title: Low maruyama index surgery for gastric cancer.
abstract: BACKGROUND
  Japanese definitions and treatment guidelines have dominated extent-of-surgery concepts in gastric cancer for over 4 decades, despite the fact that such definitions/guidelines have changed considerably over time, and the fact they have largely failed to improve survival in prospective, randomized clinical trials.
  
  
  OBJECTIVE
  To briefly review lessons from previous surgical trials in gastric cancer, and, more specifically, to review data validating the concept of "low Maruyama Index surgery" as a data-driven guide to surgical treatment.
  
  
  METHODS
  Review of results from blinded multivariate analyses of two separate, prospective, randomized clinical trials: (a) the Macdonald Trial of adjuvant postoperative chemo-radiation, Intergroup 0116, conducted in North America; and (b) the Dutch D1-D2 Trial.
  
  
  RESULTS
  Blinded univariate and multivariate analysis of both trials establish "Maruyama Index of Unresected Disease" (MI) <5 as a strong independent predictor of better disease-free and overall survival in gastric cancer. Moreover, a strong "dose response" effect for MI versus survival is apparent.
  
  
  CONCLUSIONS
  In contrast to surgery focused on achievement of a particular Japanese-defined D-level, "low Maruyama Index surgery" is associated with increased disease-free and overall survival. Further, the dose-response effect suggests MI can be used to quantify the adequacy of lymphadenectomy for a given patient. Low MI surgery can be prospectively planned by using the Maruyama Computer Program pre-operatively or intraoperatively.
authors.affiliation: Department of Surgery, U.C. Davis Surgical Service, VA Northern California Health Care System, Mather, CA 95655-1200, USA. scott.hundahl@va.gov
authors.forename: S A
authors.initials: SA
authors.lastname: Hundahl
mesh_terms: D005743:Gastrectomy; D006801:Humans; D008197:Lymph Node Excision; D011379:Prognosis; D016032:Randomized Controlled Trials as Topic; D013274:Stomach Neoplasms / Q000401:mortality / Q000601:surgery*