Prevalence and predictors of squamous intraepithelial lesions of the cervix in HIV positive women in Lusaka, Zambia
Polly Clayden, HIV i-Base
Cervical cancer is the second most common cancer among women worldwide and the most common cancer among women in resource limited settings. Each year there are an estimated 500,000 new cases and approximately 275,000 deaths and 20% of these deaths occur in sub-Saharan Africa.
HIV positive women are at higher risk for the development of HPV-induced squamous intraepithelial lesions (SIL) of the cervix. Additionally they have lower spontaneous regression rates of SIL higher progression rates of low grade SIL and higher recurrence rates after treatment.
In industrialised countries, where screening is routine, HIV-positive women are not at higher risk of invasive cervical cancer than HIV-negative women if it is detected and treated at an early enough stage. HIV-positive women living in resource-limited settings who are accessing antiretroviral therapy have the potential to live long enough for cervical cancer to manifest and progress.
Groesbeck Parham from the University of Alabama and the Centre for Infectious Disease Research in Zambia presented findings from a study evaluating the prevalence and predictors of cervical cytological abnormalities in 150 eligible, non-pregnant, HIV-infected women accessing HIV care and treatment services in Lusaka, Zambia. The women received a pelvic examination and cervical specimens were analysed with liquid-based monolayer cytology and tested for HPV.
In this cross-sectional screening study, the median age of the women was 36 years (range 20-49 years) and their mean CD4 count was 161 cells/mm3 (range 7-942 cells/mm3).
The authors reported that 77% of women were receiving antiretrovirals, but they noted that the majority had initiated treatment within the previous six months. A small number (2%) of the women were smokers. The median age of first sexual intercourse was 18 years (range 12-29 years); the median age of first pregnancy was 20 years (range 14-31 years) and the median number of pregnancies was 3 (range 0-10); 17.2% had six or more lifetime sexual partners and only 25.2% reported consistent condom use.
The cytology results showed only 6.21% of the women had normal cell samples, 17.22% atypical squamous cells of undetermined significance (ASCUS); 23.42% low grade SIL; 33.83% high grade SIL and 19.32% had lesions suspicious for squamous cell carcinoma (SCC).
Univariate analysis revealed low CD4 count (OR: 1.25 [95% CI 1.03-1.54], p=0.027) and presence of high risk HPV (OR:9.25 [2.60-32.88], p=0.001) to be significantly associated with severe cytological abnormalites. Multivariate analysis found presence of high risk HPV (Adj. OR: 12.4 [2.62-58.1], p=0.02] to be a significant predictor.
The authors concluded that this Zambian study found one of the highest prevalence rates of high-grade cervical cytology (>/=HSIL), which they attributed to severe immune suppression. They also reported a significant diversity and multiplicity of HPV types.
At the beginning of the presentation, Dr Parnham reminded us that death from cervical cancer is a direct result of absence or failure of screening programmes. In Zambia and throughout sub-Saharan Africa very few women with HIV/AIDS are ever screened for cervical cancer and he described an enormous need.
These results are shockingly high (among the highest ever reported) and, as emphasised in the report, largely preventable with proper cervical cancer screening and early and effective treatment.
The authors also highlighted several questions that need to be addressed within this setting:
- Are nutritional deficiencies significant?
- Does the prevalence of different HPV types vary with different degrees of immunosuppression?
- Are differential attributable cervical cancer risks associated with each high risk HPV type?
- Would the HPV vaccine be effective in this population/environment?
- What is the natural history of HPV-induced cervical neoplastic disease in the era of HAART?
- Can treatment of cervical neoplasia lower the risk of transmission and acquisition of HIV?
Parham G, Sahasrabuddhe V, Vermund S et al. Prevalence and predictors of squamous intraepithelial lesions of the cervix in HIV-infected women in Lusaka, Zambia. XVI International AIDS Conference, Toronto, Canada.13-18 August 2006. Oral Abstract TUAB0303.