Skin cancer is the most common cancer diagnosed in Canada as well as worldwide. (Mark Baker/Reuters)

People who took painkillers like Aspirin and ibuprofen long-term seem to have a lower risk for some forms of skin cancer, Danish researchers have found.

Nonsteroidal anti-inflammatory drugs, or NSAIDs, such as Aspirin, ibuprofen and naproxen, were associated with a lower risk of developing some types of cancer in previous studies.

For a study published in Tuesday's issue of the journal Cancer, researchers from Aarhus University Hospital in Denmark analyzed the medical and prescription records of people in northern Denmark from 1991 through 2009.

During that time, about 18,000 of the 200,000 participants had been diagnosed with of one of three types of skin cancer.

Those who filled at least two prescriptions for NSAIDs had a 15 per cent lower risk for developing squamous cell carcinoma and a 13 per cent lower risk of the rarer but more dangerous malignant melanoma, Sigrún Alba Jóhannesdóttir and her co-authors reported.

Skin cancer prevention strategy

In the study, researchers compared the painkiller records of patients diagnosed with cancer to cancer-free patients of the same age and gender.

"We hope that the potential cancer-protective effect of NSAIDs will inspire more research on skin cancer prevention," Jóhannesdóttir told reporters.

"Also, this potential cancer-protective effect should be taken into account when discussing benefits and harms of NSAID use."

Many of the prescriptions were for heart conditions or arthritis.

The higher the dose of NSAIDs and the longer someone was taking the medication, the greater the protection measured.

"Given the high skin cancer incidence and the widespread and frequent use of NSAIDs, a preventive effect of these agents may have important public health implications," the study's authors concluded.

There was no association between use of NSAIDs and risk of basal cell carcinoma, the most common and least aggressive form of skin cancer.

NSAIDs work by blocking certain enzymes involved in inflammation. High levels of these enzymes have been found in skin cancer

The researchers cautioned they didn’t know about participants’ other possible skin cancer risks, such as lifestyle factors and exposure to UV radiation. Only 60 per cent of squamous cell carcinoma and basal cell carcinoma cases were recorded in the Danish Cancer Registry.

The study also relied on dispensed prescriptions, which may not reflect actual drug use.

The Clinical Epidemiological Research Foundation funded the research.