The impact of neoadjuvant chemoradiation versus chemotherapy on short and long-term outcomes among gastric carcinoma patients.

Abstract

78 Background: There is little consensus on the use of neoadjuvant chemoradiation (NCRT) versus neoadjuvant chemotherapy (NCT) in gastric carcinoma (GC) patients. We sought to compare the outcomes of these two approaches in a large national data base. Methods: National Cancer Data Base PUF (2004-2014) of GC patients who underwent NCRT/NCT followed by resection were included. Primary outcome was overall survival (OS), secondary outcomes were pathological complete response (pCR), R0 resection and postoperative mortality. Results: A total of 4204 GC patients with NCT were included, 62% of them had additional neoadjuvant radiotherapy (NRT). NCRT had higher pCR and R0 rates [551/2613 (21%), 2314/2561 (90%)] than NCT group [148/1573 (9%), 1242/1543 (80%)], p < 0.0001. Multivariate logistic regression showed similar higher odds of pCR (OR 2.8, 95% CI 1.65-4.60, p < 0.0001) and R0 (OR 1.5, 95% CI 1.14-1.99, p = 0.004) among NCRT versus NCT. There was no significant difference in length of hospital stay, 30-day readmission rate, 30- and 90-day postoperative mortality. Median, 3- and 5-year OS for NCRT versus NCT were: (20.4 months, 24% and 11%) versus (18.3 months, 19% and 6%), p < 0.001. Univariate cox regression analysis showed superior OS with NRT (HR 0.9, 95% CI 0.80-0.91, p < 0.001). After adjusting for confounding variables, pCR (HR 0.2, 95% CI 0.18-0.24, p < 0.001) and R0 (HR 0.7, 95% CI 0.61-0.75, p < 0.001) had better OS, while NRT was not. Conclusions: NRT improved pCR and R0 rates in GC without increase in surgical morbidity/mortality. The long-term OS benefit of NRT is likely secondary to higher pCR and R0 resection.