Researchers published an article in the prestigious Journal of the American Medical Association exploring the possibility of a link between Viagra use and an increased rate of melanoma. The JAMA article suggests that the blockbuster drug could increase men’s chance of developing the deadly skin cancer.

The JAMA article that raised the possibility of a link between Viagra and melanoma described a cohort study, a study in which researchers follow a similar group of people and evaluate changes in the group over time. In 2000, researchers distributed a survey that asked questions about skin cancer and what medications participants were taking. A total of 25,848 men provided data analyzed in the final study, meaning they did not have cancer at the beginning of the study and completed the follow-ups through the end of the survey in 2010.

Researchers found 3,752 reports of skin cancer among the men surveyed. The majority of these (3,030) were basal-cell carcinomas, a relatively common and easily treated form of skin cancer. However, 142 of the men surveyed had developed melanoma, one of the most serious forms of skin cancer.

The researchers evaluated this data by performing various statistical analyses. One of the chief purposes of statistical analysis is to figure out how likely it is that the results of a study are not coincidence. For example, in the biological sciences, it is usually considered statistically significant if there is a 95 percent or greater chance that the results are not the result of coincidence. Other types of statistical analysis can help parse out different factors’ effects on the results.

In the statistical analysis for the JAMA study, it was found that only melanoma appeared related to Viagra usage. Other types of skin cancer were not linked to Viagra usage, including the more common basal cell carcinoma. One question that stuck in researchers’ minds was the possibility that it was not Viagra that made a patient more likely to develop melanoma, but erectile dysfunction itself. In statistics, this is called a cofounder, a second factor that creates confusing results. However, statistical analysis allowed researchers to test this idea, and found that patients with erectile function who did not take Viagra had no increase in their risk of developing melanoma.

A Viagra melanoma lawsuit investigation has been launched to explore the possibility of legal action against Pfizer, the makers of the drug. Such a Viagra lawsuit could allege that the makers of the drug were aware, or reasonably should have been aware, of the potential risk of Viagra melanoma. Drug makers have a legal obligation to thoroughly test their drugs and monitor research journals and FDA monitoring resources for signs their drugs have unintended side effects like Viagara melanoma. Similar lawsuits have sought to recoup the cost of medical care, lost wages due to medical downtime and disability, and legal fees associated with the case.