Recently many people have become aware of information in the media suggesting that there is a link between human papilloma virus (HPV), that might be transmitted by oral sex, and some cancers in the throat. Little is known about the natural history of oropharyngeal (throat) HPV but it is an area of rapidly emerging new knowledge. This information will be updated as new evidence is available. The answers to the following frequently asked questions are to help you understand what is known and what is not yet clear.
Frequently asked questions
Does HPV cause throat cancers?
Smoking still remains the most common cause of throat cancer but the link between some oral cancers and HPV is an area of ongoing medical research. There is growing evidence that HPV plays a role in some types of throat cancers. There are many types of HPV that live on the body and only a small number of types cause problems by turning cells from normal to abnormal. But most HPV infections go away before they cause any health problems at all. Some types of oral HPV (found in mouth or throat) can cause warts. These are Low risk (Lr) HPV and are non cancerous. Other types of oral HPV can cause cancers of the head and neck area, these are High risk (Hr) HPV Current research indicates that Hr HPV changes the host (human) cell but its growth needs additional triggers to cause cancer. Possible other co-factors that may increase the risk of developing throat cancer are smoking, chewing tobacco, having a weakened immune system, poor oral hygiene and conditions causing chronic irritation to the throat. Chronic irritation of the throat may be caused by chemicals irritants such as alcohol, or acid reflux, and chronic bacterial tonsillitis.
Does oral sex cause throat cancers?
Oral sex itself doesn't cause throat cancer but current research indicates HPV is sexually transmitted through oral genital sex because most of the oral HPV types are the same types that infect the genital area. Many people have oral sex but few develop throat cancers. Between the ages of 15-44, 80% of people have had oral sex, and so far it appears only a very small percentage of the population will develop throat cancers.
How common are throat cancers?
There a several different types of throat cancers. In New Zealand about 600 people, of whom two thirds are male, get throat cancer per year. Around 30% of these people die from their cancer. The most common area affected is the voicebox (larynx). HPV is present in about 15% of laryngeal (voice box) cancers. Cancers in the tonsil and back of the tongue occur less frequently but are most commonly linked with HPV infection (50-75%). Research suggests that HPV-related cancers occur more frequently in younger people.
What if the throat cancer is HPV Positive?
Throat cancer that has HPV in its cells responds better to treatment. That is, treatment is more effective in these HPV linked cancers than in cancers that do not contain HPV.
Is there a test for oral HPV?
There is no routine test to diagnose oral HPV and there is no recommended screening for it. Routine population screening is only offered for common conditions for which there is early treatment available and this is not the case with throat cancers. However, if a person is being investigated for lesions/cancer of the mouth or throat a 'biopsy' (small sample of tissue) is taken from the area for microscopic examination and includes testing for HPV.
What is the current sexual health advice about HPV and oral sex?
There is not enough evidence for health professionals to give informed advice specifically about oral sex and HPV. However the risk of oral HPV increases with higher numbers of oral sex partners. General safer sex practices are likely to reduce the risk of HPV being passed during oral sex, such as limiting the number of oral sexual partners and always using condoms or latex dams for giving oral sex with new or casual partners. There is no need to change sexual behaviours in long term relationships as partners usually share HPV.
What about a vaccination?
It is possible that HPV vaccines might also prevent throat cancers, since the vaccines prevent an initial infection with same HPV types that can cause some throat cancers.
The HPV vaccine is most effective given before individuals become sexually active. However research studies have not yet been done to find out whether HPV vaccines will prevent throat cancers.
The HPV vaccine, Gardasil is licensed for females between 9 and 45 years and males between 9 and 26years. In NZ vaccination is free to women aged 9 to 20 years and to people with diagnosed HIV under the age of 26 years. Ask your GP or HIV clinician about HPV vaccination.
Because of the higher rate of oral HPV rates in men, it is recommended males consider HPV vaccination and that parents consider vaccination of boys.
If you are outside the funded age range you can pay for the Vaccine which costs approximately $450 for the full 3 doses. Your family Doctor will be able to give you more information about this.
Recommended paper for Health Professionals managing HPV - Oropharyngeal Squamous Cell Carcinoma (OSCC) Discussing the diagnosis of HPV-OSCC: Common questions and answers : C Fahry, G D'Souza. Oral Oncology 49(2013) 863-871