Although the diagnostic and severity grading criteria on the 2013 Tokyo Guidelines (TG13) are used worldwide as the primary standard for management of acute cholangitis (AC), they need to be validated through implementation and assessment in actual clinical practice. Here, we conduct a systematic review of the literature to validate the TG13 diagnostic and severity grading criteria for AC and propose TG18 criteria. While there is little evidence evaluating the TG13 criteria, they were validated through a large-scale case series study in Japan and Taiwan. Analyzing big data from this study confirmed that the diagnostic rate of AC based on the TG13 diagnostic criteria was higher than that based on the TG07 criteria, and that 30-day mortality in patients with a higher severity based on the TG13 severity grading criteria was significantly higher. Furthermore, a comparison of patients treated with early or urgent biliary drainage versus patients not treated this way showed no difference in 30-day mortality among patients with Grade I or Grade III AC, but significantly lower 30-day mortality in patients with Grade II AC who were treated with early or urgent biliary drainage. This suggests that the TG13 severity grading criteria can be used to identify Grade II patients whose prognoses may be improved through biliary drainage. The TG13 severity grading criteria may therefore be useful as an indicator for biliary drainage as well as a predictive factor when assessing the patient's prognosis. The TG13 diagnostic and severity grading criteria for AC can provide results quickly, are minimally invasive for the patients, and are inexpensive. We recommend that the TG13 criteria be adopted in the TG18 guidelines and used as standard practice in the clinical setting. Free full articles and mobile app of TG18 are available at: http://www.jshbps.jp/modules/en/index.php?content_id=47. Related clinical questions and references are also included.

PURPOSE Adjuvant chemotherapy after hepatectomy is controversial in liver-only metastatic colorectal cancer (CRC). We conducted a randomized controlled trial to examine if adjuvant modified infusional fluorouracil, leucovorin, and oxaliplatin (mFOLFOX6) is superior to hepatectomy alone for liver-only metastasis from CRC. PATIENTS AND METHODS In this phase II or III trial (JCOG0603), patients age 20-75 years with confirmed CRC and an unlimited number of liver metastatic lesions were randomly assigned to hepatectomy alone or 12 courses of adjuvant mFOLFOX6 after hepatectomy. The primary end point of phase III was disease-free survival (DFS) in intention-to-treat analysis. RESULTS Between March 2007 and January 2019, 300 patients were randomly assigned to hepatectomy alone (149 patients) or hepatectomy followed by chemotherapy (151 patients). At the third interim analysis of phase III with median follow-up of 53.6 months, the trial was terminated early according to the protocol because DFS was significantly longer in patients treated with hepatectomy followed by chemotherapy. With median follow-up of 59.2 months, the updated 5-year DFS was 38.7% (95% CI, 30.4 to 46.8) for hepatectomy alone compared with 49.8% (95% CI, 41.0 to 58.0) for chemotherapy (hazard ratio, 0.67; 95% CI, 0.50 to 0.92; one-sided P = .006). However, the updated 5-year overall survival (OS) was 83.1% (95% CI, 74.9 to 88.9) with hepatectomy alone and 71.2% (95% CI, 61.7 to 78.8) with hepatectomy followed by chemotherapy. In the chemotherapy arm, the most common grade 3 or higher severe adverse event was neutropenia (50% of patients), followed by sensory neuropathy (10%) and allergic reaction (4%). One patient died of unknown cause after three courses of mFOLFOX6 administration. CONCLUSION DFS did not correlate with OS for liver-only metastatic CRC. Adjuvant chemotherapy with mFOLFOX6 improves DFS among patients treated with hepatectomy for CRC liver metastasis. It remains unclear whether chemotherapy improves OS.

Peritoneal dissemination is the most frequent, incurable metastasis occurring in patients with advanced gastric cancer (GC). However, molecular mechanisms driving peritoneal dissemination still remain poorly understood. Here, we aimed to provide novel insights into the molecular mechanisms that drive the peritoneal dissemination of GC. We performed combined expression analysis with in vivo-selected metastatic cell lines and samples from 200 GC patients to identify driver genes of peritoneal dissemination. The driver-gene functions associated with GC dissemination were examined using a mouse xenograft model. We identified a peritoneal dissemination-associated expression signature, whose profile correlated with those of genes related to development, focal adhesion, and the extracellular matrix. Among the genes comprising the expression signature, we identified that discoidin-domain receptor 2 (DDR2) as a potential regulator of peritoneal dissemination. The DDR2 was upregulated by the loss of DNA methylation and that DDR2 knockdown reduced peritoneal metastasis in a xenograft model. Dasatinib, an inhibitor of the DDR2 signaling pathway, effectively suppressed peritoneal dissemination. DDR2 was identified as a driver gene for GC dissemination from the combined expression signature and can potentially serve as a novel therapeutic target for inhibiting GC peritoneal dissemination.

4002 Background: Surgery (SUR) and radiofrequency ablation (RFA) are both known to be effective therapy for treating patients with small oligonodular hepatocellular carcinoma (HCC), however there is only insufficient evidence about which therapy is more preferred approach. This randomized controlled trial was designed to prospectively compare the efficacy of SUR and RFA as the first approach to primary HCC. Methods: In this open-label trial undertaken at 49 hospital in Japan, we recruited patients having primary HCC with tumor foci numbering less than 3, each measuring 3 cm or less, Child-Pugh score of 7 or less, ages between 20 and 79 year. Before randomization, technical and liver functional feasibility for both treatment arms were confirmed by joint chart review by surgeons and hepatologists. Patients were then randomly assigned in a 1:1 ratio to undergo SUR or RFA, stratified by age, infection of hepatitis-C virus, number of tumors, tumor size and institution. The primary endpoint was recurrence free survival (RFS) and overall survival (OS). Results: Between April 2009 and August 2015, total 308 patients were enrolled to this trial. Because of ineligibility 15 patients were excluded, therefore 145 patients underwent SUR and 148 patients underwent RFA finally. There was no perioperative mortality. Under the median follow-up of 5 years, the 3-year RFS of patients underwent SUR and RFA was 49.8%, 47.7%, respectively (hazard ration [HR] 0.96, 95% CI 0.72-1.28; p = 0.793). OS will be analyzed and published after two years. Conclusions: SUR and RFA were both safe therapeutic approaches and provided equally RFS for early stage HCC smaller than 3 cm. Clinical trial information: UMIN000001795.

4093 Background: The initial report of the multicenter SURF trial (surgery vs. radiofrequency ablation [RFA] for small hepatocellular carcinoma [HCC]) showed that recurrence-free survival (RFS) did not differ significantly between patients undergoing surgery and RFA. The focus of the present report was to assess the effect on overall survival (OS). Methods: The SURF trial was a multicenter, open-label, randomized, controlled, phase 3 trial conducted in 49 institutions in Japan. Patients (aged between 29 and 79 years) with Child-Pugh scores ≤ 7, largest HCC diameter ≤ 3 cm, and ≤ 3 HCC nodules were considered eligible. Before enrollment, both liver surgeons and hepatologists who perform RFA confirm that all the patients can be treated using both surgery and RFA. Patients were then randomly assigned in a 1:1 ratio to undergo surgery or RFA, stratified by age, hepatitis-C virus infection, numbers of HCC, largest HCC diameter, and institution. The co-primary endpoints were RFS and OS. As per the protocol, RFS was reported previously at 3 years after the last accrual of patients. OS was planned at 5 years after the last accrual. This trial is registered in UMIN000001795. Results: During 2009–2015, 308 patients were enrolled. After excluding ineligible patients, the surgery and RFA groups included 150 and 152 patients, respectively. Baseline factors did not differ significantly between the groups. In both groups, 90% of patients had solitary HCC. The median largest HCC diameter was 1.8 cm (interquartile range, 1.5–2.2 cm) in the surgery group and 1.8 cm (interquartile range, 1.5–2.3 cm) in the RFA group. The median (range) follow-up period was 6.4 (0.4–10.8) years in the surgery group and 6.6 (0–10.7) years in the RFA group. OS did not differ significantly between the surgery and RFA groups as the 5-year OS (95% confidence interval [CI]) was 74.6% (66.5%–81.0%) in the surgery group and 70.4% (62.2%–77.3%) in the RFA group (hazard ratio (HR), 0.96; 95% CI, 0.64–1.43; P= 0.828). The analysis after long-term follow-up in the current report showed that RFS was not significantly different between the surgery and RFA groups: the 5-year RFS (95% CI), 54.7% (46.0%–62.5%) vs. 50.5% (42.1%–58.3%); HR 0.90; 95% CI 0.67–1.22; P= 0.498. Conclusions: SURF trial revealed that OS and RFS were not significantly different between patients undergoing surgery and RFA for small HCC (≤ 3 cm and 3 nodules). Clinical trial information: 000001795.