By Irene O. Aninye, Chief Science Officer
Prevalent but Preventable: The HPV Dilemma
In 2006, the Centers for Disease Control and Prevention (CDC) reported almost 13,000 cases of cervical cancer in the United States. At that time, cervical cancer had the highest cancer mortality rate among women in the country – a serious public health issue that research and health care industries challenged head-on. Advances to address this crisis included the development of a vaccine (released that year in 2006) against human papillomavirus (HPV) – the primary cause of cervical cancer – and much needed updates to the screening guidelines for cervical cancer. Almost 20 years later, public awareness of HPV and its related diseases are still poor – and further inhibited by stigma that too often silences this important conversation.
Most individuals will get infected with at least one of the 100+ types of HPV in their lifetime, making HPV one of the most common sexually transmitted infections. In fact, more than 80% of women and men in the United States will acquire HPV by the age of 45. HPV infections often clear naturally from the body without issue; however, persistent infections of certain high-risk types of the virus can lead to serious diseases, such as genital warts or cancer
The current HPV vaccine protects against nine (nonavalent) high-risk types of the virus – two types of HPV that lead to genital warts and seven types that are known to cause cancer. While HPV is widely known to cause almost all cervical cancers, not as many people realize that it can also lead to other anogenital cancers – vaginal and vulvar cancers in women, penile cancers in men, and anal cancers in both women and men – all of which are highly preventable by the vaccine. The last two decades showcase many successes in tackling HPV below the belt – with the vaccine reducing up to 90% of cervical cancer incidence, especially among young women, as well as significant decreases in anal cancer. However, HPV detection in head and neck tumors has increased over the years, accounting for over 70% of oropharyngeal (throat) cancers, prompting the U.S. Food and Drug Administration in 2020 to officially approve the HPV vaccine for the prevention of oropharyngeal cancers as well.
Raising the Volume on Oral HPV
About 10% of men and 3.6% of women have oral HPV, which can lead to oropharyngeal squamous cell carcinomas (OPSCCs) that affect the base of the tongue, soft palate, tonsils, and back of the throat. Historically, OPSCC has been associated with smoking and alcohol consumption and diagnosed primarily in 60- and 70-year-old men. However, from 2015 to 2019, HPV-associated oropharyngeal cancers increased by 1.3% in women each year.
The oropharynx has now surpassed the cervix as the most common site of HPV-related cancers.
The American Cancer Society estimates that in 2023 there will be 54,540 new cases of oral cavity or oropharyngeal cancer, 70-80% of which will be attributed to high-risk HPV types. HPV 16 has been identified to account for over 90% of all HPV-positive OPSCCs, but HPV types 18, 31, 33, 58, and 59 can also lead to these cancers. Infection from all but HPV 59 is prevented by the current nonavalent HPV vaccine.
The gaps in our understanding of OPSCCs are wide and only filling incrementally. HPV infections in the oropharynx cause pre-cancerous lesions that can lead to cancer, unless they are detected and treated early. Individuals may experience a persistent sore throat, trouble swallowing or moving their tongue, a lump in their neck, or coughing up blood. Unfortunately, while a health care provider might observe swollen lymph nodes, there is no effective screening to identify precursor lesions or a primary tumor of OPSCC. Moreover, the cancer-causing process of oropharyngeal cancer is not well understood. Some studies speculate that the unique structure and function of the oropharynx may make its tissues more susceptible to HPV infection, and unfortunately, more difficult to access samples for potential screening and diagnostic tests.
Actions Speak Louder than Words
A comprehensive prevention approach for cervical cancer consists of HPV vaccination (primary), routine screening through HPV and Pap tests (secondary), and early diagnosis and treatment of precancerous lesions (tertiary) – and we have seen this work in reducing cancer rates. A similar strategy must be applied to oropharyngeal cancer prevention, with an extended focus on women’s health. According to a study published out of the University of Texas Medical Branch, although incidence of HPV-related OPSCC declined among young adults after the introduction of the HPV vaccine, 5-year survival did not significantly improve in young females the way it did for young males (ages 20-44 years).
The paradigm concerning HPV-associated OPSCC must shift from the historical focus on older men to address the rising incidence in young girls and women to ensure that this public health issue is addressed for all people. Research investment and priority must also be given to develop screening and surveillance guidelines that will effectively reduce OPSCC incidence, morbidity, and mortality.
At present, the best tool we have to combat HPV-associated oropharyngeal cancer is the HPV vaccine, although it has encountered its share of barriers (for example, the stigma associated with HPV being a sexually transmitted infection has hindered vaccination uptake). There is a need to increase awareness about the importance of HPV vaccination as a preventive measure against cancer.
First and foremost, this messaging should note that the HPV vaccine is a cancer prevention vaccine that should be widely used as recommended for adolescents as early as age nine through adults up to age 45. Further, messaging and patient-provider conversations must engage both women and men to ensure that all individuals are provided with the education and opportunity to protect themselves and their loved ones from serious HPV-related diseases like OPSCC.
Talking frequently, openly, and accurately about HPV-related cancers and the tools we have to prevent them is an invaluable use of time. So, let’s talk about it…
Browse SWHR resources about HPV, the HPV vaccine, and HPV-related cancers.