Radiation Therapy, Surgery, and Chemotherapy in Treating Patients With Rectal Cancer That Can Be Surgically Removed

OBJECTIVES:

• Compare the disease-free and overall survival in patients with resectable adenocarcinoma of the rectum treated with preoperative radiotherapy with or without preoperative fluorouracil (5-FU) combined with leucovorin calcium (CF) and/or postoperative 5-FU/CF.

OUTLINE: This is a randomized, multicenter study. Patients are stratified according to center, sex, tumor location (0-5 vs 6-10 vs 11-15 cm from anal margin), and stage (T3 vs T4). Patients are randomized to 1 of 4 treatment arms.

• Arm I: Patients undergo involved-field radiotherapy 5 days a week for 5 weeks followed 3-10 weeks later by abdominoperineal resection or anal-sparing resection according to local practice in the absence of disease progression or unacceptable toxicity.
• Arm II: Patients undergo radiotherapy as in arm I beginning on day 1 and leucovorin calcium (CF) IV followed by fluorouracil (5-FU) IV (1 hour before radiotherapy) on days 1-5 and 29-33, followed 3-10 weeks later by resection as in arm I in the absence of disease progression or unacceptable toxicity.
• Arm III: Patients undergo radiotherapy followed 3-10 weeks later by resection as in arm I. Within 3-10 weeks after resection, patients receive CF followed by 5-FU on days 1-5. Chemotherapy continues every 4 weeks for 4 courses in the absence of disease progression or unacceptable toxicity.
• Arm IV: Patients undergo preoperative radiotherapy with concurrent chemotherapy followed by resection as in arm II and postoperative chemotherapy as in arm III.

Patients are followed every 6 months.

PROJECTED ACCRUAL: A total of 992 patients will be accrued for this study within 4 years.

DISEASE CHARACTERISTICS:

• Histologically confirmed resectable adenocarcinoma of the rectum

• Any grade
• Tumor macroscopically within 15 cm of anal margin on rigid rectoscopy
• Tumor tethered or partially fixed on digital rectal exam and/or T3-4 on rectal ultrasound
• No acute or subacute bowel obstruction without colostomy diversion
• No chronic inflammatory disease of the ileum and/or colon
• No primary adenocarcinoma of the anal canal
• No distant metastasis

PATIENT CHARACTERISTICS:

Age:

• 80 and under

Performance status:

• WHO 0-1

Life expectancy:

• Not specified

Hematopoietic:

• Granulocyte count greater than 2,000/mm^3
• Platelet count greater than 130,000/mm^3

Hepatic:

• Not specified

Renal:

• Creatinine less than 1.36 mg/dL

Cardiovascular:

• No angina pectoris

Other:

• No other prior malignancy except basal cell skin cancer or carcinoma in situ of the uterine cervix

PRIOR CONCURRENT THERAPY:

Biologic therapy

• No prior biologic therapy for adenocarcinoma of the rectum

Chemotherapy

• No prior chemotherapy for adenocarcinoma of the rectum

Endocrine therapy

• No prior endocrine therapy for adenocarcinoma of the rectum

Radiotherapy

• No prior radiotherapy for adenocarcinoma of the rectum

Surgery

• No prior surgery for adenocarcinoma of the rectum