatment plan was modified and consisted of capecitabine (750 mg/m2, b.i.d., on days 1–14) and oxaliplatin (100 mg/m2, on day 1) every three weeks. The primary endpoint was overall survival (OS). G8 assessments were performed before the beginning of the treatment, every three months after the start of the treatment, and at the end of the treatment. MINI-COG assessments were performed before the beginning of the treatment, and at the end of the treatment. Results: Between November 2016 and June 2020, 108 patients were enrolled, out of which 104 were evaluated. Thirty-nine patients received the initial treatment whereas sixty-five patients received the modified treatment. The primary endpoint was met. The median OS, progression-free survival (PFS), and time-to-treatment failure (TTF) were 12.9 (95% CI: 11.7–14.8), 5.8 (95% CI: 5.1–7.1), and 4.3 (95% CI: 3.9–5.7) months, respectively, for all patients. The median OS, PFS, and TTF for the initial treatment plan were 13.4 (95% CI: 9.6–16.0), 5.8 (95% CI: 4.1–7.9), and 5.3 (95% CI: 3.5–7.3) months, respectively, and for the modified treatment plan were 12.8 (95% CI: 11.3–15.3), 5.7 (95% CI: 4.4–7.0), and 4.2 (95% CI: 3.7–5.7) months, respectively. The most common grade 3/4 toxicities in the initial treatment plan patients were neutropenia (17.9%), anemia (12.8%), thrombocytopenia (12.8%), anorexia (10.3%), and nausea (10.3%) and in the modified treatment plan patients were (13.8%) and anorexia (12.3%). Mean G8 score was 11.4 before the treatment, 13.4 during the treatment and 11.6 at the end of the treatment. Mean MINI-COG score was 4.0 before the treatment, and 4.1 at the end of the treatment and the positive screen for dementia was 13.5% before the treatment and 11.4% at the end of the treatment. Conclusions: Our results show that the modified treatment plan is favorable for the elderly patients with gastric cancer based on the OS and the toxicities. Clinical trial information: 000022450 .

381 Background: Postoperative S-1 (80 mg/m2/day for 4 weeks and 2 weeks rest in one course) for 1 year corresponding to 8 courses is a standard adjuvant chemotherapy for pathological stage (pStage) II gastric cancer. To shorten the duration of S-1 chemotherapy, we conducted a phase III trial to confirm non-inferiority in relapse-free survival (RFS) of 4 courses of S-1 to 8 courses of S-1 for pStage II gastric cancer. When 590 patients were enrolled, the study was closed at the first interim analysis because of futility. The RFS at 3 years was 89.8% for 4-courses and 93.1% for 8-courses (HR 1.84, 95% confidence interval (CI) 0.93-3.63). This is a final 5-year follow-up results of this study. Methods: Key eligibility criteria were pStage II except for T1 and T3N0 (7th edition of TNM), ECOG performance status 0-1, R0 resection with D2 lymph node dissection for >clinical stage (cStage) II or D1+ lymph node dissection for cStage I, within 7 weeks after surgery, and age between 20 and 80 years. The total sample size was determined to be 1,000 with a 3-year RFS of 85% in both arms and non-inferiority margin of hazard ratio (HR) of 1.37, with one-sided alpha of 5% and 80% power. Results: Between Feb 2012 and Mar 2017, 590 patients, 295 for each arm, were enrolled. When closing the study, the patients who were allocated to the 4-courses arm were informed of the primary results and the recommendation to continue S-1 until 8 courses as an off-protocol when they were receiving S-1. The cut-off date for the final follow-up data was March 22, 2022 with a median follow-up period for surviving patients of 6.0 years (IQR; 5.0-7.2). In 4-courses arm, 27 patients were receiving S-1 when the study was closed at the interim analysis. Among them, 22 patients expressed their will to continue until 8 courses. The RFS at 3/5 years was 90.1%/85.6% for 4-courses and 92.2%/87.7% for 8-courses (HR 1.27, 95% CI 0.85-1.89). The overall survival at 3/5 years was 93.2%/88.6 for 4-courses and 94.9%/89.7 for the 8-courses (HR 1.12, 95% CI 0.72-1.75). The HR of the cumulative incidence of the recurrence was 1.38 (95% CI 0.85-2.24) for the 4-courses against 8-courses. Recurrence was frequently observed in patients who received up to 4 courses of S-1 (38 for 4-courses vs. 28 for 8 courses). The HR of the cumulative incidence of the peritoneal recurrence was 1.54 (95% CI 0.82-2.89) for the 4-courses against 8-courses. Conclusions: This final follow-up data confirmed the primary results presented at the interim analysis. S-1 adjuvant chemotherapy for 1 year for pStage II gastric cancer is highly recommended. Clinical trial information: 000007306 .

To decrease complications associated with the treatment of coeliac axis (CA) stenosis due to median arcuate ligament (MAL) syndrome in pancreaticoduodenectomy, we performed combined preoperative endovascular stenting and intraoperative MAL resection. This technique can secure the CA blood flow to the hepatic artery before surgery in one stage and prevent CA restenosis and stent dislocation because there is no extrinsic compression of the CA after MAL resection.

Aim Neoadjuvant chemotherapy (NAC) is promising to improve the survival of resectable gastric cancer. However, suitable regimen and treatment duration for NAC have not yet been established. Methods We conducted a randomized phase II trial to compare two and four courses of neoadjuvant S‐1/cisplatin (SC) and S‐1/cisplatin/docetaxel(DCS) using a two‐by‐two factorial design for locally resectable advanced gastric cancer. Patients with M0 and either T4 or T3 in case of junctional cancer or scirrhous‐type cancer received two or four courses of SC or DCS. Then, patients underwent D2 gastrectomy and adjuvant S‐1 chemotherapy for 1 year. The primary endpoint was 3‐year overall survival. The planned sample size was 120 eligible patients. Results Between October 2011 and September 2014, 132 patients were assigned to CS (n = 66; 33 in 2‐courses and 33 in 4‐courses) and DCS (n = 66; 33 in 2‐courses and 33 in 4‐courses). The 3‐year OS was 58.1% in CS and 60.0% in DCS with hazard ratio of 0.80 (95% CI, 0.48‐1.34), while it was 53.1% in the two courses and 65.0% in the four courses with hazard ratio of 0.72 (95% CI, 0.43‐1.22). In the survival analysis by duration in each regimen, the 3‐year OS was 58.1% for both two and four courses in CS, while it was 48.5% for two courses of DCS and 71.9% for four courses of DCS. Conclusions Considering high 3‐year OS, four courses DCS has a value to be tested in a future phase III study to confirm superiority of neoadjuvant chemotherapy for locally advanced gastric cancer., Overall survival curves stratified by regimens, number of courses.

We herein report the first case of rectal stenosis that developed after internal hemorrhoid treatment with aluminum potassium sulfate and tannic acid (ALTA) therapy that was successfully treated by laparoscopic surgery. A 72-year-old man suffered from a fever and rectal stenosis after undergoing internal hemorrhoid treatment with a submucosal injection of ALTA at a previous clinic. Three months after ALTA therapy, he developed frequent mucous and bloody stools. Lower intestinal tract endoscopy revealed circumferential severe rectal stenosis. He was therefore referred to our hospital. The patient suffered from frequent stool build-up and difficulty defecating. We performed balloon-dilatation intervention. The stenosis was not improved at all. Five months after ALTA therapy, we performed laparoscopic low anterior resection with diverting ileostomy. Three months after the operation, ileostomy takedown was performed. The patient has experienced no rectal stenosis in the 2 years since his radical operation.

We here report a case of pancreatic duct rupture associated with high-grade pancreatic intraepithelial neoplasia treated by radical resection. A 71-year-old man presented to our hospital because of abdominal bloating. Diagnoses of early-stage pancreatic body cancer with pancreatic duct rupture, pancreatic ascites, and formation of a pseudocyst were made on the basis of blood tests, multidetector dynamic computed tomography, endoscopic ultrasonography, magnetic resonance cholangiopancreatography, and endoscopic retrograde cholangiopancreatography. After achieving control of the ascites by placement of a pancreatic duct stent and aspiration of the pseudocyst, distal pancreatectomy with D2 lymph node dissection was performed. Intraoperative cytologic examination of the ascites was negative. The pathological diagnosis was high-grade pancreatic intraepithelial neoplasia in the pancreatic body. The branched pancreatic duct was occluded and dilated by acute inflammation around the pancreatic neoplasm, the inflammation being in the region of the dilated branched pancreatic duct and having caused its rupture. To the best of our knowledge, this is the first published report of pancreatic duct rupture associated with high-grade pancreatic intraepithelial neoplasia.

Background/aim Surgical stress significantly decreases serum diamine oxidase (DAO), a marker of intestinal mucosal maturation and integrity. This study aimed to determine the effects of postoperative enteral and total parenteral nutrition (EN and TPN, respectively) in patients with esophageal cancer. Patients and methods This prospective randomized trial compared serum DAO activities, nutritional states, trace elements and complications between patients who underwent esophagectomy and received EN or TPN for seven days thereafter. Results Fifty-one patients were randomized to receive EN or TPN. The rates of change in serum DAO activity from the day before surgery were 0.79, 0.89 and 0.91 on postoperative days (POD) 1, 3 and 7, respectively, in the EN group, and 0.64, 0.76 and 1.06, respectively, in the TPN group, with no significant differences. Furthermore, the rates of changes in indicators of nutritional status, namely total protein, albumin, total cholesterol, trace element concentrations and infectious and non-infectious complications did not significantly differ between the groups. Conclusion EN and/or TPN can be administered for early nutritional management until resumption of oral intake after esophagectomy according to the postoperative status of individual patients with esophageal cancer.

Introduction A decompensated cirrhosis sometimes develops collateral circulation due to severe fibrosis. Rupture of this collateral circulation can induce a fatal situation. Case presentation A 59-year-old man with alcoholic cirrhosis was admitted to our emergency department with a chief complaint of impaired consciousness. The patient had hypotension upon arrival, and enhanced computed tomography (CT) revealed a massive hemoperitoneum. Imaging examinations, including interventional radiography, could not identify the source of bleeding preoperatively; therefore, emergency surgery was performed. Intraoperatively, a collapsed small vessel connecting liver segment 4 and the expanded umbilical vein as collateral circulation due to portal hypertension was detected as the source of bleeding. Ligating the stump of the small vessel and postoperative intensive care saved the patient's life. The patient was discharged from our hospital 14 days after the surgery. Clinical discussion A rupture of the umbilical vein associated with cirrhosis is rare and causes a critical situation because of the fast blood flow in the collateral circulation caused by portal hypertension. Moreover, the amount of bleeding tends to increase since the abdominal cavity is a free space and patients with cirrhosis have coagulopathies, including thrombocytopenia and prolonged prothrombin time. Although a retrospective review of the enhanced CT image could identify the minute findings, arterial portography was insufficient to detect bleeding from the umbilical vein. Therefore, emergency exploratory laparotomy was required for the diagnosis and treatment. Conclusion Rupture of the reopened umbilical vein can cause idiopathic spontaneous hemoperitoneum in patients with decompensated cirrhosis., Highlights • A rupture of the umbilical vein due to cirrhosis can induce fatal hemoperitoneum. • Interventional radiology could not detect the source of bleeding. • Emergency surgery is required for idiopathic hemoperitoneum in liver cirrhosis.

Invasive micropapillary carcinoma (IMPC) is a relatively rare subtype of gastric adenocarcinoma and has aggressive histopathologic characteristics, including lymphatic and vascular invasion. However, the associated long-term survival outcomes remain unclear. This study aimed to compare the clinicopathological characteristics and prognosis of gastric adenocarcinoma with and without IMPC using propensity score-matched (PSM) analysis. Patients with gastric adenocarcinoma who underwent gastrectomy between 2006 and 2015 were included in the analysis. PSM analysis was performed to compensate for the background heterogeneity between the groups. The primary endpoint was disease-free survival (DFS) after gastrectomy, and the secondary endpoints were disease-specific survival (DSS) and recurrence pattern. Of 882 patients who underwent gastrectomy for gastric adenocarcinoma, with a follow-up duration greater than 36 months, 35 were diagnosed as having gastric adenocarcinoma with IMPC. After PSM, 70 patients, including 35 with IMPC and 35 without IMPC, were selected. Gastric adenocarcinoma with IMPC is characterized by lymphatic invasion (94% versus 69%, p = 0.012). Patients with IMPC had significantly poorer DFS than those without IMPC, with 3-year DFS rates of 62.2% and 93.4% (p = 0.003), respectively. Furthermore, a significant difference was also observed in DSS (p = 0.016); patients with IMPC more frequently developed liver metastasis (20%) than those without IMPC (3%, p = 0.006). Resected gastric carcinoma with IMPC was associated with poorer DFS and DSS; furthermore, an increased rate of lymphatic invasion and liver metastasis was noted than in cases without IMPC.

BACKGROUND: Cisplatin (CDDP) is an important chemotherapeutic drug for treating esophageal cancer that often induces nausea and vomiting. Rikkunshito (RKT), a traditional Japanese herbal medicine, can increase levels of plasma ghrelin, which is an orexigenic gut hormone that can alleviate chemotherapy-induced nausea and vomiting (CINV) and anorexia. METHODS: This prospective randomized crossover study included 20 patients with esophageal cancer who were administered with CDDP-based chemotherapy. Ten of them were assigned to group A [1st course: with RKT 7.5 g/day on days 1–14; 2nd course: without RKT (control)] and 10 were assigned to group B [1st course: without RKT (control); 2nd course: with RKT 7.5 g/day on days 22–35]. Food intake and levels of plasma acylated ghrelin (AG) were compared between the control and RKT courses. RESULTS: Data from 18 patients were included in this analysis, as chemotherapy was immediately stopped due to deteriorating renal function in one patient and intracerebral bleeding in another. The median rate at which food intake decreased between days 4 and 6 was considerably lower in the course with, than without RKT (2% vs. 30%; P=0.02). Median levels of AG significantly increased from days 3 to 8 in patients in both courses with and without RKT (9.6 to 15.7 fmol/mL, P

A 48-year-old man with unresectable gastric cancer and widespread peritoneal dissemination received concentrated ascites reinfusion therapy, followed by systemic chemotherapy. However, leptomeningeal carcinomatosis (LMC) was diagnosed 1 year later. Spinal drainage and ventriculoperitoneal shunting improved the patient’s neurological functions for approximately 2 weeks. The patient died 2 months after LMC diagnosis, but these treatments temporarily improved the quality of life during end-of-life care.

The clinical significance of lymph node (LN) status determined by preoperative 18F-fluorodeoxyglucose-positron emission tomography (FDG-PET) has not been investigated in patients with locally advanced esophageal squamous cell carcinoma (ESCC) treated with neoadjuvant chemoradiotherapy (NCRT) followed by surgery (trimodal therapy). This study reviewed 132 consecutive patients with ESCC who had been preoperatively evaluated using FDG-PET before and after NCRT to analyze associations among LN status according to PET findings, pathologic LN metastasis, and prognosis of ESCC after trimodal therapy. Lymph nodes that were PET-positive both before and after NCRT comprised significant predictive markers of pathologic LN metastasis in station-by-station analyses (sensitivity, specificity, and accuracy respectively 41.7%, 95.0%, and 92.7% before, and 12.0%, 99.4%, and 95.6% after NCRT; both p

Microbiome analysis has attracted attention in recent years as a tool to monitor individual health status. In particular, gut microbiota is closely related to autoimmunity, and detailed study of gut microbiota may enable prediction of the health status of individuals.Here, we aimed to conduct a detailed study to identify gastric cancer-specific gut microbiota and compare the data between patients with gastric cancer and healthy individuals. Toward this, we extracted DNA from feces of patients with advanced gastric cancer enrolled in the observational/translational study, the DELIVER trial (JACCRO GC-08: UMIN000030850) which evaluated clinical outcomes of nivolumab and developed host-related biomarkers for nivolumab in 500 patients with advanced gastric cancer, and obtained their sequence data at an average of 5 Gbps using whole-genome shotgun sequencing. We then performed genus classification and functional pathway analysis using Kyoto Encyclopedia of Genes and Genomes (KEGG).We analyzed differences in bacterial composition using the data of 476 Japanese patients with advanced gastric cancer (median age 70y, median BMI 20.0, 71% male, 37.0% of patients with relapse, 55.5% with previous gastrectomy) and public database of 106 healthy cases. Bifidobacterium, Anaerostipes, and Parabacteroides were predominant in the healthy individuals, whereas Streptococcus, Lactobacillus, and Odoribacter were predominant in patients with advanced gastric cancer. Furthermore, the KEGG pathway analysis showed that butanoate and pyruvate metabolism were enriched in the healthy individuals, whereas factors such as ABC transporters and ribosomes were enriched in the patients with advanced gastric cancer. Clustering analysis broadly classified the patients with advanced gastric cancer and healthy individuals into two clusters, and the clustering using pathway data enabled clearer classification of the patients with advanced gastric cancer and healthy individuals than the clustering using flora analysis. Additionally, the healthy individuals had higher bacterial flora diversity compared to the patients with advanced gastric cancer.We thus successfully identified the molecular characteristic of microbial genera and functional pathways in the gut in patients with advanced gastric cancer. We conclude that fecal metagenomic shotgun sequencing analysis might be used to detect gastric cancer. Citation Format: Ryo Matoba, Hiroshi Iijima, Yasuhiro Sakamoto, Ryohei Kawabata, Atsushi Ishiguro, Yusuke Akamaru, Yosuke Kito, Hiroshi Yabusaki, Jin Matsuyama, Masazumi Takahashi, Akitaka Makiyama, Takahisa Suzuki, Masahiro Tsuda, Hisateru Yasui, Jun Hihara, Toru Masuzawa, Hiroyuki Okuda, Junji Kawada, Shuhei Suzuki, Hisato Kawakami, Takako Eguchi Nakajima, Kei Muro, Wataru Ichikawa, Masashi Fujii, Yu Sunakawa. Molecular characteristics of gut microbiota in patients with gastric cancer: The DELIVER trial (JACCRO GC-08) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5957.

306 Background: The combination of paclitaxel (PTX) plus ramucirumab (RAM) has been the standard regimen for advanced gastric cancer (GC) or gastro-esophageal junction cancer (GJC) patients (pts) who were treated with fluoropyrimidine-containing regimen. In a phase 2 trial, it was showen that nab-PTX plus RAM has promising activity (objective response rate [ORR], 55 %; median progression free survival [PFS], 7.6 months) [Bando H, et al. Eur J Cancer 2018] and is, therefore, a treatment option. However, high incidence of myelosuppression led to discontinuation of the nab-PTX. Therefore, we conducted this study to investigate whether schedule modification to biweekly nab-PTX plus RAM therapy is safe and effective. Methods: Pts with GC or GJC treated with fluoropyrimidine-containing regimen were enrolled and received nab-PTX (100 mg/m2) on days 1, 8, and 15 and RAM (8 mg/kg) on days 1 and 15 of a 28-day cycle. The treatment schedule of pts with severe myelosuppression during the first cycle was modified to biweekly therapy from the second cycle. The primary endpoint was PFS in modified pts. Secondary endpoints included ORR, disease control rate (DCR), overall survival (OS), and safety. The exploratory analysis evaluated PFS and OS in pts who continued standard-schedule therapy. Based on the hypothesis that biweekly nab-PTX plus RAM therapy would improve PFS from 4.5 months to 7.0 months, 40 pts were required for a power of 0.8 with a one-sided α of 0.05. Results: Of the 81 pts who were enrolled, 76 pts received standard nab-PTX plus RAM in the first cycle and 47 pts (58%) were modified to the bi-weekly therapy. Pts characteristics in the modified pts were as follows: median age, 70 years; male, 72%; ECOG PS 0, 81%; and poorly differentiated adenocarcinoma or signet ring cell carcinoma, 45%. The median relative dose intensities of the entire period and after modification were 66% and 60%, respectively. In the modified pts, median PFS was 4.7 months (95% Confidence Interval [CI]: 3.7–5.6), median OS was 13.9 months (95% CI: 9.1–16.9), ORR was 25% (95% CI: 11–39), and DCR was 75% (95% CI: 61–89). Tumor shrinkage was observed in 61% of the pts (n = 36) with measurable lesion. In pts who could continue standard-schedule therapy, median PFS was 2.7 months (95% CI: 1.8–4.0) and median OS was 8.0 months (95% CI: 5.6–14.7). Severe (Grade >3) adverse events after modification were neutropenia (55%), anemia (13%), hypertension (17%), and peripheral sensory neuropathy (13%). Conclusions: Our study could not meet the primary endpoint for PFS. However, PFS in pts with standard-schedule therapy was numerically lower than that in the modified pts. The modification to biweekly schedule might be considered to be a treatment option for GC/GJC pts with severe myelosuppression in second-line nab-PTX plus RAM therapy. Clinical trial information: jRCTs031180061.

285 Background: The efficacy of trastuzumab has been established for HER2-positive advanced gastric cancer patients with metastatic disease. However, it remains unclear if the addition of trastuzumab to preoperative chemotherapy is effective for treatment of HER2-positive locally advanced gastric cancer. Methods: Eligible patients with HER2-positive gastric cancer with extensive lymph node metastasis were randomized to preoperative S-1/cisplatin (SP) (group A) or SP plus trastuzumab (group B). In both groups, patients received S-1, 80–120 mg/body, on days 1–14 and cisplatin, 60 mg/m2, on day 1, q21, 3-4 courses. Additionally, in group B, patients received infusions of trastuzumab (first course 8 mg/kg followed by 6 mg/kg, day 1). After gastrectomy, adjuvant chemotherapy with S-1 was performed for 1 year in both groups. The primary endpoint was overall survival, and the sample size was planned to be 130 patients in total, expecting a 10% increase in the 3-year overall survival (70% vs 80%) with a 1-sided alpha of 0.2, a power of 0.75. Results: The study was terminated in March 2021 due to slow patient accrual. In total, 46 patients were randomized to either group A (22 patients) or group B (24 patients). Patient characteristics were well balanced between the groups. Planned preoperative chemotherapy was completed in 20 patients (90.9%) in group A and in 23 patients (95.8%) in group B, and R0 resection was achieved in 20 patients (90.9%) in group A and 22 patients (91.7%) in group B. The incidences of grade 3 or 4 hematological/non-hematological adverse events during preoperative chemotherapy were 27.3/18.2% in group A and 4.2/8.3% in group B. Objective response rate (CR/PR) tended to be higher in group B (66.7% [16/24]) than in group A (36.4% [8/22], p = 0.08). Pathological response rate (> grade 1b in Japanese classification, 22.7% [5/22] vs. 50.0% [12/24], p = 0.07) and the proportion of patients achieving downstage to ypStage 0/I/II (22.7% [5/22] vs. 50.0% [12/24], p = 0.07) were also higher in group B than in group A. Conclusions: Preoperative chemotherapy with SP plus trastuzumab was feasible, and tended to show better radiological and pathological response rates. Better survival outcomes are expected by adding trastuzumab to preoperative chemotherapy with SP for locally advanced gastric cancer with extensive nodal metastasis. Clinical trial information: UMIN000016920.

Specific treatment strategies are sorely needed for scirrhous-type gastric cancer still, which has poor prognosis. Based on the promising results of our previous phase II study (JCOG0210), we initiated a phase III study to confirm the efficacy of neoadjuvant chemotherapy (NAC) in type 4 or large type 3 gastric cancer. Patients aged 20–75 years without a macroscopic unresectable factor as confirmed via staging laparoscopy were randomly assigned to surgery followed by adjuvant chemotherapy with S-1 (Arm A) or NAC (S-1plus cisplatin) followed by D2 gastrectomy plus adjuvant chemotherapy with S-1 (Arm B). The primary endpoint was overall survival (OS). Between October 2005 and July 2013, 316 patients were enrolled, allocating 158 patients to each arm. In Arm B, in which NAC was completed in 88% of patients. Significant downstaging based on tumor depth, lymph node metastasis, and peritoneal cytology was observed using NAC. Excluding the initial 16 patients randomized before the first revision of the protocol, 149 and 151 patients in arms A and B, respectively, were included in the primary analysis. The 3-year OS rates were 62.4% [95% confidence interval (CI) 54.1–69.6] in Arm A and 60.9% (95% CI 52.7–68.2) in Arm B. The hazard ratio of Arm B against Arm A was 0.916 (95% CI 0.679–1.236). For type 4 or large type 3 gastric cancer, NAC with S-1 plus cisplatin failed to demonstrate a survival benefit. D2 surgery followed by adjuvant chemotherapy remains the standard treatment.

Skeletal muscle loss is a hallmark of malignancies, including advanced gastric cancer (GC). Although programmed death (PD)-1 inhibitors, including nivolumab, have promising anti-cancer effects, there is limited information regarding markers that can predict these therapeutic effects, which include PD-ligand 1 (PD-L1) expression and the tumor mutation burden. Therefore, we evaluated whether the baseline psoas muscle mass index (PMI, a surrogate for skeletal muscle mass) could predict the response of GC to nivolumab treatment, based on progression-free survival (PFS), the objective response rate, and the disease control rate. This retrospective study evaluated 31 Japanese patients who received nivolumab for advanced GC and underwent imaging analysis between November 2017 and November 2019. The computed tomography results were used to estimate the psoas major muscle mass. Sex-specific cut-off values were used for the PMI, with low PMI values defined as

Background/aim The present study aimed to determine the effects of intervals between neoadjuvant chemoradiotherapy (nCRT) and esophagectomy on therapeutic outcomes in patients with locally advanced esophageal squamous cell carcinoma (ESCC). Patients and methods We analyzed data from 134 consecutive patients who were diagnosed with locally advanced ESCC of the thoracic esophagus and were treated by nCRT followed by esophagectomy between September 2003 and September 2015. We assigned the patients to groups A and B according to whether they underwent esophagectomy ≤8 or >8 weeks after nCRT. Results The two groups were comparable in terms of age, gender, performance status, comorbidities, tumor location, clinical stage, R0 resection rates and pathological responses to nCRT. The incidences of pneumonia and respiratory failure were significantly higher in group B (p=0.03, p=0.009, respectively). Recurrence-free (RFS) and overall (OS) survival rates did not significantly differ between the two groups. However, RFS was significantly poorer among patients with R0 resection (p=0.04) and those of cStages III and IV (p=0.009) in group B. Conclusion Esophagectomy should proceed within eight weeks after nCRT from the viewpoints of respiratory morbidity and impact of RFS on patients with R0 resection.

Schwannomas are tumors originating from the Schwann cells of the peripheral nerve sheath. Only 1%-3% of schwannomas reportedly occur in the pelvis. In a 67-year-old man, a pelvic mass that was 52 mm in diameter was incidentally diagnosed during a preoperative CT evaluation for prostate cancer. Preoperative 3-D reconstruction CT showed that the feeding artery to the tumor originated from the internal iliac artery and the drainage vein from the internal iliac vein. Each vessel could be isolated, clipped, and cut with minimal bleeding. The tumor was easily dissected from adjacent structures and was completely resected via laparoscopic surgery. Histopathology and immunohistochemistry of the excised specimen revealed a benign schwannoma. Using 3-D reconstruction to recognize a tumor's positional relation with the supplying vessels is important for avoiding complications during laparoscopic resection in the narrow pelvis. Laparoscopic resection is safe, feasible, and effective for retroperitoneal schwannoma.

Highlights • Accurate diagnosis of hemolymphangioma preoperatively is difficult. • Disease may vary from simple cystic to aggressive lesions, mimicking malignancy. • Complete excision provides the best results with a lower recurrence rate., Introduction Hemolymphangioma, a rare vascular developmental condition, is characterized by malformed venous and lymphatic components in various proportions. Herein, we report a case of a retroperitoneal cystic tumor in an adult patient. Presentation of case A 68-year-old man presented to our hospital with complaints of abdominal pain and vomiting. His abdomen was distended with upper tenderness but without rebound tenderness. Computed tomography (CT) scanning demonstrated a retroperitoneal cystic tumor at the dorsal part of the pancreatic head. Thus, a diagnosis of liposarcoma or lymphoma was made. The patient was scheduled for surgery after his general condition became stable. Intraoperatively, the cystic tumor was found to have originated from the retroperitoneal space. The tumor was in contact with the pancreatic head, abdominal aorta, and inferior vena cava. There was no invasion into the surrounding tissue. The cystic tumor was resected completely. Histopathological examination revealed that the resected retroperitoneal cystic tumor was a hemolymphangioma. The patient had no recurrence during the 12-month follow-up. Discussion Hemolymphangioma is a rare benign tumor, and its accurate diagnosis before surgery is still difficult. Disease presentation may vary from simple well-defined cystic lesions to aggressive ill-defined lesions, mimicking malignancy. Complete excision provides the best results with a low recurrence rate. Conclusion Further research is needed on the preoperative radiological diagnosis of such tumors and on how to determine tumor resectability in such cases.

Highlights • Intestinal obstructions caused by external compression from the appendix are rare. • Low-grade appendiceal mucinous neoplasm (LAMN) with torsion is rarer still. • LAMN have the potential to lead to pseudomyxoma peritonei. • Surgical resection for LAMN is the standard treatment. • The appropriate surgical procedure, however, remains controversial., Introduction Intestinal obstructions due to appendiceal pathology are rare. Obstructions caused by low-grade appendiceal mucinous neoplasms (LAMNs) are rarer still. Presentation of case A 79-year-old woman was referred to our hospital for mechanical small intestinal obstruction. The patient had undergone prior left oophorectomy via a lower abdominal incision. Physical examination revealed abdominal distension and slight tenderness. Laboratory analysis was unremarkable. Contrast enhanced computed tomography (CT) demonstrated dilation of an obstructed small intestinal loop without evidence of strangulation. There appeared to be a low density mass measuring 3.0 × 1.5 cm with a potential twist in the mesentery near the transition point in the small intestine. The patient was diagnosed with mechanical small intestinal obstruction and was treated conservatively with nasogastric tube decompression for one week. After no clinical improvement, we elected to surgically explore her. Intraoperative findings revealed that the ileum was compressed by the appendix, which had a cystic mass on its tip. There was no evidence of intestinal ischemia. Laparotomy appendectomy alone was performed. Pathology revealed a LAMN measuring 3.0 × 1.5 cm. She remains disease-free with 18 months of postoperative follow-up. Discussion Intestinal obstruction due to external compression by an appendiceal mass is rare, and is often difficult to preoperatively diagnose with CT. Conclusions The etiology of small intestinal obstruction with a transition point in the right lower quadrant of abdomen includes an appendiceal mass on the broad differential for this common problem.

Highlights • Pancreatobiliary fistulas (PBF) associated with IPMNs are rare. • PBF associated with IPMNs often develop obstructive jaundice and cholangitis. • The causes of death in them without resection are cholangitis or hepatic insufficiency. • Surgery should be considered in patients with PBF associated with IPMNs., Introduction Intraductal papillary mucinous neoplasms (IPMNs) occasionally involve formation of fistulas with other adjacent organs. Pancreatobiliary fistulas associated with IPMNs are rare, but affected patients often develop obstructive jaundice and cholangitis. Presentation of case A 79-year-old man was referred to our hospital for evaluation of abnormal biliary enzymes. Contrast-enhanced computed tomography and endoscopic retrograde cholangiopancreatography demonstrated multiple cystic lesions with septa in the pancreatic head and fistulas between the cystic lesions and common bile duct. The clinical diagnosis was pancreatobiliary fistula associated with a mixed-type IPMN and accompanying obstructive jaundice. The patient underwent subtotal stomach-preserving pancreaticoduodenectomy. The resected specimen showed fistulas between the cystic lesions and common bile duct. Histopathological examination showed that the main and branch ducts of the pancreatic head were dilated and filled with mucus. The epithelia of the pancreatic ducts revealed papillary proliferation and an invasive adenocarcinoma arising from an intraductal neoplasm. Immunohistochemistry examination showed CDX2- and MUC2-positive reactions. The final diagnosis was an intraductal papillary mucinous carcinoma of the intestinal-type. The patient remained disease-free for 9 months postoperatively. Discussion The causes of death in patients who have pancreatobiliary fistulas associated with IPMNs without resection are cholangitis or hepatic insufficiency. Nonoperative treatment is limited for cases with obstructive jaundice. It is necessary to prevent obstructive jaundice and cholangitis due to a large quantity of mucinous material. Conclusions Surgical resection should be considered, if possible, in patients with pancreatobiliary fistulas associated with IPMNs. A better prognosis is expected with prevention of obstructive jaundice or cholangitis.

Background The prognoses of submucosal esophageal squamous cell carcinoma patients vary. Patients with favorable prognoses may receive less invasive or nonsurgical interventions, whereas patients with poor prognoses or advanced esophageal cancer may require aggressive treatments. We sought to identify prognostic factors for patients with submucosal esophageal squamous cell carcinoma, focusing on lymph node metastasis and recurrence. Methods We included 137 submucosal esophageal squamous cell carcinoma patients who had undergone transthoracic esophagectomy with systematic extended lymph node dissection. Submucosal tumors were classified as SM1, SM2, and SM3 according to the depth of invasion. Prognostic factors were determined by univariable and multivariable analyses. Results Lymph node metastasis was observed in 18.8%, 30.5%, and 50.0% of SM1, SM2, and SM3 cases, respectively. The overall 5-year recurrence rate was 21.9%; the rates for SM1, SM2, and SM3 tumors were 9.4%, 18.6%, and 34.8%, respectively. The SM1 tumors all recurred locoregionally; distant metastasis occurred in SM2 and SM3 cases. The 5-year overall survival rates were 83%, 77%, and 59% for SM1, SM2, and SM3 cases, respectively. On univariable analysis, lymph node metastasis, depth of submucosal invasion (SM3 versus SM1/2), and tumor location (upper thoracic versus mid/lower thoracic) were poor prognostic factors for overall survival. Multivariable Cox regression analyses identified depth of submucosal invasion (hazard ratio 2.51, 95% confidence interval: 1.37 to 4.61) and tumor location (hazard ratio 2.43, 95% confidence interval: 1.18 to 4.63) as preoperative prognostic factors. Conclusions Tumor location (upper thoracic) and infiltration (SM3) are the worse prognostic factors of submucosal esophageal squamous cell carcinoma, but lymph node metastasis is not a predictor of poorer prognosis.

Highlights • Mixed adenoneuroendocrine carcinomas (MANECs) of the distal bile duct are extremely rare. • The treatment of MANECs of the bile duct remains controversial and the prognosis is poor. • Larger studies are required to establish standard treatment regimens of MANECs of the bile duct., Introduction Mixed adenoneuroendocrine carcinomas (MANECs) of the distal bile duct are extremely rare, and only a few cases have been reported in the English literature. Presentation of case An 82-year-old man was referred to our hospital for increasing biliary enzymes. Abdominal computed tomography (CT) showed enlargement of the intrahepatic bile ducts and stenosis of the distal bile duct. Endoscopic retrograde cholangiopancreatography showed stenosis of the distal bile duct and a high-density signal at the same site on diffusion weighted imaging. PET-CT showed increased FDG accumulation (SUVmax: 4.5) at the distal bile duct stenosis. Biopsy specimens obtained by endoscopic ultrasonography-guided fine-needle aspiration revealed adenocarcinoma. The patient was diagnosed with adenocarcinoma of the distal bile duct and underwent subtotal stomach-preserving pancreaticoduodenectomy with regional lymph node dissection. The resected distal bile duct tumor was 18 × 14 × 12 mm in diameter. Hematoxylin and eosin staining revealed a composite carcinoma with adenocarcinoma and non-adenocarcinoma elements. The non-adenocarcinoma component stained positive for synaptophysin and chromogranin A. The Ki-67 labeling index was 37%. The non-adenocarcinoma component was therefore diagnosed as a neuroendocrine carcinoma. The two composite carcinoma was diagnosed as MANEC of the distal bile duct. The patient was treated with surgery alone and he remained disease-free for 7 months after the surgery. Discussion The treatment of MANECs of the bile duct remains controversial and the prognosis is poor. Conclusions There is no standard treatment for MANECs of the bile duct. Larger studies are required to establish standard treatment regimens.

Highlights • Few cases of splenic hamartomas associated with thrombocytopenia have been reported. • Imaging findings in splenic hamartomas are non-specific, variable, and making definitive preoperative diagnosis difficult. • Surgery is necessary for diagnosis when malignancy cannot be ruled out. • Surgery may also improve symptoms of hypersplenism, including thrombocytopenia., Introduction Hamartomas are rare, benign tumors of the spleen. Few cases of splenic hamartomas associated with thrombocytopenia have been reported. Presentation of case An asymptomatic 64-year-old man with myelodysplastic syndrome was found to have a splenic tumor. Laboratory tests were significant for thrombocytopenia, with a platelet count of 7.8 × 104/μL. Ultrasonography showed splenomegaly (10.8 × 6.6 cm), and a hypoechoic splenic mass (8.0 × 7.0 cm). Color doppler ultrasound revealed blood flow within the mass, and the mass density was homogeneous on abdominal computed tomography (CT). Contrast-enhanced CT showed heterogeneous enhancement of the splenic mass during the arterial phase. Positron emission tomography (PET)-CT showed no significant fludeoxyglucose (FDG) accumulation within the mass. The differential diagnosis included splenic hamartoma, splenic hemangioma, splenomegaly associated with extramedullary hematopoiesis, and malignant tumor, including solitary splenic metastasis. A laparoscopic splenectomy was performed due to the possibility of malignancy, the presence of thrombocytopenia, and the risk of splenic rupture. The resected specimen showed a localized, well-demarcated, 8.0 × 7.0 cm splenic mass. Histological examination revealed abnormal red pulp proliferation and the absence of normal splenic structures. The patient’s post-operative course was uneventful. His platelet count improved on post-operative day 1 and he was discharged on post-operative day 9. He remained in good health with a normal platelet count one month after surgery. Discussion Making definitive preoperative diagnosis is difficult in splenic hamartomas. Surgery is necessary for diagnosis when malignancy cannot be ruled out. Conclusions Surgery may also improve symptoms of hypersplenism, including thrombocytopenia.

Gastric cancer (GC) patients with positive peritoneal lavage cytology (CY1) and/or localized peritoneum metastasis (P1a) are defined as stage IV in the 15th edition of the Japanese Classification of Gastric Cancer. In Japan, the most common treatment for patients with CY1 and/or P1a is gastrectomy followed by postoperative chemotherapy. Subjects in this multi-institutional retrospective study were GC patients with CY1 and/or P1a who received surgical resection that leaves no macroscopically visible disease. Patients were selected from 34 institutions in Japan between 2007 and 2012. Selection criteria included adenocarcinoma, no distant metastasis except CY1 and P1a, and no prior treatment for GC before surgery. Among 824 patients registered, 506 were identified as eligible, with a background of P0CY1, P1aCY0, or P1aCY1 (72.5%, 16.0%, and 11.5% of subjects, respectively). Sixty-two patients had not received postoperative chemotherapy (no-Cx), whereas 444 patients had received postoperative chemotherapy: S-1 monotherapy (S-1; n = 267, 52.7%), cisplatin plus S-1 (CS; n = 114, 22.5%), and others (n = 63, 12.6%). Overall survival (OS) was 29.5, 24.7, 25.4 and 9.9 months in the S-1, CS, ‘others’, and no-Cx groups, respectively [CS vs. S-1: hazard ratio (HR) 1.15, 95% confidence interval (CI) 0.89–1.50; p = 0.275]. In multivariate analysis, OS was similar between the S-1 and CS groups (CS vs. S-1: HR 1.19, 95% CI 0.92–1.55; p = 0.18). Postoperative chemotherapy after gastrectomy that leaves no macroscopically visible disease may have some survival benefits for GC patients with CY1 and/or P1a. In contrast, S-1 plus cisplatin seems to have no additional benefit over S-1 treatment alone.

Highlights • Non-perforating acute appendicitis with septic DIC is extremely rare. • Nowadays, interval appendectomy has become popular. • However, judging the limit of conservative treatment for acute appendicitis is a critically important matter. • Appendectomy should be performed for non-perforating acute appendicitis with septic DIC., Introduction Perforating appendicitis and abscess-forming appendicitis may cause septic disseminated intravascular coagulation (DIC). However, non-perforating acute appendicitis with septic DIC is extremely rare. Presentation of case A 67-year-old man was referred to our hospital one day after starting oral antibiotic treatment for acute appendicitis. Physical examination revealed only slight spontaneous abdominal pain without tenderness and peritoneal irritation. Contrast-enhanced computed tomography demonstrated an enlarged appendix (10 mm in diameter) without fecalith, ascites, intraperitoneal free air, and abscess. There was no evidence of perforating appendicitis. Laboratory analysis revealed septic DIC. The patient was diagnosed with non-perforating acute appendicitis with septic DIC. The patient was distressed regarding whether he should be treated conservatively with an antibiotics-first strategy or undergo an appendectomy. Ultimately, a laparoscopic appendectomy was performed. Histopathological examination showed non-perforating gangrenous appendicitis. He required DIC therapy for 2 days postoperatively. He was discharged on postoperative day 9, and remained in good health 1 month after surgery. Discussion There is no absolute index of conversion to surgery with an antibiotics-first strategy of appendicitis treatment. Judging the limit of conservative treatment and determining the best moment to perform surgery is a critically important matter for patients with acute appendicitis. Conclusions The incidence of conservative treatment preceding an antibiotics-first strategy for acute appendicitis is increasing. However, it is thought that appendectomy should be performed when acute appendicitis is complicated with septic DIC, even if it is a non-perforating appendicitis in which improvement with conservative treatment is anticipated.

196 Background: The phase III trial (JCOG1104), comparing between 4- (6 months) and 8-course (1 year) of S-1 as the adjuvant chemotherapy for pathological stage II gastric cancer, registered a total of 590 patients between Feb. 2012 and Mar. 2017 until the study was terminated due to futility at the interim analysis (relapse-free survival at 3 years: 93.1% in the 8-course group and 89.8% in the 4-course group). Non-inferiority of the 4-course to the 8-course was not shown, highlighting a continuation of S-1 adjuvant chemotherapy for one year. This preplanned exploratory study investigated the risk factors for time to treatment failure (TTF). Methods: TTF was defined as the time from randomization to the date of termination of S-1 before the planned treatment period, relapse, or any cause of death, whichever came first, and censored on the last date of contact for a surviving patient after completing the planned treatment or the last date of S-1 in the patients under the protocol treatment when the trial was closed. The risk factor of TTF was analyzed by Cox proportional hazard model using the variables of the planned treatment period, PS, age, sex, body weight loss (percentile of the body weight loss at the registration compared with that before surgery: BWL), albumin, lymphocyte count, creatinine clearance (Ccr), extent of gastrectomy (total gastrectomy vs. others), surgical approach (open vs. laparoscopic approach), and blood loss during surgery. As TTF did not reach 50%, proportion of treatment completion was compared. Results: Among 590 registered patients, this study included 530 patients (273 in the 8-course group and 257 in the 4-course group) by excluding 24 ineligible patients, 7 patients who did not start the protocol treatment, and 29 patients with unavailable data for variables. Proportion of treatment completion at 6 months estimated by Kaplan-Meier method were 89.2% in the 4-course group and 84.6% in the 8-course group ( P=0.1204), and that at 1 year was 73.6% in the 8-course group. Risk factors of TTF before 6M identified by multivariable analysis with stepwise selection method including both groups, in which all patients completed treatment were censored at 6 months, were the planned treatment period (4-courses vs. 8-course, HR 0.611, 95% Confidence interval (CI) 0.375-0.996, P=0.0482), age (continuous value, HR 1.039, 95% CI 1.004-1.074, P=0.0266), and Ccr (80 ml/min, HR 1.943, 95% CI 1.105-3.415, P=0.0211). As for the TTF in the 8-course group, BWL (>10% vs 80 ml/min, HR 1.900, 95% CI 1.186-3.045, P=0.0076) were independent risk factors. Conclusions: Compared to 8-course, 4-course of S-1 adjuvant chemotherapy was associated with a higher 6-month proportion of treatment completion. When planning the adjuvant chemotherapy with S-1 for one year, BWL (>10%) and low Ccr (

To determine the preoperative ability of [We retrospectively analyzed 40 consecutive patients diagnosed with cT1N0M0 ESCC between February 2006 and April 2011. All patients were treated by esophagectomy with two- or three-field lymphadenectomy without neoadjuvant therapy. We evaluated the relevance between clinical variables including maximum standardized uptake values (SUVTumors invaded the middle submucosal layer (SM2) and beyond in 21 (52.5 %) patients, and 6 (15 %) had lymph node metastases. The areas under receiver operating characteristic (ROC) curves for SUVFDG-PET is helpful for diagnosing tumors that can infiltrate SM2 and beyond as well as occult lymph node metastasis of cT1N0M0 ESCC that are valuable indications in deciding therapeutic strategies for superficial ESCC.

TPS4646 Background: Standard surgery for resectable advanced gastric cancer is D2 (standardized extended lymph node dissection) gastrectomy with omentectomy. The reason why omentectomy has been performed is as follows; (1) principal surgery for gastrointestinal cancers is en-block resection of mesothelium including regional lymph nodes. Omentum is a part of the mesothelium of the stomach. (2) Cancer cells implanted into the peritoneal cavity aggregated in the milky-spot of the omentum and formed peritoneal dissemination in an animal model. (3) By special staining, micrometastasis detected in the omentum. There is some arguments for this theory. (1) no prospective study showed survival benefit of omentectomy as compared with omentum preservation. (2) anatomically, milky-spot is found not only in the omentum but also in other mesothelium or Douglas pouch. (3) JCOG1001 phase III study showed no survival benefit of bursectomy against non-bursectomy although bursa is a part of mesothelium of the stomach. (4) Anti-immunity is accelerated by antigen presentation by macrophage in the milky-spot of the omentum. Preservation of the omentum may have several benefits; (1) decrease in blood loss and operation time, (2) preservation of physical function by omentum such as reaction to peritonitis and prevention of adhesion, and (3) overcoming difficulties in laparoscopic omentectomy and avoidance of organ injury during surgery. Methods: The study is multicenter randomized phase III trial designed to confirm non-inferiority of omentum preservation to omentectomy for resectable advanced gastric cancer. Patients aged 20-79 years, histologically proven gastric adenocarcinoma, clinical subserosal/serosal invasion, and expected R0 (curative) resection are randomly assigned (1:1) during surgery to either omentum preservation or omentectomy. Total or distal gastrectomy with D2 dissection is performed in both arms. Laparoscopic gastrectomy is not allowed. Intraoperative photographs of the dissected field are centrally reviewed for all patients for quality control. The primary endpoint is relapse-free survival (RFS) and the secondary endpoints are overall survival, blood loss, operation time, and adverse events. Sample size was set at 1050 considering expected 3-year RFS of 77% in both arms with non-inferiority margin of 5%, one-sided alpha of 5%, and power of 80%. Planned accrual and follow up period are 6.5 years and 3 years respectively. The trial was activated in March 2019, and 177 patients are enrolled as of January 2020. Clinical trial information: UMIN000036253 .

Highlights • Appendiceal neurofibromas (AN) in Neurofibromatosis type (NF) 1 are rare. • AN in NF1 with Low-grade appendiceal mucinous neoplasms (LAMNs) are extremely rare. • AN and LAMNs have potential for malignant transformation. • Surgical resection is the standard treatment for patients with AN and LAMNs. • However, appropriate surgical procedure remains controversial., Introduction Neurofibromas are a characteristic of the autosomal dominant disorder Neurofibromatosis type 1 (NF1), also known as von Recklinghausen’s disease. Appendiceal neurofibromas are extremely rare, and low-grade appendiceal mucinous neoplasms (LAMNs) have not previously been reported in NF1. Presentation of case A 62-year-old man with NF1 was scheduled for elective surgical treatment of an asymptomatic, enlarged and diffusely thickened appendix that remained after curative antimicrobial treatment of acute appendicitis. Laboratory analysis revealed all normal. Colonoscopy showed thickened appendiceal mucosa projecting into the cecum. A sample of the mucosa was found to be pathologically benign. The patient was preoperatively diagnosed with treated acute appendicitis with chronic appendiceal inflammation versus appendiceal neoplasms. Laparoscopic cecectomy was performed. Multiple neurofibromas were observed in the muscle layer, submucosa, and mucosa of the appendix on histopathological examination. Immunohistochemical examination showed positive staining for S-100. Pathologically, the patient was diagnosed with appendiceal neurofibroma consistent with NF1 with LAMNs. His postoperative course was unremarkable. He was discharged on post-operative day 3 and remained in good health 7 month after surgery. Conclusions Appendiceal neurofibromas are often preoperatively diagnosed as appendicitis. Appendiceal neurofibromas should be considered in patients with NF1 who are suspected of having appendicitis.

The clinical significance of lymph node (LN) status determined by preoperativeThis study reviewed 132 consecutive patients with ESCC who had been preoperatively evaluated using FDG-PET before and after NCRT to analyze associations among LN status according to PET findings, pathologic LN metastasis, and prognosis of ESCC after trimodal therapy.Lymph nodes that were PET-positive both before and after NCRT comprised significant predictive markers of pathologic LN metastasis in station-by-station analyses (sensitivity, specificity, and accuracy respectively 41.7%, 95.0%, and 92.7% before, and 12.0%, 99.4%, and 95.6% after NCRT; both p 0.0001). The numbers of LNs evaluated using PET before and after NCRT were significantly associated with those of pathologic metastatic LNs. Uni- and multivariable analyses selected LN status determined by PET before NCRT as a significant independent predictor of both recurrence-free [LN-negative vs LN-positive: hazard ratio (HR) 1.90; 95% confidence interval (CI) 1.02-3.23; p = 0.045] and overall survival (HR 2.62; 95% CI 1.29-5.30; p = 0.01).The status of LN determined by preoperative FDG-PET is significantly associated with pathologic LN status and the prognosis of ESCC with trimodal therapy. Thus, FDG-PET is a useful diagnostic tool for preoperative prediction of pathologic LN metastasis and survival among patients with ESCC.

This study retrospectively evaluated the long-term results of neoadjuvant chemoradiotherapy (NCRT) followed by esophagectomy for the patients with resectable, locally advanced esophageal squamous cell carcinoma (ESCC). Altogether, 49 patients treated from 2008 to 2012 were analyzed. Chemotherapy consisted of 5-fluorouracil and cisplatin. Radiotherapy was performed with a total dose of 40 Gy in 20 fractions for primary tumor, metastatic lymph nodes, and elective nodal area. Subsequently, transthoracic esophagectomy with extensive lymphadenectomy was performed. The median follow-up time for the survivors was 86 (range, 55-111) months. Pathological complete response from NCRT was observed in 17 (35%) patients. The 5-year overall survival and relapse-free survival rates were 56% [95% confidence interval (CI): 43-71%] and 55% (95% CI: 41-69%), respectively. The 5-year locoregional control rate was 84% (95% CI: 74-95%). Multivariate analyses revealed body mass index, N-factor, and %ΔSUVmax as significant factors for overall survival. Recurrences and within-irradiation field failure were observed in 16 (31%) and 4 (8%) patients, respectively. Toxicities of NCRT were generally mild. Postoperative Grade IIIb or worse complications were seen in 14% of patients, including one Grade V case (2%). The 5-year incidence rate of late complications of Grade 3 or worse was 22% (95% CI: 7-36%). The cumulative 5-year incidence rate of metachronous malignancies was 13% (95% CI: 1-26%). NCRT followed by esophagectomy for patients with resectable, locally advanced ESCC showed favorable locoregional control and overall survival, with acceptable postoperative complications. Long-term careful follow-up for late complications and metachronous malignancies is needed.

Anal metastasis of colorectal cancer is rare, and no standardized effective therapeutic strategy exists. We report a case of abdominoperineal resection for anal metastasis of rectal cancer. A 65-year-old man underwent laparoscopic low anterior resection for rectal cancer in August 2013. Histopathological examination revealed a moderately differentiated adenocarcinoma( tub2, pSS, ly3, v2, pN1, H0, P0, M0, Stage III a, Cur A). In February 2015, he complained of anal discomfort, and tumor markers were elevated. Enhanced CT revealed a 15-mm high-density solid tumor in the anal canal. The results of needle biopsy indicated a moderately differentiated adenocarcinoma. This tumor was suspected to be metastasis from rectal cancer, and we performed abdominoperineal resection. Histopathological examination revealed a moderately differentiated adenocarcinoma, which was the same histological type as the primary rectal cancer and was covered with normal anal epithelium. Collectively, the findings indicated anal metastasis from rectal cancer. The patient is alive without recurrence for 18 months after resection. Anal metastasis should be considered as a differential diagnosis in patients with anal discomfort who have a history of colon/rectal cancer. Abdominoperineal resection may be an effective treatment modality for this condition.

The evaluation of treatment outcomes and detection of prognostic factors after recurrence are very important for tailoring optimal therapies for individual patients with recurrent esophageal cancer. We reviewed 133 patients in whom esophageal squamous cell carcinoma (ESCC) recurred after curative surgery, and assessed recurrence patterns, treatment outcomes and prognostic factors. Recurrence in 57 (42.9%), 54 (40.6%) and 22 (16.5%) patients was locoregional, distant and combined, respectively. The median amounts of elapsed time until recurrence and median survival after recurrence for all patients were 9.1 and 8.3 months, respectively. Univariate and multivariate analyses selected time to recurrence (hazard ratio [HR], 0.98; 95% confidence interval [CI], 0.97–0.999; p = 0.04), recurrence location (locoregional vs. distant: HR, 1.63; 95% CI, 1.03–2.61; p = 0.04), number of organs with recurrence (1 vs. 3: HR, 3.49; 95% CI, 1.23–9.87; p = 0.02) and treatment after recurrence (best supportive care, [BSC] vs. chemotherapy [CT] or radiation therapy [RT]: HR, 0.37; 95% CI, 0.15–0.94; p = 0.04; BSC vs. CT and RT: HR, 0.50; 95% CI, 0.26–0.94; p = 0.03; BSC vs. surgery: HR, 0.47; 95% CI, 0.25–0.88; p = 0.02) as independent factors for survival after recurrence. Seventeen (12.8%) patients who had localized lymph node recurrence and lung oligometastasis and received multidisciplinary therapy after recurrence survived for >3 years thereafter. Despite the poor survival of patients with ESCC and early or distant recurrence or recurrence in ≥3 recurrent organs, appropriate multimodal therapies should be tailored for individual patients with recurrent ESCC.