Prognostic factors in limited rectal cancer treated with intracavitary irradiation

At the Centre Georges-François Leclerc of Dijon, 91 limited rectal tumors received a complete intracavitary 50 kV contact radiotherapy alone or associated with interstitial brachytherapy according to the guidelines of J. Papillon. Nineteen had a villous adenoma and 72 a well or moderately differentiated rectal adenocarcinoma. The majority of patients had contra-indications for major surgical procedures. The median age was 70 years. Seventy-six percent (69/91) of the rectal tumors remained free from local recurrence. After salvage therapy, the local control was 91% (83/91). Sphincter preservation was obtained in 85% (77/91). "De novo" adenocarcinomas developed on pre-existing benign pathology and villous adenomas were not significantly different with regard to local control (76% resp. 75% versus 59.5%; p = 0.22). According to the Dijon clinical staging system, the local relapse-free survival at 5 years was 97% for CS T1A, 77% for CS T1B, 65% for CS T2A, and 60% for CS T2B. Tumors of the anterior rectal wall had a better local control rate than lateral and posterior primaries (100% versus 63% versus 67%). For the middle rectum, the local relapse-free survival was 94% compared to 54% of the upper and 77% of the lower rectum. Four additional patients had a preoperative intracavitary therapy and salvage surgery for incomplete tumor regression; the complete remission rate is 96% (91/95). Intracavitary radiotherapy alone is an effective treatment for limited rectal cancers. Contact X ray therapy can be used alone in CS T1A whereas a combination of contact X ray therapy and interstitial brachytherapy is often the optimal approach in CS T1B and CS T2A. In CS T2B, our data do not support the use of intracavitary techniques alone. In these cases, the sequence external irradiation followed by an interstitial implant seems of interest and deserves further evaluation with more patients and follow-up.