Michael Douglas's announcement that his throat cancer was caused by human papillomavirus, a sexually transmitted disease, has raised awareness about a men's health trend doctors have been alarmed about for years.
Douglas, the 68-year-old star of the new Liberace biopicThe Guardian in an interview when asked if he regretted his drinking and smoking habits in light of his cancer battle, that he did not, in part because his disease was caused by oral sex.told
"No. Because without wanting to get too specific, this particular cancer is caused by HPV, which actually comes about from cunnilingus," Douglas told the paper. "I did worry if the stress caused by my son's incarceration didn't help trigger it. But yeah, it's a sexually transmitted disease that causes cancer."
Douglas' representatives denied The Guardian's headline stating that oral sex caused the actor's cancer on Monday morning, telling USA Today: "Michael Douglas did not say cunnilingus was the cause of his cancer. It was discussed that oral sex is a suspected cause of certain oral cancers as doctor's in the article point out but he did not say it was the specific cause of his personal cancer."
However, a link between oral sex and throat cancer is no surprise to experts.
"This is not a surprise by any stretch," Dr. Eric Genden, professor and chair of otolaryngology at Icahn School of Medicine at Mt. Sinai Hospital in New York City, told CBSNews.com. "There's an epidemic of HPV-related throat cancers."
Throat cancer, also known as oropharyngeal cancer, refers to tumors that occur in the tonsils, base of the tongue and upper throat. Smoking and alcohol use have been associated risk factors, but in recent years throat cancers related to the sexually transmitted virus human papillomavirus (HPV) have been on the rise.
HPV is an STD transmitted by oral and genital sex.
The 2013 "Annual Report to the Nation on the Status of Cancer" found about 13,000 new cases of oropharyngeal in both men and women linked to HPV in 2009 (the last year of available data), more than 10,500 of which were in men. More than 60 percent of oropharyngeal cancers are caused by HPV, according to the National Cancer Institute, which was an author in the report.
From 2000 to 2009, incidence rates} , the report also found.
Previous research found HPV fueled a, amounting for an additional 10,000 U.S. cases each year.
Genden said HPV-related throat cancers are now more common in men than cervical cancer -- which is caused by the same virus -- in women. These cancers are also more commonly found in younger populations, adults between ages 40 and 65, a group typically younger than those affected by smoking-related throat cancers.
People who are developing throat cancer now likely had gotten HPV more than 10 or 15 years earlier, Genden pointed out.
"It's the norm now, unfortunately," Dr. Mumtaz Khan, a head and neck cancer surgeon at the Cleveland Clinic in Ohio, said to CBSNews.com.
Not everyone with HPV will develop oral cancer though. One 2012 study in the Journal of the American Medical Association estimatedwhen fewer than 15,000 will develop the cancer. The researchers estimated about 10 percent of men had oral HPV, while almost 4 percent of women do.
HPV has also been associated with cancers of the cervix, vulva, vagina, penis and anus, according to the Centers for Disease Control and Prevention.
Overall, more cancers are still caused by drinking and smoking, Khan pointed out.
Genden explained that 90 percent of people infected with HPV will clear it from their bodies within a year, but for the 10 percent with chronic disease, they are at this greater cancer risk. He said if you smoke and drink, there is some data to suggest this will increase throat cancer risk in people with oral HPV.
Asked by Letterman about his personal habits, the Oscar-winning actor said he had smoked and consumed alcohol.
He had complained about health problems for
after battling the disease for six months, with radiation treatments and chemotherapy.
Douglas told The Guardian his treatment worked and he's been clear more than two years, but gets check-ups every six months, "and with this kind of cancer, 95 percent of the time it doesn't come back".
Khan pointed out that HPV-related throat cancers have a high cure rate, more so than the stage IV equivalents of throat cancers caused by drinking and smoking.
"The good thing is the HPV-related tumors prognostically are far better than those related to smoking and alcohol," he said.
With no test to diagnose oral HPV, what can be done to reduce risk? Future generations may be protected by the HPV vaccine, which is now given to boys and girls as young as 11 through the time they turn 21 (for males) and 26 (for females), according to the Centers for Disease Control and Prevention.
For older generations who may have already been exposed to HPV, Genden emphasized the importance of knowing the signs of oral cancer, since it can be treated so well if caught early. An adult in his 50s might have a sore throat for a month and ignore it, he said, when it could be cancer.
"Most people just carry on, and don't think about looking into this," said Genden.
Khan also reiterated the importance of following safe sex practices, and for those who develop HPV-related throat cancer, he added that surgeries today are minimally invasive and often performed by robotic instruments, so quality of life is improved for these patients compared to years past.
"That's the biggest advantage we have now in controlling these cancers," he said. "We can do a lot more with a lot less."