Time Interval After Various Types of Gastrectomy Until Metachronous Multiple Gastric Cancer: Analysis of Data From A Nationwide Japanese Survey

Background The time interval between initial partial gastrectomy and diagnosis of cancer in the remnant stomach reportedly differs according to the reconstruction procedure used in the initial gastrectomy. However, factors correlated with the time interval from the initial surgery for gastric cancer to the detection of metachronous multiple gastric cancer (MMGC) remain unclear. This study was performed to evaluate the association between the type of initial gastrectomy or reconstruction procedure and the time interval from initial gastrectomy to detection of MMGC as well as the association between the type of initial gastrectomy and the procedure performed for MMGC. Methods A questionnaire survey on remnant stomach cancer was conducted by the Japanese Society for Gastro-Surgical Pathophysiology in 2018. Participating facilities were asked to indicate the number of patients who underwent surgery for MMGC between 2003 and 2017, in accordance with the time interval from the initial gastrectomy until treatment for MMGC by type of initial gastrectomy or reconstruction procedure. The number of patients who underwent each treatment procedure (completion total gastrectomy or partial gastrectomy) was also collected. Results Analyses were performed using data from 45 facilities. Gastrectomy for MMGC was performed in 1,234 patients during the period. Billroth-II and Roux-en Y accounted for 22.3% (103/462) and 1.3% (6/462), respectively, of patients who underwent surgery for MMGC ≥ 10 years from initial DG, while these 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. Likewise, the proportion of each reconstruction procedure differed by the time interval from initial proximal gastrectomy to treatment for MMGC. In terms of the treatments performed for MMGC, the proportion of patients who underwent partial gastrectomy increased in accordance with the size of the remnant stomach after the initial gastrectomy. Conclusions The types of gastrectomy or reconstruction procedures for initial gastrectomy differed significantly by time interval between the initial gastrectomy and treatment for MMGC, and their time trends were assumed to be a major cause of the differences. The proportion of patients who underwent completion total gastrectomy deceased as the size of the remnant stomach increased.