1. There are over 200 types of human papillomavirus (HPV). About seventy percent of oropharyngeal cancers can be attributed to HPV.
HPV is a group of over 200 types of related viruses, and infection is common. HPV falls into either low-risk or high-risk groups. Low-risk HPV types rarely lead to cancer. However, several types of cancer can be caused by high-risk HPV. High-risk types of HPV are attributed to about half of HPV infections.1
Most infections clear on their own within one to two years. However, if a high-risk HPV infection does not clear and persists for many years, it may lead to cellular changes, and left untreated, it may become precancerous or cancerous (malignant).1
The oropharynx includes the soft palate and uvula, base of the tongue, vallecula, tonsillar region, and the posterior and lateral pharyngeal walls.2 Squamous cells that line the surface of organs, including the mouth and oropharynx, are those affected by HPV, making most oropharyngeal cancers squamous cell carcinomas.1,3 About seventy percent of oropharyngeal cancers can be attributed to HPV.1
1. HPV and Cancer. (2023, October 18). NIH: National Cancer Institute. https://www.cancer.gov/about-cancer/causes-prevention/risk/infectious-agents/hpv-and-cancer
2. Oropharyngeal Cancer Treatment (PDQ) – Health Professional Version. (2023, September 5). NIH: National Cancer Institute. https://www.cancer.gov/types/head-and-neck/hp/adult/oropharyngeal-treatment-pdq
3. Oropharyngeal Cancer Treatment (Adult) (PDQ) - Patient Version. (2023, May 10). NIH: National Cancer Institute. https://www.cancer.gov/types/head-and-neck/patient/adult/oropharyngeal-treatment-pdq
2. Which oropharyngeal structure(s) do most HPV-positive cancers affect?
HPV-positive cancers predominantly affect the palatine or lingual tonsils. The base of the tongue and tonsillar site tumors show a 62% HPV-positivity rate. In comparison, other oropharyngeal sites show a 25% HPV-positivity rate.
Malignant anterior tonsillar pillar lesions may appear with areas of dysplasia, inflammation, or superficial spreading. Malignant lesions that begin in this area can spread across a broad region, including the tonsillar fossa, lateral soft palate, retromolar trigone, and buccal mucosa.
Posterior tonsillar tumors can extend to the posterior aspect of the thyroid cartilage and inferiorly to the pharyngoepiglottic fold.
Malignant tonsillar fossa lesions may appear as exophytic or ulcerative. Their pattern of spread is similar to those of anterior tonsillar pillar lesions. These lesions present as advanced-stage diseases more frequently than malignancies of the tonsillar pillar. Patients with malignant tonsillar fossa lesions present with stage III or stage IV disease in 75% of cases.
Oropharyngeal Cancer Treatment (PDQ) – Health Professional Version. (2023, September 5). NIH: National Cancer Institute. https://www.cancer.gov/types/head-and-neck/hp/adult/oropharyngeal-treatment-pdq
3. Which of the following is not a high-risk HPV type?
Of the over 200 types of HPV, twelve are considered high-risk due to their ability to cause several types of cancer. High-risk HPV types include 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, and 59. Most attributed to HPV-related cancers are HPV-16 and HPV-18.1
Low-risk types rarely cause cancer and include both HPV-6 and HPV-11. These types can cause warts on or around the genitals, mouth, and throat.1,2 Respiratory papillomatosis is a condition that can cause breathing problems when warts form in the larynx or respiratory tract.1
1. HPV and Cancer. (2023, October 18). NIH: National Cancer Institute. https://www.cancer.gov/about-cancer/causes-prevention/risk/infectious-agents/hpv-and-cancer
2. Low-risk HPV. (n.d.). NIH: National Cancer Institute. https://www.cancer.gov/publications/dictionaries/cancer-terms/def/low-risk-hpv
4. It is estimated that ____ percent of adults have been exposed to HPV-16.
It is estimated that 90 percent of adults have been exposed to HPV-16. The presence of HPV-16 antibodies can be found in 70 percent of adults, showing evidence of previous infection.
In contrast to previous exposure prevalence, it’s been found that three to five percent of adolescents and five to 10 percent of adults have an active HPV infection. HPV-16 is detectable in one percent of adult women and three percent of adult men at any one time.
Human HPV and Throat/Oral Cancer Frequently Asked Questions. (n.d.). Mount Sinai. https://www.mountsinai.org/locations/head-neck-institute/cancer/oral/hpv-faqs
5. HPV-16 has the highest clearance rate of all high-risk HPV types.
Clearance rate refers to the time it takes for the immune system to “clear” an infection, making it unable to be spread.1 HPV-16 has the highest incidence rate and lowest clearance rate among high-risk HPV types.2
1. Questions and Answers about the HPV Vaccine. (2021, February 9). Children’s Hospital of Philadelphia. https://www.chop.edu/centers-programs/vaccine-education-center/questions-answers-about-hpv-and-vaccine
2. Taylor, S., Bunge, E., Bakker, M., Castellsague, X. The Incidence, Clearance, and Persistence of Non-cervical Human Papillomavirus Infections: A Systemic Review of the Literature. BMC Infectious Diseases. 2016; 16; 293. https://bmcinfectdis.biomedcentral.com/articles/10.1186/s12879-016-1633-9
6. Which of the following are symptoms of oropharyngeal cancer?
Not everyone with oropharyngeal cancer will develop symptoms, but for those that do symptoms include:1,2
- Long-lasting sore throat
- Earaches
- Hoarseness or change in voice
- Swollen lymph nodes
- Pain or difficulty when swallowing
- Pain while chewing
- The feeling of a persistent lump in the throat
- Unexplained weight loss
1. HPV and Oropharyngeal Cancer. (2023, September 12). Centers for Disease Control and Prevention. https://www.cdc.gov/cancer/hpv/basic_info/hpv_oropharyngeal.htm
2. Human HPV and Throat/Oral Cancer Frequently Asked Questions. (n.d.). Mount Sinai. https://www.mountsinai.org/locations/head-neck-institute/cancer/oral/hpv-faqs
