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.

The efficacy of simple oral nutritional supplements versus usual care in postoperative patients with gastric cancer: study protocol for a multicenter, open-label, parallel, randomized controlled trial.

BACKGROUND: Body weight loss (BWL) after gastrectomy impact on the short- and long-term outcomes. Oral nutritional supplement (ONS) has potential to prevent BWL in patients after gastrectomy. However, there is no consistent evidence supporting the beneficial effects of ONS on BWL, muscle strength and health-related quality of life (HRQoL). This study aimed to evaluate the effects of ONS formulated primarily with carbohydrate and protein on BWL, muscle strength, and HRQoL. METHODS: This will be a multicenter, open-label, parallel, randomized controlled trial in patients with gastric cancer who will undergo gastrectomy. A total of 120 patients who will undergo gastrectomy will be randomly assigned to the ONS group or usual care (control) group in a 1:1 ratio. The stratification factors will be the clinical stage (I or ≥ II) and surgical procedures (total gastrectomy or other procedure). In the ONS group, the patients will receive 400 kcal (400 ml)/day of ONS from postoperative day 5 to 7, and the intervention will continue postoperatively for 8 weeks. The control group patients will be given a regular diet. The primary outcome will be the percentage of BWL (%BWL) from baseline to 8 weeks postoperatively. The secondary outcomes will be muscle strength (handgrip strength), HRQoL (EORTC QLQ-C30, QLQ-OG25, EQ-5D-5L), nutritional status (hemoglobin, lymphocyte count, albumin), and dietary intake. All analyses will be performed on an intention-to-treat basis. DISCUSSION: This study will provide evidence showing whether or not ONS with simple nutritional ingredients can improve patient adherence and HRQoL by reducing BWL after gastrectomy. If supported by the study results, nutritional support with simple nutrients will be recommended to patients after gastrectomy for gastric cancer. TRIAL REGISTRATION: jRCTs051230012; Japan Registry of Clinical Trails. Registered on Apr. 13, 2023.

A case of pancreatic body cancer with disappearance of the dilated pancreatic duct on the tail side during preoperative treatment.

This is a case of a 67-year-old woman diagnosed with a 35-mm pancreatic body cancer with a chief complaint of epigastric discomfort. Computed tomography demonstrated invasion of the common hepatic artery, portal vein, and stomach, and chemotherapy was initiated for locally advanced pancreatic cancer. After 9 months of chemotherapy, the tumor remained stable on imaging, and the tumor markers were within the normal range. After additional chemoradiotherapy, the patient underwent a conversion surgery, a pancreaticoduodenectomy. Magnetic resonance cholangiopancreatography (MRCP) at the time of diagnosis demonstrated main pancreatic duct (MPD) dilatation on the tail side of the tumor; however, most of the MPD signal disappeared on MRCP after chemotherapy. Surgical findings failed to identify MPD on the first pancreatic resection plane, and additional resection was conducted; however, no MPD was found. As a pancreatic duct anastomosis was not available, pancreatic reconstruction was selected for pancreaticogastric anastomosis using the invagination method. Pathologically, the pancreatic tissue on the tail side of the tumor was replaced by fibrotic tissue, and MPD could not be identified. To the best of our knowledge, this is the first case report of the disappearance of a dilated pancreatic duct on the tail side accompanied by exocrine tissue loss during preoperative treatment for pancreatic cancer.

Neoadjuvant therapy with intensity-modulated radiotherapy combined with S-1 for borderline-resectable pancreatic cancer.

AIM: We evaluated the efficacy of neoadjuvant chemotherapy with intensity-modulated radiotherapy (NAC-IMRT) in patients with borderline-resectable pancreatic cancer (BRPC). METHODS: BRPC patients were treated with IMRT (45 Gy/15fr) combined with two courses of S-1 (40 mg/m2 bid) before surgery. Outcomes after NAC-IMRT, surgery, and survival were then evaluated. This single-center retrospective study assessed 26 consecutive patients. RESULTS: Twenty-six patients (BR-PV: 7, BR-A: 19) with a median age of 73 years were enrolled from 2016 to 2021. Ten (38%) patients were 75-years-old and above. Twenty-three patients completed NAC-IMRT treatment. The median reductions in tumor size and cancer antigen 19-9 level were 13.6% and 69%, respectively. All 26 patients underwent resection within a median time of 71 days after NAC-IMRT initiation. R0 resection was achieved in 24 patients (92%). The median overall survival (OS) was 28.0 months, and the 1- and 3-year OS rates were 100% and 34%, respectively. The median progression-free survival (PFS) was 12.5 months, and the 1- and 3-year PFS rates were 50% and 32%, respectively. No significant differences were observed in OS between the patients under and over the age of 75 (29 vs. 20 months, p = 0.86). The 12 patients who completed NAC-IMRT, resection, and subsequent adjuvant chemotherapy (AC) exhibited a 3-year survival rate of 73%, which was significantly better than that of the patients who did not receive or complete AC (median OS, not reached vs. 19 months, p < 0.001). CONCLUSION: NAC-IMRT showed outstanding clinical efficacy with acceptable tolerability in patients with BRPC, including geriatric patients.

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.

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.

A Multicenter, Phase II Trial of Schedule Modification for Nab-Paclitaxel in Combination with Ramucirumab for Patients with Previously Treated Advanced Gastric or Gastroesophageal Junction Cancer: The B-RAX Trial (JACCRO GC-09).

BACKGROUND: This study investigated whether schedule modification of bi-weekly nanoparticle albumin-bound paclitaxel (nab-PTX) plus ramucirumab (RAM) is efficacious against gastric cancer (GC) or gastroesophageal junction cancer (GJC). PATIENTS AND METHODS: Patients with unresectable GC or GJC who were previously treated with fluoropyrimidine-containing regimens 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. Based on the incidence of severe adverse events (AEs) during the first cycle, patients were modified to bi-weekly therapy from the second cycle. The primary endpoint was progression-free survival (PFS) in the bi-weekly therapy population. Based on the hypothesis that bi-weekly nab-PTX plus RAM would improve PFS from 4.5 to 7.0 months, 40 patients were required for power of 0.8 with a one-sided α of 0.05. RESULTS: Of the 81 patients enrolled, 47 patients (58%) were assigned to bi-weekly therapy. Patient characteristics were Eastern Cooperative Oncology Group performance status of 1 (19%) and diffuse type (45%). Median PFS was 4.7 months (95% confidence interval [CI] 3.7-5.6 months) and overall response rate was 25% (95% CI 11-39%). Severe AEs of grade 3 or worse were mainly neutropenia (83%) and hypertension (23%). EQ-5D scores were maintained during the treatment. In patients who continued standard-schedule therapy, median PFS was 2.7 months (95% CI 1.8-4.0 months). CONCLUSIONS: The primary endpoint for PFS was statistically not met, but modification of nab-PTX plus RAM to a bi-weekly schedule might be a feasible treatment option as second-line treatment for advanced GC/GJC patients, especially elderly patients, with severe AEs during the first cycle.

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.

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.

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.

Poor association between dihydropyrimidine dehydrogenase (DPYD) genotype and fluoropyrimidine-induced toxicity in an Asian population.

OBJECTIVE: Dihydropyrimidine dehydrogenase (DPYD) genotype is closely associated with fluoropyrimidine (FP)-induced toxicities in Caucasian population and European Medicines Agency now recommends DPYD genotype-based FP dosing strategy. PATIENTS AND METHODS: The current study aimed to investigate their impact on FP-related toxicities in an Asian population using genome-wide association study (GWAS) data set from 1364 patients with colon cancer. RESULTS: Among 82 variants registered in the Clinical Pharmacogenetics Implementation Consortium, 74 DPYD variants were directly genotyped in GWAS cohort; however, only 7 nonsynonymous DPYD variants (CPIC variants) were identified and none of the four recurrent DPYD variants (DPYD*2A, c.2846A>T, c.1679T>G, c.1236G>A) were included. Seven CPIC variants were investigated for their association with the incidence of FP-related toxicities; however, none of these variants revealed a significant correlation with FP-related toxicities. CONCLUSION: These data suggested that the DPYD genotype registered in CPIC plays a minor role in FP-related toxicities in an Asian population.

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.

Final Analysis of 3 Versus 6 Months of Adjuvant Oxaliplatin and Fluoropyrimidine-Based Therapy in Patients With Stage III Colon Cancer: The Randomized Phase III ACHIEVE Trial.

PURPOSE: The phase III ACHIEVE trial conducted in Japan was one of six prospective studies included in the International Duration Evaluation of Adjuvant Therapy collaboration, which explored whether 3 months of adjuvant fluorouracil, leucovorin, and oxaliplatin (FOLFOX) or capecitabine and oxaliplatin (CAPOX) therapy would be noninferior to 6 months of treatment in patients with curatively resected stage III colon cancer. We report the final analyses of survival and long-term safety. PATIENTS AND METHODS: Eligible patients were randomly assigned (1:1) to either 3 or 6 months of adjuvant chemotherapy (modified [m]FOLFOX6 or CAPOX, as selected by the treating physician). Random assignment was stratified according to number of involved lymph nodes, center, regimen, primary site, and age. The primary end point was disease-free survival, assessed in the modified intention-to-treat population. Overall survival (OS) was a secondary end point. RESULTS: The modified intention-to-treat population comprised 1,291 patients: 641 in the 6-month treatment group and 650 in the 3-month treatment group. Median follow-up for this analysis was 74.7 months. Five-year OS rates were comparable: 87.0% in the 3-month treatment group and 86.4% in the 6-month treatment group (hazard ratio, 0.91; 95% CI, 0.69 to 1.20; P = .51). Subgroup analysis of OS did not reveal a significant interaction between baseline characteristics and treatment duration. Peripheral sensory neuropathy lasting longer than 5 years was more common in the 6- compared with 3-month treatment group (16% v 8%, respectively), and in those receiving mFOLFOX6 compared with CAPOX (14% v 11%, respectively). CONCLUSION: In Asian patients, shortening adjuvant therapy duration from 6 to 3 months did not compromise efficacy and reduced the rate of long-lasting peripheral sensory neuropathy. In this setting, 3 months of CAPOX therapy is an appropriate adjuvant treatment option.

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.

Phase II Study of Third-Line Panitumumab Rechallenge in Patients with Metastatic Wild-Type KRAS Colorectal Cancer Who Obtained Clinical Benefit from First-Line Panitumumab-Based Chemotherapy: JACCRO CC-09.

BACKGROUND: Regorafenib and trifluridine/tipiracil are standard third-line chemotherapies for colorectal cancer patients, but their efficacy is limited. Anti-epidermal growth factor receptor antibody rechallenge has been reported to be promising for patients who have obtained clinical benefit from first-line cetuximab-based chemotherapy. Moreover, panitumumab showed non-inferior efficacy to cetuximab. OBJECTIVE: This study assessed the efficacy and safety of third-line panitumumab rechallenge in patients with metastatic KRAS exon 2 wild-type metastatic colorectal cancer who obtained clinical benefit from first-line panitumumab-based chemotherapy. PATIENTS AND METHODS: This was a prospective, multicenter, phase II trial conducted from October 2013 to August 2017. Major eligibility criteria included KRAS exon 2 wild-type and achievement of complete response, partial response, or continued stable disease for at least 6 months in first-line panitumumab-based therapy. Irinotecan plus panitumumab treatment was continued until disease progression or unacceptable toxicity was observed. The primary endpoint was the 3-month progression-free survival (PFS) rate. RESULTS: Twenty-five patients were enrolled in this study. Their median age was 66.5 years, and the 3-month PFS rate was 50.0% (95% confidence interval 30.0-70.0). The median PFS and overall survival were 3.1 months and 8.9 months, respectively. The response rate and disease control rate were 8.3% and 50.0%, respectively. Common grade 3/4 adverse events were acneiform rash (17%), hypomagnesemia (13%), and dry skin (13%). No treatment-related deaths occurred. CONCLUSION: Irinotecan plus panitumumab rechallenge is a promising third-line treatment regimen in patients with metastatic wild-type KRAS colorectal cancer. CLINICAL TRIAL IDENTIFICATION: UMIN000015916.

Intrahepatic bile duct rupture associated with IgG4-related sclerosing cholangitis presenting hepatic inflammatory pseudotumor.

A 67-year-old man with a low-grade fever was found to have a 25-mm diameter tumor of the left hepatic umbilical portion. The tumor was accompanied by occlusion of the left portal vein. Positron emission tomography using fluorodeoxyglucose showed that the tumor had abnormally high metabolic activity. Magnetic resonance imaging revealed the left hepatic duct segmental narrowing. There was a mild elevation in serum IgG4 (206 mg/dL). Intrahepatic cholangiocarcinoma was suspected. Instead of planned hepatectomy, the patient was forced to undergo emergency surgery for biliary panperitonitis caused by intrahepatic bile duct rupture. Intraoperative ultrasonography revealed a hypoechoic tumor-like thickened Glissonean sheath and needle biopsy was performed. Histologic examination confirmed fibrous tissue with IgG4-positive plasma cell infiltration without neoplastic proliferation. He was diagnosed with IgG4-related sclerosing cholangitis (IgG4-SC) presenting hepatic inflammatory pseudotumor. After his general condition improved, he underwent left hepatectomy. Macroscopic findings showed extreme fibrosis of the Glissonean sheath of the umbilical portion, and diffuse granular lesion aggregated in the left lateral segment. Microscopic examination confirmed chronic cholangitis and dense portal fibrosis in the umbilical portion and diffuse xanthogranulomatous inflammation. This is the first case report of spontaneous rupture of the intrahepatic bile duct in patient with IgG4-SC.

PTEN is a predictive biomarker of trastuzumab resistance and prognostic factor in HER2-overexpressing gastroesophageal adenocarcinoma.

Poor trastuzumab (Tmab) response of patients with human epidermal growth factor receptor 2-overexpressing gastric or gastroesophageal junction adenocarcinoma (HER2-GEA) is associated with the inhibition of phosphatase and tensin homolog (PTEN) expression. In this multicenter, retrospective observational study, pathological samples of patients with HER2-GEA receiving Tmab-combined chemotherapy were immunohistochemically analyzed for PTEN expression. The primary endpoints were disease control rate (DCR), progression-free survival (PFS), and overall survival (OS). We assessed the effect of conventional chemotherapy and Tmab alone or combined with PI3K pathway inhibitors in vitro in HER2-GEA cells with or without PTEN expression. Twenty-nine and 116 patients were in the PTEN-loss and PTEN-positive groups, respectively. In patients with the target region, DCR was significantly lower in PTEN-loss patients than in PTEN-positive patients (67% and 87%, respectively, p = 0.049). The multivariate analysis demonstrated that PTEN loss was significantly associated with shorter PFS (HR = 1.63, p = 0.035) and OS (HR = 1.83, p = 0.022). PTEN knockdown did not affect the cytostatic effect of 5-FU and cisplatin, whereas Tmab combined with the PI3K/mTOR inhibitor NPV-BEZ235 suppressed PTEN-knockdown cell proliferation. In patients with HER2-GEA, PTEN loss is a predictive biomarker of Tmab resistance and prognostic factor. Molecular-targeted therapy with a PI3K/mTOR inhibitor would be effective for HER2-GEA with PTEN loss.