THE BLOG

Sex and Cancer Connection in the Spotlight

07/06/2013 09:06 BST | Updated 06/08/2013 10:12 BST

A topic that's dominated the news this week is the link between throat cancer and oral sex. In a recent interview, Hollywood actor Michael Douglas brought this topic into the spotlight by saying that genital human papillomavirus (HPV) transmitted through oral sex caused his 2010 throat cancer diagnosis. Although this statement was later denied, it certainly sparked a media frenzy around the connection between sex and cancer.

The main question that the headlines have splashed about is: can you get throat cancer from oral sex? Well, the answer is yes. Some types of throat or mouth cancer can be caused by a certain strain of HPV, a common sexually transmitted disease. But it's important to remember that smoking and excessive alcohol consumption are your biggest risk factors of throat cancer and dwarf that of HPV infection. Something that the papers seem to be currently overlooking.

Before we look specifically at the mouth cancer and HPV connection, I want to give a bit of background to the virus in general.

HPVs are a group of more than 150 related viruses, with each group given a number. The viruses live in cells that are found on the surface of your skin and in moist surfaces such as the vagina, anus, cervix, vulva, head of the penis, mouth, throat and trachea (windpipe). More than 40 of these viruses can be spread through direct skin-to-skin contact during vaginal, anal or oral sex.

Some types of genital HPV can cause warts on or around your genitals, anus, cervix or vagina. These types are known as 'low risk' because these warts very rarely become cancerous. Other types of genital HPV are 'high risk' because they are linked with certain cancers in both men and women.

Infection with HPV is very common. In fact, many of you reading this will be infected with one or more types of HPV at some point in your life. Anyone who has ever had sex can get HPV, even if you've only had sex with one person in your lifetime.

In most instances, your body is able to clear the infection on its own. In about 90 percent of people, the immune system clears the HPV infection within two years. It's only when the infection becomes chronic that is can cause cancer, especially if it's a high-risk type.

Some cancers caused by HPV are now successfully being prevented, for example, cervical cancer with an HPV vaccine. The focus has now shifted to other areas of the body where HPV could cause cancer, mouth cancer being one of them, with younger people flagged as particularly at risk. A recent study in the USA connected over 20,000 mouth cancer cases to HPV in the last five years.

Furthermore, cancers at the back of the tongue and in the tonsils have become more common over the past 20 years, with many of these linked to HPV 16 infection. Some experts believe that one of the main ways the virus spreads to the back part of the mouth and throat is through oral sex.

Non HPV-positive cancers, potentially caused by excessive drinking or smoking, tend to be located at the front of the tongue, floor of the mouth, the inside of the cheeks or the ridge area around the teeth. This demonstrates different cancerous sites depending on whether the HPV infection is present or not; although this isn't always the case.

But an increase in the number of people being diagnosed with mouth or throat cancer shouldn't solely be linked to HPV infection - two of mouth cancer's biggest risk factors, smoking and excessive drinking, are still mostly to blame. Around three out of four (75 percent) head and neck cancers are linked to tobacco or alcohol use. Drinking excessive amounts of alcohol can increase your risk of developing mouth cancer by four times. And, because alcohol helps the absorption of tobacco into your mouth, if you also smoke, you're up to 30 times more likely to develop the disease. The best way to significantly cut your risk of mouth cancer is to stop smoking and keep alcohol to a minimum.

The high-profile story surrounding Michael Douglas has certainly brought this topic to the foreground, but isn't giving the right message. Yes, oral sex can cause throat cancer, but remember, sex on the whole comes with a wide range of health risks if it's not practiced safely. So, the overarching message shouldn't be to stop enjoying yourself or to panic about your sexual history. It's the same message time and time again: the basic principle of safe sex and making sure you get anything out of the ordinary checked out.