Half of Men may be Infected with Human Papillomavirus (HPV)

Half of men may be infected with human papillomavirus (HPV), the main cause for cervical and other cancers, strengthening the case for vaccinating boys against HPV, U.S. researchers quoted by Reuters. The researchers examined the incidence and clearance of genital HPV among men because little is known about the subject.

HPV vaccination of boys and young men has generated a whole controversy among researchers and authorities on the grounds that all the vaccine costs would be higher than the benefits.

HPV infection is best known as the primary cause of cervical cancer, the second most common cancer in women worldwide. But various strains of HPV also cause anal, penile, head and neck cancers. Vaccinating men and boys would prevent some of these cancers.

The prospective HPV in Men (HIM) study involved 1,427 men in Tampa, 1,443 in Sao Paulo, Brazil, and 1,429 in Cuernavaca, Mexico, who were examined for HPV infection at 6-month intervals for a median of 27.5 months. The men were aged 18-70 years at baseline, with a median age of 32 years. All subjects were HIV negative and had no history of cancer.

At each visit, three specimens of penile and scrotal cells were obtained from the coronal sulcus, glans penis, penile shaft, and scrotum for the detection of HPV DNA and for HPV genotyping. Sociodemographic and sexual behavior data were obtained using a questionnaire.

"We found that there is a high proportion of men who have genital HPV infections. At enrollment, it was 50 percent," Dr. Anna Giuliano of the H Lee Moffitt Cancer Center and Research Institute in Tampa, Florida, whose study appears online in the journal Lancet.

Researchers also found that the rate at which men acquire new HPV infections is very similar to women, founding that about 6 percent of men per year will get a new HPV 16 infection, the strain that is known for causing cervical cancer in women and other cancers in men.

"The biology seems to be very similar (to women). What is different is men seem to have high prevalence of genital HPV infections throughout their life spans," Dr. Giuliano said in a telephone interview.

Vaccine experts said the study builds momentum for widespread HPV vaccination among boys.

"This study highlights the high incidence of HPV infection in men, which emphasizes their role in transmission of HPV to women. It must surely strengthen the argument for vaccination of men, both for their own protection, and that of their partners," Dr. Anne Szarewski of the Wolfson Institute of Preventive Medicine in London said in a statement.

The National Cancer Institute supported the study. Dr. Giuliano reported ties to Merck, the manufacturer of the HPV vaccine.

Half of Men may be Infected with Human Papillomavirus (HPV)