Trimodality therapy for resectable gastric cancer: analysis of the benefit in radiation

Abstract

Background: Gastric cancer is a common cause of cancer mortality worldwide, and due to its often advanced stage at the time of diagnosis, surgery alone is often inadequate treatment. Both chemotherapy (CH) and chemoradiation therapy (CHR) are used in the adjuvant setting and are both supported by randomized clinical trials. In this report, we compare the overall survival (OS), disease-free survival (DFS), and treatment toxicities of multimodal therapy with and without radiation. Patients and methods: Data from 193 patients diagnosed with stage IB-III gastric cancer treated with surgery (S group), surgery plus chemotherapy (S+CH group), or surgery plus chemoradiation (S+CHR group) were retrospectively analyzed. OS, DFS, and toxicities were compared in the various treatment modalities. Results: The S+CH (N=69) and S+CHR group (N=92) both had significant reduction in hazard ratio (HR) of death (HR, 0.24; P<0.001; HR, 0.33; P<0.001, respectively) when compared with the S group (N=32). Although S+CHR showed no significant benefit in OS or DFS (P=0.73, 0.16, respectively) when compared with S+CH, in a subgroup of patients with clinically lymph node–positive disease, S+CHR had significant improvement in DFS (HR, 1.83; P=0.047). Significantly higher rates of esophagitis were observed in the S+CHR, but no significant difference in grade 3 to 4 hematologic toxicities. One treatment related death was recorded in S+CH from postsurgical grade 5 sepsis. The clinical nodal classification was borderline significantly different between the S+CH and S+CHR groups (P=0.05) with a greater percentage of the S+CHR group being node positive. Conclusions: Multimodal therapy was associated with improved OS in our report when compared with surgery alone. Although patients who received CHR along with surgery did not have a significant difference in OS or DFS when compared with those receiving only chemotherapy with surgery, there was a difference in DFS in those patients who were clinically lymph node positive.