Time interval after various types of gastrectomy until metachronous multiple gastric cancer: Analysis of data from a nationwide Japanese survey

The factors influencing the time interval from the initial surgery for gastric cancer to the detection of metachronous multiple gastric cancer (MMGC) remain to be elucidated. The present study was performed to evaluate the association between the type of initial gastrectomy or reconstruction procedure and the time interval from initial gastrectomy to the detection of MMGC. A questionnaire survey on remnant stomach cancer was performed by the Japanese Society for Gastro-Surgical Pathophysiology in 2018. Participating facilities were requested to indicate the number of patients who underwent surgery for MMGC between 2003 and 2017, in association with the time interval from the initial gastrectomy until treatment for MMGC by type of initial gastrectomy or reconstruction procedure. Analyses were performed using data from 45 facilities. Gastrectomy for MMGC was performed on 1,234 patients during this period. Pylorus-preserving gastrectomy (PPG) accounted for only 3.6% (20/557) of the patients who underwent surgery for MMGC >= 10 years from initial gastrectomy, while PPG accounted for 10.1% (40/396) of patients who underwent surgery for MMGC within 5 years after initial gastrectomy. Billroth-II and Roux-en Y reconstruction accounted for 22.3% (103/462) and 1.3% (6/462), respectively, of patients who underwent surgery for MMGC 10 years from initial distal gastrectomy (DG), while such patients accounted for 8.0% (23/286) and 21.7% (65/286), respectively, of patients who underwent surgery for MMGC within 5 years after initial DG. Similarly, the proportion of each reconstruction procedure differed according to the time interval from initial proximal gastrectomy to treatment for MMGC. The types of gastrectomy or reconstruction procedure for initial gastrectomy differed significantly according to the time interval between the initial gastrectomy and treatment for MMGC, and the fact that PPG and R-Y reconstruction in DG is a relatively new method were assumed to be a major cause of these differences.