Studies Examine Ways to Prevent Cervical Cancer With Few Resources
December 5, 2005
Faster, more aggressive cervical cancer treatment could benefit low-income American women and women in developing countries who test positive for high-grade precancerous lesions, two recently published studies suggest. Though some of these women may be treated unnecessarily, the trade-off could save lives in resource-poor countries, where the International Agency for Research on Cancer says 80 percent of the 230,000 cervical cancer deaths worldwide occur each year.
In affluent countries, many women get annual Pap smears, in which cells are scraped from the cervix and examined in a lab. If the test is abnormal, a patient returns for a biopsy. If the biopsy indicates signs of cancer, the woman and her physician discuss treatment options.
But in poor countries, lab testing and biopsies are rare. Poor U.S. women may not get regular Pap exams, or may fail to return for follow-up testing, said Dr. Wendy Brewster, a University of California-Irvine researcher and co-author of one of the studies.
To examine ways to get more poor women tested and treated, Brewster and colleagues studied 3,521 women in largely Hispanic neighborhoods in Orange County, Calif., who underwent Pap smears. One group of the women remained at the clinic to await results. If their test indicated high-grade precancerous lesions, the women underwent a procedure that day to remove a layer of the cervix. Women in the comparison group who had abnormal results were referred for later follow-up care.
At six- and 12-month follow-up, researchers found that women in the single-visit group were considerably more likely to have completed their care than women in the comparison group. Biopsy samples taken before treatment showed that two out of 14 women had the procedure unnecessarily because their biopsies were negative. While the procedure is considered safe, it still carries risks.
"We may have to decide what's feasible, what we can afford and what's the best care for different groups," noted Brewster.
In the second study, funded by the Bill and Melinda Gates Foundation, researchers conducted two different screenings on 6,555 women in South Africa. One test was for human papillomavirus (HPV), a common STD that causes most cervical cancer, and the other was a simple, inexpensive test for precancerous lesions. The women were divided into three groups. In the first group, only those women who tested HPV-positive were given cryotherapy, a procedure that kills cervical cells by freezing them with nitrous oxide. In the second group, only the women who tested positive for precancerous lesions had cryotherapy. Treatment for the third group was six months later.
According to the researchers at Columbia University and the University of Cape Town, the HPV test was more accurate than the cheaper test, but both exams reduced the incidence of precancerous lesions. However, four out of five women in the two groups that received immediate treatment did not have a precancerous condition. Co-author Dr. Thomas C. Wright Jr. of Columbia said the trade-off between benefits and risks was reasonable in order to save lives.
"The important thing is to link testing with treatment," said Dr. Paul Blumenthal of Johns Hopkins University, co-author of an accompanying editorial on the studies. "If you do that without a diagnostic step, as long as treatment is safe, you're well within the bounds of good medicine."
The studies, "Feasibility of Management of High-Grade Cervical Lesions in a Single Visit," and "Screen-and-Treat Approaches for Cervical Cancer Prevention in Low-Resource Settings," and the editorial, "Cervical Cancer Prevention; Making Programs More Appropriate and Pragmatic," were published in the Journal of the American Medical Association (2005;294(17):2182-2187, 2173-2181, and 2225-2228, respectively.)
11.01.05; Carla K. Johnson
This article was provided by CDC National Prevention Information Network. It is a part of the publication CDC HIV/Hepatitis/STD/TB Prevention News Update.