Aspirin use and endometrial cancer risk and survival

The role of acetylsalicylic acid (aspirin) as a chemo-preventive and adjuvant therapeutic agent for cancers is generating attention. Mounting evidence indicates that aspirin reduces the incidence and mortality of certain obesity-related cancers, particularly colorectal cancer. In endometrial cancer, previous studies examining the effect of aspirin remain inconsistent as to the reduction in the risk of endometrial cancer. While some evidence indicates protective effects in obese women, other studies have showed a potential deleterious effect of these medications on endometrial cancer outcomes. However, exposure measurement across studies has been inconsistent in recording dose, duration, and frequency of use; thus making comparisons difficult. In this article, we review the evidence for the association between endometrial cancer and obesity, the pharmacological differences between regular- and low-dose aspirin, as well as the potential anti-tumor mechanism of aspirin, supporting a possible therapeutic effect on endometrial cancer. A proposed mechanism behind decreased cancer mortality in endometrial cancer may be a result of inhibition of metastasis via platelet inactivation and possible prostaglandin E₂ suppression by aspirin. Additionally, aspirin use in particular may have a secondary benefit for obesity-related comorbidities including cardiovascular disease in women with endometrial cancer. Although aspirin-related bleeding needs to be considered as a possible adverse effect, the benefits of aspirin therapy may exceed the potential risk in women with endometrial cancer. The current evidence reviewed herein has resulted in conflicting findings regarding the potential effect on endometrial cancer outcomes, thus indicating that future studies in this area are needed to resolve the effects of aspirin on endometrial cancer survival, particularly to identify specific populations that might benefit from aspirin use.