In the Women's Health Initiative, researchers observed US women aged 50 to 79 years for an average of 12 years and noted which individuals developed cancer. At the beginning of the study, the women were asked which medications they took, what they ate, and what activities they performed.
When Jean Tang MD, PhD, of Stanford University School of Medicine in Palo Alto, and her colleagues analyzed available data from 59,806 Caucasian women in the study, they found that women who took more aspirin were less likely to develop melanoma skin cancer during the 12 years of follow up. Overall, women who used aspirin had a 21 percent lower risk of melanoma relative to non-users. Each incremental increase in duration of aspirin use (less than one year of use, one to four years of use, and five or more years of use) was associated with an 11 percent lower risk of melanoma. Thus, women who used aspirin for five or more years had a 30 percent lower melanoma risk than women who did not use aspirin. The researchers controlled for differences in pigmentation, tanning practices, sunscreen use, and other factors that may affect skin cancer risk.
"Aspirin works by reducing inflammation and this may be why using aspirin may lower your risk of developing melanoma," said Dr. Tang. Other pain medications, such as acetaminophen, did not lower women's melanoma risk. Dr. Tang noted that the findings support the design of a clinical trial to directly test whether aspirin can be taken to prevent melanoma.