Rationale for a phase I/II radiation dose-escalation study with concurrent amifostine (ethyol) and infusional 5-FU chemotherapy for preoperative treatment of unresectable or locally recurrent rectal carcinoma

Rectal adenocarcinoma almost invariably requires extirpative surgery to be cured. Although radiation therapy and concurrent chemotherapy often will elicit dramatic responses, the treatment morbidity limits the tolerable dose of radiation to about 45 to 50 Gy. Strategies to reduce procto/enteritis may permit higher doses of radiation to be delivered. This report reviews a recently activated radiation dose-escalation study that combines the radioprotector amifostine (Ethyol, WR-2721) with 3-dimensionally planned radiation therapy and concurrent infusional 5-fluorouracil chemotherapy.