Molecular and clinicopathological features of KIT/PDGFRA wild-type gastrointestinal stromal tumors.

Approximately 10% of gastrointestinal stromal tumors (GISTs) harbor reportedly no KIT and PDGFRA mutations (wild-type GISTs). The clinicopathological features and oncologic outcomes of wild-type GISTs based on molecular profiles are unknown. We recruited 35 wild-type GIST patients from the two registry studies of high-risk GISTs between 2012 and 2015 and primary GISTs between 2003 and 2014. Molecular profiling of wild-type GISTs was performed by targeted next-generation sequencing (NGS) using formalin-fixed paraffin-embedded tumor samples. Among 35 wild-type GISTs, targeted NGS analysis detected NF1, SDH, or BRAF mutation: 16 NF1-GISTs with various NF1 mutations, 12 SDH-GISTs (4 with SDHA mutations, 4 with SDHB mutations, and 4 with SDHB-negative staining), and 5 BRAF-GISTs with the V600E mutation. Two GISTs showed no mutations based on our targeted NGS analysis. Additional gene mutations were infrequent in primary wild-type GISTs and found in TP53, CREBBP, CDKN2A, and CHEK2. Most NF1-GISTs were located in the small intestine (N = 12; 75%) and showed spindle cell features (N = 15; 94%) and multiple tumors (N = 6, 38%) with modest proliferation activities. In contrast, SDH-GISTs were predominantly found in the stomach (N = 11; 92%), exhibiting epithelioid cell (N = 6; 50%) and multiple (N = 6, 50%) features. The overall survival of patients with SDH-GISTs appeared to be better than that of BRAF-GISTs (p = 0.0107) or NF1-GISTs (p = 0.0754), respectively. In conclusion, major molecular changes in wild-type GISTs include NF1, SDH, and BRAF. NF1-GISTs involved multifocal spindle cell tumors in the small intestine. SDH-GISTs occurred in young patients and were multifocal in the stomach and clinically indolent.

Management challenges and the role of adjuvant chemotherapy in remnant gastric cancer: an analysis of 313 patients from the KEGG multicenter observational study.

BACKGROUND: Clinical findings and postoperative follow-up data on remnant gastric cancer (RGC) are limited due to its rarity. Additionally, the preoperative staging, radical surgery, and managing recurrence in RGC present significant clinical challenges. METHODS: We analyzed the clinicopathological findings, adjuvant chemotherapy, and patterns of postoperative recurrence of 313 consecutive patients who underwent curative surgery for RGC at 17 Japanese institutions. This study investigated the optimal management of RGC and the impact of adjuvant chemotherapy (AC) on recurrence-free survival (RFS). RESULTS: Pathological stages I, II, and III were observed in 55.9% (N = 175), 24.9% (N = 78), and 19.2% (N = 60) of the patients, respectively. The overall concordance rate between clinical and pathological T staging was 58.3%, with a clinical T4 sensitivity of 41.4% for diagnosing pathological T4. During the median follow-up period of 4.6 years, disease recurrence occurred in 24.3% of patients. Most recurrences (over 80%) occurred within 2.5 years, and 96.1% within 5 years after RGC surgery. Peritoneal recurrence was the most common in patients with advanced RGC, accounting for 14.1% in stage II and 28.3% in stage III. Multivariable regression analysis showed that AC was significantly associated with a longer RFS, with a hazard ratio of 0.45 (95% confidence interval: 0.26-0.76). CONCLUSIONS: Our study underscores the importance of early detection, accurate preoperative staging, and postoperative surveillance in managing advanced RGC cases. Despite some limitations, our findings indicate that AC may provide survival benefits comparable to those seen in primary gastric cancer.

Comparison of Minimally Invasive Surgery with Open Surgery for Remnant Gastric Cancer: A Multi-institutional Cohort Study.

BACKGROUND: Despite growing evidence of the effectiveness of minimally invasive surgery (MIS) for primary gastric cancer, MIS for remnant gastric cancer (RGC) remains controversial due to the rarity of the disease. This study aimed to evaluate the surgical and oncological outcomes of MIS for radical resection of RGC. PATIENTS AND METHODS: Patients with RGC who underwent surgery between 2005 and 2020 at 17 institutions were included, and a propensity score matching analysis was performed to compare the short- and long-term outcomes of MIS with open surgery. RESULTS: A total of 327 patients were included in this study and 186 patients were analyzed after matching. The risk ratios for overall and severe complications were 0.76 [95% confidence interval (CI): 0.45, 1.27] and 0.65 (95% CI: 0.32, 1.29), respectively. The MIS group had significantly less blood loss [mean difference (MD), -409 mL; 95% CI: -538, -281] and a shorter hospital stay (MD, -6.5 days; 95% CI: -13.1, 0.1) than the open surgery group. The median follow-up duration of this cohort was 4.6 years, and the 3-year overall survival were 77.9% and 76.2% in the MIS and open surgery groups, respectively [hazard ratio (HR), 0.78; 95% CI: 0.45, 1.36]. The 3-year relapse-free survival were 71.9% and 62.2% in the MIS and open surgery groups, respectively (HR, 0.71; 95% CI: 0.44, 1.16). CONCLUSIONS: MIS for RGC showed favorable short- and long-term outcomes compared to open surgery. MIS is a promising option for radical surgery for RGC.

A novel method of anvil placement of circular stapler for esophagojejunostomy in laparoscopic total gastrectomy for gastric cancer: results of consecutive 200 cases.

BACKGROUND: Laparoscopic total gastrectomy for gastric cancer is still a demanding operation because of technical difficulties, especially of intracorporeal esophago-jejunal anastomosis. METHODS: We introduced a newly designed method of anvil placement of circular stapling devices (CS) for laparoscopic esophagojejunostomy (EJS). A small incision was made on the anterior wall of the stomach, from which the anvil was inserted into the stomach and proceeded to the thoracic esophagus. Then, the abdominal esophagus was transected by a linear stapler, and the anvil into the esophagus was drawn back to the esophageal stump by pulling out the cotton tape pre-attached to the anvil. Intracorporeal EJS by Roux-en-Y reconstruction was performed by CS inserted into the abdominal cavity from the umbilical wound. RESULTS: A total of consecutive 200 gastric cancer patients underwent laparoscopic total gastrectomy using this method. There was no operative mortality. Anastomotic complications occurred in 12 cases (6.0%): 9 cases of stenosis (4.5%) and 3 cases of bleedings (1.5%). Anastomotic leakage was not observed. As for non-anastomotic complications, there occurred 2 pulmonary complications (1.0%), 3 pancreatic leakages (1.5%), and 8 bowel obstructions due to internal hernia (4.0%). With a median follow-up period of 47.1 months, 5-year overall survival for assessable patients (n = 193) was 60.3% (95% CI 52.6-67.2). The total rate of peritoneal recurrence was 9.8%. CONCLUSION: Our new method of anvil placement for laparoscopic EJS with CS is safe and feasible with favorable survival outcomes. It eliminates the need for suturing, and will promote the clinical application of laparoscopic total gastrectomy for gastric cancer. CLINICAL TRIALS: UMIN000046119.

Laparoscopic-assisted robotic distal gastrectomy for gastric cancer by Billroth II reconstruction.

BACKGROUND: There are several reconstructions in distal gastrectomy for gastric cancer, and there is no clear definition regarding the method selection. The optimal reconstruction is likely to vary according to the surgical setting, and the optimal reconstruction for robotic distal gastrectomy is urgently needed. In addition, as robotic gastrectomy is getting popular, cost and operative time are pressing issues of robotic gastrectomy. METHODS: Gastrojejunostomy was planned with Billroth II reconstruction using a linear stapler arranged specifically for a robotic approach. After firing the stapler, the common insertion orifice of the stapler was closed using a 30 cm long non-absorbable barbed suture, and continuously, the afferent loop of the jejunum was lifted to the stomach with the same barbed suture. In addition, we introduced laparoscopic-assisted robotic gastrectomy, using extracorporeally inserted laparoscopic devices from the assistant port. Scissors, clips, and linear staplers were all laparoscopic tools inserted extracorporeally. RESULTS: Twenty-one gastric cancer patients underwent laparoscopic-assisted robotic distal gastrectomy by Billroth II reconstruction with our modifications. There were no anastomosis-related complications such as leakage, stenosis, or bleeding. There were 2 cases of aspiration pneumonia (Clavien-Dindo grade 2), 1 case of pancreatic juice leakage (grade 3a), and 1 case of delayed gastric emptying (grade 1). CONCLUSION: We successfully arranged Billroth II reconstruction for robotic distal gastrectomy with fewer operative and postoperative complications. Laparoscopic-assisted robotic gastrectomy using extracorporeally inserted devices, and continuous suturing using a barbed suture will reduce the time and cost of robotic gastrectomy.

Long-term results of a phase 2 study of neoadjuvant chemotherapy with molecularly targeted agents for locally advanced rectal cancer.

BACKGROUND: We previously reported the feasibility and efficacy of neoadjuvant chemotherapy without radiotherapy for locally advanced rectal cancer. Here, we report the results of a long-term follow-up study. METHODS: This was a multi-institutional, prospective phase 2 study of patients with locally advanced rectal cancer. Patients received neoadjuvant chemotherapy with molecularly targeted agents before undergoing total mesorectal excision. Six cycles of modified FOLFOX (mFOLFOX6) with bevacizumab were administered to KRAS-mutant patients, and mFOLFOX6 with cetuximab was administered to KRAS-wild-type patients. Here, we report the secondary end points of overall survival, relapse-free survival, and local recurrence rate. RESULTS: Sixty patients were enrolled in this study. R0 resection was achieved in 98.3% (59/60) patients, and pathological complete response was achieved in 16.7% (10/60) patients. After a median follow-up of 5.4 years, the 5 year overall survival was 81.6%, the 5 year relapse-free survival was 71.7%, and the 5 year local recurrence rate was 12.6%. None of the patients who achieved pathological complete response developed recurrence within 5 years. CONCLUSIONS: The use of molecularly targeted agents in the neoadjuvant setting for locally advanced rectal cancer has an acceptable prognosis.

Safety assessment of robotic gastrectomy and analysis of surgical learning process: a multicenter cohort study.

BACKGROUND: The safety of robotic gastrectomy (RG) for gastric cancer in daily clinical settings and the process by which surgeons are introduced and taught RG remain unclear. This study aimed to evaluate the safety of RG in daily clinical practice and assess the learning process in surgeons introduced to RG. METHODS: Patients who underwent RG for gastric cancer at Kyoto University and 12 affiliated hospitals across Japan from January 2017 to October 2019 were included. Any morbidity with a Clavien-Dindo classification grade of II or higher was evaluated. Moreover, the influence of the surgeon's accumulated RG experience on surgical outcomes and surgeon-reported postoperative fatigue were assessed. RESULTS: A total of 336 patients were included in this study. No conversion to open or laparoscopic surgery and no in-hospital mortality were observed. Overall, 50 (14.9%) patients developed morbidity. During the study period, 14 surgeons were introduced to robotic procedures. The initial five cases had surprisingly lower incidence of morbidity compared to the following cases (odds ratio 0.29), although their operative time was longer (+ 74.2 min) and surgeon's fatigue scores were higher (+ 18.4 out of 100 in visual analog scale). CONCLUSIONS: RG was safely performed in actual clinical settings. Although the initial case series had longer operative time and promoted greater levels of surgeon fatigue compared to subsequent cases, our results suggested that RG had been introduced safely.

Mesenteric closure after laparoscopic total gastrectomy with Roux-en-Y reconstruction is effective for prevention of internal hernia: a multicenter retrospective study.

BACKGROUND: Internal hernia (IH) is one of the critical complications after gastrectomy with Roux-en-Y reconstruction, which can be prevented by closing mesenteric defects. However, only few studies have investigated the incidence of IH after laparoscopic total gastrectomy (LTG) with Roux-en-Y reconstruction for gastric cancer till date. This study aimed to assess the efficacy of defect closure for the prevention of IH after LTG. METHODS: This multicenter, retrospective cohort study collected data from 714 gastric cancer patients who underwent LTG with Rou-en-Y reconstruction between 2010 and 2016 in 13 hospitals. We evaluated the incidence of postoperative IH by comparing closure and non-closure groups of Petersen's defect, jejunojejunostomy mesenteric defect, and transverse mesenteric defect. RESULTS: The closure group for Petersen's defect included 609 cases, while the non-closure group included 105 cases. The incidence of postoperative IH in the closure group for Petersen's defect was significantly lower than it was in the non-closure group (0.5% vs. 4.8%, p < 0.001). The closure group for jejunojejunostomy mesenteric defect included 641 cases, while the non-closure group included 73 cases. The incidence of postoperative IH in the closure group of jejunojejunostomy mesenteric defect was significantly lower than that in the non-closure group (0.8% vs. 4.1%, p = 0.004). Out of 714 patients, 41 underwent retro-colic reconstruction. No patients in the transverse mesenteric defect group developed IH. CONCLUSION: Mesenteric defect closure after LTG with Roux-en-Y reconstruction may reduce postoperative IH incidence. Endoscopic surgeons should take great care to prevent IH by closing mesenteric defects.

Re-do laparoscopic esophagojejunostomy for anastomotic stenosis after laparoscopic total gastrectomy in gastric cancer.

PURPOSE: Anastomotic stenosis of esophagojejunostomy after total gastrectomy has a substantial impact on the postoperative quality of life of the patient. If conservative treatment doesn't work, surgical intervention should be considered. However, redoing esophagojejunostomy is an extremely demanding procedure. Especially in the case where the primary surgery was performed laparoscopically, it is an unmet problem to maintain minimal invasiveness in re-do surgery. METHODS: We report 3 cases of re-do esophagojejunostomy laparoscopically performed for anastomotic stenosis after laparoscopic total gastrectomy in gastric cancer, in whom endoscopic balloon dilation did not work. RESULTS: Each patient underwent a re-do esophagojejunostomy laparoscopically. The mean operation time was 293 min, and the mean blood loss was 56 ml. There was no anastomosis-related complication, and they were discharged from hospital on 11-16 postoperative days. At the time of discharge, oral food intake was 100% in each patient. One year after the operation, follow-up endoscopic exams showed no anastomotic stenosis. CONCLUSION: Re-do laparoscopic esophagojejunostomy for anastomotic stenosis after laparoscopic total gastrectomy was safely and successfully performed. It brings patients minimal invasiveness continuously from the initial surgery. Re-do laparoscopic esophagojejunostomy could be one of the options for anastomotic stenosis resistant to conservative treatment.

Phase 2 study of irinotecan plus cetuximab rechallenge as third-line treatment in KRAS wild-type metastatic colorectal cancer: JACCRO CC-08.

BACKGROUND: Regorafenib or trifluridine/tipiracil as third-line treatment have limited efficacy in metastatic colorectal cancer (mCRC). METHODS: This Phase 2 trial evaluated the efficacy and safety of irinotecan plus cetuximab rechallenge as third-line treatment in KRAS wild-type mCRC patients who achieved clinical benefit with first-line cetuximab-containing therapy. The primary endpoint was 3-month progression-free survival (PFS) rate. A sample size was calculated; 30 patients with a 3-month PFS rate of 45% deemed promising and 15% unacceptable. Patients with greater and less than the cut-off value of cetuximab-free intervals (CFIs) were classified into the long and short CFI groups, respectively, in subgroup analyses. RESULTS: Among 34 eligible patients who received treatment at least once, 3-month PFS rate was 44.1% (95% confidence interval, 27.4-60.8%). The median PFS and overall survival (OS) were 2.4 and 8.2 months, respectively. The response and disease control rates were 2.9 and 55.9%, respectively. PFS and OS were significantly longer in the long- than in the short CFI group. CONCLUSIONS: Irinotecan plus cetuximab rechallenge as third-line treatment for KRAS wild-type mCRC was safe and had promising activity, especially in those with a long CFI, warranting further investigation in a Phase 3 randomised trial. CLINICAL TRIAL REGISTRATION: UMIN000010638.

Changes in the sexual function of male patients with rectal cancer over a 2-year period from diagnosis to 24-month follow-up: A prospective, multicenter, cohort study.

BACKGROUND AND OBJECTIVES: This prospective study aimed to identify long-term changes in sexual function of men with rectal cancer from point of diagnosis to 24 months postoperatively. METHODS: Male patients undergoing laparoscopic rectal cancer surgery were prospectively enrolled. International Index of Erectile Function (IIEF) Questionnaire scores were collected at diagnosis; first follow-up; and 6, 12, and 24 months postoperatively. Missing values were managed via multiple imputations using the propensity score method. Paired t tests were applied to examine changes in IIEF scores over time. RESULTS: This study analyzed 115 patients. For erectile function, there were no significant changes in scores from the point of diagnosis to first treatment (9.4 vs. 9.8 as mean scores; p = .227). Scores deteriorated postoperatively and recovered until 12 months post-surgery, but did not improve significantly from 12 months to 24 months post-surgery (8.7 vs. 8.2 as mean scores; p = .440). This pattern of change was observed in all other domains: orgasmic function, sexual desire, orgasmic satisfaction, and overall satisfaction. CONCLUSIONS: Sexual function was not influenced by a rectal cancer diagnosis. Sexual function deteriorated following surgery and recovered until 12 months post-surgery; however, it did not significantly improve from 12 months to 24 months postoperatively.

Linear or circular stapler? A propensity score-matched, multicenter analysis of intracorporeal esophagojejunostomy following totally laparoscopic total gastrectomy.

BACKGROUND: Presently, there is no consensus as to what procedure of intracorporeal esophagojejunostomy (EJS) in totally laparoscopic total gastrectomy (TLTG) is best to reduce postoperative complications. The aim of this study was to demonstrate the superiority of linear stapled reconstruction in terms of anastomotic-related complications for EJS in TLTG. METHODS: We collected data on 829 consecutive gastric cancer patients who underwent TLTG reconstructed by the Roux-en-Y method with radical lymphadenectomy between January 2010 and December 2016 in 13 hospitals. The patients were divided into two groups according to reconstruction method and matched by propensity score. Postoperative EJS-related complications were compared between the linear stapler (LS) and the circular stapler (CS) groups. RESULTS: After matching, data from 196 patients in each group were analyzed. The overall incidence of EJS-related complications was significantly lower in the LS group than in the CS group (4.1% vs. 11.7%, p = 0.008). The incidence of EJS anastomotic stenosis during the first year after surgery was significantly lower in the LS group than in the CS group (1.5% vs. 7.1%, p = 0.011). The incidence of EJS bleeding did not differ significantly between the groups, although no bleeding was observed in the LS group (0% vs. 2.0%, p = 0.123). The incidence of EJS leakage did not differ significantly between the groups (2.6% vs. 3.6%, p = 0.771). CONCLUSION: The use of linear stapled reconstruction is safer than the use of circular stapled reconstruction for intracorporeal EJS in TLTG because of its lower risks of stenosis.

Randomised phase II trial of mFOLFOX6 plus bevacizumab versus mFOLFOX6 plus cetuximab as first-line treatment for colorectal liver metastasis (ATOM trial).

BACKGROUND: Chemotherapy with biologics followed by liver surgery improves the resection rate and survival of patients with colorectal liver metastasis (CRLM). However, no prospective study has compared the outcomes of chemotherapy with bevacizumab (BEV) versus cetuximab (CET). METHODS: The ATOM study is the first randomised trial comparing BEV and CET for initially unresectable CRLM. Patients were randomly assigned in a 1:1 ratio to receive mFOLFOX6 plus either BEV or CET. The primary endpoint was progression-free survival (PFS). RESULTS: Between May 2013 and April 2016, 122 patients were enrolled. Median PFS was 11.5 months (95% CI 9.2-13.3 months) in the BEV group and 14.8 months (95% CI 9.7-17.3 months) in the CET group (hazard ratio 0.803; P = 0.33). Patients with a smaller-number but larger-sized metastases did better in the CET group. In the BEV and CET groups, the response rates were 68.4% and 84.7% and the resection rates were 56.1% and 49.2%, respectively. CONCLUSION: Although CET achieved a better response rate than BEV for patients with a small number of large liver metastases, both biologics had similar efficacy regarding liver resection and acceptable safety profiles. To achieve optimal PFS, biologics should be selected in accordance with patient conditions. TRIAL REGISTRATION: This trial is registered at ClinicalTrials.gov (number NCT01836653), and UMIN Clinical Trials Registry (UMIN-CTR number UMIN000010209).

[Successful Administration of Alternate-Day, Low-Dose S-1 in a Patient with Recurrent Esophageal Cancer with a Poor Compliance Profile].

A 79-year-old woman had recurrence in the mediastinal lymph node 6 months after curative resection of advanced esophageal cancer(pStage Ⅲ). After radiation therapy and 12 courses of chemotherapy with docetaxel, new recurrent tumors progressed in the mediastinum and apical region of the left lung, and her performance status(PS)deteriorated to grade 3. Alternate-day, low-dose S-1 chemotherapy was started at a dose of 60mg/day. Tumors decreased in size within 6 months, and her PS improved from grade 3 to 0. She had been treated for 33 months without severe adverse events until disease progression. So far, we have experienced in clinical practices that the alternate-day S-1 administration was tolerable for patients who were unfit for the standard daily administration. Alternate-day, low-dose S-1 administration may be a sustainable and effective option in S-1 chemotherapy in patients with recurrent esophageal cancer with impaired PS.

[A Case of Type 1A Charcot-Marie-Tooth Disease Manifested by Oxaliplatin Administration of Neoadjuvant Chemotherapy in a Gastric Cancer Patient].

Herein, we report the manifestation of type 1A Charcot-Marie-Tooth disease(CMT)in a 54-year-old female gastric cancer patient caused by oxaliplatin(L-OHP)of neoadjuvant chemotherapy containing S-1 plus L-OHP(G-SOX). In this case, peripheral sensory neuropathy(PSN)appeared in both upper limbs immediately after the administration of L-OHP. Subsequently, we observed sensory neuropathy of gloves-socks type in both the upper and lower limbs and motor neuropathy in both lower limbs, which caused the patient to be unable to sit up. Physical examination revealed upside-down champagnebottle- like mild atrophy in both lower limbs and hollow feet in both legs, as well as the disappearance of deep tendon reflexes in both lower limbs. In her family history, her eldest daughter had undergone Achilles tendon elongation surgery for suspected CMT at the age of 3 years. Considering these, she was suspected to have CMT and was finally diagnosed with type 1A CMT based on genetic testing. In anti-cancer treatments that cause PSN(not just by L-OHP), possible involvement of occult peripheral nerve disease like CMT should be considered when more rapid and untypical PSN appears after the administration of anti-cancer drugs.

[Rupture of Ovarian Metastasis from Cecal Cancer during Chemotherapy - A Case Report Suggestive of Bilateral Salpingo-Oophorectomy].

A 66-year-old woman was diagnosed with advanced cecal cancer with metastases to her right ovary, peritoneum, and liver. Ileocecal resection and right salpingo-oophorectomy were performed as cytoreduction surgery before systemic chemotherapy. The colon cancer metastasized to her left ovary during chemotherapy and grew rapidly until it ruptured spontaneously, although the other metastases sites continued to respond to treatment. Emergent left salpingo-oophorectomy was performed. Pathological findings confirmed ovarian metastasis from colon cancer. Ovarian metastases are less responsive to systemic chemotherapy compared to extra-ovarian metastasis and the rapid growth sometimes occurs as a related symptom. Bilateral salpingo-oophorectomy might be recommended in cytoreduction surgery even if the ovarian metastasis is unilateral.

[Vitamin K deficiency caused by nutritional malabsorption accompanying afferent loop obstruction:a case report].

This case involves a 73-year-old man who visited a clinic because he was experiencing dyspnea on exertion and acid reflux. He was diagnosed with anemia and referred for a medical check-up and treatment by his primary care physician. Iron deficiency anemia and prolonged prothrombin time were confirmed with a blood test and an abdominal enhanced CT revealed marked expansion of the afferent loop after a gastrectomy. The medical check-up revealed abnormal blood coagulation due to afferent loop obstruction, which resulted in vitamin K deficiency. He was supplemented with vitamin K, and surgery was performed for the afferent loop obstruction. Postoperatively, his anemia, nutritional status, serum vitamin K levels, and prothrombin time improved steadily. In conclusion, nutrient malabsorption may occur in cases of afferent loop obstruction and abnormal blood coagulation due to vitamin K deficiency.

A Multicenter Phase 2 Study on the Feasibility and Efficacy of Neoadjuvant Chemotherapy Without Radiotherapy for Locally Advanced Rectal Cancer.

BACKGROUND: This prospective multicenter phase 2 study aimed to evaluate the feasibility and efficacy of neoadjuvant chemotherapy (NAC) without radiotherapy for locally advanced rectal cancer (LARC). METHODS: Patients with LARC (cStage II and III) were included in the study. Those with cT4b tumor were excluded. Six cycles of modified FOLFOX6 (mFOLFOX6) plus either bevacizumab or cetuximab, depending on KRAS status, were administered before surgery. The primary end point of the study was the R0 resection rate. The secondary end points were adverse effect, rate of NAC completion, postoperative complications, and pathologic complete response (pCR) rate. RESULTS: The study enrolled 60 patients from eight institutions. For the study, mFOLFOX6 was administered with cetuximab to 40 patients who had wild-type KRAS and with bevacizumab to 20 patients who had KRAS mutations. The completion rate for NAC was 88.4%. Sphincter-preserving surgery was performed for 43 patients and abdominoperineal resection for 17 patients. The median operation time was 335 min, and the median blood loss was 40 g. The R0 resection rate was 98.3%, and the pCR rate was 16.7%. The overall postoperative complication rate (≥grade 2) was 21.7%. The complications included anastomotic leakage (11.6%), surgical-site infection (6.7%), and urinary dysfunction (3.3%). The patients with wild-type KRAS did not differ significantly from those with KRAS mutations in terms of response rate, postoperative complication rate, and pCR rate. CONCLUSION: The findings show that NAC is a feasible and promising treatment option for LARC (This study is registered with UMIN-CTR, UMIN000005654).

Multi-institutional phase II study on the feasibility of liver resection following preoperative mFOLFOX6 therapy for resectable liver metastases from colorectal cancers.

BACKGROUND: Although liver resection combined with preoperative chemotherapy is expected to improve outcomes of patients with resectable colorectal liver metastasis (CRLM), there is as yet insufficient clinical evidence supporting the efficacy of preoperative systemic chemotherapy. The aim of this phase II study was to assess the feasibility and efficacy of preoperative FOLFOX systemic chemotherapy for patients with initially resectable CRLM. METHODS: A prospective multi-institutional phase II study was conducted to evaluate the feasibility and efficacy of preoperative chemotherapy for resectable CRLM (ClinicalTrials.gov identifier number NCT00594529). Patients were scheduled to receive 6 cycles of mFOLFOX6 therapy before liver surgery. The primary endpoint was the macroscopic curative resection rate. RESULTS: A total of 30 patients were included in this study. Two patients who were diagnosed with hepatocellular and intrahepatic cholangiocellular carcinoma based on pathology were excluded from the analysis. More than half of the patients (57 %) had solitary liver metastasis. The completion rate of preoperative chemotherapy was 64.3 % and the response rate was 53.6 %. Two patients were unable to proceed to liver resections due to disease progression and severe postoperative complications following primary tumor resection. Macroscopic curative resection was obtained in 89.3 % of eligible patients. Postoperative mortality and severe complication (≥Gr. 3) rates were 0 and 11 %, respectively. The 3-year overall and progression-free survival rates were 81.9 and 47.4 %, respectively. CONCLUSION: Our phase II study demonstrated the feasibility of liver resection combined with preoperative mFOLFOX6 therapy in patients with initially resectable CRLM. Further study is warranted to address the oncological effects of preoperative chemotherapy.