The reason why oropharynx cancers are on the rise
Throat cancer, in particular oropharynx cancer, is such a concerning cancer now, because it is one of the few head and neck cancers with a rising incidence, unlike others which are decreasing due to the general decrease in smoking worldwide. Currently more than half of oropharynx cancers are caused by the Human Papilloma Virus (HPV).
What is the oropharynx?
It is the middle part of the throat behind the mouth. Most cancers start in the palate tonsils (or where they used to be) and the base of the tongue.
HPV is the most common sexually transmitted disease and it is thought that over 85% of sexually active adults have been exposed to the virus over their lifetime. Most people who have the viral infection never know since there are no symptoms, and the immunity clears the virus within two years of exposure. The risk of developing oropharynx cancer is significantly increased, the more vaginal and oral sex partners one has. One good note is that patients with HPV-related throat cancer are not contagious.
The problem is head and neck cancer may be missed, unless you, the patient, or your doctor are thinking about it. Also, another big challenge patients face is not knowing who to see and where to go. Ear, nose and throat (ENT) surgeons are trained to manage head and neck cancer, but ideally, because it is a complex problem, working in a multi-disciplinary team is the best proven approach.
A sore throat and, sometimes, a very large neck swelling are the usual presenting problems. The typical HPV oropharynx cancer patient is a 55-year-old, non-smoking man.
After a scope examination by the ENT, the initial investigations include imaging – usually with a contrast CT scan. The next quickest and safest test is a fine needle aspiration biopsy (FNAB) of the neck mass, under ultrasound guidance. Excision biopsies of neck nodes are not recommended, however, sometimes biopsies from the throat are necessary to be taken, which are often done under general anaesthesia. FNAB or biopsy specimens should be sent for an assessment of tumour HPV status. This is not done with blood tests.
Decisions regarding treatment should be made by a multi-disciplinary team that meet weekly, and is dependent on patient factors, tumour factors and the clinician/hospital factors.
In early cancers, treatment could include primary surgery with a transoral laser technique confirming intraoperative clear margins, and a neck dissection to remove lymph nodes in the neck which may harbour cancer. These methods are only used in early cancers.
For more advanced cancers, radiation with chemotherapy at the same time, is the treatment of choice. The treatment is tough and requires a lot of planning, with many visits to different members of the multi-disciplinary team prior to treatment, in order to avoid problems related to the treatment itself.
HPV status currently only tells us how well we think patients will do, but it is thought that we are over-treating HPV positive patients, and the ideal treatment regimen is yet to be determined.
HPV positive oropharyngeal cancers have significantly improved survival, when compared to similarly staged HPV negative patients: 83% vs. 57% respectively. Short-term follow-ups involve seeing many members of the team, but the head and neck surgeon is the primary care physician in the long term.
Repeated examination and imaging after treatment are crucial to confirm whether control has been achieved.
To reduce the risk of contracting HPV-associated oropharynx cancer, it is recommended to give HPV vaccinations to pre sexually-active girls and boys. Unfortunately, there is no screening test for throat cancer. Testing whether one has or had HPV does not predict the risk of getting a throat cancer, and is also not recommended.
The wise thing to do is not to ignore symptoms, and to get treatment under the guidance of a multi-disciplinary head and neck team, in order, to get the best possible results. Abstinence, faithful marriages and HPV immunisation is the best preventative medicine.