Development of a Prognostic Nomogram for Overall Survival in Gastric Cancer Patients Who Underwent Adjuvant Chemoradiotherapy.

[PURPOSE] The aim of this study was to identify prognostic factors influencing overall survival (OS) in patients with gastric cancer treated with adjuvant chemoradiotherapy (CRT) and to develop a predictive model.

[METHODS] We retrospectively evaluated 245 non-metastatic gastric cancer patients who received adjuvant CRT or radiotherapy from 2010 to 2020. Survival analyses were performed using the Kaplan-Meier method. Prognostic factors were identified through univariate and multivariate Cox regression analyses. A nomogram was constructed based on significant predictive factors for OS, including lymph node ratio, T classification, tumor location, and local recurrence.

[RESULTS] The median follow-up duration was 41.5 months (range, 6-144.8 months). The 2- and 5-year OS and progression-free survival were 77% and 53% and 64% and 49%, respectively. In multivariate analysis, tumor location (distal vs. proximal), pT classification (pT1-2 vs. pT3-4), lymph node ratio (< 0.18 vs. ≥ 0.18), and presence of local recurrence were independent prognostic factors for OS. The optimal cut-off value for the total nomogram score predicting OS was 116 points. Patients with < 116 points had 2- and 5-year OS rates of 87% and 73%, respectively, compared to 67% and 30% for those with ≥ 116 points.

[CONCLUSION] A nomogram was constructed incorporating lymph node ratio, T classification, tumor site, and local recurrence for gastric cancer patients receiving adjuvant CRT. Patients with a total score below 116 demonstrated higher survival rates. This nomogram may aid in defining optimal follow-up intervals.