Spotlight on aspirin and GI cancers
Aspirin use did not increase survival from colorectal cancer, but it was associated with lower risk of pancreatic cancer in patients with type 2 diabetes, recent studies showed.
Two recent studies analyzed the effects of aspirin on GI cancers.
The first, published by The Lancet Gastroenterology & Hepatology on Jan. 14, was a trial including 1,587 patients in the Middle East and Asia who had colon or rectal cancer and had undergone resection and standard adjuvant therapy. They were randomized to aspirin, 200 mg daily, or placebo for three years and followed for five years. Among the 1,550 patients included in the modified intention-to-treat analysis, five-year disease-free survival was 77.0% among those who were assigned to aspirin versus 74.8% with placebo (hazard ratio, 0.91 [95% CI 0.73 to 1.13]; P=0.38). Any-grade adverse events were reported in 49% and 51%, respectively. The authors concluded that in patients with colorectal cancer, aspirin was well tolerated but did not significantly improve disease-free survival. An accompanying editorial noted several reasons that the trial might not have found a significant effect, including sample size; timing, duration, and dose of aspirin; and exclusion of patients with cardiovascular disease.
The other study, published by Gut on Jan. 2, was a retrospective analysis of newly diagnosed type 2 diabetes patients in Hong Kong in 2001 to 2015. Patients with pancreatic cancer diagnosed within one year of diabetes diagnosis were excluded. Among the 343,966 patients, 1,224 (0.36%) developed pancreatic cancer over a median follow-up of 10.5 years. In the overall patient population, 14.9% died during follow-up, 0.2% of pancreatic cancer. Aspirin use was associated with lower pancreatic cancer risk in both time-dependent (adjusted hazard ratio [aHR], 0.58; 95% CI, 0.49 to 0.69) and propensity-score matched (aHR, 0.61; 95% CI, 0.48 to 0.77) analyses. Aspirin was also associated with lower risk for death from pancreatic cancer (aHR, 0.43; 95% CI, 0.34 to 0.53) and all causes (aHR, 0.78; 95% CI, 0.76 to 0.80). The study authors concluded that aspirin may be an effective preventive strategy to reduce pancreatic cancer risk in patients with type 2 diabetes and called for additional research to validate their findings.