A new study showed that women who take aspirin for 12 years or more lowered their risk of melanoma skin cancer by thirty percent, according to a study published online in the journal CANCER.

For the study the researchers examined the health records of 60,000 postmenopausal Caucasian women between the ages of 50 and 79. Researchers found women who used aspirin had a 21-percent lower risk of melanoma. Taking the medication for at least 5 years reduced the risk 30 percent. 

"Aspirin works on a slightly different inflammatory pathway than NSAIDs, and some of these pathways may be specific to melanoma," said lead researcher Dr. Jean Tang, PhD, of Stanford University School of Medicine in Palo Alto, CA. "Aspirin could be used as a way to prevent melanoma, however clinical trial testing has to be done first before it can be recommended."

Melanoma is one of three types of skin cancer. Its symptoms can include moles that change color or size, and those that have irregular borders.

The longer women used aspirin, the lower the rate of the potentially fatal skin cancer. Those who had used aspirin for one to four years had an 11 percent reduction in risk, as compared to 30 percent among those taking aspirin for five or more years.

The researchers don't know how aspirin lowers melanoma risk, but they've got some theories.

"Aspirin reduces inflammation," Tang said. "Cancer cells with a lot of inflammation grow more and are more aggressive." Tang added that cancer cells tend to produce in excess the very same substance that aspirin and other NSAIDs knock back. 

The study also looked at other pain medications such as acetaminophen and found those drugs did not lower a woman's risk of melanoma.

However, taking aspirin can cause other health problems, including bleeding. Dermatologist Jashin Wu told CBS more research is needed, and urges patients to stick with proven prevention methods.