Can Aspirin and Cancer Prevention be Ageless Companions?

According to the World Health Organization (WHO), the rate of cancer has been increasing worldwide due to the increase in population and average life expectancy.This has prompted health organizations to search for effective and inexpensive strategies to prevent cancer.Over the past two decades epidemiological studies suggested that non-steroidal anti-inflammatory drugs (NSAIDs) may provide some promise for the prevention of several cancers.Accumulating evidence supports an effect of aspirin in reducing overall cancer incidence and mortality in the general population.Aspirin is considered a cheap, widely accessible and easily administered drug.It is widely used as a preventive measure against vascular occlusive diseases, yet with no sufficient evidence to support its use [1].The anti-cancer effects of aspirin were first identified in animal models four decades ago.Although, there is a growing body of evidence to indicate that aspirin causes a reduction in the incidence of cancer and its associated mortality, a clear role of the drug has not yet been established in human [2].The results from observational studies remain controversial as NSAIDs are the most frequently used over-the-counter medicines.Another confounding factor was the lack of data on total number of agents.In the case of aspirin use, there is inconsistency in its dose, duration and frequency.Inference from most studies favors that high dose and long-term use of aspirin may reduce the risk of common cancers like colorectal cancer, gastric cancer, breast cancer, lung cancer and prostate cancer [3].Evidence is most compelling for the potential benefit in the primary prevention.However, it is still unclear whether aspirin can reduce the recurrence of cancers (i.e.secondary prevention).Current evidence highlights a gap in medical research and emphasizes the need to carry out intervention studies using specific aspirin doses in order to validate the data, as currently, there are no direct comparisons between doses.The design of these studies remains an ethical challenge, as the randomization of aging participants to the non-aspirin arm may increase their risk for vascular events [4].Moreover, whether long-term use of aspirin in higher doses will be associated with worse risk-benefit profile given the potential bleeding adverse effects, is unknown.