ORLANDO — Intriguing data from a prospective colon cancer trial suggest that aspirin and exercise might help protect survivors from recurrence of the disease.
Only 75 patients (8.9%) in the 846-patient trial reported regular aspirin use; the dosages ranged from 81 mg to 325 mg per day. At an average follow-up of 2.7 years after completion of treatment, their risk of recurrence and death was reduced by more than 50%, compared with patients who were occasional users.
A second analysis from the same trial found that the equivalent of walking an hour a day, 6 days a week, was associated with a 40%–50% reduction in risk over the same time period. “The [disease-free survival] hazard ratio of 0.55 is as strong an effect as seen for adjuvant chemotherapy as compared to observation,” the investigators noted.
Based on these findings, Jeffrey A. Meyerhardt, M.D., Ph.D., and his coinvestigators are urging further study of the potential of lifestyle changes to improve outcomes in colorectal cancer.
“Primary care doctors are going to see increasing numbers of cancer survivors, and we need to understand, we all need to understand, other things people can do once they are through with their treatment,” Dr. Meyerhardt said in an interview at the annual meeting of the American Society of Clinical Oncology.
Dr. Meyerhardt, an oncologist at the Dana-Farber Cancer Institute in Boston, presented two posters reporting the data on behalf of investigators from the multicenter Cancer and Leukemia Group B (CALGB) trial.
The prospective study assessed postoperative adjuvant chemotherapy regimens in stage 3 colon cancer patients.
Charles Fuchs, M.D., a professor of medicine at Dana-Farber, led the aspirin analysis, which was based on surveys conducted midway through and 6 months after adjuvant chemotherapy. About 830 patients completed both surveys.
The investigators also found a trend toward lower risk of recurrence in patients who reported using cyclooxygenase-2 inhibitors. Just 41 patients (4.7%) used rofecoxib or celecoxib. No benefit was documented for patients taking acetaminophen.
The physical activity data came from the survey conducted 6 months after completion of adjuvant chemotherapy. It excluded patients who had a recurrence or died within 3 months of the physical activity measurement.
The 832-patient physical activity study involved collection of information on a range of activities, which were assigned metabolic equivalent (MET) conversion scores for every hour reported. For example, walking at a normal pace for an hour was scored at 3. Bicycling for the same time period received 7 points.
The investigators concluded that the “protective effect was most apparent in patients engaging in at least 18 total MET-hours per week,” which they interpreted as the equivalent of walking 1 hour per day, 6 days a week.
Stratification by age, gender, baseline performance status, body mass index, and number of positive nodes did not alter the consistency of the results.