Preoperative radiation therapy for rectal cancer. personal experience

PURPOSE: Comparison of the effectiveness of preoperative and "sandwich" (preoperative and postoperative) radiation therapy in the treatment of midrectum and lower rectum carcinoma, based on a prospective clinical trial. MATERIAL AND METHOD: Over the period between 1990 and 1997, we treated 115 patients suffering from mid-rectum and lower rectum carcinoma at the Budapest Oncoradiological Centre, using sandwich therapy (22.5 Gy preoperative-27.5 Gy postoperative) in the case of 36 patients and 36 Gy preoperative radiation therapy in the case of 79 patients with external-beam megavoltage therapy with mostly telecobalt radiation and to a smaller number of cases 6 MV energy. The external-beam radiation therapy was nearly always applied with a 4-field box technique, and radical surgery was performed within 10 days following the preoperative radiation treatment. Effectiveness was evaluated in terms of a Log-Rank and Peto-Wilcoxon tests and the Kaplan-Meier survival curve. RESULTS: The effectiveness of the different therapies was compared in terms of the percentage of local failure and the rate of disease-free survival. The results show that when using the "sandwich" radiation therapy local failure is expected to occur in 13.8% of all cases, compared with 17.7%, when only preoperative radiation therapy is used. In terms of five-year disease-free survival, the sandwich therapy seems to be better, but for a higher number of years, namely 7.5, the preoperative radiation therapy yielded better results. CONCLUSION: In terms of local failure, the effectiveness of the preoperative and the "sandwich" radiation therapies for the treatment of mid-rectum and lower rectum carcinoma was nearly identical, while preoperative radiation therapy provided longer disease-free survival. Further trials using multivariation analysis need to be performed to evaluate the two types of radiation treatments, taking into account other parameters, such as grading, age and lymphatic spread.