Approximately 650,000 people worldwide are diagnosed with head and neck cancer each year, and more than 330,000 deaths are attributed to these diagnoses on an annual basis.1 More than 90% of these tumors arise from the mucosa of the oral cavity, oropharynx, and larynx, and the majority are histologically verified squamous cell carcinomas.2 Overall, in 2020 the 5-year survival rate of oral and oropharyngeal cancer is estimated to be approximately 65%. In the United States, these cancers account for about 50,000 new cancer diagnoses each year and almost 1 death every hour of every day. Risk factors for oral and oropharyngeal cancer include the use of smokeless and inhalational tobacco, use of alcohol, the synergistic interaction of tobacco and alcohol, human papillomavirus (HPV) and use of betel quid (paan).
Improved Survival Rates
Improved survival rates are noted when these cancers are diagnosed at early stages- approximately 84% for localized disease, 66% for regional disease, and 39% for distant disease. A delay in diagnosis has been shown to increase the risk of experiencing progression to advanced stages of disease and increased mortality. Thus, early detection of potentially malignant and overtly malignant mucosal disease will enhance the possibility for complete recovery and increase the quality of life for patients with oral and oropharyngeal cancers.
Oral health care professionals are the best suited among all health care professionals to perform effective screening for oral and oropharyngeal cancer, which should consist of an assessment of risk factors and a detailed oral and oropharyngeal examination. The reference standard for screening remains a clinical examination and tissue biopsy. Although, numerous adjunctive tests are available, all have shown a level of sensitivity and specificity that makes them ill-suited to be used for routine screening. As early diagnosis can decrease both morbidity and mortality of oral and oropharyngeal cancer, the oral health care community is in an ideal position to perform screening, and we need to understand our critical role in affecting the epidemiology of these devastating cancers, which unfortunately has not improved significantly in the past decades.
The management of oral potentially malignant disorders (OPMD) is an important step in the prevention and early detection of oral cancer. In 2018, the American Dental Association produced guidelines for the management of OPMD, which for high-risk lesions should involve monitoring for changes, followed by serial biopsies with histologic confirmation for high-risk lesions. It is important to recognize that all patients, and particularly those at high risk of developing OPMD, should be educated about the risk of experiencing malignant transformation and should be monitored in a structured follow-up program.
Recently, HPV has garnered a great interest as a virally induced variant of head and neck cancer. HPV is the most commonly sexually transmitted disease in the United States, and it has been identified in 70% of oropharyngeal cancers and 10% of oral cancers. In 1999, cervical cancer (13,125 new diagnosed cases) was the most common HPV-associated cancer with 3,750 more cases of cervical cancer diagnosed than oropharyngeal cancer. In 2015, oropharyngeal cancer (18,917 new diagnosed cases) was the most common HPV-associated cancer, including 15,479 cases in men and 3,438 cases in women, which represent a 2.7% increase in incidence in only 16 years. Several factors might account for the increase in oropharyngeal cancers, including changes in sexual behaviors, which include risk factors of early sexual debut and lifetime number of oral sex partners. The lack of routine tonsillectomies in the current Millennial generation might also explain the increased incidence of oropharyngeal cancer during this time.
Vaccination strategies for HPV have existed since 2006 when the US Food and Drug Administration licensed the quadrivalent Gardasil (Merck) vaccine to protect against HPV types 6, 11, 16 and 18. Thereafter, the US Food and Drug Administration licensed the bivalent Cervarix (GlaxoSmithKline) vaccine to protect against HPV types 16 and 18 in 2009 and the 9-valent Gardasil vaccine to protect against HPV types 6, 11, 16, 18, 31, 33, 45, 52, and 58 in 2018. Although the Centers for Disease Control and Prevention established a target of 80% US HPV vaccination rate as part of its Healthy People 2020 initiative, the national HPV vaccination rate has fallen behind other vaccination rates. In 2018, 51.1% of adolescents aged 13 through 17 years were current with their HPV vaccine series, and 68.1% had received 1 or more doses.
Increased survival rates of oral and oropharyngeal cancer have been realized over the past 20 years, likely owing to earlier detection by providers, aggressive surgical and adjuvant chemoradiotherapy protocols, precautionary statements on smokeless tobacco and cigarette packages, and other public health measures. Just as routine cervical examinations and Papanicolaou tests (PAP smears) have led to a decrease in cervical cancer, oral health care and medical health care professionals alike must develop a sense of urgency regarding routine examination of the mucosa of the oral cavity and oropharynx to provide earlier detection of potentially malignant lesions and obvious cancers. With improved vaccination strategies and adherence outcomes with Gardasil 9, it is possible that oropharyngeal cancer rates will begin to decrease. Over time, hopefully, HPV vaccination will decrease the incidence of cervical cancer further. Therefore, all health care providers, including all oral health care professionals, must engage in conversation with young patients regarding the highly beneficial and safe nature of the HPV vaccination. HPV vaccination is recommended for boys and girls aged 11 or 12 years before HPV exposure occurs. The vaccine can be started as early as age 9 years and should be completed before the child’s 13th birthday. The vaccine is given in 2 injections with 6 through 12 months between injections. Three injections of the HPV vaccine are required for children who start the vaccine at age 15 years or older, and it can be administered up to age 26 years. The benefit of vaccinating after the age of 26 years is unclear.
Copyright 2020 American Dental Association. All rights reserved.
Eric R. Carlson, DMD, MD, EdM, FACS; Deepak Kademani, DMD, MD, FACS