Background
Both perioperative chemotherapy (PC) and adjuvant chemoradiotherapy (CRT) improve survival in resectable gastric cancer; however, these treatments have never been formally compared. Our
Conclusions
Despite the rapid adoption of PC, overall, CRT is associated with better survival than PC. Specifically, clinical node negative and signet ring histology patients had better survival when treated with CRT compared to PC. Based on these findings, we recommend against indiscriminate adoption of PC and consideration for CRT over PC in clinical node negative patients.
Methods
We performed a retrospective population-based cohort study between 2007 through 2013 using California Cancer Registry data. Patients diagnosed with stage IB-III gastric adenocarcinoma and treated with total or partial gastrectomy were eligible for this study. Based on the type of treatment received, patients were grouped into surgery-only, PC, or CRT. Primary and secondary outcomes were overall survival (OS) and gastric cancer-specific survival (GCCS) respectively. Mortality hazards ratios (HRs) for each of these outcomes were computed using propensity score weighted and covariate-adjusted Cox regression models, stratified by clinical node status.
Results
Of 2,146 patients who underwent surgical resection, 1,067 had surgery-only, while 771 and 308 received PC or CRT, respectively. Median OS was 25, 33, and 52 months for surgery-only, PC, and CRT, respectively; P<0.001. Overall, patients treated with PC had significantly poorer survival compared to CRT (HR =1.45; 95% CI: 1.22-1.73). PC was also associated with higher mortality in patients with signet ring histology (HR =1.66; 95% CI: 1.21-2.28) and clinical node negative cancer (HR =1.85; 95% CI: 1.32-2.60). Survival was not different between PC vs. CRT in clinical node positive patients (HR =1.29; 95% CI: 0.84-2.08). Of note, the percentage of patients receiving PC increased from 17.5% in 2007-2008, to 41.5% in 2013-2014; P<0.001. Conclusions: Despite the rapid adoption of PC, overall, CRT is associated with better survival than PC. Specifically, clinical node negative and signet ring histology patients had better survival when treated with CRT compared to PC. Based on these findings, we recommend against indiscriminate adoption of PC and consideration for CRT over PC in clinical node negative patients.