(UPDATED) Boys should also be vaccinated for the Human Papillomavirus HPV, which is the leading cause of cervical cancer. HPV infection leads to mens risk
- Men and women should be protected from infection.
- Human Papillomavirus HPV is largely transmitted through sexual contact.
Vaccinating boys as well as girls for the Human Papillomavirus (HPV) would have a dual advantage as it would protect both men and their female partners from infection, experts said.
Recent Updates: According to Head of gynecological oncology at Stellenbosch University, Hennie Botha, estimates that 80% of sexually active adults will be exposed to a cancer-causing strain of the virus. She said,“Although women have a much higher risk of developing cancer than men, the virus also causes cancer in men. About one in every four head and neck cancers are associated with HPV. The risk of HPV infection is exactly the same in men and women.”
Human papillomavirus (HPV) is a DNA virus from the papillomavirus family that is capable of infecting humans. Like all papillomaviruses, HPVs establish productive infections only in keratinocytes of the skin or mucous membranes. Most HPV infections are subclinical and will cause no physical symptoms; however, in some people subclinical infections will become clinical and may cause benign papillomas (such as warts [verrucae] or squamous cell papilloma), or cancers of the cervix, vulva, vagina, penis,oropharynx and anus. In particular, HPV16 and HPV18 are known to cause around 70% of cervical cancer cases.
More than 40 types of HPV are typically transmitted through sexual contact and infect the anogenital region (anus and genitals). HPV types 6 and 11 cause genital warts. Persistent infection with “high-risk” HPV types—different from the ones that cause skin warts—may progress to precancerous lesions and invasive cancer. High-risk HPV infection is a cause of nearly all cases of cervical cancer. However, most infections do not cause disease. New vaccines have been developed to protect against infection with HPV.
70% of clinical HPV infections, in young men and women, may regress to subclinical in one year and 90% in two years.However, when the subclinical infection persists—in 5% to 10% of infected women—there is high risk of developing precancerous lesions of the vulva and cervix, which can progress to invasive cancer. Progression from subclinical to clinical infection may take years, providing opportunities for detection and treatment of pre-cancerous lesions.
Over 170 HPV types have been identified and are referred to by number. Types 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 68, 73, and 82 are carcinogenic “high-risk” sexually transmitted HPVs and may lead to the development of cervical intraepithelial neoplasia(CIN), vulvar intraepithelial neoplasia (VIN), penile intraepithelial neoplasia (PIN), and/or anal intraepithelial neoplasia (AIN).
Worldwide in 2002, an estimated 561,200 new cancer cases (5.2% of all new cancers) were attributable to HPV, making HPV one of the most important infectious causes of cancer. 84% of new cervical cancers were in the developing world, compared with about 50% of all new cancers. High-risk oncogenic HPV types (including HPV 16 and HPV 18) are associated with 99.7% of all cervical cancers.
About a dozen HPV types (including types 16, 18, 31, and 45) are called “high-risk” types because they can lead to cervical cancer, as well as anal cancer, vulvar cancer, vaginal cancer, and penile cancer.
Several types of HPV, in particular type 16, have been found to be associated with HPV-positive oropharyngeal cancer (OSCC), a form of head and neck cancer. HPV-induced cancers often have viral sequences integrated into the cellular DNA. Some of the HPV “early” genes, such as E6 and E7, are known to act as oncogenes that promote tumor growth and malignant transformation.
HPV can induce a tumorigenic process by integration in host genome associated with alterations in DNA copy number, no functional alternative splicing, inter- and intrachromosomal rearrangements and changes in patterns of DNA methylation, the latter also produced by the virus extra chromosomal.
Oral infection with HPV increased the risk of HPV-positive oropharyngeal cancer independent of tobacco and alcohol use. In the United States, HPV is expected to replace tobacco as the main causative agent for oral cancer.
There are more than 100 types of HPV “of which 13 are cancer-causing”, World Health Organisation said. South African Journal of Gynaecological Oncology estimates that 70% of HPV infections in women are cleared naturally by the immune system
The head of the National Institute of Communicable Diseases, Shabir Madhi, says men are the ones who transmit HPV to women. “If you want to interrupt the circulation of the virus sooner, then you should be targeting boys as well. But in addition to that there’re also complications of HPV infection in boys, men can develop diseases like penile or throat cancer, as well as genital warts, because of HPV.”IMAGE/abcnews.go.com