BACKGROUND

The role of adjuvant radiotherapy (RT) in gastric cancer (GC) patients has not been well-established. This study initiated a retrospective case-control study to explore the survival impact of adjuvant RT on these patients.

METHODS

All patients were collected from the Surveillance, Epidemiology, and End Results (SEER) database. The cohort was assigned into patients without adjuvant RT versus those with adjuvant RT. Descriptive chi-square test was adopted to compare categorical variates between the 2 groups. Kaplan-Meier (KM) method was adopted to estimate the patients' cancer-specific survival (CSS) and overall survival (OS). Cox proportional hazard models were utilized to characterize the prognostic factors of their CSS.

RESULTS

Totally 7,194 patients were recruited in this study, 3,326 (46.2%) patients didn't have RT and 3,868 (53.8%) patients had adjuvant RT. Survival analysis of the entire population showed that adjuvant RT had remarkable survival benefits for the GC patients. The median CSS was 47.0 (42.0-52.0) months in RT group versus 32.0 (29.7-34.3) months in no RT group (P<0.001). Age >60, histologic type 8490, tumor size >50 mm, higher stage TNM, and surgery type 40/50 were independent risk factors for poor prognosis. Comparatively, adjuvant RT and LN examined >0 were independent factors for improving prognosis. Subgroup analysis demonstrated that adjuvant RT had significant survival benefits for patients with 1-14 and 15-29 lymph nodes (LNs) retrieved.

CONCLUSIONS

Adjuvant radiotherapy may have significant survival benefits for GC patients with 1-29 LNs retrieved. Our study upholds adjuvant RT for this subset of patients.