Change in Oral Sex Attitudes Causing Rise in HPV-Related Throat Cancer

Cases of throat cancer have been skyrocketing in recent years, mainly due to increased levels of HPV (human papillomavirus) infections, caused by oral sex.

Oropharyngeal cancer is mainly caused by HPV infections, and is now more common than cervical cancer—also caused by HPV—in both the U.S. and U.K., according to an article in the Conversation by Hisham Mehanna, a professor of cancer and genomic sciences at the University of Birmingham in the U.K.

According to the article, the main risk factor for oropharyngeal cancer is the number of sexual partners you have in your lifetime, particularly oral sex, with those who have had six or more lifetime oral-sex partners being 8.5 times more likely to develop oropharyngeal cancer. Changes in attitudes towards sex and oral sex may therefore be driving the rise in oropharyngeal cancers.

"HPV is a virus that infects types of cells caused by keratinocytes," Sarah Allinson, a senior lecturer in genetics and cancer biology, Lancaster University, told Newsweek. "These cells are found in our skin and other similar surfaces in our body such as in our cervix, mouth and throat. There are lots of different types of HPV and some of them cause nothing more serious than a wart or a verruca. However, there are some sexually-transmitted high-risk types that infect mucosal surfaces like the cervix and throat and are able to cause cancer."

According to the CDC, HPV is very common, with 40 percent of 15- to 59-year-olds having contracted the virus.

The virus multiplies in our keratinocyte skin cells by hijacking the machinery that cells use to divide, allowing the virus to produce lots more viruses. The virus also makes the keratinocytes multiply as well, which often causes a wart to grow. In some cases, the virus can cause cells in the cervix or throat to grow uncontrollably, leading to cancers.

HPV is thought to cause 70 percent of oropharyngeal cancers in the U. S., the CDC says. However, HPV rarely causes cancers, considering its prevalence in the population: only 19,400 women and 12,100 men experience cancers caused by HPV each year.

"The vast majority of cases of cervical-cancer-causing HPV infections are transmitted through sexual intercourse," Christian Yates, a senior lecturer in mathematical biology at the University of Bath in the U.K., told Newsweek. "Over 60 percent of all cervical cancers are caused by two strains of the human papillomavirus (HPV). Indeed, HPV is the most frequent sexually transmitted disease in the world. Men can carry the virus asymptomatically and pass it to their sexual partners, contributing to cervical cancer's status as the fourth most common cancer in women, with around half a million new cases and quarter of a million deaths reported worldwide each year."

The Conversation article states that the increases in oropharyngeal cancers may be due to increases in oral sex in young people, possibly "in an effort to abstain from penetrative intercourse."

"Evidence suggests that the reason why rates of throat cancer caused by HPV infection are increasing is because of changing attitudes towards oral sex," Allinson said. "The more sexual partners you have the more chance you have of becoming infected with HPV."

This form of cancer being caused by oral sex made headlines in 2013 when actor Michael Douglas told The Guardian that his throat cancer could have been brought on by oral sex.

HPV can also lead to a number of other, non-cancerous conditions.

"There are many different types of HPV virus. Some cause cancer and some don't," Yates said. "The types of HPV that cause genital warts, for example, are not the same as the type which cause cancer. If you've ever had a wart or a verruca then you will have harbored at least one of five types of HPV."

As well as causing cervical cancer, HPV types 16 and 18 contribute to 50 percent of penile cancer, 80 percent of anal cancers, 20 percent of mouth, and 30 percent of throat cancers," Yates explained.

HPV and all the conditions it can lead to can be protected against using the HPV vaccine.

"People can protect themselves against HPV by being vaccinated—the vaccine protects against all HPV-related cancers, including throat cancer, penile cancer and anal cancer, as well as cervical cancer," Allinson said. "They should also attend cervical screening at regular intervals even if vaccinated. This is because the vaccines in use don't protect against all of the types of HPV that can cause cancer, just the most high-risk ones. In most countries, cervical cancer screening now involves testing for the presence of HPV and so by being tested people can be informed about whether they are carrying an infection that could put themselves and their sexual partners at risk of cancer."

The HPV vaccine was primarily developed to prevent cervical cancer and cancers of the reproductive system, but it protects against the HPV types that cause cancer and so may prevent oropharyngeal cancers too.

"More than half of oropharyngeal cancers are linked to a single high-risk HPV type, HPV 16, which is covered by the FDA-approve vaccines," Yates said.

It's not completely clear how long the effects of the vaccine last, however, since it is a relatively new vaccine.

"Studies have shown that it provides some protection against HPV infection for at least 10 years, although many experts believe the protection will last much longer than that," Yates said.

Despite men also being able to contract the virus and spread it to other sexual partners, boys are often not offered the vaccine at the same time that girls are. There is some evidence that men can be protected by herd immunity so long as over 85 percent of women are vaccinated, however, this protection fades with fewer vaccinated women. According to the Conversation article, only 54.3 percent of adolescents aged 13 to 15 years had received two or three HPV vaccination doses in 2020.

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