Low-tech screening for cervical cancer saves lives of HIV-infected women in Zambia

16 Dec 2010

A new study undertaken in Zambia shows that, using setting-appropriate human resources and technology, morbidity and mortality from cervical cancer among HIV-infected women can be reduced.

More than half a million women are newly diagnosed with invasive cervical cancer (ICC) globally each year, and in the same period more than a quarter million die from the disease.

In low-income regions, cervical cancer kills more women than any other malignancy. HIV-infected women without access to cervical cancer prevention services have a greater risk than uninfected individuals for persistent human papillomavirus (HPV) infections, cervical intraepithelial neoplasia (CIN), and invasive cervical cancer (ICC).

Unfortunately, in low-income nations like Zambia, less than 5% of women are ever screened for cervical cancer. However, one prevention method that has been extensively evaluated is visual inspection with dilute acetic acid (VIA) combined with same-visit treatment by cryotherapy. This screening method has been shown to be safe, acceptable, and clinically effective in reducing cervical cancer incidence and mortality.

The study was lead by Dr Groesbeck Parham, Professor of Gynecologic Oncology and Infectious Diseases, University of Alabama at Birmingham, USA, and Director of the Centre for Infectious Disease Research in Zambia’s Cervical Cancer Prevention Program. The research was published in the December issue of HIV Therapy.

The new study is the first to evaluate this approach in routine program implementation settings in the developing world. The authors launched the Zambian Cervical Cancer Prevention Program, which targeted HIV-infected women, with the ultimate goal of expansion to all Zambian women to decrease cervical cancer-associated morbidity and mortality.

They systematically analysed the screening implementation efforts by measurement and modeling of the real world program effectiveness through measurement of outcomes of program uptake, screening test efficacy, and treatment effectiveness, and then extrapolation of its impact on mortality reductions.

Nurses undertook VIA screening aided by digital cervicography (photography). Women with visible lesions were offered same-visit cryotherapy or referred for histologic evaluation. Those with ICC were referred for surgery or radiation. Measures of clinical outcomes and modeled program effectiveness among HIV-infected women by estimating the total number of ICC deaths prevented through the screening and treatment efforts.

Between January 2006 to December 2008 21,010 women were screened for cervical cancer. Among the 31% (6,572) who were HIV-infected, 53.6% (3,523) had visible lesions, of whom 58.5% (2,062) were eligible for cryotherapy and 41.5% (1,461) were referred for histologic evaluation. 75% (1,095/1,462) of patients referred for histologic evaluation complied and underwent therapy.

Pathology results from 65% (715/1,095) of women revealed benign abnormalities in 21% (151), CIN Grade 1 in 30% (214), CIN Grade 2/3 in 33% (235), and ICC in 16.1% (115). Of ICCs, 69% were early stage.

Using a conditional probability model, the authors estimate that the program prevented 142 cervical cancer deaths (high/low range 238-96) in 6,572 HIV-infected women screened, or one cervical cancer death prevented per 46 (corresponding range: 28-68) HIV-infected women screened.

The authors state, “By using a setting-appropriate protocol for cervical cancer prevention, ie nurse-led visual screening and same-visit cryotherapy for eligible women, and linkage to a tertiary care centre for evaluation, our program has not just saved lives but has also established a new paradigm for routine prevention interventions in resource-constrained environments.”

The authors point out that these positive results show that concerted efforts and financial support for implementing cervical cancer prevention programs integrated within HIV/AIDS care programs are warranted. The claim that their prevention model can serve as the implementation platform for future low-cost HPV-based screening methods and that the results of the study may provide the basis for comparison of effectiveness of future prevention programs.

With respect to the effectiveness of the study, Dr Parham states, “The major outcome of the program was that while the screening method (VIA) has moderate effectiveness, because it was implementable it had a high intervention to impact ratio: for every 46 HIV-infected women that we screened we were able to prevent 1 death from cervical cancer. There are more effective tests than VIA, but they have not been adoptable in this setting. However effective a screening intervention, it will have no impact if it is not adoptable”.

Dr Parham goes onto to explain, “We started the program in the capital, Lusaka, and have now expanded to cover more rural areas. We recently had a meeting with the directors of provincial hospitals in the other provinces and in a couple of months we will start to roll out a national screening program under the leadership of the Zambian Ministry of Health”.

From such a low-tech ‘screen and treat’ program, the effectiveness results are very encouraging, meriting national recognition and providing a model for expansion in other resource-limited settings.

The full article is available at: www.futuremedicine.com/toc/hiv/4/6