Human papillomavirus and oropharyngeal cancer in Greenland in 1994-2010.
BACKGROUND
Oropharyngeal squamous cell carcinoma (OPSCC) is associated with the sexually transmitted human papillomavirus (HPV), smoking and alcohol. In Greenland, a high rate of HPV-induced cervical cancer and venereal diseases are found, which exposes the population for high risk of HPV infection. In Greenland, only girls are included in the mandatory HPV vaccination program.


OBJECTIVE
To investigate the annual incidence of OPSCC and the proportion of HPV-associated OPSCC (HPV+ OPSCC) in Greenland in 1994-2010.


METHODS
At Rigshospitalet, University of Copenhagen, we identified all Greenlandic patients diagnosed and treated for OPSCC from 1994 to 2010. Sections were cut from the patient's paraffin-embedded tissue blocks and investigated for p16 expression by immunohistochemistry. HPV analyses were performed with 2 sets of general HPV primers and 1 set of HPV16-specific primer. HPV+ OPSCC was defined as both >75% p16+ cells and PCR positive for HPV.


RESULTS
Of 26 Greenlandic patients diagnosed with OPSCC, 17 were males and 9 were females. The proportion of HPV+ OPSCC in the total study period was 22%, without significant changes in the population in Greenland. We found an increase in the proportion of HPV+ OPSCC from 14% in 1994-2001 to 25% in 2002-2010 (p=0.51). Among males from 20 to 27% (p=0.63) and in females from 0 to 20% (p=0.71). The annual OPSCC incidence increased from 2.3/100,000 (CI=1.2-4.2) in 1994-2001 to 3.8/100,000 (CI=2.4-6.2) in 2002-2010: among males from 2.4/100,000 (CI=1.0-5.7) to 5.0/100,000 (CI=2.9-8.9).


CONCLUSIONS
Even though the population is at high risk of HPV infection, the proportion of 22% HPV+ OPSCC in the total study period is low compared to Europe and the United States. This might be explained by our small study size and/or by ethnic, geographical, sexual and cultural differences. Continuing observations of the OPSCC incidence and the proportion of HPV+ OPSCC in Greenland are needed.
Department of Otolaryngology, Head & Neck Surgery, Rigshospitalet, University of Copenhagen, Denmark.
Magnus Balslev
MB
Avnstorp
Ramon Gordon
RG
Jensen
Emilie
E
Garnæs
Marianne Hamilton
MH
Therkildsen
Bodil
B
Norrild
Lena
L
Specht
Christian
C
von Buchwald
Preben
P
Homøe
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000453:epidemiology / Q000209:etiology* / Q000382:microbiology; D005260:Female; D006116:Greenland / Q000453:epidemiology; D006801:Humans; D017589:Immunization Programs / Q000331:legislation & jurisprudence / Q000592:standards; D015994:Incidence; D008297:Male; D037141:Mandatory Programs; D008875:Middle Aged; D009959:Oropharyngeal Neoplasms / Q000453:epidemiology / Q000209:etiology* / Q000382:microbiology; D030361:Papillomavirus Infections / Q000150:complications* / Q000453:epidemiology / Q000209:etiology / Q000517:prevention & control; D053918:Papillomavirus Vaccines / Q000008:administration & dosage; D012189:Retrospective Studies; D015229:Sexually Transmitted Diseases, Viral / Q000150:complications / Q000453:epidemiology / Q000209:etiology
D053918:Papillomavirus Vaccines
HPV; HPV vaccine; Inuit; PCR; head and neck cancer; immunization; p16 immunohistochemistry