The number of patients who die from causes other than gastric cancer after R0 resection is increasing in Japan, due in part to the aging population. However, few studies have comprehensively investigated the clinicopathological risks associated with deaths from other causes after gastrectomy. This study aimed to build a risk score for predicting such deaths.

We retrospectively reviewed clinical data for 3575 patients who underwent gastrectomy for gastric cancer at nine institutions in Japan between January 2010 and December 2014.

The final study population of 1758 patients were assigned to Group A (n = 187): patients who died from other causes within 5 years of surgery, and Group B (n = 1571): patients who survived ≥ 5 years after surgery. Multivariate analysis identified nine characteristics as risk factors for poor survival: age ≥ 75 years, male sex, body mass index < 22 kg/m2, Eastern Cooperative Oncology Group Performance Status (≥ 1), diabetes mellitus, cardiovascular/cerebrovascular disease, other malignant diseases, preoperative albumin level < 3.5 g/dL, and total gastrectomy. Patients with risk scores of 0–2, 3–4, or 5–9 (based on 1 point per characteristics) were classified into Low-risk, Intermediate-risk, and High-risk groups, respectively. The 5-year survival rates were 96.5%, 85.3%, and 56.5%, for the Low-, Intermediate-, and High-risk groups, respectively, and the hazard ratio (95% confidence intervals) was 16.33 (10.85–24.58, p < 0.001) for the High-risk group.

The risk score defined here may be useful for predicting deaths from other causes after curative gastrectomy.