Can Oral Sex Really Cause Cancer? It's Complicated

For a while during the spring of 2023, you couldn't venture anywhere online without reading about how oral sex causes cancer. But is that the truth?

Does performing oral sex lead to an increased risk of throat cancer?

Where did the idea that oral sex causes throat cancer originate?

After The Conversation published an article in April by Hisham Mehanna, M.B.Ch.B., claiming that "oral sex is now the leading risk factor for throat cancer," it didn't take long for the brow-raising headline to spread fast through social media.

Publications ranging from the New York Post to Business Insider to Huffington Post relayed the contents of the article to their respective corners of the internet. Beyond the clickbait factor, though, the line between the political and the medical begins to blur.

How much truth is there really behind the claim? It depends on how you look at it.

Is there a link between oral sex and throat cancer?

Throat cancer is one of the areas of illness and treatment designated as head and neck cancer, which refers to any cancer that affects those areas of the body. Throat cancer most often refers to oropharyngeal cancer, which affects the middle portion of the throat (pharynx) known as the oropharynx.

Other cancers of the throat area are often referred to by specific names, such as laryngeal cancer and esophageal cancer. Approximately 55,000 people will be diagnosed with oropharyngeal cancer in 2023, according to the American Cancer Society.

The leading cause of these oral and throat cancer diagnoses is human papillomavirus (HPV).

That HPV causes cancer is no surprise to any medical professional. The virus is an identified leading cause of many cancers and is responsible for more than 95 percent of cervical cancers.

High-risk HPV is responsible for an estimated 5 percent of all global cancer cases, a number that health organizations are fighting to lower with the widespread administration of the HPV vaccine, Gardasil 9.

Gardasil 9 immunizes recipients against the nine most common cancer-causing strains of HPV. It can prevent an estimated 90 percent of HPV-related cancers—including the widespread oral cancers causing the throat cancer "epidemic” in the United States and the United Kingdom.

Oropharyngeal cancer cases now outnumber cervical cancer cases, according to the Conversation article. However, it's important to note that this statistic only pertains to the U.S. and U.K. Cervical cancer accounts for 605,000 cases worldwide, with oropharyngeal cancer cases numbering about 450,000.

What does the HPV vaccine mean for throat cancer rates?

What the article fails to mention explicitly is the massive gender disparity in the prevalence of throat cancer and the likely reason for the imbalance. Men are nearly three times more likely to be diagnosed with throat cancer than women; they are also significantly less likely to have received the HPV vaccine.

The Centers for Disease Control and Prevention (CDC) initially recommended the vaccine solely for young women. They expanded the recommendation in 2011, but the vaccination rates were slow to equalize. In 2013, the vaccination rate for men and women was 7.7 percent and 36.8 percent, respectively, according to a CDC report.

More recent studies of HPV vaccination rates in adolescents indicate the gender gap is closing, but a majority of sexually active adults are unvaccinated against HPV and, therefore, at a higher risk of developing cancers as a result of the virus.

The vaccine is significantly less effective after any HPV exposure, so experts highly recommend vaccination for adults younger than age 26.

The benefits of an increase in the rate of adolescent HPV vaccination aren't apparent immediately, as HPV-related cancers often take years to develop after the initial infection.

It's possible that cases of oropharyngeal cancer could fall once the number of vaccinated individuals surpasses the number of those who did not receive the vaccine. It is, in many ways, a waiting game.

Why does the wording regarding HPV-related oropharyngeal cancer matter?

It may seem like parsing words to highlight the distinction between "oral sex causes cancer" and "HPV infections acquired through unprotected oral sex cause cancer."

The latter is certainly not headline material, lacking the implied undercurrent of scandal that creeps through in the former. But the idea is more sinister than just a sensationalist headline.

Sex education in the U.S. is lacking: 30 states encourage abstinence-only sex education.

Placing the burden on oral sex itself paints the act as a dangerous and unpredictable factor responsible for cancer while failing to offer any solution or prevention outside suggested abstinence. In essence, it sends a message: If you have sex and get cancer, it is your choice and your fault.

Even if this wasn't the intended message of the original article or any of the follow-up pieces, they fail to discuss a number of factors that significantly inform the public's perception and understanding of HPV and sex.

Mehanna leaves out a few relevant key facts, including the prevalence of HPV or the number of people affected.

Approximately 43 million people were infected with HPV in 2018—just in the U.S.

"HPV is so common that almost every sexually active person will get HPV at some point if they don't get vaccinated," according to the CDC.

Many of these HPV infections will clear on their own and most people remain asymptomatic. There is no test for HPV in the throat, nor is there a blood or urine test to check for infection. Only a Pap smear can identify the presence of HPV.

The bottom line

Oral sex isn't going anywhere. For the time being, HPV isn't either. As the medical community works to raise vaccine administration rates and the vaccinated generations mature, it can only do so much to fight the transmission of HPV.

Condoms or dental dams are effective but not foolproof, and the virus has many other ways of spreading between sexual partners.

People inside and outside the medical community can control the way they talk about HPV, though, and the way information is disseminated. We can change the state of sex education in the country and the attitudes surrounding sex in general.

In one way, Mehanna was right: "As always, when dealing with populations and behavior, nothing is simple or straightforward."