The Survival Benefit From the Addition of Radiation to Chemotherapy in Gastric Cancer Patients Following Surgical...

The survival benefit of radiation therapy in gastric cancer patients who underwent curative resection remains contentious.

Gastric cancer patients who underwent curative resection followed by adjuvant chemotherapy or chemoradiation therapy (CRT) between 2004 and 2014 were identified from the National Cancer Database. Survival analyses were carried out with the Kaplan-Meier method and the Cox regression model.

In total, 4347 patients were included in this study. Of these patients, 1185 patients received postoperative chemotherapy alone and 3162 patients received postoperative CRT. For all patients included in the analysis, patients who received CRT had significantly better overall survival than those who received chemotherapy alone (5-year overall survival: 54.8% versus 46.8%, P < 0.001). The survival benefit primarily occurred in patients with stage II (5-year overall survival: 58.7% versus 53.8%, P = 0.03), stage III (42.5% versus 30.3%, P < 0.001) and lymph node-positive (5-year overall survival: 52.2% versus 41.9%, P = 0.03) gastric cancer. Multivariable analysis confirmed the improvement in overall survival in patients who received postoperative CRT (hazard ratio = 0.78; 95% confidence interval, 0.661-0.926; P < 0.001) was independent of all known prognostic factors. For lymph node-positive patients with lymphovascular invasion (LVI), postoperative CRT significantly improved overall survival compared with chemotherapy alone (5-year overall survival: 49.0% versus 39.4%, P = 0.001). However, there was no survival difference between CRT and chemotherapy alone if lymph node-positive patients had no LVI (5-year overall survival: 54.5% versus 52.7%, P = 0.55).

The current study suggests that postoperative CRT provides a survival benefit in gastric cancer patients with concurrent lymph node-positive and LVI-positive disease. A randomised clinical trial may further evaluate the benefit of adjuvant CRT in this subgroup.