my personal edition > colorectal cancer > news


  E-Mail this DGDispatch to a colleague

DGDispatch

Aspirin May Prevent Colon Cancer Recurrence: Presented at ASCO

By Charlene Laino

ORLANDO, FL -- May 20, 2005 -- Regular aspirin use after a diagnosis of stage III colon cancer is associated with a significant improvement in both recurrence-free and disease-free survival rates, researchers report.

Also, consistent use of cyclooxygenase-2 (COX-2) inhibitors is associated with a nonsignificant trend toward improved outcome, according to the study, presented here on May 16^th at the American Society of Clinical Oncology Annual Meeting (ASCO).

While regular use of aspirin has already been shown to lower the risk of ever developing colon cancer, the current study is the largest to demonstrate that it benefits people who already have the disease, too, said coinvestigator Jeffrey A. Meyerhardt, MD, MPH, associate physician, Dana-Farber Cancer Institute in Boston, Massachusetts.
.
The study included 846 patients with stage III colon cancer enrolled in a randomized trial of postoperative adjuvant chemotherapy. Midway through adjuvant therapy and again 6 months after it was completed, participants filled out detailed medication and lifestyle questionnaires that asked how many times a week, on average, they took aspirin and COX-2 inhibitors.

Seventy-five patients (8.9%) said they took aspirin on a regular basis, most frequently a 325-mg tablet every day or every other day; 4.5% reported using either celecoxib or rofecoxib.

After adjusting for age, gender, baseline performance status, N stage, T stage, bowel obstruction and perforation, level of differentiation, treatment arm, and body mass index, regular aspirin users had better scores on almost every measure at 50 months follow-up compared with the 771 subjects who did not use aspirin, Dr. Meyerhardt reported.

Recurrence-free survival was 55% higher in aspirin users than nonusers (95% CI, 0.21-0.96), disease-free survival was 54% higher (95% CI 0.23-0.95), and overall survival was 51% higher (95% CI 0.19-1.30). "Overall survival will probably reach significance with time," he said.

Also, 54% of the patients on the COX-2 inhibitors were still alive and cancer-free at the end of the follow-up, but because the numbers were too small, the findings did not reach significance. "There clearly could be benefit," Dr. Meyerhardt said, noting that further studies are planned.

Rofecoxib (Vioxx) was voluntarily withdrawn from the market last fall after a study of colorectal polyp prevention showed a higher risk of cardiovascular events. Celecoxib (Celebrex) is still on the market.

There aspirin cohort was too small to determine the role that dose plays in survival, but Dr. Meyerhardt said he recommends the equivalent of 325 mg a day to his patients based on this study and other evidence showing that this dose reduces the risk of colorectal neoplasia.

Stephen Shibata, MD, associate professor, department of medical oncology, City of Hope Comprehensive Cancer Center, Duarte, California, said that he would share the "interesting" findings with his patients, but cautioned that even aspirin carries a risk of adverse effects, chiefly bleeding.


[Presentation title: Influence of Regular Aspirin Use on Survival for Patients With Stage III Colon Cancer: Findings From Intergroup Trial CALGB 89803. Abstract 3530]

E-Mail this DGDispatch to a colleague

To print, use this version