Phase III study of adjuvant chemotherapy and radiation therapy compared with chemotherapy alone in the surgical adjuvant treatment of colon cancer: results of intergroup protocol 0130.
OBJECTIVE
Some patients with colon cancer have a high risk of local recurrence postoperatively. This trial was undertaken to determine whether radiation therapy added to an adjuvant chemotherapy regimen improves outcome in high-risk patients.


METHODS
Patients with resected colon cancer with tumor adherence or invasion of surrounding structures, or with T3N1 or T3N2 tumors of the ascending or descending colon were randomly assigned to receive fluorouracil and levamisole therapy with or without radiation therapy. Patients who received chemotherapy and radiation therapy (chemoRT) received 45 to 50.4 Gy in 25 to 28 fractions beginning 28 days after starting chemotherapy. Patient enrollment was terminated because of slow accrual after 222 patients enrolled (original goal was 700 patients); 187 patients were assessable.


RESULTS
Overall 5-year survival was 62% for chemotherapy patients and 58% for chemoRT patients (P >.50); 5-year disease-free survival was 51% for both groups (P >.50). Toxicity (>/= grade 3) occurred in 42% of chemotherapy patients and 54% of chemoRT patients (P =.04). Leukopenia (>/= grade 3) occurred in 10% of chemotherapy patients and 22% of chemoRT patients (P =.02). No significant difference in nonhematologic toxicity (>/= grade 3) was observed between chemoRT and chemotherapy patients (35% v 44%; P =.26).


CONCLUSIONS
Patients who received chemotherapy or chemoRT had similar overall survival and disease-free survival. Toxicity was higher among chemoRT patients. These results must be interpreted with caution because of the high number of ineligible patients and the limited power of the study to detect potentially meaningful differences.
Martenson
James A
JA
North Central Cancer Treatment Group, Mayo Clinic, 200 First St SW, Rochester, MN 55905, USA. jmartenson@mayo.edu
Willett
Christopher G
CG
Sargent
Daniel J
DJ
Mailliard
James A
JA
Donohue
John H
JH
Gunderson
Leonard L
LL
Thomas
Charles R
CR
Fisher
Barbara
B
Benson
Al Bowen
AB
Myerson
Robert
R
Goldberg
Richard M
RM
D000284:Administration, Oral; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D017024:Chemotherapy, Adjuvant; D003110:Colonic Neoplasms / Q000188:drug therapy* / Q000532:radiotherapy* / Q000601:surgery; D003131:Combined Modality Therapy; D018572:Disease-Free Survival; D005260:Female; D005472:Fluorouracil / Q000008:administration & dosage; D006801:Humans; D007262:Infusions, Intravenous; D007978:Levamisole / Q000008:administration & dosage; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000517:prevention & control*; D018714:Radiotherapy, Adjuvant; D012307:Risk Factors; D016896:Treatment Outcome
D007978:Levamisole; D005472:Fluorouracil