从1973至1999年间，美国监测、流行病学及预后数据显示18,962例口咽癌被确诊。[2]Cavarlho AL, Nishimoto IN, Califano JA, et al. Trends in incidence and prognosis for head and neck cancer in the United States: a site-specific analysis of the SEER database. Int J Cancer. 2005;114:806-816.http://www3.interscience.wiley.com/cgi-bin/fulltext/109859040/HTMLSTARThttp://www.ncbi.nlm.nih.gov/pubmed/15609302?tool=bestpractice.com大多数患者确诊时已是晚期（70%）。
在英国，2006年报道了5300例口腔癌，1063例发生在口咽部，约1600发生在舌。2002年，欧洲头颈部鳞癌年粗略统计发病率，男性为36/100 000，女性为7/100 000；相应的死亡率分别为每年18/100 000和3/100 000。[3]Pivot X, Felip E. Squamous cell carcinoma of the head and neck: ESMO clinical recommendations for diagnosis, treatment and follow-up. Ann Oncol. 2008;19(suppl 2):ii79-ii80.http://annonc.oxfordjournals.org/cgi/reprint/19/suppl_2/ii79http://www.ncbi.nlm.nih.gov/pubmed/18456779?tool=bestpractice.com
由于HPV-16阳性肿瘤数量的增加，HPV感染已被广泛一致地认为是一种肿瘤致病因素。[4]Nasman A, Attner P, Hammarstedt L, et al. Incidence of human papillomavirus (HPV) positive tonsillar carcinoma in Stockholm, Sweden: an epidemic viral-induced carcinoma? Int J Cancer. 2009;125:362-366.http://www.ncbi.nlm.nih.gov/pubmed/19330833?tool=bestpractice.com多发生于年轻患者（年龄40-60岁）。HPV相关的口咽肿瘤主要涉及扁桃体癌，其次是舌根癌。有多个性伴侣的人是HPV引起的口咽癌的高危人群。[5]D'Souza G, Kreimer AR, Viscidi R, et al. Case-control study of human papillomavirus and oropharyngeal cancer. N Engl J Med. 2007;356:1944-1956.http://content.nejm.org/cgi/content/full/356/19/1944http://www.ncbi.nlm.nih.gov/pubmed/17494927?tool=bestpractice.com目前HPV相关口咽癌在受影响的黑人和非西班牙裔男性中正变得流行。[6]Ryerson AB, Peters ES, Coughlin SS, et al. Burden of potentially human papillomavirus-associated cancers of the oropharynx and oral cavity in the US, 1998-2003. Cancer. 2008;113(10 suppl):2901-2909.http://www.ncbi.nlm.nih.gov/pubmed/18980273?tool=bestpractice.com和头颈部癌症的其他发病部位一样，口咽癌与吸烟和酒精滥用有关。[2]Cavarlho AL, Nishimoto IN, Califano JA, et al. Trends in incidence and prognosis for head and neck cancer in the United States: a site-specific analysis of the SEER database. Int J Cancer. 2005;114:806-816.http://www3.interscience.wiley.com/cgi-bin/fulltext/109859040/HTMLSTARThttp://www.ncbi.nlm.nih.gov/pubmed/15609302?tool=bestpractice.com[7]Chaturvedi AK, Engels EA, Anderson WF, et al. Incidence trends for human papillomavirus-related and -unrelated oral squamous cell carcinomas in the United States. J Clin Oncol. 2008;26:612-619.http://jco.ascopubs.org/cgi/content/full/26/4/612http://www.ncbi.nlm.nih.gov/pubmed/18235120?tool=bestpractice.com在发展中国家，口咽癌与咀嚼烟草和槟榔相关，即使现在咀嚼槟榔已是公认的口腔癌症危险因素。[8]Critchley JA, Unal B. Health effect associated with smokeless tobacco: a systematic review. Thorax. 2003;58:435-443.http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1746661/pdf/v058p00435.pdfhttp://www.ncbi.nlm.nih.gov/pubmed/12728167?tool=bestpractice.com
口咽癌的发病率从1974-1976年间的17.6%明显增加到1998-1999年间的22.6%。在美国，该肿瘤最初报道于20-44岁的成年白人之间。[9]Shiboski CH, Schmidt BL, Jordan RC. Tongue and tonsil carcinoma: increasing trends in the U.S. population ages 20-44 year. Cancer. 2005;103:1843-1849.http://www3.interscience.wiley.com/cgi-bin/fulltext/110431181/HTMLSTARThttp://www.ncbi.nlm.nih.gov/pubmed/15772957?tool=bestpractice.com在烟草控制和教育方面的公共卫生工作成功地降低吸烟率。
在斯堪的纳维亚国家，尽管烟草的使用显著减少，口咽癌的发病率还是出现了类似的增长。[10]Hammarstedt L, Dahlstrand H, Lindquist D, et al. The incidence of tonsillar cancer in Sweden is increasing. Acta Otolaryngol. 2007;127:988-992.http://www.ncbi.nlm.nih.gov/pubmed/17712680?tool=bestpractice.com
