Helicobacter pylori prevalence and its spontaneous eradication rate after distal or proximal gastrectomy for gastric cancer: A multicenter prospective cohort study

Background: Helicobacter pylori (H. pylori) eradication is recommended in patients undergoing endoscopic resection for early gastric cancer to reduce recurrence. However, due to the possibility of spontaneous regression secondary to dynamic changes in the remnant stomach, the immediate eradication after gastrectomy for H. pylori carriers remains unclear. This study aimed to investigate the prevalence of H. pylori in Japanese patients with gastric cancer and the spontaneous eradication rate after distal or proximal gastrectomy. Methods: This multicenter prospective cohort study was conducted at 22 institutions. Eligibility criteria was patients over 20 years planned to undergo R0 gastrectomy for gastric cancer. The primary endpoint was spontaneous eradication rate 1 year after distal or proximal gastrectomy. The prevalence of H. pylori infection before surgery and clinical features related to spontaneous eradication were examined. Results: A total of 1247 patients were included in this study. The preoperative H. pylori status was positive in 756 patients and negative in 491. Seventy-nine of the negative patients had an eradication history, totaling 835 (67%) patients preoperatively infected with H. pylori. The infection status of 541 patients was examined 1 year postoperatively; 285 were negative, with a 52.7% spontaneous eradication rate. Spontaneous eradication was significantly higher in male and older patients (>70 years); other factors, such as histological type, gastrectomy method and adjuvant chemotherapy presence, did not affect the rate. Conclusions: As spontaneous H. pylori eradication occurred in more than half of the analyzed patients, retesting for H. pylori. should be considered before postoperative eradication therapy (UMIN000020280).