Factors affecting local control and survival after treatment of carcinoma of the rectum by endocavitary radiation: A retrospective study of 97 cases

Abstract

Purpose: Endocavitary radiation therapy constitutes an alternative to surgical therapy for some early rectal carcinomas. We studied the prognostic factors for locoregional or metastatic relapse after endocavitary radiation, and their impact for therapeutic strategy. Methods and Materials: Our study reports the outcome of 97 patients with adenocarcinomas of the rectum treated from 1978 to 1998 by endocavitary irradiation (100 Gy), exclusive or combined with an interstitial brachytherapy boost of 20 Gy. The indications consisted mostly of polypoid, mobile tumors, less than 4 cm in diameter, and well differentiated. But the indications were extended to elderly patients, who presented with a high surgical risk or who refused mutilating surgery. Results: The mean follow-up was 82 months. One patient presented with an isolated distant metastatic relapse, and 27 patients presented with locoregional recurrence, surgically salvaged in 16 cases. Disease-free survival was 71% at 5 years and 68% at 10 years. Multifactorial analysis suggests that clinical stage T1A, well-differentiated tumors, and early and complete response are favorable prognostic factors for disease-free survival. Response to therapy is the most powerful prognostic factor for relapse. Conclusion: This retrospective study confirms the efficacy of endocavitary radiotherapy combined with brachytherapy as a safe conservative treatment in well-selected patients.