Predictors of tolerability for postoperative adjuvant S1 plus docetaxel chemotherapy for gastric cancer: a multicenter retrospective study

Adjuvant docetaxel plus S1 (DS) chemotherapy after gastrectomy with D2 lymph node dissection is the standard treatment for stage III gastric cancer in Japan; however, some patients are unable to receive adequate drug administration because of the deterioration of their conditions. This study aimed to investigate the correlation between tolerability for postoperative adjuvant DS chemotherapy and prognosis, and the factors affecting tolerability. This retrospective study involved patients with stage III gastric cancer who underwent curative resection between 2018 and 2021 from a multicenter database. Patients with a cumulative dose of docetaxel and S1 greater than 120 and 8400 mg/m , respectively, were considered tolerable. The prognostic impact and factors predicting tolerability were analyzed. Of the 103 patients, the tolerable group comprised of 63 (61%) patients and had a significantly better 3-year recurrence-free survival than the intolerable group (83% vs. 64%, P = 0.02). Among the preoperative factors, only performance status (PS, P = 0.04) was significantly correlated with tolerability in the univariate analysis. Among the postoperative factors, PS (P = 0.001) and perioperative weight loss rate (P = 0.02) were significantly correlated with tolerability in the univariate analysis. The multivariate analysis showed significant differences in the PS (odds ratio [OR]: 4.94, 95% confidence interval [CI] 1.79-14.98, P = 0.002) and weight loss rate (OR: 1.10, 95% CI 1.01-1.21, P = 0.03). Tolerance to postoperative adjuvant DS chemotherapy has a significant prognostic impact. Postoperative PS and perioperative weight loss rates were independent predictors of tolerability.