Current State of Gastric Stump Carcinoma in Japan: Based on the Results of a Nationwide Survey

BACKGROUND: Carcinoma of the gastric remnant after partial gastrectomy for benign disease or cancer is unusual but an important cancer model. The Japanese Society for the Study of Postoperative Morbidity after Gastrectomy (JSSPMG) performed a nationwide questionnaire survey to understand the current state of gastric stump carcinoma in Japan. METHODS: In the questionnaire survey of November 2008, gastric stump carcinoma was defined as an adenocarcinoma of the stomach occurring 10 years or more after Billroth I or Billroth II gastrectomy for benign condition or cancer disease. The survey was conducted at the request of reports on five or more patients with gastric stump carcinoma for each institution. Items for the survey included gender, age, methods of reconstruction in an original gastrectomy, original diseases, time interval between original gastrectomy and first detection of stump carcinomas, locations of stump carcinomas, tumor histology, tumor depth, and extent of lymph node metastasis. The questionnaire was sent to 163 surgical institutions in the JSSPMG. RESULTS: Ninety-five institutions (58.3%) responded to the survey, and the data of 887 patients satisfied the required conditions for the survey. A total of 887 patients were composed of 368 patients who received Billroth I distal gastrectomy and 519 who received Billroth II. The Billroth II group has a significantly higher number of original benign lesions than the Billroth I group (P < 0.001). This study confirmed the following issues: (1) The remnant stomach after gastrectomy for cancer disease had a higher prevalence to develop stump carcinomas occurring in a shorter time interval since original gastrectomy; (2) Patients with Billroth II gastrectomy had stump carcinomas most frequently in the anastomotic area, but not in the non-stump area as in Billroth I gastrectomy; (3) Tumor histology of 72.4% of 304 stump carcinomas at an early stage was intestinal type adenocarcinoma, i.e., well or moderately differentiated adenocarcinoma, whereas it decreased to 42.2% at the locally advanced stage of 521 stump carcinomas (P = 0.0015), suggesting that stump carcinoma mostly may develop from intestinal type and change to diffuse type during the evolution to advanced stage cancers. CONCLUSIONS: This large series of surveys suggest that there are two distinct biological plausibilities in the development of gastric stump carcinoma: (1) it develops in a shorter time interval of 10 years or less since the original gastrectomy, may come from a higher risk of gastric mucosa after gastrectomy for cancer diseases that highly predisposes to cancer, and (2) it develops during a longer time interval of 20 years or more, may come from gastrectomy-relating mechanisms after gastrectomy for original benign diseases.