Comparison of Postoperative Adjuvant Radiation therapy alone vs. Chemoradiotherapy in Adenocarcinoma of the Rectum / 대한방사선종양학회지

ABSTRACT

PURPOSE: To investigate the role of adjuvant chemoradiotherapy in adenocarcinoma of the rectum, we retrospectively compared the treatment results between postoperative adjuvant radiotherapy alone and combined chemoradiotherapy. MATERIAL AND METHODS: From October 1989 to May 1994, 141 patients with rectal carcinoma were treated by postoperative adjuvant therapy in Yonsei Cancer Center. Sixty eight patients were treated by radiation therapy alone. Seventy three patients were treated by combined chemoradiotherapy. Radiation therapy was delivered with 10 MV linear accelerator, 180cGy fraction/5 days per week. Total radiation doses were 5400cGy in the postoperative radiotherapy alone group. Three to twelve cycles of Fluorouracil (mean dose 393.9mg/m2) with Leucovorin (20mg/m2) and 5040cGy of radiation were delivered in the combined chemoradiotherapy group. Third and 4th cycle of chemotherapy were administrated during the radiation treatment in the combined group. The median follow up was 38 months with a range of 3 to 81 months. RESULTS: The 5 year overall survival rate of radiation alone group and combined group were 60.1% and 66.3%, respectively. The 5 year disease free survival rate of radiation alone group and combined group were 54.2% and 65.5%, respectively. There was no significant difference of overall survival and disease free survival between RT alone group and combined group (P<0.05). But the 5 year Local failure free survival rate of combined group was significantly better than radiotherapy alone group (65.8% vs. 50.3%, P=0.04). CONCLUSION: There was no significant difference in overall survival, disease free survival, and distant metastasis free survival between postoperative adjuvant radiotheray alone group and combinded chemoradiotherapy group. Only the Local failure free survival rate was superior in the combined treatment group. These results confirm the radiosensitizing effect of the chemotherapeutic agent in the combined chemoradiotherapy treatment.