INCREASING INCIDENCE OF PENILE CANCER

A dramatic increase in the incidence of penile carcinoma in situ (PCIS), a premalignant disease that can transform into penile cancer years later, has been found in England and other European countries.

The incidence of PCIS in England rose from 19 new cases reported in 1979 to 193 new cases in 2011, the year for which the most recent data are available.

The data come from the cancer registration and mortality records maintained by the Office for National Statistics in England.

This trend in the annual number of cases reported represents a 915% increase," say the researchers, who presented the findings in a poster here at theEuropean Association of Urology (EAU) 2017 Congress.

"The trend in age-standardized incidence rate increased from 0.08 per 100,000 in 1979 to 0.66 per 100,000 in 2011, an overall increase of 725% over 32 years," they add.  

"The data suggest there have been huge increases, but the question is, is it just a reporting issue, and we are getting better at reporting, or are there actually more men with this disease?" lead author, Simon Rodney, MBBS, MRCS, MA, MSc, a doctoral research fellow in onco-urology at University College London, commented to Medscape Medical News. 

Most men present with a rash, and the disease is diagnosed by biopsy, he explained. There is now more education about the issue, as well as less inhibition among men to approach the medical profession with genital problems, but these changes in attitudes are unlikely to explain the huge increase in incidence, he suggested.  

Also, similar increases in PCIS have been seen during this time period in Denmark, the Netherlands, and North America, which suggests that the increase is real, he

added.The main driver of this disease is human papillomavirus (HPV). Rates of other HPV-associated conditions have increased in recent years, including genital warts and anal cancer and head and neck cancer. In particular, there has been a large increase in HPV-associated throat cancer in men, which has been linked to oral sex and more generally to an increase in sexual partners, a result of the "sexual revolution" of the 1960s.

"Generally the risk of HPV infection increases with the number of sexual partners," Dr Rodney commented, and since the 1960s there has been a trend toward having a greater number of partners.

Indeed, Dr Rodney and colleagues wrote in a recent review that "Human papillomavirus…infection can be considered a major pandemic, causing both benign and malignant disease around the world. It is the most frequently acquired sexually transmitted disease, with more than 6 million new cases transmitted annually in the US. HPV is implicated in the oncogenesis of at least 5% of all cancers, including cervical, head and neck, anal, and penile cancers."

But there is another factor that is specific to PCIS — circumcision, which protects against HPV infection and penile cancer, Dr Rodney noted. Neonatal circumcision rates in the United Kingdom have decreased substantially over recent decades, from an estimated rate of 49%, reported in a paper published in 1949, to more recent estimates of 3.8% (before age 15 years), from a paper published in 2000. Of interest, this more recent estimate is much lower than reported in the United States, where the Centers for Disease Control and Prevention in 2011 estimated a 55.8% to 59.1% national rate of infant circumcision. (All these figures on circumcision are from a 2015 paper on trends in penile cancer.)

The decreasing rates of circumcision and increasing rates of HPV infection could together explain the increase in PCIS, Dr Rodney suggested.   

Increase in Penile Cancer 

PCIS is a precursor to penile cancer and has a higher rate of conversion to cancer than seen with ductal carcinoma in situ conversion to breast cancer, Dr Rodney commented.

An increase in penile cancer has also been reported. A 2013 paper reviewing the incidence of penile cancer in England found 9690 men diagnosed between 1979 and 2009. The age-standardized incidence rates increased by 21%, from 1.10 to 1.33 per 100,000.

"The 21% increase in penile cancer incidence in England since the 1970s may be explained by changes in sexual practice, greater exposure to sexually transmitted oncogenic human papilloma viruses, and decreasing rates of childhood circumcision," those authors wrote, adding: "There is a need for public health education and potential preventative strategies to address the increasing incidence."

Dr Rodney has disclosed no relevant financial relationships.

European Association of Urology (EAU) 2017 Congress.  Abstract 707. Presented March 27, 2017.