Researchers estimate that a cervical cancer screening programme for HIV-positive Zambian women prevented one death from cervical cancer for every 32 women screened.
Cervical cancer is the biggest cause of cancer deaths among women in sub-Saharan Africa, due in large part to lack of screening.
However, HIV infection and immunodeficiency exacerbate the progression of pre-cancerous lesions, and the high prevalence of cervical cancer and pre-cancerous changes in women with HIV has led to efforts to incorporate cervical screening into HIV clinics and other health services in countries with a high burden of HIV infection.
Dr Groesbeck Parham of the University of Alabama at Birmingham reported to the 17th Conference on Retroviruses and Opportunistic Infections (CROI) on one of these pilot programmes, in Zambia.
A pilot study by Dr Parham and colleagues to assess the need for cervical screening among women with HIV had found in 2006 that among a cohort of 150 women, almost one in five had signs suggestive of cervical cancer and only 6% of women had a normal PAP smear. Almost 50% had high-grade cervical changes.
In response to these findings a screening programme was implemented at 15 public-sector health facilities in Lusaka.
The programme used the most basic method of screening available in order to detect abnormalities. Cotton wool soaked in vinegar was applied to the cervix for three minutes, long enough to ensure that any abnormalities would show up as white or red marks.
Nurses were trained to evaluate patients via visual inspection and digital cervicography, which stored digital photographs that could be sent to a gynaecologist for a second opinion where necessary.
Women with grade 3 SIL (squamous intraepithelial lesions) were offered immediate cryotherapy; those with major lesions were referred for excisional biopsy.
The programme used community volunteers to promote cervical screening to women with HIV at local health centres, but once word got round that screening was available, HIV-negative women also began to turn up to request screening.
Between January 2006 and December 2008 21,000 women were screened, of whom 6572 were HIV-positive.
Among the 6572 HIV-positive women screened, 3523 (54%) had abnormal results. Those women were either offered immediate cryotherapy, if they met treatment criteria (n = 2062), or were referred for further evaluation (n = 1461).
Seventy-eight percent of the women offered cryotherapy underwent the procedure.
Forty-nine percent of the women referred for further evaluation underwent histological confirmation, which led to the diagnosis of 235 pre-cancers (CIN [cervical intraephithelial neoplasia] 2/3); 79 early-stage cancers (stage 1A-1B); and 36 late-stage cancers (>stage 2A). Most of the early stage cancers (78%) were stage 1A (micro-invasive).
The full cohort of HIV-positive women had a median CD4 cell count of 188 cells/mm3 (interquartile range, 100-302 cells/mm3).
Researchers used published estimates of disease progression rates, cure rates and prevention rates to assess the impact of the programme on women’s health. Going on the premise that treatment would be provided to all women who needed it, they concluded that the intervention prevented 203 cases of invasive cervical cancer among the 6572 HIV-positive women screened.
Multivariate analysis showed that a low income (
The 'screen and treat' service may provide a potential platform for the introduction of a cervical cancer vaccine, said Dr Parham, but ensuring long-term follow-up of women will require a significant investment of time to ensure that women return to the clinic.
Parham G et al. Effectiveness of a program to prevent cervical cancer among HIV-infected women in Zambia. Seventeenth Conference on Retroviruses and Opportunistic Infections, San Francisco, abstract 29, 2010.