CIHR-UBC Strategic Training Program for
Translational Research in Infectious Diseases
Address: D452 – 2733 Heather Pavilion, Vancouver, BC V5Z 3J5
E-mail: tonychow@interchange.ubc.ca
Voice: (604) 875-5063 Fax: (604) 875-4013 Website: http://cmdr.ubc.ca/trainingprogram
Research Theme:
HIV/AIDS, STD, hepatitis C, blood-borne infections
Sub-theme:
Human papillomavirus infection and anal canal cell dysplasia in gay men
Principal Investigator:
Dr. Robert Hogg, PhD
Telephone:
Fax:
E-mail:
604-806-8516
604-806-8464
bobhog@hivnet.ubc.ca
Human papillomaviruses (HPV) are among the most common sexually transmitted infections and are implicated in the
pathogenesis of a number of anogenital diseases ranging from external genital warts to cervical and anal cancers. In
women, invasive squamous cervical cancer is preceded by pre-neoplastic lesions that can be identified with 20-70%
success using cervical cytology (Pap smear). Screening for these precursor lesions has been associated with a 90%
reduction of cervical cancer in some Western countries. Pap smears detect cell changes, but do not explicitly test for
HPV infection. A screening test for HPV has been developed, and is now commercially available. Over 85 HPV
genotypes have been identified, and HPV types 16, 18, 45, and 56 are thought to be high-risk or have the highest
oncogenic potential. Thus, from a prevention standpoint, anal cytological screening combined with HPV screening and
typing for high and low-risk strains may provide an effective means to detect dangerous strains of HPV for early
treatment. Men who have receptive anal sex with men (MSM) are among the groups at highest risks for anal HPV
infection and anal cancer. The incidence of anal cancer among MSM in the US is estimated to be several times higher
than the current incidence of cervical cancer, and is similar to the incidence of cervical cancer before introduction of
routine cytological screening. Currently, very little is known of the prevalence and incidence of anal HPV, anal canal
cell changes and anal cancer among MSM in Canada.
Specific aims are:
1.
To determine the prevalence of HPV infection and anal canal cell dysplasia among MSM in the Vanguard Cohort
over a period of 2 years.
2.
To identify the prevalence of high and low risk oncogenic strains of HPV among MSM testing positive in HPV at
screening.
3.
To identify sociodemographic and behavioural risk factors for HPV and anal canal cell dysplasia among
participants.
4.
To determine the incidence of HPV infection among MSM in the Vanguard Cohort over a two year period.
Updated: August 2003
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