There has been much media attention paid to celebrities’ health issues recently, with Angelina Jolie’s revelation about her genetic risk for breast cancer and Michael Douglas’ remarks regarding his throat cancer. Both have sparked national discussions.
Following Douglas’ comments, I asked Dr. Banu Symington, one of our very talented Mountain States Tumor Institute medical oncologists, to write about human papillomavirus and the associated risk for cancer. Dr. Symington is a passionate advocate for cancer prevention, and I am sure you will learn as much from what she has written as I did. Her report follows:
If you own a TV or radio, you have probably heard the furor over Michael Douglas’ statement to a British newspaper regarding the cause of his throat cancer.
The Guardian reported that when “asked whether he now regretted his years of smoking and drinking, usually thought to be the cause of the disease, Douglas replied: “No. Because without wanting to get too specific, this particular cancer is caused by HPV …”
He did us all a favor by raising awareness about human papillomavirus. But was he telling the truth? Let’s look at the facts.
By the way, if you have never had sex, kissed anyone on the mouth, or touched someone else’s genitals, you can stop reading right now. You are not at risk for HPV-related disease and don’t need to read the rest of this article. If you have engaged in any of these activities, read on.
So what’s the big deal? HPVs are a group of viruses that are sexually transmitted. The virus lives in the cells of an infected person’s genital area and throat.
There are many HPV types, and most simply cause genital warts, unsightly, contagious, but otherwise not dangerous. However, HPV types 16 and 18 have been causally linked to cancers of the cervix, anus, penis, vagina, vulva, tonsils, base of the tongue, and perhaps other areas.
The genetic material of HPV 16 viruses has been found blended into the genetic material (DNA) of these tumors. And laboratory tests have shown that HPV infection leads to cellular growth changes that cause cancer.
It is estimated that overall, 7 percent of American men have oral HPV, and 1 percent have HPV type 16 in their oral mucosa.
As with many cancer-causing viruses, there is a long “latency period” between infection and the development of cancers. This means your actions as a youth can have consequences in adulthood.
Transmission of HPV has been demonstrated via genital-genital contact, digital –genital contact, and digital-anal contact. In other words, you can acquire an infection without having intercourse.
Once infected, you may have warts, but most often you have no symptoms until you develop cancer. This is the scary thing about HPV and many other sexually transmitted diseases.
And while a linkage between oral HPV infection and oral sex seems logical, it has never been demonstrated. Links between sexual activity and HPV-related cancers have been demonstrated, however. HPV-related cancer incidence increases with an increasing number of sexual partners and with earlier age at which sexual activity starts.
Can we treat HPV infections? Some patients can spontaneously eradicate or “clear” HPV 16 and 18 from their bodies. For others, there is no treatment, and the virus lays in wait, slowly causing genetic changes that lead to cancer. Not everyone who is infected gets cancer, but we have no predictive tool to tell who is susceptible to HPV carcinogenesis.
What we do have is an early cancer detection tool. Pap smears can be used to detect early HPV-mediated cervical and anal cancer, and tests are under way to see if they can be used for early detection of tongue and tonsil cancer. Early diagnosis can lead to cure with surgery or chemotherapy and radiation, but we currently have no way to get rid of chronic infections.
If we can’t treat chronic HPV infections, what can we do?
The best offense is a good defense. In the past decade, the Gardasil and Cervarix vaccines have been developed that protect against HPV 16 and 18 infection. They have been demonstrated to reduce the risk of cervical and anal cancer, and studies are under way to see if they reduce the risk of HPV-related oral cancers.
The vaccine only works to prevent infection, so it has to be given to people before exposure to HPV. It is recommended that both girls and boys be immunized in their early teens, before they become sexually active in any way.
Although most insurers and Medicaid cover the cost of this three-shot series, only a third of girls and about 10 percent of young boys have been vaccinated.
Why don’t people take a simple precaution that can save lives?
Some of this is due to lack of knowledge and some due to irrational fear of vaccines, but the biggest deterrent has been parental fear that vaccination will lead to sexual promiscuity.
Here’s what I have to say to parents with this concern. We are fortunate in Idaho that the public health districts will vaccinate those under the age of 19 for just the vaccine administration fee.
The vaccine is normally expensive, so this is a heck of a deal. Do you want your kids to miss the opportunity for cheap lifetime protection? And how would you feel if you had to watch your kid battle or die of an HPV-related cancer that could have been prevented?
Back to Michael Douglas. What’s the take-home message? People should be vaccinated before they become sexually active, never start to smoke, keep alcohol use to a minimum, and remember to get regular physical and oral exams. Stay healthy, Idaho!
For more information on HPV and the vaccines, watch this short video: http://www.youtube.com/watch?v=LOBSAhuotnM
And here’s an article written by Idaho native Sage Coe Smith, a University of Washington medical student completing a clinical rotation with St. Luke’s family medicine physicians: HPV Hailey article
Facts about HPV-related oral cancers
Until this millennium, most tongue and tonsil cancers were caused by smoking and alcohol use. More recently, 70 percent of these cancers have been shown to be HPV-related.
Part of this apparent increase may be due to the availability of sophisticated tests that detect HPV DNA in oral cancers. Nevertheless, HPV-related oral cancers are often misdiagnosed, leading to delayed diagnosis.
For unknown reasons, these cancers occur more frequently in men. They occur in younger patients than other types of oral cancers, and they seem to respond better to treatment than other types of oral cancers.
Smoking and drinking have been shown to increase susceptibility to oral HPV infection and to increase the risk of HPV-related throat cancer in individuals with chronic HPV infections.
And although this cancer has received a lot of recent publicity, it is still relatively uncommon.
Perhaps the biggest mystery about HPV16-related cancers is why the incidence of oral (and penile) cancers is so much lower than the incident of cervical and anal cancers.