PATIENT CHARACTERISTICS: Age: 18 and over Performance status: Karnofsky 60-100% OR ECOG 0-2 Life expectancy: Not specified Hematopoietic: WBC at least 3000/mm3 Platelet count at least 100,000/mm3 Hepatic: Bilirubin less than 2.0 mg/dL Renal: Creatinine no greater than 1.5 mg/dL Cardiovascular: No congestive heart failure No New York Heart Association class III and IV heart disease Other: Not pregnant No concurrent medical problems that would increase the side effects or morbidity of chemoradiation No concurrent medical condition that would make patient ineligible to receive external beam radiation such as: Crohn's disease Inflammatory bowel disease No active infection requiring systemic antibiotics