Aspirin and prostate cancer prevention

Area of Science:

• Oncology
• Epidemiology
• Pharmacology

Background:

• Aspirin is linked to reduced colorectal cancer risk.
• Observational studies suggest aspirin may lower prostate cancer risk.
• Existing data show heterogeneity and lack of dose-response relationships.

Purpose of the Study:

• To evaluate the association between aspirin use and prostate cancer risk.
• To synthesize evidence from observational studies and randomized controlled trials (RCTs).

Main Methods:

• Meta-analysis of 25 observational studies (case-control and cohort).
• Analysis of data from RCTs on vascular events, focusing on prostate cancer outcomes.
• Assessment of risk estimates, confidence intervals, and heterogeneity.

Main Results:

• Observational studies indicate a modest reduced risk of prostate cancer (RR 0.91).
• RCTs show a non-significant reduced risk of prostate cancer death after 5 years (RR 0.52) and a trend after 20 years (RR 0.81).
• Risk estimates are heterogeneous, with no clear dose-response or duration relationship.

Conclusions:

• Evidence from observational studies and RCTs suggests a potential modest benefit of aspirin for prostate cancer.
• Causality and public health implications remain inconclusive due to data heterogeneity and lack of dose-response information.
• Further research is needed, particularly on prostate cancer survival.