Good Example Of Oropharyngeal Cancer: Its Epidemiological Association With Smoking And The Development Of HPV-Related Squamous Cell Carcinoma Literature Review

Currently, oropharyngeal cancer, or the cancer of oral and pharyngeal cavity grouped together is considered to be the 6th most common type of cancer worldwide (Warnakulasuriya 309; Saman 1). Annually, there is an estimated 650,000 new cases of head and neck cancer with 275,000 cases of oral cancer while pharyngeal cancer accounts for another 130,000 (Warnakulasuriya 309; Herrington 3). It is also reported that in such number of patients actually diagnosed as having oropharyngeal cancer, 350,000 actually die from it although survival rate is relatively higher (Herrington 3; Warnakulasuriya 313). In total, 90% of oropharyngeal cancer is commonly identified to be squamous cell carcinoma in type, occurring mostly in the posterior pharyngeal wall, tongue base, soft palate, and tonsillar complex (Herrington 3; Cohan et al. 90-92; Evans et al. 1; “Oropharyngeal Cancer Treatment”). Affecting primarily the mouth and throat, extensive research has been conducted over decades to find a relationship between oropharyngeal cancer and smoking—especially with all the proven carcinogenic contents of cigarettes and other substances used (Dikshit & Kanhere 614; Herrington 3; Blot et al. 3282). The findings since those researches began manifested an undeniable association between smoking and oropharyngeal cancer—with the former being the number one cause of the latter (Blot et al. 3282; Warnakulasuriya 314; Herrington 3; Saman 2; “Oropharyngeal Squamous Cell Carcinoma”). Smoking is worsen by alcohol consumption which is reported to be a causative factor too on its own and presenting an even greater risk when used with cigarettes (Saman 2; Dikshit & Kanhere 609; Blot et al. 3282; Warnakulasuriya 314; “Oropharyngeal Squamous Cell Carcinoma”). To date, Asia, particularly the regions of South and Southeast, are considered to have the highest prevalence rate of oropharyngeal cancer—a finding that is associated with wide use of tobacco, betel quid (normally chewed), and alcohol (Warnakulasuriya 311 & 314; Dikshit & Kanhere 609). Sri Lanka, Pakistan, and India are the three Asian countries reported to have the most prevalent incidences of oropharyngeal cancer—with the cases in India attributed to the prevalent use of bidis as well as cigarettes (Warnakulasuriya 309 & 311; Dikshit & Kanhere 609). Oropharyngeal cancer also affects developed countries such as those in the USA, Europe, and Australia, but it is much more prevalent in developing countries especially in Asia (Warnakulasuriya 311; Evans et al. 1). Commonly, oropharyngeal cancer affects people aged 50 or older (Warnakulasuriya 312). However, recent reports and studies have found an increasing prevalence of the disease in younger people who are non-smokers and non-drinkers—an emerging condition caused by the recent finding of the association between human papilloma virus (HPV) and oropharyngeal cancer (Herrington 24; Evans et al. 1; Haddad 1; Gillison et al. 407).
HPV-related oropharyngeal squamous cell carcinoma (OPSCC) has astounding differences compared to non-HPV-associated OPSCC. HPV is the virus that causes almost all the incidences of cervical cancer worldwide and is also identified as one of the most common sexually-transmitted viruses (Haddad 1; “HPV/Oral Cancer Facts”; “HPV and Head & Neck Cancer”). Aside from causing cervical infection and cancer, HPV may also be present as warts and/or papilloma in the respiratory, causing what is known as oral HPV infection (Herrington 13; Hennessey et al. 301; “HPV and Head & Neck Cancer”). Oral HPV infection is now being assessed for its potential to cause the cancer as oral route is reported to be the vehicular mode utilized by OPSCC-causing HPV (Herrington 35). Other hypotheses formulated to explain the possible cause behind HPV’s relation to the emergence of OPSCC is the similarity between the histology of oropharyngeal region and cervical as well as other epithelial, mucosal regions where HPV is most commonly present (Haddad 1). The deep invagination of the mucosal surface in oropharyngeal region is said to “favor the capture and processing of antigens” that facilitate HPV’s entry to the basal cells, therefore promoting HPV’s penetration and proliferation (Haddad 1). HPV-related OPSCC is now commonly identified due to the presence and overexpression of the p16 gene, which, under regular OPSCC conditions, is usually underexpressed (Evans et al. 2). Worldwide, HPV-related OPSCC affects white men usually at their 40s (Herrington 32 & 23). HPV-related OPSCC is often worsened with drinking and smoking and such can affect the course of treatment and complete recuperation from the disease (Herrington 23; Evans et al. 1 & 2). Unlike non-HPV-related OPSCC, HPV-related OPSCC has better survival rate seemingly regardless of the intervention applied (Evans et al. 2; Ang et al. 24).

Works Cited

Ang, K. Kian, et al. “Human Papillomavirus and Survival of Patients with Oropharyngeal Cancer.” The New England Journal of Medicine 363 (2010): 24-35. Web. 01 March 2015.
Blot, William J., et al. “Smoking and Drinking in Relation to Oral and Pharyngeal Cancer.” Cancer Research 48 (1988): 3282-3287. Web. 01 March 2015.
Cohan, David M., et al. “Oropharyngeal cancer: current understanding and management.” Current Opinion in Otolaryngology & Head & Neck Oncology 17 (2009): 88-94. Web. 01 March 2015.
Dikshit, Rajesh P., and S. Kanhere. “Tobacco habits and risk of ung, oropharyngeal and oral cavity cancer: a population-based case-control study in Bhopal, India.” International Journal of Epidemiology 29 (2000): 609-614. Web. 01 March 2015.
Evans, Mererid, et al. “Human Papillomavirus-associated oropharyngeal cancer: an observational study of diagnosis, prevalence and prognosis in a UK population.” BMC Cancer 13.220 (2013): 1-10. Web. 01 March 2015.
Gillison, Maura L., et al. “Distinct Risk Factor Profiles for Human Papillomavirus Type-16 Positive and Human Papillomavirus Type-16 Negative Head and Neck Cancers.” Journal of the National Cancer Institute 100 (2008): 407-420. Oxford Journals. Web. 01 March 2015.
Haddad, Robert I. “Human Papillomavirus Infection and Oropharyngeal Cancer.” Medscape (17 Jul. 2007). Web. 01 March 2015.
Henessey, P.T., et al. “Human Papillomavirus and Head and Neck Squamous Cell Carcinoma: Recent Evidence and Clinical Implications.” Journal of Dental Research 88.4 (2009): 300-306. NIH. Web. 01 March 2015.
Herrington, Heather. “Oropharyngeal Cancer: Not Just for Smokers Anymore (Manifestations of HPV in the Head & Neck).” Fletcher Allen Health Care (9 Feb. 2012). Web. 01 March 2015.
“HPV and Head & Neck Cancer.” The John Hopkins Head and Neck Cancer Center (no date). Web. 01 March 2015.
“HPV/Oral Cancer Facts.” The Oral Cancer Foundation (2015). Web. 01 March 2015.
“Oropharyngeal Cancer Treatment: General Information About Oropharyngeal Cancer.” National Cancer Institute (13 Feb. 2015). Web. 01 March 2015.
“Oropharyngeal Squamous Cell Carcinoma.” Merck Manuals (2013). Web. 01 March 2015.
Saman, Daniel M. “A review of the epidemiology of oral and pharyngeal carcinoma: update.” Head & Neck Oncology 4.1 (2012): 1-7. Web. 01 March 2015.
Warnakulasuriya, Saman. “Global epidemiology of oral and oropharyngeal cancer.” Journal of Oral Oncology 45 (2009): 309-316. Elsevier. Web. 01 March 2015.