Why Does HPV Increase Your Risk of Cancer?

You might have heard of HPV, and the HPV vaccine. They’ve both been in the news a lot this year. But unless you’ve gone out of your way to research it, you might not know what it is, what it means, or why the vaccine is so important. Or why a virus can somehow cause cancer. So today we're going to look at HPV under the microscope.

What is HPV?

HPV (or Human Papillomavirus) is the name for a group of viruses with over 200 types that cause infection on the surface of the skin. The infection can be there even if you can’t see it, so most people don’t know they have it. Most sexually active people will come into contact with HPV during their lifetime since it’s passed on through close skin-to-skin contact, usually through sexual contact, but not exclusively. It’s not spread through bodily fluids, so prolonged or frequent skin-to-skin contact can spread it too.

Almost everyone will have HPV on their skin at some point in their life. For most people, it causes no issues and goes away on its own. In fact, someone could have multiple different types of HPV at once and not know it. Some strains (around 40 of them) will cause minor symptoms, mainly warts on the genitals or hands. The immune system is very good at clearing the majority of HPV infections from your body within 1-2 years, so you may not know at all that you’ve had it, or when.

But sometimes, it’s not that simple.

There are around 14 nasty variations of HPV that can develop into cancers, including:

·         Cervical cancer (the most common)

·         Anal cancer

·         Vaginal cancer

·         Vulval cancer

·         Penile cancer

·         Some types of mouth and throat cancer

Globally, HPV is responsible for around 630,000 cancer diagnoses every year.

Why Does HPV Cause Cancer?

Those 14 variations of HPV are known as ‘high risk’ strains. These are different from other HPV infections, because the virus produces two key proteins called E6 and E7 inside the infected cells. Those proteins then turn off the body’s natural tumour suppressor proteins, which are responsible for halting cell division, repairing damaged DNA and triggering programmed cell death in damaged cells. The problem is, our bodies produce damaged cells everyday that have the potential to become cancerous, and without those tumour suppressor proteins any of those cells could mutate, accumulate damage and turn into one of those cancers.

But there’s also a reason that HPV is most commonly connected with cervical cancer. If the HPV virus hasn’t been cleared by the immune system naturally, then it can infect the skin cells in the cervix and cause them to grow abnormally. This process is cervical dysplasia, and if it goes unnoticed it gets worse, eventually developing into cervical cancer.

Can It Be Prevented?

The good news is that yes, HPV-related cancers can be easily prevented. The HPV vaccine was first approved in 2006, and is now part of the routine vaccination program in the UK. It’s offered to boys and girls aged 12-13 in year 8, and older people can also be given initial doses or top-ups if their doctor feels its necessary. It’s actually one of the most successful vaccines out there – it’s 90%-97% effective at preventing cervical cancer, pre-cancers and genital warts if it’s been given before you’re exposed to the virus. And new data from a study into the lives saved by the vaccine shows that it’s reduced the risk of cervical cancer death before age 30 to effectively 0. Which is absolutely incredible! And all the more reason that the HPV vaccine should keep being given.

It's also important for women or AFAB people to attend regular smear tests. These are offered to everyone with a cervix from the age of 25 every 5 years until the age of 64. After 64, research shows that you’re much less likely to develop cervical cancer if you have a history of negative tests, though there are exceptions of course.

There aren’t many cancers that are preventions for, let alone such effective ones! So just as you should check your breasts/testicles regularly, you should get your smear tests and your HPV vaccine too. Prevention is better than cure, after all.