Other Gastrointestinal/Endocrine Cancers

An observational study demonstrated significantly improved survival among aspirin users with esophageal, hepatobiliary, and CRC (HR, 0.52; 95% CI, 0.44-0.63).8

Another observational study from the same database demonstrated significantly improved OS among aspirin users with esophageal cancer (adjusted RR, 0.42; 95% CI, 0.30-0.57; P < .001).9

A meta-analysis of observational studies found that post-diagnosis aspirin use was significantly associated with improved OS with rectal cancer (HR, 0.90; 95% CI, 0.50-0.85).7

A case-control study of 761 patients with pancreatic cancer and 794 controls found that ever-regular aspirin use decreased the risk of pancreatic cancer (odds ratio [OR], 0.54; 95% CI, 0.40-0.73; P = 10-4.2) by about 8% for each cumulative year of use (OR, 0.92; 95% CI, 0.87-0.97; P = .0034).10

Breast Cancer

An observational study of 15,140 patients with newly diagnosed breast cancer found no association between post-diagnosis use and disease-specific mortality, even with increasing duration of use.11

A meta-analysis of 13 prospective cohort studies that included 857,831 patients did not find a significant reduction in risk of breast cancer with aspirin use (RR, 0.94; 95% CI, 0.87-1.01; P = .051).12

Another meta-analysis of 8 cohort studies and 2 nested case-control studies that included 26,931 subjects with post-diagnosis aspirin use and 673,453 with pre-diagnosis use demonstrated that post-diagnosis use decreased breast cancer–specific mortality (RR, 0.73; 95% CI, 0.54-0.98; P = .04), but not all-cause mortality.13