Danish researchers suggest that anti-inflammatory drugs such as aspirin, ibuprofen and naproxen could decrease the risk of skin cancer. Image: Dean Bertocelej/Shutterstock
Common painkillers may protect against skin cancer.
Nonsteroidal anti-inflammatory drugs (NSAIDs) such as aspirin, ibuprofen and naproxen have been previously linked to a decrease in the risk of developing some types of cancer, especially colorectal cancer. After analysing the impact of these drugs on the rates of three major types of skin cancer (basal cell carcinoma, squamous cell carcinoma and malignant melanoma), researchers at the Department of Clinical Epidemiology at Aarhus University Hospital, Denmark, indicate that skin cancer prevention may be added to the benefits of these commonly used medications.
The researchers led by Sigrún Alba Jóhannesdóttir analysed medical records from northern Denmark from 1991 through 2009. They identified 1,974 diagnoses of squamous cell carcinoma; 13,316 diagnoses of basal cell carcinoma and 3,242 of malignant melanoma. Then, the researchers compared this information, including prescription data from the patients, with information from 178,655 healthy individuals.
Based on this data, individuals who filled more than two prescriptions for NSAIDs on a regular basis had a 15 per cent decreased risk for developing squamous cell carcinoma, and a 13 per cent decreased risk for developing malignant melanoma than those who filled two or fewer prescriptions for the medications, especially when the drugs were taken for seven or more years. According to the researchers, the individuals who took NSAIDs did not seem to benefit from a reduced risk of developing basal cell carcinoma in general, although they did have a 15 per cent reduced risk of developing this type of cancer on less-exposed sites, body areas other than the head and neck. “The results were similar for all types of NSAIDs, except that we observed no protective effect of certain newer types (COX-2 inhibitors) on risk of malignant melanoma or basal cell carcinoma,” says Jóhannesdóttir.
NSAIDs work by inhibiting specific enzymes involved in inflammation. Previous studies have demonstrated that elevated levels of these enzymes are found in skin cancer and that they are involved in important steps of cancer development. “Inhibition of these enzymes may protect against skin cancer development, such as inhibition of cell death, suppression of the immune system, and stimulation of invasiveness and blood vessel growth,” Jóhannesdóttir explains. “However, we could not examine the molecular mechanism behind our results.”
Regardless of the benefits, NSAIDs could also have adverse effects, such as gastrointestinal ulceration, bleeding and cardiovascular complications. Jóhannesdóttir stresses that more studies are needed before their results are confirmed to be beneficial for patients, and that sun protection remains the most important prevention against skin cancer.
Terry Slevin, Chair of the National Skin Cancer Committee for the Cancer Council Australia, states that although the study is interesting, it should be give some careful thought as the incidence of skin cancer in Australia and in Denmark, as well as the exposure to UV levels, is different. “The study does not attempt to collect or report levels of UV exposure and as UV exposure is a major determinant of skin cancer risk there is a prospect that UV exposure is a major unmeasured cofounder in the study.”
“This potential cancer-protective effect should be taken into account when discussing benefits and harms of NSAID use,” says Jóhannesdóttir. “We hope that the potential cancer-protective effect of NSAIDs will inspire more research on skin cancer prevention.”
