Taking painkillers such as aspirin and ibuprofen may lower the risk of skin cancer, a new study from Denmark suggests.
Researchers found that people who took nonsteroidal anti-inflammatory drugs (NSAIDs) were less likely to have three types of skin cancer, including the deadliest type, malignant melanoma.
The new findings do not mean that people should start taking NSAIDs for the purpose of preventing skin cancer, said study author Sigrún Jóhannesdóttir, an epidemiology researcher at Aarhus University Hospital. The drugs come with their own risks, such as ulcers and bleeding, she noted.
"We want to stress that sun protection remains the most important prevention against skin cancer," Jóhannesdóttir said.
The study showed an association, and not a cause-and-effect link, between the drugs and skin cancer risk.
Still, the researchers found a general lowering of skin cancer risk among people in the study who took NSAIDs for a longer time, and in those who took the drugs more frequently over a given amount of time. And other recent studies have suggested that lowering inflammation may reduce the risk of colorectal cancer. Further studies should further explore this connection, Jóhannesdóttir said.
The study is published today (May 29) in the journal Cancer, and was funded by the Clincial Epidemiological Research Foundation of Denmark.
Skin cancer and inflammation
Skin cancer is the most common type of cancer in the U.S. In 2012, more than 2 million cases of non-melanoma skin cancers will be diagnosed; fewer than 1,000 people will die from their disease, according to estimates from the National Cancer Institute.
Melanoma is a much deadlier cancer — about 76,000 new cases will be diagnosed this year, and 9,000 people will die of the disease.
In the study, the researchers collected the medical records of people in Denmark who were diagnosed with skin cancer between 1991 and 2009. They found nearly 2,000 people with squamous cell carcinoma, about 13,000 people with basal cell carcinoma, and 3,000 people with malignant melanoma. The researchers then searched a medical database and for each person with skin cancer, they identified 10 people without the disease who were the same age and gender, and who lived in the same county.
The researchers compared people's prescriptions for NSAIDs over the study period. In Denmark, the vast majority of people who need the drugs get prescriptions (rather than buying them off the shelf), because the government then covers part of the cost.
People who filled more than two prescriptions for NSAIDs were 15 percent less likely to develop squamous cell carcinoma, and 13 percent less likely to develop malignant melanoma, than people who fewer NSAIDs. For basal cell carcinoma, the effect of NSAIDs applied only to tumors located on areas of the body that typically get less sun, Jóhannesdóttir said.
Additionally, the researchers found that among people who took NSAIDs frequently and over a long time period (for at least 7 years) the cancer risk was reduced by 17 to 46 percent, depending on type and site of skin cancer.
"Inflammation is seen in many disorders," including allergies and autoimmune diseases, Jóhannesdóttir said. "Various drugs inhibit inflammatory processes in the body, but the most commonly used today are NSAIDs."
NSAIDs include ibuprofen and naproxen as well as newer drugs, called Cox-2 inhibitors, such as Celecoxib (sold in the U.S. under the brand name Celebrex) and Meloxicam (Mobic). In Denmark, only aspirin and low-dose ibuprofen are available over the counter, Jóhannesdóttir said.
People at high risk for skin cancer
The new study included people in the general population. Previous studies conducted among people at high risk for skin cancers found a stronger association between NSAIDs and basal cell carcinoma, and COX-2 inhibitors and squamous cell carcinoma, Jóhannesdóttir said.
It could be that people at high risk benefit more from the effects of the drugs, but this would have to be confirmed in further studies, she said.
While the reduced risk of skin cancer has not been proven, it's a potential effect that should be part of the discussion of the harms and benefits of NSAID use, she said.
Pass it on: A review of Danish health records finds a lower risk of skin cancer among patients who take nonsteroidal anti-inflammatory drugs.
Live Science newsletter
Stay up to date on the latest science news by signing up for our Essentials newsletter.