A sexually transmitted virus that causes some cervical cancers could also be to blame for half of all cases of cancer of the penis, a new study suggests.
The finding means available vaccines for human papillomavirus or HPV "are likely to be effective in [preventing] penile tumours," Dr. Silvia de Sanjose and colleagues of the Catalan Institute of Oncology in Barcelona concluded in Tuesday's online issue of the Journal of Clinical Pathology.
Merck & Co.'s Gardasil and GlaxoSmithKline's Cervarix vaccines are both used to immunize girls against HPV infection.
Penile cancer is a relatively rare form of cancer accounting for one per cent of cancers among men in Europe and North America. The incidence rises up to 10 per cent in parts of Africa and Asia.
Researchers reviewed 21 studies from 1986 to 2008, including more than 1,400 samples of penile tumours.
Overall, 46.9 per cent of tumours worldwide were associated with HPV. The HPV strains 16 and 18 accounted for nearly all of these penile cancers, the researchers found.
The finding is not unexpected, since penile cancer is like the male equivalent of urogenital cancer seen in women, but it's harder to gather evidence for men since it is less prevalent, said Dr. Glenn Bauman, medical director for the genitourinary disease site team at London Health Sciences Centre.
Since evidence is mounting that HPV is responsible for cancers in both men and women, it's worth vaccinating the general population against it, said Bauman, adding it's important to make sure that are no serious side-effects associated with the vaccines.
If people are vaccinated against these HPV viruses, there could be dramatic fall in urogenital cancers of the penis, anus, labia, cervix as well as some cancers of the head and neck that can also be caused by HPV, Bauman said.
Last November, Merck said the results of clinical trials suggested Gardasil helped to prevent lesions caused by HPV in men. The vaccine is not currently approved for use in males in Canada or the U.S.
In most women, HPV clears up on its own, but for some, the infection persists and can lead to cervical cancer.