Evidence of Recurrence-Free, Disease-Free, and Overall Survival Benefit of Aspirin and COX-2 Inhibitors in Stage III Colon Cancer
In a study reported in the Journal of the National Cancer Institute, Ng et al found consistent trends suggesting benefit of aspirin use and COX-2 inhibitor use on recurrence-free, disease-free, and overall survival in patients with stage III colon cancer.
Study Details
This prospective observational study involved 799 patients in the Cancer and Leukemia Group B (CALGB) 89803 trial evaluating the addition of irinotecan to adjuvant fluorouracil/leucovorin; the trial showed no difference in outcomes between the study groups. A self-administered questionnaire assessing diet, lifestyle, and medication use was conducted midway through chemotherapy and 6 months after chemotherapy.
In the current analysis, consistent aspirin use was defined as any aspirin use reported at both time points, and COX-2 inhibitor use was defined as any use reported at the second time point. Overall, 9.4% of patients were aspirin users and 7.0% were COX-2 inhibitor users. Aspirin users were older and more likely to be male, and COX-2 inhibitor users were less likely to have a family history of cancer, had higher body mass index, and reported more acetaminophen use.
Aspirin Use
On multivariate analysis, hazard ratios (HRs) for consistent aspirin use vs nonconsistent use were 0.51 (95% confidence interval [CI] = 0.28–0.95) for recurrence-free survival, 0.68 (95% CI = 0.42–1.11) for disease-free survival, and 0.63 (95% CI = 0.35–1.12) for overall survival. In analysis censored at 5 years to minimize effects of noncancer deaths, hazard ratios were 0.61 (95% CI = 0.36–1.04) for disease-free survival and 0.48 (95% CI = 0.23–0.99) for overall survival.
COX-2 Inhibitor Use
Hazard ratios for COX-2 inhibitor users vs nonusers were 0.53 (95% CI = 0.27–1.04) for recurrence-free survival, 0.60 (95% CI = 0.33–1.08) for disease-free survival, and 0.50 (95% CI = 0.23–1.07) for overall survival. In analysis censored at 5 years, hazard ratios were 0.47 (95% CI = 0.24–0.91) for disease-free survival and 0.26 (95% CI = 0.08–0.81) for overall survival.
The investigators concluded: “[T]his observational study of stage III colon cancer patients found statistically significant associations between aspirin and COX-2 inhibitor use and reduced cancer recurrence and mortality. Results from the ongoing CALGB 80702 and ASCOLT trials are eagerly awaited. Further exploration of predictive biomarkers of aspirin and COX-2 inhibitor activity is warranted.”
Kimmie Ng, MD, MPH, of Dana-Farber Cancer Institute, is the corresponding author for the Journal of the National Cancer Institute article.
The study was supported by the National Cancer Institute, Conquer Cancer Foundation of the American Society of Clinical Oncology, Damon Runyan Cancer Research Foundation, and the Pharmacia and Upjohn Company, now Pfizer Oncology.
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.
