Proposal of a Scoring Scale to Estimate Risk of the Discontinuation of S-1 Adjuvant Monotherapy in Patients with Stage II to III Gastric Cancer: A Multi-Institutional Dataset Analysis.

Background: Discontinuation of postoperative S-1 adjuvant monotherapy is a frequent problem in the management of patients with gastric cancer.

Methods: A total of 355 stage II/III gastric cancer patients who underwent gastrectomy and adjuvant S-1 were retrospectively analyzed using a multicenter dataset. We randomly assigned patients into either discovery or validation cohort in a 2:1 ratio.