A new study of 1.5 million men from Houston’s Baylor College finds a link between curved penises and an increased risk of cancer.

Dr. Alexander Pastuszak and his team of researchers found that Peyronie’s disease (PD) increases the risk of malignancy, particularly cancers of the stomach and testicles. The connective tissue disorder is estimated to affect around 10 percent of men across the globe.

Men with Peyronie’s were found to have a 40 percent higher risk of testicular cancer, a 29 percent greater risk of developing melanoma and a 40 percent higher likelihood of developing stomach cancer.

Peyronie’s disease, which is caused by a buildup of scar tissue under the skin of the penis, causes painful erections and an increased curvature of the male reproductive organ. The abnormal bend formed during an erection can cause numerous problems during sexual intercourse. And although researchers have not defined the exact underlying cause of the disease, trauma stemming from sexual intercourse or other physical activity is often directly correlated. According to the Mayo Clinic, Peyronie's disease causes a significant bend or pain in some men that can prevent them from having sex or may "make it difficult to get or maintain an erection (erectile dysfunction). For many men, Peyronie's disease additionally causes stress and anxiety."

An example image of Peyronie's disease is available here

Using the Truven Health MarketScan claims database, Dr. Pastuszak and his team at Baylor identified 48,423 men with PD, nearly 1.2 million men with Erectile Dysfunction (ED) as a secondary internal control group, and 484,230 controls. On average, the men between the ages of 48 and 50 and were followed for a little more than 4 years. The team analyzed genetic data between fathers and sons, while also using men with Erectile Dysfunction as a means of testing potentially related symptoms.

"We think this is important because these conditions are largely taken for granted,” Dr Pastuszak, said at the American Society for Reproductive Medicine, MDLinx first reported. He also compared Peyronie’s disease with Dupuytren’s disease, a condition where one or several fingers become permanently bent into a flexed position.

“Just taking this at face value, clinically, this could be interesting because nobody has ever made these associations, and this is effectively where the abstract we submitted to ASRM ends but we've now taken this and tried to translate it back to actual genetic data that do demonstrate increased risk in men with PD and Dupuytren's disease.”

The study authors reiterated that Peyronie’s research should closely monitor any links to the development of cancer, and that additional research would be needed to justify wide-scale screenings for men.

“While they’re significant in the sexual and reproductive life-cycles of these patients, linking them to other disorders suggest that these men should be monitored for development of these disorders disproportionately in contrast to the rest of the population,” Dr. Pastuszak added.

University of Istanbul research found that Peyronie’s affects between 3.7 percent and 7.1 percent of men worldwide. However, the research cautions that this data may be skewed because of “patients’ reluctance to report this embarrassing condition to their physicians.”