Role of external irradiation in high-risk resected colon cancer.
OBJECTIVE
The best therapeutic modality for colon cancer "one of the most common malignancies of human being" is surgical resection of primary tumor. Adjuvant chemotherapy can help surgery to have a higher control and survival rate in high-risk resected patients, but the role of radiation therapy is the place of debate. This study was carried out to evaluate the possible role of adjuvant radiotherapy in such cases.


METHODS
This retrospective trial evaluated 65 eligible patients with surgically resected high-risk colon carcinoma (serosal and/or lymph node involvement), from May 1986 to February 2000. The patients were categorized into two groups. The first group was treated with chemotherapy alone and the other with chemo-radiotherapy. Chemotherapy included 5.FU 500 mg/m2sub/5days for 6-8 courses and radiotherapy consisted 45-55 Gy with 1.5-2 Gy/fraction. Minimum follow-up was 36 months.


RESULTS
Mean event-free survival was 140 and 101 months in chemotherapy and combined-therapy groups, respectively (P = 0.099). Local recurrence rate was detected as 9.7% in the chemotherapy arm and 23.5% in the combined-therapy arm (P > 0.1). Treatment-related morbidity and mortality has been significantly higher in the radiation arm (P < 0.001).


CONCLUSIONS
Postoperative external radiation as adjuvant treatment does not improve local control of the patients with colon carcinoma.
Niloofar
Ahmadloo
A
Department of Radiation Oncology, Nemazee Hospital, Shiraz University of Medical Sciences, Shiraz, Iran.
Mosalaei
Ahmad
A
Shapour
Omidvari
O
Mohammadianpanah
Mohammad
M
D000328:Adult; D000368:Aged; D000964:Antimetabolites, Antineoplastic / Q000008:administration & dosage / Q000627:therapeutic use*; D017024:Chemotherapy, Adjuvant; D015179:Colorectal Neoplasms / Q000188:drug therapy / Q000532:radiotherapy* / Q000601:surgery; D005260:Female; D005472:Fluorouracil / Q000008:administration & dosage / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local; D011182:Postoperative Care; D018714:Radiotherapy, Adjuvant; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D016019:Survival Analysis
D000964:Antimetabolites, Antineoplastic; D005472:Fluorouracil