Rectal Cancer Treatment (PDQ®): Treatment - Health Professional Information [NCI] - Stage III Rectal Cancer
Median follow-up was 5.7 years. Lethal toxicity was less than 1%, with grade 3 to 4 hematologic toxicity in 55% and 49% of patients in the two bolus arms, respectively (i.e., arms 1 and 3) versus 4% of patients in the continuous-infusion arm. No disease-free survival (DFS), OS, or locoregional failure (LRF) difference was detected (across all arms: 3-year DFS, 67% to 69%; 3-year OS, 81% to 83%; 3-year LRF, 4.6% to 8%).[Level of evidence: 1iiA]
The German Rectal Cancer Study Group (CAO/ARO/AIO-94 [Working Group of Surgical Oncology/Working Group of Radiation Oncology/Working Group of Medical Oncology of the Germany Cancer Society]) randomly assigned 823 patients with ultrasound-staged T3 or T4 or node-positive rectal cancer to either preoperative chemoradiation or postoperative chemoradiation (50.4 Gy in 28 daily fractions to the tumor and pelvic lymph nodes concurrent with infusional 5-FU 1,000 mg/m2 daily for 5 days during the first and fifth weeks of radiation therapy). All patients received a TME and an additional four cycles of 5-FU-based chemotherapy. The 5-year OS rates were 76% and 74% for preoperative and postoperative chemoradiation, respectively (P = .80). The 5-year cumulative incidence of local relapse was 6% for patients assigned to preoperative chemoradiation therapy and 13% in the postoperative-treatment group (P = .006). Grade 3 or 4 acute toxicity occurred in 27% of the patients in the preoperative-treatment group as compared with 40% of the patients in the postoperative-treatment group (P = .001); the corresponding rates of long-term toxicity were 14% and 24%, respectively (P = .01).[Level of evidence: 1iA] There was no difference in the number of patients receiving an APR in each arm. However, among the 194 patients with tumors that were determined by the surgeon before randomization to require an abdominoperineal excision, a statistically significant increase in sphincter preservation was achieved among patients who received preoperative chemoradiation therapy (P = .004).
These results have now been updated with a median follow-up of 11 years. The 10-year OS is equivalent in both arms (10-year OS, 59.6% vs. 59.9%, P = .85). However, a local control benefit persists among patients treated with preoperative chemoradiation compared with postoperative chemoradiation (10-year cumulative of local relapse, respectively; 7.1% vs. 10.1%, P = .048). There were no significant differences detected for 10-year cumulative incidence of distant metastases or DFS. Among the patients assigned to the postoperative chemoradiation treatment arm, 18% actually had pathologically determined stage I disease and were overestimated by endorectal ultrasound to have T3 or T4 or N1 disease. A similar number of patients were possibly overtreated in the preoperative treatment group.