Aspirin Lowers Melanoma Risk In Post-Menopausal Women
March 12, 2013

Aspirin Lowers Melanoma Risk In Post-Menopausal Women

Lawrence LeBlond for - Your Universe Online

A 2010 study led by Oxford University found that taking low-dose aspirin every day could help reduce the risk of cancer by up to 20 percent. That good news has now been upgraded for women, after a Stanford University study has recently found that aspirin may also guard against melanoma, the deadliest form of skin cancer.

In a study of nearly 60,000 post-menopausal women, researchers found that those who used aspirin on a regular basis were less likely to be diagnosed with melanoma, and longer use of the popular pain killer translated into even more protection, with those on the pill for more than five years seeing the biggest benefit.

The results of the study, published in the American Cancer Society´s (ACS) journal Cancer, were gleaned from the Women´s Health Initiative (WHI), which observed US women from ages 50 to 79 for an average of 12 years. At the beginning of the study, women were asked which medications they took, what they ate, and what activities they carried out, including the amount of time spent tanning in the sun and the use of sunscreen.

When Stanford University School of Medicine´s Jean Tang, MD, PhD, and her colleagues analyzed the results of the 12-year study, they discovered that women who took aspirin were less likely to develop melanoma: 21 percent less likely for regular use up to a year; 11 percent less likely for regular use one to four years; 30 percent less likely for regular use five years or longer.

While significant, the study does not conclude that aspirin causes the drop in cancer risk for everyone — it only shows that twice-weekly use of the drug was linked to a decreased risk among Caucasian women in their 50s, 60s and 70s. Also, since the data comes from a study that relied on self-reported use of aspirin, and did not control for some factors, such as family history and hair color, more research would likely be needed to confirm the findings.

As for hair color, it has been shown that natural redheads, those who are most often fair-skinned, have a significantly higher risk of developing skin cancer of all types.

Still, the “findings suggest that aspirin may have a chemopreventive effect against the development of melanoma," wrote Tang and her colleagues, acknowledging that “further clinical investigation is warranted."

More than 61,000 skin cancer diagnoses were made in the US in 2009, according to the US Centers for Disease Control and Prevention (CDC). Deaths from melanoma alone cost $3.5 billion in lost productivity every year. Despite increased awareness of the dangers of prolonged sun exposure, diagnoses have climbed 2 percent per year from 2000 to 2009, the latest year for which the CDC had data.

Despite limitations in the study, the findings are exciting for the prevention of cancer, especially since aspirin is widely available and inexpensive. However, Tang and her colleagues say in order to confirm their results, clinical studies should be set up in which some patients are given aspirin on a regular basis, and some are not. Any benefits would need to be weighed against the risks of taking aspirin, which include stomach bleeding and clotting disorders.

In all, eight separate studies have been conducted that “have looked at melanoma, and about half of them find slightly lower risk and half find no connection at all. You look at the totality of the evidence, and right now it´s rather mixed,” Eric Jacobs, an epidemiologist with the ACS told NPR.

Until data on aspirin´s effects on skin cancer can be confirmed, Jacobs and other experts in cancer science recommend avoidance of tanning beds, and prolonged sun exposure. If you must be in the sun, a sunscreen with SPF above 15 should be used for greater protection. Otherwise, covering up with clothing or finding shade is best when outdoors to lower the chances of developing skin cancer.

"This is one of many studies looking at the relationship between aspirin use and melanoma," said ABC News' chief health and medical editor Dr. Richard Besser. "Some have found an association between taking aspirin and having a lower risk of melanoma and some have not."

Acetylsalicylic acid, the main ingredient that gives aspirin its potency, has been used for millennia. The first uses of the ancient painkiller date back to about 400 BC, when people used willow tree bark (which contains a form of the acid) to treat pain and inflammation. The drug also interferes with blood-clotting thromboxanes, which is why many people take a low-dose daily supplement to reduce the risk of heart attack and stroke.

Tang´s study adds to the growing evidence that aspirin may help prevent cancers. The drug has been linked to reductions in the risk of colon, liver, breast, ovarian and skin cancer. Another recent study, published in May 2012, found that men and women who use NSAIDs such as aspirin were 15 percent less likely to develop the non-melanoma skin cancer squamous cell carcinoma, and 13 percent less likely to develop malignant melanoma.

"[The WHI] study builds on our knowledge of these medications being protective for the skin as well," said Dr. Josh Zeichner, assistant professor of dermatology at Mount Sinai Medical Center in New York City, who explained that aspirin's anti-inflammatory effects might be responsible for the drop in cancer risk. "We just don't yet know enough to make definite conclusions."

The Women´s Health Initiative study was funded in part by the National Heart, Lung and Blood Institute (NHLBI) and the National Institutes of Health (NIH).