Long-term results from a randomized phase II trial of neoadjuvant combined-modality therapy for locally advanced rectal cancer.

Background: This study evaluated the effectiveness and safety of preoperative chemoradiotherapy with capecitabine in patients with locally advanced resectable rectal cancer. This report summarizes the results of the phase II study together with long-term (5-year) follow-up.

Methods: Between June 2004 and January 2005, 57 patients with operable, clinical stage II-III adenocarcinoma of the rectum entered the study. Radiation dose was 45 Gy delivered as 25 fractions of 1.8 Gy. Concurrent chemotherapy with oral capecitabine 825 mg/m² twice daily was administered during radiotherapy and at weekends. Surgery was scheduled 6 weeks after the completion of the chemoradiotherapy. Patients received four cycles of postoperative chemotherapy comprising either capecitabine 1250 mg/m² bid days 1-14 every 3 weeks or bolus i.v. 5-fluorouracil 425 mg/m²/day and leucovorin 20 mg/m²/day days 1-5 every 4 weeks (choice was at the oncologist's discretion). Study endpoints included complete pathological remission, proportion of R0 resections and sphincter-sparing procedures, toxicity, survival parameters and long-term (5-year) rectal and urogenital morbidity assessment.

Results: One patient died after receiving 27 Gy because of a pulmonary embolism. Fifty-six patients completed radiochemotherapy and had surgery. Median follow-up time was 62 months. No patients were lost to follow-up. R0 resection was achieved in 55 patients. A complete pathological response was observed in 5 patients (9.1%); T-, N- and overall downstaging rates were 40%, 52.9% and 49.1%, respectively. The 5-year overall survival rate, recurrence-free survival, and local control was 61.4% (95% CI: 48.9-73.9%), 52.4% (95% CI: 39.3-65.5%), and 87.4% (95% CI: 75.0-99.8%), respectively. In 5 patients local relapse has occurred; dissemination was observed in 19 patients and secondary malignancies have occurred in 2 patients. The most frequent side-effect of the preoperative combined therapy was dermatitis (grade 3 in 19 patients). The proportion of patients with severe late (SOMA grade 3 and 4) rectal, bladder and sexual toxicity was 40%, 19.2% and 51.7%, respectively.

Conclusions: This study confirms data from other non-randomised studies that capecitabine-based preoperative chemoradiation is a feasible treatment option for locally advanced rectal cancer, with positive 5-year overall survival, recurrence-free survival, and local control rates.