Infection with human papilloma virus (HPV) is the cause of almost all cervical cancers. There are specific strains of HPV that are cancer causing, most notably HPV 16 and 18.
But what is the risk of getting cancer from HPV?
Here are some eye-opening stats.
HPV 16 and 18 are more cancer causing than cigarettes. If you are a smoker then your risk of getting lung cancer increases 8 times (an 800% increase). In epidemiological terms, that’s mega huge (and why health experts prattle on so much about cigarettes). The combination of estrogen and Provera (a synthetic progesterone) increased the risk of breast cancer for menopausal women 1.3 fold (a 30% increase). This was enough of an increase that the trial was stopped.
The biggest player in cervical cancer is HPV 16. Infection with HPV 16 increases a woman’s risk of cervical cancer 434 fold and HPV 18 increases that same woman’s cancer risk 248 times. Cigarettes are but a drop in the cancer bucket when compared with HPV.
And 5% of young women will become infected with HPV 16 and 2% with HPV 18 within 4 years of initiating sexual activity (all told approximately 80% of sexually active women will be exposed to and infected with some kind of HPV virus by the age of 24).
The good news is that 80% will also clear the virus. Their immune system will kick in and contain it. However, for 15% of women with HPV 16 and 5% with HPV 18, over 3 years their infection will not be contained and will develop into a pre-cancer, which left untreated will almost certainly progress to a cancer.
And that is why we need the HPV vaccine, because both commercially available vaccines target the two HPV strains that are the most oncogenic (likely to cause cancer).
HPV 16 and 18 are FAR MORE cancer causing than cigarettes and 7% of young women will be infected with this virus when it can do the most damage, when they are young.
Brown et al. (2005) J Infect Diseases
Winer et al. (2003) Am J Epidemiol
Winer et al. (2006) NEJM