A phase II study of neoadjuvant chemoradiotherapy with oxaliplatin and capecitabine for rectal cancer

Abstract

Purpose: This study evaluated the efficacy and safety of neoadjuvant chemoradiotherapy with the XELOX regimen in rectal cancer patients.

Patients and methods: Twenty-five patients with histopathologically confirmed and locally advanced rectal cancer (T3/T4 or N+) were enrolled in the study. Radiotherapy of 5000 cGy was delivered in 25 fractions of 200 cGy five times per week for a total of 5 weeks. During the first, second, fourth and fifth weeks of radiotherapy, the patients also received the following chemotherapy: 50 mg/m2 oxaliplatin on day one and 850 mg/m2 capecitabine bid for 5 days. Surgery was scheduled 5-6 weeks after the completion of the preoperative chemoradiotherapy. Four weeks after the surgery, four more cycles of chemotherapy were administered every 3 weeks. The postoperative chemotherapy consisted of 130 mg/m2 oxaliplatin on day 1 and 1000 mg/m2 capecitabine bid from day 1 to day 14. The end points were the downstage rate, R0 resection rate, and sphincter preservation rate.

Results: Twenty-five patients received the neoadjuvant chemoradiotherapy. The overall regression rate was 85%, with a Grade 3/4 regression rate of 30% and a pathological complete response rate of 12%. Among the 17 patients with lower rectal cancer, thirteen (76%) were originally indicated for abdominal-perineal resection (APR). However, after the neoadjuvant chemoradiotherapy, the anus could be preserved in nine patients (53%). The most frequent toxicities of the chemoradiotherapy were diarrhea (64%) and hematological toxicity (60%), followed by nausea and vomiting (48%), urinary tract irritation (28%), and anal pain (24%). Grade 3 or 4 adverse events were relatively infrequent and presented as diarrhea (12%), myelosuppression (8%), and elevated transaminase (4%). Six cases also experienced long-term anal exudates after surgery.

Conclusions: Neoadjuvant chemoradiotherapy using the XELOX regimen in rectal cancer patients obviously reduced the TNM staging and improved the pathological complete response rate. The therapy was well-tolerated and had mild adverse events and no serious perioperational complications.