Experts are calling for boys to be vaccinated against a sexually-transmitted virus after figures showed half of men are carrying the infection.
Certain strains of the human papilloma virus (HPV) are known to cause cervical cancer in women and have been linked to big increases in rates of oral cancer.
A study, published in The Lancet, found that 50 per cent of men are infected with the virus. It also discovered every year 6 per cent of men in the general population will acquire the cancer-causing HPV type 16.
The research - conducted by scientists at the Cancer Centre and Research Institute in Florida - has prompted British experts to call for boys being vaccinated to stem the spread of the virus and prevent genital warts and anal cancers, which are also thought to be caused by HPV.
The well-known link between HPV and cervical cancer has led to the routine vaccination of girls aged 12 to 13 in the UK since 2008.
Head of the College of Medical and Dental Sciences at the University of Birmingham, Professor Lawrence Young, said: 'Although the study is a little unclear about how incidence is defined, it confirms something that we have suspected for some time - that men are a reservoir of HPV infection and transmit this virus to women.
'Thus, HPV vaccination of men would not only contribute to preventing cervical cancer in women but also impact on the rising incidence of HPV-associated oral cancer - a tumour which has risen by 50 per cent in men in the UK since 1989 and accounts for almost 2,000 deaths per year.'