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

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.