PS01.134: WHERE TO START? COMPARING INDUCTION CHEMORADIOTHERAPY AND UPFRONT SURGERY IN THE TREATMENT OF CLINICAL T2N0 ESOPHAGEAL CANCER

Abstract

Abstract Background The purpose of this study was to evaluate the survival difference in clinical T2N0 esophageal cancer patients receiving neoadjuvant chemoradiotherapy (CRT) vs. upfront surgery. Methods Between 1/1/1995 to 12/31/2012, a prospectively maintained database was used to identify patients with cT2N0 esophageal adeno- and squamous cell carcinoma. Exclusion criteria included: lack of endoscopic esophageal ultrasonographic (EUS) staging, incomplete resection, and prior treatment with endoscopic mucosal or submucosal resection. Cox-proportional hazard ratios were used to compare the primary outcomes of overall (OS) and disease-free survival (DFS). Secondary outcomes included: rate of postoperative complications, rate of pathologic upstaging/response, and induction/adjuvant treatment completion rate. Pre-hoc subgroup analysis compared pathologically upstaged patients receiving upfront surgery followed by adjuvant chemotherapy to those treated with neoadjuvant CRT. Results A total of 161 cT2N0 esophageal cancer patients were identified based on EUS staging. Upfront surgery was offered to 134 patients (83%), with 27 patients (17%) receiving induction CRT. Univariate analysis did not demonstrate any significant baseline differences between the two groups. In the upfront surgery group, 53 (39.6%), 28 (20.9%) and 53 (39.6%) patients were pathologically down-staged, accurately staged and upstaged respectively. Upstaging was higher in the upfront surgery group (53/134, 39.6% vs. 4/27, 14.8%; P = 0.02), while 11/27 (40.7%) patients receiving neoadjuvant CRT demonstrated complete pathologic response. Of those eligible for adjuvant chemotherapy, only 21/55 (38.2%) received treatment. In the neoadjuvant CRT group, 51.9% completed all planned therapy, compared to 23.6% of patients treated with upfront surgery followed by adjuvant chemotherapy (P = 0.01). Cox proportional hazard ratio did not demonstrate an advantage to induction CRT in terms of OS (HR = 1.64, P = 0.43) or DFS (HR = 1.36, P = 0.69). In general, patients with pathologic upstaging had worse OS (HR = 2.73, P = 0.001) and DFS (HR = 4.18, P = 0.003). Conclusion EUS was only accurate in staging T2N0 patients in 20.9% of cases. While neoadjuvant CRT did not confer a survival advantage, these results likely reflect the low number of patients being referred for induction therapy. Neoadjuvant CRT was however associated with lower rates of pathologic upstaging and higher rates of treatment completion. Further research should evaluate the survival outcomes in pathologically upstaged cT2N0 patients not receiving neoadjuvant therapy. Disclosure All authors have declared no conflicts of interest.