Week 2: It's all about the viruses...
Given that we are currently in lockdown from the Covid19 pandemic, I thought that I’d focus this week’s post on the virus that has caused my cancer. From my very first post, I admitted that I was profoundly ignorant that the human papillomavirus (HPV) could cause cancer in men, thinking that it only caused cervical cancer in women. For these past few weeks I’ve been reading up on HPV cancers in general, and in particular those that lead to oropharyngeal squamous cell carcinoma (OPSCC) e.g. of the tonsils, which is what I’ve been diagnosed with. Part of my ignorance is my demographic – I don’t have kids, so I’ve not been aware of the debates on whether or not vaccinate boys in schools (girls in the UK have been part of an HPV vaccination programme since 2008); and I’ve not needed to go to specialist sexual health services (SSHS) clinics for some time, where free vaccination is now offered to MSM (men who have sex with men) under the age of 45. Here, I want to share the information I’ve found out on one of the fasted growing HPV-related cancers in adult men in the developed world, because maybe one of you readers will spot the symptoms and act early.
Human papillomaviruses (HPV) are very common sexually transmitted diseases (STDs), that are also implicated in a number of very preventable cancers. They are spread mainly by skin to skin contact, and infect squamous cells in the surfaces of the skin, in the lining of the digestive and respiratory tracts, and in the hollow organs of the body,such as the oesophagus, stomach, and heart. There are over 100 types of HPV, but only a few (under 15) are high-risk (e.g. HPV16, HPV18) types which cause cancer. Low risk types such as HPV-6 and HPV-11 cause around 90% of cases of genital warts.
HPV is ubiquitous in humans, with over 80% of us having been infected at some time in our lives. But for most people, our bodies fight the virus off within a few years with little to no symptoms. For a very few people, however, their bodies are not able to fight off the infection, and it can lie dormant for decades, and in a few of those people, this can lead to cancer.
HPV causes 4.5% of all cancers worldwide, with significant gender disparity – 8.6% of cancers in women, but only 0.8% cancers in men. In 1983, a team led by virologist Professor Harold zur Hausen demonstrated the link between cervical cancer and HPV16. The latest figures for the UK suggest that 80% of all HPV cancers occur in women, with about 66% of those linked to cervical cancer. HPV also causes cancers in the vulva, vagina, and, in both men and women, the anus (anogenital cancers). The fact that so few HPV cancers are found in men goes some way to understanding why their impacts on men are far less well known, including amongst health professionals.
And it is here that I will start to focus the blog towards my own HPV-cancer type.
As well as the anogenital cancers, HPV also causes head and neck cancers, technically called Head and Neck Squamous Cell Carcinomas (HNSSC). These include the cancer I have: Oropharyngeal Squamous Cell Carcinoma (OPSCC) of the tonsils. Although by far the majority of head and neck cancers are linked to heavy smoking and / or drinking, in recent decades these have been in decline (see the figure below). Instead, oropharyngeal cancer rates in developing countries have been increasingly linked to HPV16, e.g. in Europe HPV16 account for 31% of these cancers, while in North America the rate is much higher at 60%. In Britain this figure lies between the two at about 52%.
Age-adjusted incidence of HNSCC between 1973 – 2006:
So who are most susceptible? This quote seems to fit me quite well!! 😳
“Patients with HPV-positive OPSCC are typically middle-aged, non-smoking white men of higher socioeconomic status and with a history of exposure to multiple sexual partners. These patients may have some previous exposure to smoking, but most are not current smokers”
Effective treatments for Head and Neck cancers are very different depending on if they are caused by factors such as smoking and drinking, versus high-risk HPV viruses, especially the sexually transmitted HPV viruses such as the type HPV16. So when I first got my diagnoses from the doctor, because I hadn’t heard of HPV-linked OPSCC, I immediately assumed that my younger socialising days had come back to haunt me. But the consultant said that they still needed to get the test from the biopsy to see if they could find HPV16. She explained that the treatment would be the same if I was HPV positive or negative, but what I hadn’t appreciated until later on, was that the treatment outcomes were very different. These differences are summarised in the table below, based on patients from two studies in North America (Fakhry et al. 2008; Marur et al. 2010).
So from the table above, I immediately fit the pattern of HPV positive cancer. I’m a 53 year old man, in a now high socioeconomic status, I’ve never had smoking or alcohol dependencies, and it’s fair to say that I’ve had multiple sexual partners 😬.
But not everything fits the pattern: I rarely used marijuana, and my tumour was larger than ‘expected’ and at a less advanced stage than is typical from the above table. Of immediate and selfish interest to me is that cancers caused by HPV16 have a much higher survival rate after 2 years (94%) than cancers not caused by HPV (58%). This is probably due to a number of factors, including pre-existing health of those dependent on smoking and alcohol, but also HPV-cancers are much more sensitive to concurrent chemoradiation therapy, hence why the status is actually very important.
I’d like to end this blog to highlight the recent recommendations for HPV testing and vaccination in young men, as this is where there was, until very recently, some controversy in the UK. In 2008, the Joint Committee on Vaccination and Immunisation (JVCI) recommended a universal programme of HPV vaccination in girls in schools aged 11-13 years, which has been highly successful, although vaccination rates in recent years has been falling. So why not extend vaccination to 11-13 year old boys as well? In the main, such a vaccination programme would need to have significant impact and be cost-effective for the NHS. Which is what the JVCI have assessed in their most recent 2018 report. By moving towards gender-neutral vaccination of adolescents, this should provide protection for girls not taking up the vaccination at the moment due to stigmatization that HPV is a STD, and will provide protection for MSM who are unlikely to get immunity due to fewer sexual encounters with women. A gender neutral vaccination programme for all adolescents started in the UK in September 2019 using Gardasil, which protects against both high and low risk HPV types, thereby significantly reducing risks from genital warts, cervical and other anogenital cancers, and will surely see a reduction in oropharyngeal cancers in the future.
But if you are middle-aged, male, and have had multiple sexual partners in the past, get the following symptoms checked out, especially if they have persisted for more than 2 weeks. Even if you just make an enquiry to your GP online, these are red-flag symptoms:
a painless lump in your neck (which was my symptom)
a difficulty swallowing
a a persistent sore throat