Definitive (chemo)radiotherapy in patients with esophageal cancer: A population-based study in northeast Netherlands.

Abstract

83 Background: Definitive (chemo)radiation as primary treatment modality is offered to esophageal cancer (EC) patients, as an alternative for patients considered medically unfit for surgery or having irresectable tumors. We evaluated the results in our cohort to improve selection of patients for intensified non-surgical strategies and to identify which clinical factors have a prognostic impact on the overall (OS) and disease free survival (DFS). Methods: EC patients treated with definitive radiotherapy (RT) or chemoradiotherapy (CRT) from 4 radiotherapy referral centers between 1996 and 2008 were used. Only patients with squamouscellcarcinoma (SCC) or adenocarcinoma (AC) were included in the analyses. Results: In total 278 patients were identified of whom 106 (38.1%) were treated with CRT (platinum based, median 50.4 (46.8 – 70)Gy) and 172 (61.9%) with RT alone (median 60 (40-70)Gy). T- stage was cT1=5.6%;cT2=15.3%;cT3=60.9% and cT4=18.2%. Nodal stage consisted of cN0=35%;cN1=65%, including cM1a=5.8%. The male/female ratio was 78.3% to 21.7%. AC occurred in 57.6% and 42.4% had a SCC. The median age was 69 years. Median OS time was 11 (1-166) months with an OS of 45%, 22% and 6% and a DFS of 32%, 18% and 6% at 1, 2 and 5 years, respectively. There was no significant difference between the CRT and RT group in OS (p=0.09) and DFS (p=0.17). The DFS after 2 and 5 year was 25% and 12% for SCC patients versus 11% and 0% for AC patients (p=0.007). The OS at 2 and 5 year was 28% and 11% for SCC versus 14% and 0% for AC patients (p=0.020). Initial recurrence was seen locoregionally in 66.7% and distant metastases occurred in 33.3%. Common sites for distant recurrence were the liver with 52.4%, 17.5% bones and 15.5% lungs. Patients with SCC had a better response to (chemo)radiotherapy considering the OS (p=0.02, HR=0.7) and DFS (p=0.01, HR=0.69) in a multivariate analysis. Conclusions: Patients with a SCC esophageal tumor have better long-term results then AC patients after definitive (chemo)radiation. In this patient group SCC seems to be a strong prognostic factor for both OS and DFS. Furthermore the difference between RT and CRT is still small.