Preoperative concurrent chemotherapy and radiotherapy in rectal cancer patients

The management of rectal cancer has changed significantly in recent years. The key end-point is no longer survival but rather preservation of sphincter function with improved quality of life. Preoperative radiation can not only render a low-lying rectal tumor amenable to sphincter-preserving surgery but has also been reported to give better local control and lower toxicity than postoperative radiotherapy. From October 1991 through July 1996, 46 patients with local advanced or low-lying rectal cancer were treated with preoperative high-dose radiotherapy and concurrent chemotherapy. All patients underwent pelvic radiotherapy with 5,000 to 5,400 cGy in 25 to 27 fractions. Chemotherapy was given concomitantly and consisted of two courses of 5-fluorouracil (5-FU) at 1,000 mg/m2 for 4 days in week 1 and week 5 plus mitomycin C 10 mg/m2 single bolus on day 1 of week 1. In 30 patients, postoperative adjuvant chemotherapy with 5-FU and levamisole weekly was also given, for a total of 12 months. The most common acute toxicity was grade 1 to 2 diarrhea and tenesmus during radiation or soon afterward. Only five of the 46 patients experienced symptomatic grade 3 acute toxicity. Forty-two patients underwent subsequent surgery 6 to 8 weeks after concurrent chemoradiotherapy. Pathologic examination disclosed complete tumor regression in eight patients and microscopic residual disease in 13 patients after preoperative chemoradiation. Of the 42 patients who completed the intended treatments, only one had local recurrence. The sphincter was preserved in 21 of the 26 patients in whom the tumor was located within 5 cm above the anal verge. Twelve of the 16 evaluable patients had good to excellent sphincter function. The 2-year overall survival rate was 93% and the disease-free survival was 81%. Our findings indicate that preoperative concurrent chemoradiotherapy not only allows low-lying rectal tumors to be resected while preserving sphincter function but also results in good local control and acceptable toxicity.