Michael Douglas caught major flak for saying oral sex gave him throat cancer. But if you’re laughing, it’s time to grow up. Oral cancers caused by the sexually transmitted human papillomavirus (HPV) have skyrocketed 225 percent in the past 15 years, with men accounting for 75 percent of all cases. The number-one culprit: HPV passed via oral sex.

It used to be that cigarettes caused most of these cancers. But since smoking rates have plummeted over the past few decades, and we’re having way more oral sex today than even our fathers’ generation, HPV has become the most common STD in the U.S. – inevitably leading to more oral cancer cases. It only takes one time going down on someone to contract HPV, and experts estimate that 80 percent of us will be exposed to the virus at some point in our lives. This STD sometimes causes genital warts, but according to the Centers for Disease Control and Prevention, that’s not very common. In most cases, HPV has no symptoms. And since no test exists to detect HPV in guys, you won’t know you have the virus until years later – if it turns into cancer.

“It’s very hard to determine when you acquired HPV,” says Dr. William Schaffner, chairman of the Department of Preventive Medicine at Vanderbilt University. “It doesn’t usually come from just one sexual episode. That said, every once in a while, cancer develops within two years of when you think you acquired HPV. But most often it comes 10, 12, even 20 years later.”

Still, not all HPV cases lead to oral cancer. Far from it. So even though the rapidly rising prevalence of these cancers is scary – and nothing we should take lightly – we need to keep the actual risk in perspective. “It’s true that within the world of oral cancer, HPV-caused cases have become an epidemic,” says Brian Hill, executive director of the Oral Cancer Foundation. “They are rapidly increasing at a rate never seen before, and it’s going to get much worse by 2020. However, in the grand scope of the U.S. population, the term ‘epidemic’ is overstating the reality. Only a small percentage of sexually active people wind up with an HPV-related oral cancer. For 99 percent of those who get HPV, their immune system clears it within 12 to 24 months, and that’s that. So we have to look at the relative risk. Don’t stop having sex. That’s not an appropriate response.”

So what is the right response? To protect yourself without killing your sex life, there are HPV vaccines like Gardisil. These are proven to protect against HPV-caused anal and cervical cancers, and doctors overwhelmingly believe they also prevent oral cancers. However, the CDC recommends vaccination only for men under age 26, and most insurance plans won’t cover it for older guys. Still, that doesn’t necessarily mean you should rule out the vaccine if you’re past 26.

“The CDC’s recommendations are based on a generality,” Schaffner says. “Statistics show that most guys, by age 26, have had multiple sexual partners and have probably been exposed to HPV. But every individual is different. A guy may have been in a long-term monogamous relationship that’s ended, and now he’s reentering the social scene and going to have sex. It won’t do him any harm to get immunized. Insurance probably won’t cover the vaccine, but he can certainly pay the $300 to $400 out of pocket.”

But if you’ve had a handful of partners – and, if the stats are correct, have probably already come in contact with HPV – the decision boils down to whether you want that extra piece of mind, says Schaffner. After all, you could be one of the lucky few who’s had lots of sex but never been exposed. “It’s kind of like wearing a belt and suspenders,” he explains. “Wearing both may be unnecessary, but at least can be sure your pants won’t fall down. By getting the vaccine, you know you’ve done everything you can to protect yourself from HPV.”

Besides being immunized, which only spares you from HPV if you haven’t been exposed, you should limit your sexual partners and always use protection. But even then, condoms and dental dams aren’t surefire HPV blockers, Schaffner says, because you can get the virus from skin-to-skin contact. “HPV can be present on the penis shaft and vaginal lips, not just on mucus membranes, semen, or vaginal fluid,” he says. “Therefore, condoms – both male and female types – are very helpful, but they don’t offer complete protection, even if they’re used as directed and don’t break.”

Schaffner says gay men aren’t necessarily at less risk of oral cancer just because they’re not performing oral sex on women. It has more to do with how often a guy has sex and how many different men he’s slept with. However, the CDC says gay and bisexual men are 17 times more likely to develop anal cancer – also caused by HPV – than men who only sleep with women.

Even if you already have HPV – and don’t know it – you can take steps to decrease your chances of oral cancer. Schaffner says to stop smoking immediately and cut back on booze. “We’re not sure why, but smoking and drinking too much both increase HPV’s likelihood of developing into cancer,” he explains.

To be safe, you should also be on the lookout for early signs of oral cancer, which tend to be subtle, so guys often ignore them, says Hill. Unlike tobacco-caused oral cancers, which present in visible symptoms like white lesions or red spots on the tongue, HPV-related cancer cells love lymph tissue and the way back of your tongue. “HPV-caused oral cancers have very stealthy signs, so you really have to pay attention if you feel changes,” he says.

Here’s what to look for: “If you notice it’s become more difficult to swallow, or you’re suddenly always hoarse or have a sore throat, those are definite cancer red flags, and you need to get examined,” Hill says. “Also, if a lymph node in your neck becomes enlarged – and it’s painless – that’s a warning sign of cancer starting inside the mouth and spreading to your neck. When lymph nodes swell up from ear infections or abscessed teeth, they hurt. But these ones don’t. And if you can’t push it around, that’s a definite sign.”

Thankfully, all you dads and future fathers can help spare your sons from these health issues. Get them vaccinated long before they wind up going down on a girl in the back seat of your car. “Don’t put it off until they’re 17,” Schaffner says. “Have them immunized when they’re 11.”

Related links:

Can Oral Sex Cause Cancer?

How to Minimize HPV and Cancer Risk

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