What's the cause for the alarming 225 percent increase in oral cancer? Could it be heavy smoking or drinking? Well a new study in Clinical Oncology shows human papillomavirus (HPV) and oral sex are the culprit.

Certain oral cancers have declined by more than 50 percent thanks to decreases in tobacco use. Meanwhile, HPV related head, neck and throat cancers have exploded along with the popularity of oral sex (and deep kissing).

One long-term effect of the HIV epidemic has been an oral sex free-for-all. Also, many young people don't think being orally receptive is committing a sexual act. So as the the popularity of oral sex zoomed one unintended consequence appears to be an increase in HPV related oral cancers.

A 2007 New England Journal of Medicine study showed that having oral sex with more than 6 different partners increased the risk of developing throat cancer by 3.4%. Performing oral sex with 26 or more partners tripled that risk. That's because having more sexual partners increases the chance of being exposed to HPV cancer causing types 16 and 18.

The Journal of Clinical Oncology study also revealed that oral sex may increase oral cancer risk more than smoking! And if trends continue, by 2020, HPV related throat cancer may be more common than HPV related cervical cancer.

HPV related cancers: A men's problem also

Another report published in JAMA shows that cancer causing oral HPV infections are now more common in men than women, as are HPV oral cancers themselves. According to the study about 7 percent of the population, ages 14 and 69, are infected with oral HPV with the rate of infection three times higher in men than women.

Even more alarming is that 1 percent of the population may be infected with cancer causing HPV type 16, the study shows. Among men, the rate of oral HPV-16 infection is five times more common than in women. HIV at-risk and HIV-positive adults are infected with oral HPV-16 at even higher levels.

That high rate of oral HPV-16 explains the explosion of HPV-related oral cancers among men. Patients infected with oral HPV-16 have a 14 times greater risk of developing these cancers which can form on the tonsils or the back of the tongue.

HPV vaccines working

According to recent studies (in the NEJM and The Lancet) the HPV vaccines are decreasing the development of cervical and anal/rectal pre-cancers in those vaccinated.

Only some types of HPV are known to cause cancers. Cervarix, the bivalent vaccine (effective against 2) protects against the two types of HPV most associated with HPV cancers, HPV-16 and HPV-18. Gardasil, the quadrivalent vaccine (effective against 4), protects against those two HPV types as well as HPV-6 and HPV-11, which cause genital warts.

Shots for the boys  

Women may still bear the brunt of HPV related cancers. That's because, in addition to developing HPV related cervical cancer, more women develop HPV related anal cancer than men (even more so than gay men).

But HPV is an equal opportunity virus. It's a men's health issue too. In addition to HPV related anal cancer, men can get HPV related penile cancer, not to mention HPV related oral cancers.

With this in mind, the federal the Advisory Committee on Immunization Practices recommended routine use of the HPV quadrivalent vaccine Gardasil in males aged 11 or 12 years and for males aged 13 through 21 years. Some men aged 22 through 26 years may still benefit from  vaccination as well.

One reason for doing so is "herd immunity". The theory that, overtime, as more become vaccinated there will be an increase in the protected population, or herd. That also means fewer people to spread HPV-16 and HPV-18.

HPV vaccination for gay, bisexual males and those with HIV  

Gay and bisexual men (MSM) are at higher risk for conditions associated with HPV types 6, 11, 16, and 18 than heterosexual men. These include a higher incidence of HPV genital warts, anal intraepithelial neoplasia (a cancer precursor) and anal cancers. Recent data on the HPV vaccines have demonstrated efficacy in preventing genital warts (Gardasil only) and precursors of anal cancer.  

For people with HIV, HPV genital warts are more common and difficult to treat. Anal intraepithelial neoplasias and anal cancer are also common in HIV-infected MSM with data suggesting that effective HIV therapy has not reduced development of HPV related anal cancer. One small trial in HIV-infected boys and girls and another with HIV-infected men found the HPV vaccine Gardasil to be safe and effective in establishing an HPV immune response. Ongoing studies will evaluate the efficacy and duration of that HPV immune response.

Few health problems caused by vaccines, report finds

Despite what some presidential candidates have said there are few health problems connected with vaccinations. That's at least according to new study done by a committee of experts convened by the Institute of Medicine. Those experts scoured the scientific literature - up to 1,000 research articles - on the adverse effects of vaccines. They found evidence of 14 vaccine "health outcomes" -- including seizures, inflammation, fainting -- yet these occurred very rarely. The study also refutes any real connection between the MMR vaccine and autism, the flu vaccine and bells palsy and asthma, or the Dtap vaccine and diabetes. These vaccinations do cause, though not often, allergic reactions and temporary joint pain.

Statements of unsubstantiated vaccine side-effects have angered physicians and public health officials for undermining serious, life-saving, public health initiatives. For a glimpse of why check out the website of The Consul on Foreign Relations. It has a map that plots global outbreaks of diseases preventable through vaccination. The map is at http://www.cfr.org/.

If you build it, will they come?

So, vaccines work and are pretty safe. But that doesn't mean people will take them, even those who really need too. One recent study demonstrates that reluctance. Published in the American Journal of Public Health – the study centered on a major vaccine trial. Vaccine misconceptions by those in the study mirrored concerns of much of the public.

The study sought to find out what high-risk communities understood about HIV vaccines and how that impacted their willingness to enter a study. Participants expressed fear that vaccines involve being injected with dangerous amounts of the pathogen they sought protection from. It was a falsehood that affected their willingness to be vaccinated.

When some in the study became infected with HIV (though behavior, not the vaccine) they felt it wasn't an unforeseen consequence and that the researchers running the study should have been able to predict it.

There was also confusion surrounding why research targets people at high-risk. Some study participants thought this unfair but it is a very important strategy for studying and controlling infectious disease. The study shows that better communication is needed so both people at-risk and the general public better understand vaccine risks and research.