No Difference in Survival between Neo-Adjuvant Chemotherapy and Neo-Adjuvant Chemoradiation Therapy in Gastric Cardia Cancer Patients: A Contemporary View from the National Cancer Database

INTRODUCTION
Both neo-adjuvant chemoradiation therapy (NACRT) and neo-adjuvant chemotherapy (NAC), in addition to surgical resection of gastric cardia cancer, improves survival outcomes. We assessed whether NACRT or NAC had superior overall survival (OS) and relative survival (RS) outcomes using the National Cancer Database (NCDB).

METHODS
The NCDB from 2006 to 2014 was reviewed to identify non-metastatic adult gastric cardia cancer patients who underwent surgical resection and received NACRT or NAC. Advanced statistical models were applied to assess survival outcomes.

RESULTS
Of the 5,371 patients included, 4,520 (84.2%) were male, the mean age was 61.2 years (SD 10.0), 4,229 (78.7%) underwent NACRT, and 1,142 (21.3%) underwent NAC. NACRT patients more often had an R0 resection compared to NAC (91.4 vs. 86.6%, p < 0.001, respectively). Univariate 5-year OS rates were 40.0% (95% CI 38.2-41.8) for NACRT and 40.1% (37.0-43.6) for NAC (p = 0.302). No differences in OS for NAC vs. NACRT were found after multivariable analysis (hazard ratio [HR] 0.95, 95% CI 0.86-1.05, p = 0.290). There were no survival differences after stepwise, propensity score, RS analyses, nor after near-far-matching (HR 0.94, 95% CI 0.82-1.07, p = 0.332).