Two new peer-reviewed studies about the incidence of HPV-related oropharyngeal cancer provides more evidence for the importance of the HPV vaccine. There are so few evidence-based methods to prevent cancer, it is shocking that so many people forgo the HPV vaccine for their children and for themselves.
I think one of the misunderstandings about HPV and the HPV vaccine is that it’s all about cervical cancer, a serious disease by itself. But many people overlook that possibly half of HPV-related cancers are not about cervical cancer, but numerous other cancers that are just as deadly.
In fact, HPV-associated cancers are increasing in men, but are dropping in women, because women had a head-start in getting the HPV vaccine.
We can all predict that the anti-vaccine crackpots will claim that HPV has nothing to do with cancer or a good organic, GMO-free, blueberry kale smoothie will prevent oropharyngeal cancer. However, for those of us who care about scientific evidence, please read on.
All about HPV and HPV vaccines
I know I add this section to every article I write about HPV or the HPV vaccine. However, there are some readers who want to know more about HPV, and this section can help someone get up-to-speed quickly.
Genital and oral human papillomavirus (HPV) infections are the most common sexually transmitted infections (STI) in the USA. HPV is generally transmitted from personal contact during vaginal, anal or oral sex.
It’s important to note that there are more than 150 strains or subtypes of HPV that can infect humans – however, only 40 of these strains are linked to one or more different cancers. Of those 40 strains, most are extremely rare.
Although the early symptoms of HPV infections aren’t serious and many HPV infections resolve themselves without long-term harm, HPV infections are causally linked to many types of cancers in men and women. According to current medical research, here are some of the cancers that are linked to HPV:
In addition, there is some evidence that HPV infections are causally linked to skin and prostate cancers. The link to skin cancer is still preliminary, but there is much stronger evidence that HPV is linked to many prostate cancers.
HPV is believed to cause nearly 5% of all new cancers across the world, making it almost as dangerous as tobacco in that respect. According to the CDC, roughly 79 million Americans are infected with HPV – approximately 14 million Americans contract a new HPV every year. Most individuals don’t even know they have the infection until the onset of cancer. The CDC also states that over 43,000 HPV-related cancers are diagnosed in the USA every year. It may be several times that amount worldwide.
There were two HPV vaccines on the world market before 2014. GSK, also known as GlaxoSmithKline, produced Cervarix, a bivalent (protects against two HPV strains) vaccine. It has been withdrawn from the US market (although available in many other markets), because of the competition from the quadrivalent (immunizes against four different HPV strains) and 9-valent (against nine HPV strains) Gardasil vaccines.
Merck manufactures Gardasil, probably the most popular HPV vaccine in the world. The first version of the vaccine, quadrivalent Gardasil, targets the two HPV genotypes known to cause about 70% of cervical cancer and two other HPV genotypes that cause genital warts. In Europe and other markets, Gardasil is known as Silgard.
The newer Gardasil 9, approved by the FDA in 2014, is a 9-valent vaccine, protecting against HPV types 6, 11, 16, 18, 31, 33, 45, 52, and 58. It targets the four HPV strains found in the quadrivalent version, along with five additional ones that are linked to cervical and other HPV-related cancers. Both versions of Gardasil are prophylactic, meant to be given to females or males before they become exposed to possible HPV infection through intimate contact.
Gardasil is one of the easiest and best ways to prevent a few dangerous and, to abuse the definition slightly, common cancers that afflict men and women. Without a doubt, the HPV vaccine prevents cancer.
Currently, in the United States, the Advisory Committee on Immunization Practices (ACIP) recommends that preteen girls and boys aged 11 or 12 are vaccinated against HPV. The immunization is also recommended for teenage girls and young women up to the age of 26 who did not receive it when they were younger, and teenage boys and young men up to the age of 21.
Let me sum this all up so that if you come away from this section with nothing else, you get this summary. HPV is a sexually transmitted disease. HPV causes 43,000 cancers a year in the USA alone. The HPV vaccine prevents becoming infected by HPV, which means you are protected from these cancers.
HPV-associated oropharyngeal cancer papers
The first paper, from lead author Danielle N Margalit and published in Cancer Epidemiology Biomarkers & Prevention, examined data from the Surveillance, Epidemiology and End Results (SEER) HPV-status database which included over twelve thousand patients with various types of oropharyngeal cancer which were diagnosed from 2013-2014. Here are some of the key results:
- The incidence of HPV-positive oropharyngeal squamous cell carcinoma (OPSCC) was 4.62 per 100,000 persons versus 1.82 per 100,000 for HPV-negative OPSCC. In other words, about 72% of these cancers are HPV-related, and the risk of oropharyngeal cancer is 2.53X higher in those who have HPV than those who do not.
- The highest incidence for HPV-positive OPSCC was for whites (5.47 per 100,000) and males (8.00 per 100,000).
I know that people have a tendency to deny evidence about what is linked to cancer – I’m still appalled that there are people who think that tobacco is not linked to lung cancer. But this is clear evidence that HPV is linked to oropharyngeal cancer.
The second paper, by Miriam Lango, MD and published in Oral Oncology, examined tonsil cancer (a form of oropharyngeal cancer) incidence in the USA using the same SEER database. Although the study did not look at incidence of HPV-related oropharyngeal cancer directly, the results are still important to the conversation about HPV.
The researchers found that the incidence rates for tonsil cancer have increased between 2010 and 2014, about 4.4% in low socioeconomic status counties and about 2.9% in high socioeconomic status counties. This compares to larynx cancer rates which did not change significantly over that time.
Furthermore, the increase in this type of oropharyngeal was most likely to be younger and white.
The authors stated that:
These results suggest that since the incidence of tobacco-related head and neck malignancies is decreasing overall, the increasing tonsil cancer incidence trends in low SES regions may be attributable to HPV-mediated disease.
From 2000 through 2014, the incidence of tonsil cancer increased equally in low SES counties and as in higher SES counties while incidence rates for larynx cancer declined or remained stable. Prevention efforts which currently involving education to promote awareness of the importance of HPV vaccination should include lower income populations.
In other words, this study suggested that prevention strategies for tonsil cancer are critical. Those efforts should be focused on HPV prevention, including the HPV vaccine for all socioeconomic groups.
The evidence provided by these two peer-reviewed articles makes it clear – HPV-associated oropharyngeal cancer is on the rise. And it’s also clear that the increase is substantial and is not concerned about socioeconomic groups (meaning that kale blueberry shake has no value to the privileged crowd).
I know some vaccine deniers will say “we don’t know if the HPV vaccine will prevent oropharyngeal cancer.” This is the same ignorance when someone tries to claim that not smoking cigarettes has nothing to do with stopping lung cancer. If we can prevent the virus that is linked to oropharyngeal cancer, then we prevent that cancer. It’s not rocket science.
And you know those same vaccine-ignorant nutjobs will claim “HPV isn’t dangerous and most of the time, it just goes away.” Well, it is dangerous, and sometimes it doesn’t go away, and that leads to cancer.
But if you’re sitting on the fence, thinking that somehow the HPV vaccine is only for cervical cancer, think again. It prevents dangerous and deadly cancers.
- Mahal BA, Catalano PJ, Haddad RI, Hanna GJ, Kass JI, Schoenfeld JD, Tishler RB, Margalit DN. Incidence and Demographic Burden of HPV-associated Oropharyngeal Head and Neck Cancers in the United States. Cancer Epidemiol Biomarkers Prev. 2019 Jul 29;. doi: 10.1158/1055-9965.EPI-19-0038. [Epub ahead of print] PubMed PMID: 31358520.
- Tang JA, Lango MN. Diverging incidence trends for larynx and tonsil cancer in low socioeconomic regions of the US. Oral Oncol. 2019 Apr;91:65-68. doi: 10.1016/j.oraloncology.2019.02.024. Epub 2019 Mar 4. PubMed PMID: 30926064.