It has been well established that oncogenic (cancer causing) strains of HPV are the cause of cancer of the cervix and in fact it could probably be considered a form of sexually transmitted disease. Over the last few years vaccines have become available (Gardasil and Cervarix) for the prevention of HPV related cervical cancer. Gardasil covers 4 strains of the virus and Cervarix covers 2. Within Australia Gardasil has been made available for young women up to the age of 26 on the Pharmaceutical Benefits Scheme. It is expected that over the next few years we are likely to see a fall in abnormal pap smears (pre-cancer) and frank cancers of the cervix and early indications in my practice over the last few years would support this.
A recent patient who attended with an abnormal pap smear asked about other types of cancers implicated with HPV which prompted this blog. Broadly there are a large number of strains of HPV and certain strains (HPV 16 and 18 in particular) have been associated with the development of cervical cancer and increasing evidence is indicating these agents in the development of oropharyngeal and anal cancer.
Oropharyngeal cancer is now the sixth most common cancer in the world and over the last few decades there have been an increasing number of oropharyngeal cancers in a younger population. It appears there may be two types of this cancer. Firstly a traditional HPV negative type cancer which appears to be associated with the use of tobacco and alcohol and secondly an HPV positive form which is linked to oral sex. Epidemiological studies indicate increasing lifetime numbers of vaginal sex partners (26 or more) and oral sex partners (6 or more) significantly increase the risk.Unfortunately there is no screening test for oropharyngeal cancer as the early phase of the disease is not well understood.
HPV has also been associated with an increasing number of anal cancers and again the risks relate to sexual activity with increasing numbers of anal sexual partners heightening the risk. Recipients of anal sex whose partners are HPV positive are at a higher risk. There have been attempts to screen with this and in some clinics anal pap smears are performed as there does appear to be a pre-invasive course to this particular cancer.
With this increasing evidence there have been calls around the world to extend the range of vaccination to include boys and young men. Australia has recently introduced HPV vaccination for boys. There is also evidence to show that vaccination is useful for both men and women over the age of 26 although it is known that the effectiveness of the vaccine decreases with age. Depending on your circumstances and past exposure to HPV, it may be reasonable to consider vaccination for men and women over the age of 26.
HPV vaccination is likely to lead to a reduction in rates of cervical, oropharyngeal and anal cancers. If you have not already been vaccinated it is certainly worth considering.
