A pilot study of preoperative continuous infusion 5-fluorouracil, externalmicrowave hyperthermia, and external beam radiotherapy for treatment of locally advanced, unresectable, or recurrent rectal cancer

Purpose: To determine the feasibility of combining external beam radiothera py, continuous infusion 5-fluorouracil (5-FU), and external microwave hyper thermia in patients with locally advanced, unresectable, or recurrent adeno carcinoma of the rectum. Methods and Materials: From 7/95 through 2/99, 15 patients were enrolled in the study. The treatment regimen consisted of continuous infusion 5-FU 250 mg/m(2)/d 7 days/week beginning on day 1, external beam radiotherapy to th e pelvis, 4500 cGy, 180 cGy/d 5 days/week using a 3 or ii-field technique, and external microwave hyperthermia on days 3, 8, 15, 22, and 29, Chemother apy was stopped on the last day of radiotherapy. Surgical resection, if fea sible, was scheduled 3-6 weeks after completing thermochemoradiotherapy. Fo r this regimen to be considered feasible, no more than 2 of the 15 patients should fail to complete therapy due to life-threatening toxicity. Toxicity was scored using National Cancer Institute Criteria. Results: All patients completed the chemoradiotherapy portion of the protoc ol. Eleven of the 15 patients completed all 5 hyperthermia treatments. Of t he 4 patients who did not receive the full course of hyperthermia, only 1 p atient had treatment stopped due to life threatening toxicity. The other 3 patients did not complete hyperthermia due to scheduling errors (n = 2) or patient request (n = 1). Five of 15 patients required a treatment interrupt ion due to toxicity greater than or equal to Grade 3. Seven patients experi enced lesser degrees of toxicity which did not require treatment interrupti on. Three patients experienced no side effects. The most common toxicities were dermatitis and diarrhea. Of the 14 patients in whom surgery was planne d, 11 (79%) were resectable. There was one pathologic complete response. Conclusions: It is feasible to deliver thermochemoradiotherapy, as prescrib ed in this study, to patients with locally advanced, unresectable, or recur rent rectal cancer. The therapy is moderately toxic, with one-third of pati ents requiring temporary treatment interruptions. The regimen appears activ e against rectal cancer, and appears to warrant further consideration as a treatment option for this patient population. (C) 2000 Elsevier Science Inc .