Epidemiologic and Molecular Features of Cervical Cancer in Nigeria - Project Itoju (Care)
BACKGROUND: Cervical cancer, caused by persistent infection with approximately 15-20
genotypes of carcinogenic human papillomavirus (HPV) infection, is the second leading cause
of female cancer. Cytology (Pap smears) and the new HPV vaccines are not widely available in
poor regions. Immediate treatment of HPV-infected older women by cryotherapy might have
Although the same HPV types cause cervical cancer everywhere, and the same stages
(infection, persistence vs. clearance, progression to precancer, and invasion) typify
cervical carcinogenesis, the patterns of age-specific prevalence of HPV vary widely. These
patterns are important for secondary prevention strategies relying on HPV DNA testing.
In many regions, including the US, HPV infections appear as classical sexually-transmitted
agents, with peak cervical DNA prevalence at young ages (approximately 20) and low
prevalence at older ages. However, in Nigeria, HPV prevalence is high (greater than or equal
to 15%) at all ages according to the one study performed in urban Ibadan by Franceschi's
group at IARC (n=932 women). This pattern is very uncommon. High prevalence at all ages
would preclude use of HPV testing in low-cost strategies, due to poor positive predictive
value. One possibly relevant element is the marital structure in Nigeria; a man often has
OBJECTIVES: The major objectives are: 1) To estimate age-specific HPV prevalences in Irun,
Nigeria; 2) To investigate epidemiologic risk factors for HPV and cervical intraepithelial
neoplasia in this population; 3) To examine the performance of screening options; 4) To
assess the correlation of HPV among co-wives, comparing households with multiple wives with
those with single wives; and 5) To validate the performance of rapid HPV, an inexpensive HPV
test designed for public-sector use in settings like Irun.
ELIGIBILITY: All non-pregnant women aged 15+, without hysterectomy, will be eligible if they
can provide written informed consent. Unmarried women less than 21 will be enrolled only
with parental consent. Sexually active women will be examined and asked for cervical
specimens; self-reported virginal women will be asked for a 10-ml blood sample only.
DESIGN: This is a cross-sectional screening study of 1500 women in Irun, a Nigerian village.
Unlike the IARC study, we will incorporate cytology, visual inspection, and colposcopic
biopsy of women that test positive by any of the three screening tests. We will determine
whether HPV infection at various ages is related to risk of cervical abnormalities. The
analyses will include descriptive trend data, multivariable modeling of HPV determinants,
and clinical epidemiologic analysis of relative screening test performance in detecting
Time Perspective: Prospective
Mark H Schiffman, M.D.
National Cancer Institute (NCI)
United States: Federal Government