Sex infection behind 50% of penis cancers

Around half of the cases of penis cancer are linked to a sexually transmitted infection, according to research from Spain.

Snowman penis Penis cancer is very rare. Fewer than 500 men are diagnosed with it each year (compared to say 35,000 prostate cancer diagnoses). The new study, published in the Journal of Clinical Pathology, suggests that some 250 or so of these cases are probably linked to the sexually transmitted human papillomavirus (HPV).

The researchers from the Cancer Epidemiology Research Program at the Catalan Institute of Oncology in Barcelona, Spain reviewed details of 1,466 penile cancers in 31 major penile cancer studies published between 1986 and June 2008 to come up with their conclusion.

Of the more than 100 types of HPV, the researchers found that HPV16 was the most common among the cases in the studies — accounting for 61.5% of cancers. The next most common type was HPV18 (detected in 13.2% of cases).

Should boys be vaccinated?

HPV is already linked to cancers of the cervix, vulva, vagina and anus which has led to mass HPV vaccination programmes in women. In the UK, for example, there has been a national programme since September 2008 to vaccinate girls against HPV including types 16 and 18.

These new findings on penile cancer will reignite the debate on whether boys should vaccinated too. (In men, HPV can also lead to cancers of the anus.) The researchers, who believe that the 'available HPV vaccines are likely to be effective', reckon that worldwide 7,000 cases of penile cancer could be prevented every year by eradicating HPV16 and 18.

In a malehealth Snap Survey in 2007, 55% of men and 88% of women said boys should be vaccinated against HPV.

Other factors in penis cancer are thought to include having an unretractable foreskin, not being circumcised, poor hygiene, history of smoking, multiple sexual partners and history of genital warts or other sexually transmitted infections.

An international study is under way to collect and analyse a large number of penile cancer samples from more than 17 countries — something the authors welcome as a way of obtaining new evidence to evaluate the contribution of other HPV types and multiple HPV infection.