"Screen and treat” cervical cancer programs effective in poorly resourced areas

Nov 2 2005

According to a new study two "screen and treat" cervical cancer prevention programs developed for high-risk women in low-resource settings resulted in a lower prevalence of precancerous cervical lesions and cervical cancer, according to a study in the November 2 issue of JAMA: The Journal of the American Medical Association.

Every year 471,000 cases of cervical cancer are diagnosed and 233,000 women die from it worldwide.

The bulk of these cases occur in poorer countries with inadequate cancer treatment resources, where women are at a higher risk of developing cervical cancer.

Presently in most developed countries, Cytology (cell) -based screening programs have considerably reduced the risk.

Such screening programs have been difficult to implement in poorer areas, but recently, a new approach has been proposed that avoids the complex health infrastructure required by traditional approaches.

Lynette Denny, M.D., Ph.D., of the University of Cape Town, South Africa, and colleagues conducted a study to determine the safety and efficacy of two screen-and-treat approaches for cervical cancer prevention.

This approach combines testing for human papillomavirus (HPV) by DNA testing, visual inspection with a weak acetic acid solution, VIA, and then treating the lesions by using cryotherapy, a treatment that involves applying nitrous oxide to lesions of all eligible women with positive test results.

Cryotherapy is a relatively low-technology treatment method and the approach has the advantage for low-resource settings because it does not require specialized equipment for examination of the vagina and the cervix, overcoming two of the greatest barriers to cervical cancer prevention.

To date however, the efficacy of these screen-and-treat approaches has not been established, and there has been only limited safety data.

In the clinical trial 6,555 nonpregnant women, aged 35 to 65 years were included, and the it was conducted between June 2000 and December 2002 at mobile women’s health clinics in Khayelitsha, South Africa.

All patients were screened using human papillomavirus (HPV) DNA testing and visual inspection with VIA.

Women were subsequently randomized to 1 of 3 groups: cryotherapy if she had a positive HPV DNA test result; cryotherapy if she had a positive VIA test result; or evaluation was delayed.

The researchers found that compared with the delayed evaluation group, the screen-and-treat approach using HPV DNA testing was associated with a 77 percent lower prevalence of cancer than in the delayed evaluation group at 6 months, whereas the screen-and-treat approach using VIA was associated with a 37 percent lower prevalence.

When data from 2,708 of the women was examined the prevalence of cancer by 12 months in both screen-and-treat groups continued to be lower than in the delayed evaluation group. In the HPV DNA group, 1.42 percent had the cancer by 12 months compared with 2.91 percent in the VIA group and 5.41 percent in the delayed evaluation group.

The researchers say this means that 1 case of cancer was averted for every 25 women enrolled in the HPV DNA group and 1 case was averted for every 40 women enrolled in the VIA group.

Although minor complaints, such as discharge and bleeding, were common after cryotherapy, major complications were rare.

The researchers say the trial has shown that screening and treating women based on the results of two alternative screening tests HPV DNA testing and VIA, is safe and has a significant impact on the prevalence of cervical cancer among women participating in such a program.

In settings with poorer resources, screen-and-treat approaches they say may be able to reduce the risk of a common and easily preventable cancer in women.

The study was funded by the Bill and Melinda Gates Foundation through a grant to the Alliance for Cervical Cancer Prevention, the Cancer Association of South Africa, and the Department of National Health, South Africa.

In an accompanying editorial, Paul D. Blumenthal, M.D., M.P.H., of Johns Hopkins University, Baltimore, and Lynne Gaffikin, Dr.P.H., of Evaluation and Research Technologies for Health Inc., Oakland, Calif., say the study shows that safe, acceptable, effective, and pragmatic public health approaches to cervical cancer prevention can be designed to diagnose and treat cervical cancer and until a vaccine to prevent human papillomavirus infection is available several generations of women worldwide will still need conventional care.

The study is published in the November 2 issue of JAMA: The Journal of the American Medical Association.