title: Tongue and tonsil carcinoma: increasing trends in the U.S. population ages 20-44 years.
abstract: BACKGROUND
  An increasing incidence of oral carcinoma among young adults has been reported in the U.S. and Europe. Although the association between human papillomavirus infection and tonsillar carcinoma is now well established, to the authors' knowledge little is known about incidence trends in tonsillar carcinoma among younger adults. The objective of the current study was to explore the trends in both oral cavity and pharyngeal squamous cell carcinoma (SCC) in younger U.S. populations, in particular tongue and tonsillar SCC.
  
  
  METHODS
  Using the 1973-2001 Surveillance, Epidemiology and End Results (SEER) database, we computed age, race, and site-specific trends of oral and pharyngeal (excluding nasopharynx) carcinoma incidence rates. The percent change (PC) and annual percent change (APC) were computed to explore trends in incidence rates over time.
  
  
  RESULTS
  There were 2262 SCC of the oral cavity and 1251 SCC of the pharynx reported to the SEER program from 1973 to 2001 in adults aged 20-44 years. There was a statistically significant increase in the incidence of oral tongue SCC (APC = +2.1; P < 0.001), base of tongue SCC (APC = +1.7; P = 0.04), and palatine tonsil SCC (APC = +3.9; P < 0.001) among younger white individuals, whereas the incidence of SCC in all other oral and pharyngeal sites decreased or remained constant.
  
  
  CONCLUSIONS
  The increase in tonsil SCC incidence from 1973 to 2001 paralleled the increase in tongue SCC, whereas SCC in all other oral and pharyngeal sites remained constant or decreased. This may suggest similar etiologic factors for SCC affecting the palatine tonsils and tongue in younger populations.
authors.affiliation: Department of Stomatology, Division of Oral Pathology, Oral Medicine, Oral Radiology, School of Dentistry, University of California San Francisco, San Francisco, California 94143-0422, USA.caro@itsa.ucsf.edu
authors.forename: Caroline H
authors.initials: CH
authors.lastname: Shiboski
authors.forename: Brian L
authors.initials: BL
authors.lastname: Schmidt
authors.forename: Richard C K
authors.initials: RC
authors.lastname: Jordan
mesh_terms: D000328:Adult; D017677:Age Distribution; D000368:Aged; D002294:Carcinoma, Squamous Cell / Q000175:diagnosis / Q000453:epidemiology* / Q000401:mortality; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D018426:SEER Program; D015996:Survival Rate; D014062:Tongue Neoplasms / Q000175:diagnosis / Q000453:epidemiology* / Q000401:mortality; D014067:Tonsillar Neoplasms / Q000175:diagnosis / Q000453:epidemiology* / Q000401:mortality; D014481:United States / Q000453:epidemiology