Cancer of the tonsils and back of the tongue are not very common. Until recently, most of these cancers were caused by smoking and drinking. Now, a strain of HPV which is sexually transmitted has been associated with cancer of the tonsils and back of the tongue. As a result, the media has had a field day claiming that oral sex is the cause of oral cancer. There are also physicians and celebrities who are making statements about oral sex and oral cancer which are not based in science. Here are the facts versus the hype.
There are at least 120 types or strains of human papillomavirus (HPV). Approximately 40 of the HPV strains are passed through sexual contact. While many of these strains cause no symptoms, others can cause warts, and a few of the HPV strains can cause cancer, including cancer of the cervix.
Most sexually active people will get HPV at some point in their lives, although few people ever know they have it. HPV is nearly impossible to avoid unless you never have sex. It’s also nearly impossible to know who you got HPV from because HPV usually doesn’t cause symptoms. One of the fascinating things about HPV is that 90% of the cases clear on their own within one or two years. It doesn’t matter if it is a strain that causes warts or cancer, the immune system usually gets rid of it.
Years ago, researchers discovered that strains 16 and 18 of the human papillomavirus caused most cervical cancers. They also found that women who had a greater number of sexual partners had a higher risk for getting cervical cancer. So when researchers recently discovered that cancer of the tonsils and cancer of the back of the tongue could be caused by HPV as well as by smoking and drinking, they started asking questions about sexual behavior. As it turned out, some of the studies showed that people who had oral cancers that were associated with HPV had a higher number of oral sex partners than people who didn’t get these cancers. So it seemed reasonable to claim that oral sex was the cause of HPV-positive oral cancers. Researchers also noticed that the HPV-positive oral cancers, although uncommon, were on the rise. This matched nicely with the idea that oral sex must be the cause, because oral sex has become increasingly popular during the last fifty years.
A headline-grabbing oral-sex panic was in the making. Captions such as the following from CBS News in 2011 have been common: “Oral sex now main cause of oral cancer” followed by “What’s the leading cause of oral cancer? Smoking? Heavy drinking? Actually, it’s oral sex.” It wouldn’t be long before an exuberant HPV-cancer researcher was advising parents to warn their children about the dangers of oral sex.
What the media forgot to mention is the average age of people who are diagnosed with HPV-related oral cancer is sixty-one years, and these are usually men. This means it will be thirty to forty-five years before today’s teenagers start getting oral cancer—if they get oral cancer, which very few will. The chances of a teenager being killed in a car wreck during the next thirty years are almost a million times greater than the chances he or she will die from oral cancer during that time. Parents should be far more concerned about their teens driving than having oral sex, but oral sex makes for better headlines.
The media also forgot to report that billions of people have had oral sex with multiple partners, yet only a tiny percent have gone on to have an HPV-positive oral cancer. Clearly, something else is involved besides just oral sex. Otherwise, oral cancer would be the most common cancer on the planet instead of being one of the most uncommon.
This past week, USA Today quoted a throat-cancer specialist as saying that individuals should use barriers when performing oral sex to keep from getting oral cancer. They forgot to mention that there is not a single study that shows using barriers when giving oral sex will prevent oral cancer. Also, none of this week's oral cancer stories mentioned a recent study that found an association between gastric reflux and some forms of oral cancer. That's because it’s far more interesting to quote physicians who warn about “the dangers of oral sex” than nutritionists who warn about dietary changes.
Contrary to the reader-grabbing headlines, we don’t yet understand what leads to persistent HPV infection in the throat and mouth, and we don’t understand why a very small group of men and some women who get persistent oral HPV infections will go on to develop oral cancers. We also don’t know why men get HPV-related oral cancers at a higher rate than women.
Fortunately, oral cancer is an uncommon cancer, being number 14 on the list of cancers that women get and number 8 among the cancers that men get. Also, a significant percent of oral cancers are caused by tobacco and alcohol rather than HPV. This will continue to be the case as long as people smoke, drink, and chew tobacco. Unfortunately, oral cancers can be devastating regardless of the cause. If there is good news, it’s that the oral cancers that are associated with HPV are less resistant to treatment than those that are associated with smoking or chewing tobacco.
While HPV is certainly involved with some of the oral cancers, the National Institute of Health has stated that we don’t yet know how it’s involved as we do for cervical cancer. As for the relationship between oral sex and oral cancer, one of the latest studies concludes: “...oral sexual contact in the form of both oral-oral and oral-genital contact could play a role in the transmission of oral HPV.” That’s the most we currently know. It will probably be years before we know the rest of the story.
As for myself--I can’t help but wonder why the one sexual act that gives women pleasure and does not cause pregnancy is now being described as harmful to men, especially when we know so little about oral sex and throat cancer.