Adjuvant radiation therapy increases overall survival in node-positive gastric cancer patients with aggressive...

To determine the outcomes of postoperative radiation therapy on survival in gastric cancer.

An analysis of patients with surgically resected and nonmetastatic gastric cancer from the Surveillance, Epidemiology, and End Results database from 1990 to 2003 was carried out. Survival curves were calculated according to the Kaplan-Meier method. Multivariate analysis was carried out by the Cox proportional hazard model.

We identified 11,630 patients who met inclusion criteria. Radiation therapy was associated with increased survival in patients with American Joint Committee on Cancer stage IB to IV. The median survival for stage IB and II patients treated with radiation was 96 months and 37 months, respectively, versus 56 months and 23 months for patients who did not receive adjuvant radiation (P=0.0281 for stage IB and <0.0001 for stage II). The 5-year overall survival for node-positive patients treated with radiation was 30.4% versus 21.4% for patients who did not receive adjuvant radiation (P<0.0001). The survival benefit of radiation therapy was maintained even if ≥15 lymph nodes were removed for N1 and N2 disease and if ≥30 lymph nodes were removed for N3 disease. For node-positive patients with ≥15 lymph nodes removed, adjuvant radiation was linked to increase survival in patients who underwent partial gastrectomy, total gastrectomy, and en bloc gastrectomy with other organs removed. Radiation was a strong independent factor for survival on multivariate analysis.

There is a correlation between survival and radiation therapy in node-positive gastric cancer patients and is independent of the extent of surgical resection and lymph node dissection.