Diagnoses and deaths from anal cancer, which is related to the human papillomavirus (HPV), have risen dramatically over the last 15 years according to a new peer-reviewed article. This study was the first to compare and categorize HPV-related anal cancer by stage at diagnosis, year of birth, and mortality.
One of the myths about the HPV vaccine is that its only purpose is to prevent cervical cancer in women. Although that is important, this study shows that preventing anal cancer should be one of the goals of getting the HPV vaccine.
Like I usually do with anything related to the HPV vaccine, let’s take a look at the disease and the study.
All about HPV vaccines
Many of you have read this section an enormous number of times, however, for some of the readers of this blog, this article might be their first bit of research into the human papillomavirus (HPV) vaccine. Thus, it’s important to get a brief overview of HPV and the vaccines. If you’ve read this section before, just skip to the next section if you want.
Genital and oral 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. 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:
These are all dangerous and disfiguring cancers that can be mostly prevented by the HPV cancer vaccine. If you’re a male, and you think that these are mostly female cancers, penile cancer can lead to amputation of your penis. Just think about that guys.
Anal cancer occurs where the gastrointestinal tract ends, the anus. It is not related to colorectal cancer – its cell type and location are substantially different than anal cancer.
Interestingly, anal cancer is similar to cervical cancer, which, of course, was one of the reasons for the development of the vaccine. Nevertheless, nearly 90% of anal cancers are caused by HPV.
In fact, 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. Accordingly, over 31,000 HPV-related cancers are diagnosed in the USA every year.
There were two HPV vaccines on the world market before 2014. GSK, also known as GlaxoSmithKline manufactured Cervarix, a bivalent 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 subtypes) and 9-valent (against nine subtypes) 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. It targets the four HPV genotypes 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 before females or males become exposed to possible HPV infection through intimate contact.
Gardasil is one of the easiest and best ways to prevent a few deadly cancers that are related to HPV. It is definitely a cancer-preventing vaccine.
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.
Anal cancer and HPV – the study
In a study published in the Journal of the National Cancer Institute, by Ashish A. Deshmukh, Ph.D., MPH, and others at the UTHealth School of Public Health. The researchers used the US Cancer Statistics database to examine trends in anal cancer incidence from 2001-2015 and mortality rates from 2001-2016.
They analyzed data from the database in the USA which included 68,809 cases of anal cancer and 12,111 deaths from the disease from 2001-2016.
The study was the first to compare contemporary US trends in the incidence of squamous cell carcinoma of the anus (SCCA), the particular type of anal cancer caused by HPV, by stage at diagnosis, year of birth, and mortality. The researchers found that anal cancer diagnoses and mortality rates have more than doubled for individuals in their 50s and 60s.
The study also determined that new diagnoses of anal cancer among black men born after 1985 increased 5X compared to that same group born in the mid-1940s. They also found that anal cancer rates and mortality increased by approximately 2.7% per year. This may make anal cancer one of the most rapidly rising cancers today.
Other findings of the study:
- Late-stage SCCA incidence tripled among men and 7.5% among women from 2001-2016.
- The risk of anal cancer doubled among white men and white women over that same period.
- Anal cancer mortality rates increased by 3.1% per year in all individuals 50 years and older.
The authors of this remarkable study concluded that:
SCCA is preventable through HPV vaccination; however, vaccination coverage (50% in 2017) remains suboptimal in the US and less than 30% vaccine-eligible individuals or their family members received recommendation for HPV vaccination from their health care
Even if high HPV vaccine coverage is attained in the next 5 years, the
benefits of vaccination may not be evident for at least 15-20 years given the lengthy time between initial HPV infection and development of SCCA.
Squamous cell carcinoma of the anus (SCCA) incidence has increased dramatically in elderly women and young Black men. Advanced stage SCCA incidence tripled with a prominent rise in SCCA mortality. Our findings call for future studies to identify reasons for the increase in SCCA incidence and mortality. Improved prevention strategies are urgently needed to mitigate the rising SCCA burden among a rapidly growing number of aging US adults.
In addition, the authors suggested that there is a stronger need for anal cancer screening. Currently, only those in high-risk groups, such as homosexual men, are regularly screened for the disease. This study suggests that we should not only increase the rate of HPV vaccinations, but we should also evaluate broader screening efforts.
It’s troubling that too many people across the world do not know that HPV is linked to a number of cancers, especially anal cancer.
This is a preventable cancer – the HPV vaccine prevents the HPV infection, thereby preventing anal cancer. A blueberry-kale smoothie and a handful of useless supplements are not going to prevent this deadly cancer.
Men and women should get the cancer-preventing HPV vaccine. Yeah, make that appoint right now, save the lives of yourself and your loved ones. Easy peasy.
- Deshmukh AA, Suk R, Shiels MS, Sonawane K, Nyitray AG, Liu Y, Gaisa MM, Palefsky JM, Sigel K. Recent trends in squamous cell carcinoma of the anus incidence and mortality in the United States, 2001-2015. J Natl Cancer Inst. 2019 Nov 19;. doi: 10.1093/jnci/djz219. [Epub ahead of print] PubMed PMID: 31742639.