Laparoscopic Versus Open Surgery for Gastric Adenocarcinoma: Innovation Continues to Challenge Tradition.

S ince first described by Kitano et al in 1994, laparoscopic surgery has been established as an alternative to the traditional open approach for gastric adenocarcinoma at a number of experienced centers. Twelve prospective randomized trials have published data comparing postoperative outcomes between laparoscopic and open surgery. Only one of these trials was performed outside of Asia. Generally, laparoscopic surgery resulted in similar short-term complication and mortality rates, and there was some evidence suggesting laparoscopic surgery was associated with shorter hospital stay and earlier return of bowel function. These results were durable in the trials that included advanced gastric cancer patients or examined advanced gastric cancer exclusively. A recent Cochrane meta-analysis of prospective randomized controlled trials comparing laparoscopic versus open surgery showed no significant difference in short-term mortality and short or long-term outcomes, but the authors note these conclusions are based on low-quality evidence. The updated results from 2 large phase III multicenter, noninferiority, prospective randomized controlled trials were recently published. The Korean Laparoendoscopic Gastrointestinal Surgery Study (KLASS) group reported short-term outcomes from its study in clinical stage I gastric cancer patients. The investigators randomized 1416 patients to laparoscopic or open surgery. The overall complication rate (laparoscopic vs open 13.0% vs 19.9%; P 1⁄4 0.001) and wound complication rate (3.1% vs 7.7%; P < 0.001) were significantly lower in the laparoscopic group. There was no significant difference in mortality (laparoscopic vs open 0.6% vs 0.3%; P 1⁄4 0.687). The Chinese Laparoscopic Gastrointestinal Surgery Study (CLASS) group examined 1056 patients with T2–4a/ N0–3/M0 disease, randomized evenly into laparoscopic versus open surgery. There was no difference in postoperative morbidity (laparoscopic vs open 15.2% vs 12.9%; P1⁄4 0.285) or mortality (0.4% vs 0.0%; P 1⁄4 0.249). Survival data from these 2 trials are pending, and there are several ongoing multicenter trials from Asian and European institutions that have not yet disclosed results. Thus, whether laparoscopic surgery for gastric adenocarcinoma results in equivalent survival compared with open surgery is still up for debate. In this issue of Annals of Surgery, Honda et al retrospectively analyze over 4000 patients undergoing potentially curative gastrectomy in Japan for clinical stage I gastric adenocarcinoma via open and laparoscopic surgery. They then use propensity score matching (PSM) with 30 preoperative factors to define an open surgery group (n 1⁄4 924) and a laparoscopic surgery group (n 1⁄4 924), and find no difference between the groups in terms of overall survival and recurrence-free survival. The authors conclude that ‘‘laparoscopic gastrectomy is oncologically comparable with open gastrectomy for gastric cancer. ’’ Honda et al have performed a very nice study to support the hypothesis that laparoscopic gastrectomy is not inferior to open gastrectomy in terms of overall survival in stage I patients. One primary advantage of this study over other retrospective studies is the use of PSM with 30 factors in a large number of patients. The second advantage is that all the factors used are variables known preoperatively, which is how PSM was originally meant to be used. A similar case-matched study from several centers in South Korea, which included stage I to III patients, found similar results, but this study included some variables only known after surgery. For those not familiar with PSM, this is a statistical matching technique that attempts to estimate the effect of a treatment (in this case laparoscopic or open surgery) by accounting for covariates that predict receiving the treatment. The possibility of bias arises because the apparent difference in outcome between 2 groups may depend on characteristics that affected whether or not a patient received a given treatment rather than an effect of the treatment. In randomized clinical trials,