Increasing body mass index (BMI) is associated with a greater likelihood of invasive penile cancer and more advanced penile cancer at presentation, according to study findings published online in European Urology.
In addition, the findings showed that the odds of invasive penile cancer increased twofold with each 5-unit increment in BMI, and each 5-unit increase in BMI is associated with a 49% increased odds of higher cancer stage at diagnosis. For the study, researchers at the University of Iowa in Iowa City led by Amit Gupta, MD, matched 77 penile cancer patients with 12,420 cancer-free controls.
“The biologic mechanism for this increased risk is unknown but might be mediated by impaired genital hygiene because of obesity,” the authors wrote. “Obesity can hamper genital self-examination and cleansing and can cause a buried penis with resultant smegma accumulation and functional phimosis.”
Dr. Gupta’s group also noted that obesity may impair examination by health care providers, “which may lead to delayed recognition of symptoms that leads to presentation at higher stage.”
The investigators pointed out that their study is limited by its retrospective design, the possibility of selection bias, and limited generalizability because of referral patterns at an academic medical center.
Noting that therapeutic options for advanced penile cancer are limited and mortality is high, the authors stated that successful control of obesity “might prevent development of penile cancer and lead to earlier diagnosis, when treatment is more effective.”