November/December 2017 | Page 45

AU T H O R S: Marcyann Bencivenga, BA Penn State Cancer Institute Eugene J. Lengerich, VMD, MS Associate Director, Penn State Cancer Institute Kurt Summersgill, DDS, PhD University of Pittsburgh School of Dental Medicine Lynne Williams, MD Phd. Southwest PA Area Health Education Center, Pittsburgh Oral health professionals can make an important impact upon infections with human papillomavirus (HPV) and HPV- related cancers in Pennsylvania. The prevention of HPV infection and HPV-related cancers has been identified as a high priority by the Centers for Disease Control and Prevention (CDC), the Pennsylvania Department of Health and the Pennsylvania Comprehensive Cancer Control Plan. HPV virus and 1 its What role is in the cancer? The human papillomavirus (HPV) is a very common family of viruses (nearly 200 different types and subtypes) that affect epithelial tissue. While most strains are harmless and do not cause cancer, nine strains may lead to cancers of the cervix and cancer in the anogenital and oropharyngeal regions. Oral cancers are mostly associated with type 16, which is also a primary cause of cervical and anogenital cancers. Oral HPV infection can also produce non-cancerous warts in the mouth or throat. In addition, some head and neck cancers can be associated with HPV infection. Persons infected with HPV who also use tobacco and alcohol are at increased risk for certain types of head and neck cancers. Each year, HPV is responsible for approximately 31,500 cancers in the United States. Approximately 12,500 women are diagnosed with cervical cancer yearly, resulting in 4,100 deaths. In Pennsylvania, there are approximately 470 new cases of cervical cancer and 170 deaths from cervical cancer. Approximately 2,000 cases of cancer of the oropharynx occur each year in Pennsylvania, with 70 percent of these cancers occurring among men. What is HPV infection? 2 Every day in the United States, about 12,000 people ages 15 to 24 years are infected with HPV. It is estimated that by adulthood, at least 80 percent of the population will have been exposed to HPV. The virus is spread by intimate skin-to-skin contact; peak transmission is during the teen to young adult years. Most people who are infected with HPV never know it because the virus produces no signs and symptoms. The vast majority of individuals clear the infection naturally with their own immune response. does HPV affect 3 How the oral cavity? At any given time, approximately 11 percent of people, including children, can have HPV detected in the oral cavity and oropharynx. Most of the time these infections are by low-risk HPV types which are cleared by the immune system without causing lesions or cancer. The most common HPV-associated lesions in the oral cavity include warts and papillomas. Clinically, these typically look like warts, with a rough, white surface and finger-like projections. Although they are caused by a virus, they don’t spread very easily to other people. Treatment is simple surgical removal. Another very common low- risk-HPV-caused lesion is a papilloma. These can be found on the ventral tongue, but more commonly in the posterior oral cavity – the soft palate, uvula, or tonsillar pillars. These are usually pink (rather than white), with round, finger-like projections, or may look like little cauliflowers. These are a lso unlikely to spread to other people, and are treated by surgical removal. On the other hand, squamous cell carcinoma (SCC) is relatively uncommon as compared to warts and papillomas; however, it is the most common malignancy of the oral cavity and oropharynx. Very few SCCs in the oral cavity contain HPV, and if HPV is present, it is probably not the actual cause of the cancer. The main concern with HPV is cancer in the oropharynx. The oropharynx is a very different cellular and tissue environment, as compared to the oral cavity, and is much more likely to have a high-risk HPV infection. When an SCC occurs in the oropharynx, somewhere between 46 and 80 percent are caused by the high-risk HPV types, most commonly HPV-16. Early detection is key to better treatment outcomes; however, SCCs in this location are very hard to detect early due to difficulty visualizing the tonsillar pillars and the base of the tongue. Therefore, prevention of HPV-associated SCC is of great importance. N OVEM BER/DECEM BER 2017 | P EN N SYLVAN IA DEN TAL JOURNAL 43