Aspirin Use May Improve Survival in Breast, Bladder Cancers

Older patients with breast cancer or bladder cancer may increase their survival by taking aspirin, according to a study.

Data were collected from the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial. The study included participants who were aged 65 years or older at baseline or who turned 65 during follow-up. The main outcome was incidence of and survival from bladder, breast, esophageal, gastric, pancreatic, and uterine cancers.

Final analysis consisted of 139,896 participants. The mean age at baseline was 66.4 years (standard deviation, 2.4 years), and 71,884 participants were female (51.4%). Over the course of the study, 32,580 incident cancers were reported: 1,751 (5.4%) bladder, 4,552 (14%) breast, 332 (1%) esophageal, 397 (1.2%) gastric, 878 (2.7%) pancreatic, and 716 (2.2%) uterine.

Aspirin use was not found to increase the risk of incident cancer for any of the cancer types. However, aspirin use at least three times a week increased survival in patients with bladder (hazard ratio [HR], 0.67; 95% confidence interval [CI], 0.51-0.88) and breast (HR, 0.75; 95% CI, 0.59-0.96) cancers, as did any aspirin use (bladder cancer: HR, 0.75; 95% CI, 0.58-0.98; and breast cancer: HR, 0.79; 95% CI, 0.63-0.99).

Survival was not increased by aspirin use in the other cancers investigated in the study, which was published in JAMA Network Open.

“Several hypotheses regarding aspirin’s mechanism of action and its impact on bladder and breast cancer survival have been developed. Compared with normal epithelial cells, RNA and protein expression of cyclooxygenase-2 (COX-2) and urinary prostaglandin E2 is increased in urothelial carcinoma, suggesting upregulation of the COX-2 pathway during cancer progression,” the researchers elaborated. “Similarly, elevated expression of COX-2 in breast cancer has been shown to be a predictor of disease outcome (eg, progression, decreased survival). This may be partly due to the mechanistic interplay between angiogenesis, cell proliferation, apoptosis, and inflammatory processes.”

The study authors noted that while their findings suggest a protective benefit of aspirin, it is important to also remember potential harms associated with regular aspirin use.