Importance Laparoscopic distal gastrectomy is gaining popularity over open distal gastrectomy for gastric cancer because of better early postoperative outcomes. However, to our knowledge, no studies have proved whether laparoscopic distal gastrectomy is oncologically equivalent to open distal gastrectomy. Objective To examine whether the long-term survival among patients with stage I gastric cancer undergoing laparoscopic distal gastrectomy is noninferior to that among patients undergoing open distal gastrectomy. Design The Korean Laparoendoscopic Gastrointestinal Surgery Study (KLASS) group, which includes 15 surgeons from 13 institutes, conducted a phase 3, multicenter, open-label, noninferiority, prospective randomized clinical trial (KLASS-01) of patients with histologically proven, preoperative clinical stage I gastric adenocarcinoma from January 5, 2006, to August 23, 2010. Survival and recurrence status of the patients was determined in December 2016. Interventions Patients were randomly assigned (1:1) to laparoscopic distal gastrectomy (n = 705) or open distal gastrectomy (n = 711). Of these patients, 85 received a surgical approach opposite the one to which they were randomized (63 randomized to the open surgery group and 22 to the laparoscopic group). Main Outcomes and Measures Difference in 5-year overall survival between the laparoscopic and open distal gastrectomy groups. The noninferiority margin was prespecified as −5% (corresponding hazard ratio of 1.54), with an assumed survival of 90% after 5 years in the open surgery group. Results Among the 1416 patients (mean [SD] age, 57.3 [11.1] years; 940 [66.4%] male) included in the study, the 5-year overall survival rates were 94.2% in the laparoscopic group and 93.3% in the open surgery group (log-rankP = .64). Intention-to-treat analysis confirmed the noninferiority of the laparoscopic approach compared with the open approach (difference, 0.9 percentage points; 1-sided 97.5% CI, −1.6 to infinity). The 5-year cancer-specific survival rates were similar between the 2 groups (97.1% in the laparoscopic group and 97.2% in the open surgery group, log-rankP = .91; difference, −0.03 percentage points; 1-sided 97.5% CI, −1.8 to infinity). Per-protocol analysis results were consistent with the intention-to-treat results for overall and cancer-specific survival rates. Conclusions and Relevance The KLASS-01 trial revealed similar overall and cancer-specific survival rates between patients receiving laparoscopic and open distal gastrectomy. Laparoscopic distal gastrectomy is an oncologically safe alternative to open surgery for stage I gastric cancer. Trial Registration ClinicalTrials.gov identifier:NCT00452751

To compare short-term surgical outcomes including financial cost of robotic and laparoscopic gastrectomy. Despite a lack of supporting evidence, robotic surgery has been increasingly adopted as a minimally invasive modality for the treatment of gastric cancer because of its assumed technical superiority over conventional laparoscopy. A prospective, multicenter comparative study was conducted. Patients were matched according to the surgeon, extent of gastric resection, and sex. The primary endpoint was morbidity and mortality. Outcomes were analyzed on an intention-to-treat and per-protocol basis. A total of 434 patients were enrolled for treatment with either robotic (n = 223) or laparoscopic (n = 211) gastrectomy for intention-to-treat analysis, and a total of 370 patients (n = 185 per treatment) were compared in per-protocol analysis. Results were similar between both analyses. In per-protocol analysis, both groups showed similar overall complication rates (robotic = 11.9% vs laparoscopic = 10.3%) and major complication rates (robotic = 1.1% vs laparoscopic = 1.1%) with no operative mortality in either group. Patients treated with robotic surgery showed significantly longer operative time (robotic = 221 minutes vs laparoscopic = 178 minutes; P < 0.001) and significantly higher total costs (robotic = US$13,432 vs laparoscopic = US$8090; P < 0.001), compared with those who underwent laparoscopic gastrectomy. No significant differences between groups were noted in estimated blood loss, rates of open conversion, diet build-up, or length of hospital stay. The use of robotic systems is assumed to provide a technically superior operative environment for minimally invasive surgery. However, our analysis of perioperative surgical outcomes indicated that robotic gastrectomy is not superior to laparoscopic gastrectomy. Clinical trials identification: NCT01309256.

Importance Fluorescent imaging with indocyanine green can be used to visualize lymphatics. Peritumoral injection of indocyanine green may allow for visualization of every draining lymph node from a primary lesion on near-infrared imaging. Objectives To evaluate the role of fluorescent lymphography using near-infrared imaging as an intraoperative tool for achieving complete lymph node dissection and compare the number of lymph nodes retrieved with the use of near-infrared imaging and the number of lymph nodes retrieved without the use of near-infrared imaging. Design, Setting, and Participants This prospective single-arm study was conducted among 40 patients who underwent robotic gastrectomy between August 30, 2013, and July 21, 2014, at a single-center, tertiary referral teaching hospital. After propensity score matching, the results of these 40 patients were compared with the results of 40 historical control patients who underwent robotic gastrectomy without indocyanine green injection between January 1, 2012, and August 31, 2013. Statistical analysis was performed from January 1, 2015, to July 31, 2016. Interventions Robotic gastrectomy with systemic lymphadenectomy and retrieval of lymph nodes under near-infrared imaging after peritumoral injection of indocyanine green to the submucosal layer 1 day before surgery. Main Outcomes and Measures The primary outcome was the number of retrieved lymph nodes in each nodal station. Results Among the 40 patients in the study (19 women and 21 men; mean [SD] age, 52.2 [11.7] years), no complications related to indocyanine green injection or near-infrared imaging were observed. On completion of the lymphadenectomy, the absence of fluorescent lymph nodes in the dissected area was confirmed. A mean (SD) total of 23.9 (9.0) fluorescent lymph nodes were recorded among a mean (SD) total of 48.9 (14.6) overall lymph nodes retrieved. The mean number of overall lymph nodes retrieved was larger in the near-infrared group than in the historical controls (48.9 vs 35.2;P < .001), with a significantly greater number of lymph nodes retrieved at stations 2, 6, 7, 8, and 9. In the near-infrared group, 5 patients exhibited lymph node metastases, and all metastatic lymph nodes were fluorescent. Conclusions and Relevance This study’s findings suggest that fluorescent lymphography may be useful intraoperatively for identifying and retrieving all necessary lymph nodes for a complete and thorough lymphadenectomy.

Background: Laparoscopic and robotic gastrectomy have been adopted rapidly despite lack of evidence concerning technical safety and controversy regarding additional benefits. This study aimed to compare clinically relevant complications after open, laparoscopic and robotic gastrectomy. Methods: This was a retrospective analysis of prospectively collected data on surgical complications in patients undergoing gastrectomy with curative intent for histologically proven adenocarcinoma between 2005 and 2010 at the Department of Surgery, Yonsei University College of Medicine in Seoul, Korea. Complications were categorized into wound infection, bleeding, anastomotic leak, obstruction, fluid collection and other. Results: In a total of 5839 patients (4542 open, 861 laparoscopic and 436 robotic gastrectomies), overall complication, reoperation and mortality rates were 10·5, 1·0 and 0·4 per cent respectively. There were no significant differences between the three groups. Ileus (P = 0·001) and intra-abdominal fluid collections (P = 0·013) were commoner after conventional open surgery. However, tumour stage was higher and more complex resections were performed in the open group. Anastomotic leak, the leading cause of death, occurred more often after a minimally invasive approach (P = 0·017). Conclusion: Laparoscopic and robotic gastrectomy had overall complication and mortality rates similar to those of open surgery, but anastomotic leaks were more common with the minimally invasive techniques.

Background and Objective The relationship between survival in gastric cancer patients and the status of microsatellite instability (MSI) has not yet been established. The purpose of this meta‐analysis was to obtain integrated and more precise data for the value of MSI as a prognostic marker in gastric cancer. Methods A comprehensive systematic review and meta‐analysis were conducted using major electronic databases (PubMed, EMBASE, and the Cochrane Central) with keywords related to “microsatellite instability,” “gastric cancer,” and “prognosis.” Results Twenty‐four studies with 5,438 participants (712 cases were MSI gastric cancer) were included for pooling risk estimates of MSI in gastric cancer. Seventeen studies reported overall survival. The pooled hazard ratio (HR) for overall survival of MSI vs. non‐MSI was 0.72 (95%CI: 0.59–0.88, P = .001) in a random‐effects model. In the sensitivity analysis, the result from the most recent study showed the most heterogeneity. Conclusion MSI gastric cancer was associated with good prognosis but there was heterogeneity in the recent studies. Changed epidemiology and effects of chemotherapy are potential causes of heterogeneity. Establishing a consensus for defining MSI in gastric cancer should be preferred for future studies. J. Surg. Oncol. 2014; 110:129–135.