Dramatic Worldwide Drop in Cervical Cancer Possible through Use of Simple, Cost-Effective Methods
For immediate release: November 16, 2005
Boston, MA The number of women dying from cervical cancer could be lowered by 30 to 50 percent if simple, cost-effective methods were used to screen women in poor countries once or twice between the ages of 35 and 45, according to an analysis in the November 17 issue of The New England Journal of Medicine.
Cervical cancer is a leading cause of death from cancer among women in low-resource regions of the world and often kills young women at a time in their lives when they are particularly critical to their children, families and communities. Cervical cancer is preventable by identifying precancerous lesions using repeated cytology-based (Pap smear) screening and then treating those lesions before they progress to cancer. Cytology screening programs have been difficult to implement in poor countries because of the required laboratory and technical expertise and the required multiple visits for screening, diagnosis and treatment.
Led by HSPH Associate Professor Sue Goldie, a team of researchers used computer-based models to assess the benefits and cost-effectiveness of cervical-cancer screening strategies in India, Kenya, Peru, South Africa, and Thailand. Data were drawn from studies conducted within the five countries and from published scientific literature. Strategies differed according to screening test, targeted age group, interval of screening, and number of clinic visits required. Unlike many other analyses, this assessment considered costs of lab equipment and supplies, specimen transportation, training, administration, and other costs associated with running a screening program.
The team found that the most cost-effective strategies in all five countries were those that relied on less laboratory infrastructure than did conventional cytologic methods and those that enhanced the linkage between screening and treatment by eliminating the diagnostic confirmation step and reducing the number of required visits.
The most effective screening test was DNA testing for HPV, in which cervical samples are chemically probed for the genetic material of HPV -- the virus that causes cervical cancer. A second screening method -- visual inspection of the cervix using acetic acid, which turns precancerous tissue white -- was less accurate but still better than Pap smears since women could be screened and treated in the same visit.
The investigators reported that screening women once in their lifetimes at the age of 35 years with a one-visit or two-visit screening strategy using visual inspection or HPV DNA testing, followed by immediate treatment for women with abnormal results, reduced the lifetime risk of cancer by approximately 25 to 36 percent. Cancer risk was reduced by about 50 percent when women were screened twice in their lifetimes, at ages 35 and 40. Although the average costs per woman varied widely among the five countries, ranging from $24.20 to $33.56 for a single lifetime screening in India to $78.86 to $110.95 in South Africa, there were strategies identified in each country that would be considered cost-effective.
The relationship between the cost of a particular cervical cancer screening strategy and the average gain in life expectancy associated with each strategy was expressed using a cost-effectiveness ratio or a "cost per year of life saved." For example, the cost per year of life saved for screening twice in a lifetime with a one-visit visual-inspection strategy was $91 in India and $319 in Kenya; this same strategy with the use of HPV DNA testing was $310 per year of life saved in Thailand, $453 in Peru, and $1,093 in South Africa. According to the Commission on Macroeconomics and Health, which considers interventions with a cost per year of life saved that are less than the country's per capita gross domestic product to be "good buys," these strategies would all be considered cost-effective.
"Young women dying from cervical cancer is a public health tragedy in light of effective and cost-effective screening methods," said Dr. Goldie. "Our analysis is not intended to dictate that one particular approach is best for every country -- but it adds strong support to changing the longstanding perception that screening will be too difficult to implement and sustain in the world's poorest countries."
The analysis was funded by the Bill and Melinda Gates Foundation through the Alliance of Cervical Cancer Prevention and was part of a five-country policy analysis of cervical cancer prevention programs through grants to EngenderHealth, the International Agency for Research on Cancer, JHPIEGO, the Pan American Health Organization, and the Program for Appropriate Technology in Health; and by a grant to Dr. Goldie from the National Cancer Institute.
The special article, "Cost-Effectiveness of Cervical-Cancer Screening in Five Developing Countries," will appear in The New England Journal of Medicine, November 17, 2005, Volume 353, number 20. A related Perspective, "The Promise of Global Cervical-Cancer Prevention," will appear in the same issue.
Contact: Christina Roache
Harvard School of Public Health
677 Huntington Avenue
Boston, MA 02115