Twenty Year Treatment Results of Radiation Therapy for T1N0M0 Esophageal Cancer

Abstract

We assessed 20 years-treatment results of radiation therapy (RT) for patients with T1N0M0 esophageal cancer. An analysis was performed of 158 patients with T1N0M0 esophageal cancer treated by definitive RT at a single institution from 1992 to 2011. Median age was 70 and there were 16 females and 142 males. Histology was 157 squamous cell carcinomas and 1 adenocarcinoma. Tumor depth was mucosal in 61 and submucosal in 97 patients. We divided treatment term into the previous term (1992-2001) and the latter term (2002-2011). There were 93 patients (47 mucosal and 46 submucosal cancer patients) treated in the previous term and 65 (14 mucosal and 51 submucosal) in the latter term. RT methods were intra-cavitary brachytherapy (ICBT) with or without external beam RT (EBRT) in 88 patients, RT alone without ICBT in 25, chemoradiation therapy (CRT) in 43 and CRT+ICBT in 2. ICBT was mainly performed in the previous term and CRT was performed mainly in the latter term. Follow-up times for survival patients in the previous and latter term were 90 and 41 months, respectively. Three-year overall survival rates (OS) for mucosal and submucosal cancer patients treated in the previous term were 89% and 50%, respectively. Three-year cause-specificsurvival (CSS) rates for them were 100% and 66%, respectively. Three-year OS for mucosal and submucosal cancer patients treated in the latter term were 93% and 86%, respectively. Three-year CSS for them were 100% and 94%, respectively. A significant difference was seen in OS (p < 0.01) and CSS (p < 0.01) between mucosal and submucosal cancer patients treated in the previous term. There was no significant difference in OS and CSS between mucosal and submucosal cancer patients treated in the latter term. OS and CSS for submucosal cancer patients in the latter term improved significantly in comparison with the previous term. In submucosal cancer patients, multivariate analysis showed that operability and concurrent use of chemotherapy were prognostic factors for OS and that concurrent use of chemotherapy was a prognostic factor for CSS. Recurrences were observed in 29 (18%) patients. Locoregional failure was main pattern of failures (24/29). In submucosal cancer patients, locoregional failure decreased significantly; 28% in the previous term and 8% in the latter term (p = 0.014). Cardiac death was seen in 5 (3%) patients and 3 of them had history of heart disease before RT. The number of mucosal cancer patients treated by RT decreased significantly in the latter term compared with the previous term due to advance of endoscopic treatment technique for mucosal cancer. In submucosal cancer, survivals improved significantly in the latter term compared with the previous term. Introduction of concurrent chemotherapy contributed to the improvement of treatment results.