Abstract 1436P
Background
The standard approaches for resectable gastric cancer involve postoperative chemoradiation (PCR) or perioperative chemotherapy (PC). Limited evidence is available regarding comparable efficacy and toxicities of the two approaches. There are no randomized trials to address this question. In this population based cohort study, we compare the efficacy and toxicities of PCR with PC.
Methods
Patients with operable stomach cancer diagnosed between the period of January 2005 and December 2015 in the province of Saskatchewan were identified and grouped into PCR and PC. A Cox proportional multivariate analysis was performed to assess independent prognostic variables including survival advantage of PC over PCR.
Results
88 eligible patients with a median age of 66 (56-71) and M:F of 1:0.44 were identified. 67 (76%) received PCR and 21 (24%) received PC. 83% had pathologically node positive disease. There were no significant differences in baseline characteristics between the two groups. The median overall survival of the whole group was 34 months; 38 months (95%CI: 24.6-51.3) in the PCR group vs. 30 months (14.3-45.7) in the PC group (p=0.29). Median relapse free survival was 34 months (20.7-47.3) in the PCR group vs. 23 months (6.7-39.3) in the PC group (p=0.20). Five year relapse free and overall survival rates were 29% and 39% in PC vs. 33% and 29% in the PCR group, respectively (p=NS). Overall toxicities were comparable except diarrhea was more common in the PCR group (p 0.002). On multivariate analysis, T ≥3, HR: 3.57 (1.39-8.56), positive resection margins, HR: 1.89 (1.06-3.37) and neutrophil: lymphocyte (LNR) >2.8, HR:1.85 (1.05-3.25) were independently correlated with inferior survival. The treatment approach (PC vs. PCR) was not associated with survival.
Conclusions
This well-designed population based cohort study suggests a lack of survival benefit of PC over PCR. However, deeper tumors, positive resection margins and elevated LNR were associated with poor survival. Both treatment options remain viable approaches for resectable gastric cancer.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Saskatchewan Cancer Agency.
Disclosure
All authors have declared no conflicts of interest.