New research shows that older men and women take far longer than younger people to clear the sexually-transmitted, cancer-causing HPV-16 virus (Cancer Prevention Research, published online Jan. 9, 2015). Men over 45 years of age appear to suffer a high rate of being infected with HPV-16, the virus that causes most cases of cancers of the cervix, throat, mouth, tongue, neck, tonsils, penis and skin. The incidence of oral cancers increases markedly with age. This study also showed that old HPV infections persist longer than newly acquired infections.
Twenty-three men, aged 18 to 64 years, who had HPV in their mouths were followed for 44.4 months. Thirteen acquired a new infection and 10 entered the study with an already-existing infection. Of those who entered the study with an infection, 38.5 percent persisted for at least one month and 10 percent persisted for at least 24 months; none persisted for more than 36 months (median duration, seven months). However, 100 percent of the men over 44 and 50 percent of those 31-44 kept the virus for more than a year. None of the men between ages 18-30 kept the virus for a year. That means that younger men get rid of the cancer-causing HPV faster than older men do. Of the entire study population, 40 percent of oral HPV infections persisted for more than four years. It now looks like long-term persistent oral HPV-16 infection may predict future cancers of the mouth and neck.
Multiple Partners Increase Risk of Oral HPV Seven percent of North Americans have the Human Papilloma Virus (HPV) actively growing in their mouths (Journal of the American Medical Association, Jan. 25, 2012;307(4):335-421). This study shows that transmission by casual, nonsexual contact is unusual.
• Oral HPV is spread through sexual contact, rather than casual contact such as kissing. The incidence of oral HPV is lower than that of genital HPV.
• HPV is found far more frequently in sexually-active people compared to abstainers, and the most significant risk factor for being infected with these viruses is the lifetime number of sexual partners. The more partners in your lifetime, the more likely you are to carry HPV and suffer oral cancer.
• The younger you begin having sex, the greater your chances of carrying oral HPV.
• Men are three times more likely than women to have HPV in their mouths. The authors believe that this is probably because the rate of men performing oral sex on women is higher than the rate of women performing oral sex on men (Emerg Infect Dis, 2008;14(6):888-894). Oral HPV prevalence increased more sharply with the number of sexual partners for men than for women.
• The two age groups with the highest incidence of oral HPV are 30-34 and 60-64-year-olds.
• HPV vaccines can prevent anal and genital cancers, but we do not have data showing that they prevent oral HPV.
• The signs and symptoms of mouth cancer are mouth ulcers, sores, or red or white patches that last longer than three weeks, persistent pain on swallowing, difficulty swallowing, a change in voice, ear pain,
• feeling of a ball in the throat, a neck mass, or unexplained weight loss.
• Tobacco, alcohol and a diet low in fruits and vegetables increase risk for oral cancer.
Many other studies show that:
• You get HPV through direct skin to skin contact with an infected person, through vaginal, penile, oral, or anal sexual contact, even if a person has no warts.
• These viruses cause virtually all cases of cervical cancer and many cancers of the skin, vagina, penis, anus, mouth, nose, head and neck.
• Using condoms helps reduce your chances of becoming infected, but does not offer complete protection.
• Six million North Americans are newly infected each year, Twenty million are infected now with HPV, and more than 80 percent of sexually-active men and women have been infected.
Types of HPV More than 150 different HPV viruses have been found. The ones most likely to cause cancers are types 16, 18, 52 and 59. These are also the types that persist the longest, and are most likely to cause abnormal PAP smears.
Can I Get Rid of HPV? Doctors cannot cure HPV, they can only destroy the warts caused by these viruses with chemicals or remove them with surgery. Most infections appear to clear themselves without any treatment (Am J of Ob and Gyn, 2000;183(3): 561-567). DNA tests of HPV show that 70 percent of women clear HPV infections within one year, and only nine percent continue to be infected after two years (NEJM, 1998;338(7):423-428). A summary of several studies shows that 90 percent of HPV tests become negative in about two years. The current theory is that you become infected with HPV through sexual contact and it can disappear without treatment, as cultures fail to find it. We do not know if the virus really goes away, but we often cannot find it. However some people never clear the high-risk HPV types and it is the persistent infections that can lead to cancers (Trends in Microbiology, 2011(Jan);19(1):33-39).
Each additional sexual exposure increases your chances of acquiring additional HPV viruses and the specific viruses that cause cancer. You can have several different HPV virus types at the same time. Infected people who continue to have the most sexual contacts are the ones most likely to continue to be infected with HPV, as each new exposure carries risk for a new infection.
How Long Does it Take for the Virus to Become Undetectable? The average time for a person who has acquired HPV to have the virus unavailable for culture is six months. However, those with high risk HPV 16 and 18 took an average of almost eight months for the virus to become non-detectable. Again, we do not know if it really goes away. Most women who are infected with HPV will not develop a positive PAP test.
Immunization Immunization protects you from infection with the viruses in that vaccine. It does not protect you from the many other HPV viruses not in the vaccine. High risk HPV subtypes are associated with almost all cervical cancers. The two available HPV vaccines contain high risk HPVs 6, 11, 16 and 18; and just 16 and 18.
Skin Cancers and HPV Both squamous cell skin cancers and actinic keratoses (pre-cancers) can be caused by a combination of ultra-violet light exposure and infection with HPV (Expert Review of Dermatology, April 2010). Most actinic keratoses (pre-skin cancer) cells are infected with HPV (New England Journal of Medicine, May 15, 2003). Dr. Eggert Stockfleth, of the Charité Hospital in Berlin, found specific types of HPV (21, 5, 8, 16 and 18) that convert normal skin to the pre-cancerous actinic keratoses, which may then progress to become squamous cell carcinomas (Disease Markers, April 2007).
Chronic exposure to ultraviolet light damages DNA in skin cells. Your immunity tries to repair this damage, but HPV can prevent your immunity from repairing the DNA. Most of the time when your DNA is damaged, the cells die because they have a programmable cell death called apoptosis. However, the HPV virus prevents DNA from healing and also prevents the programmable cell death that would have removed the damaged cells (Cancer Detection and Prevention, June 2001). Then you develop scaly areas and bumps on your skin called actinic keratoses. Combined with continued exposure to sunlight, HPV infection can cause these damaged cells that do not die to develop into squamous cell skin cancers that can spread through your body.
More about HPV and cervical cancer
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