The two screen-and-treat methods, human papillomavirus (HPV) DNA testing and visual inspection with acetic acid (VIA), followed by treatment using cryotherapy for all eligible women with positive test results, were found to perform as well or better than traditional cytology-based screening (Pap smear) for identifying high-grade cervical cancer precursor lesions. Cryotherapy – freezing the cervix – is a relatively low-technology treatment method that has been shown to be highly efficacious with minimal morbidity. This study was the first time these methods were tested for efficacy in reducing the prevalence of cervical cancer precursor lesions.
"These are highly effective, low cost methods to reduce the unnecessary mortality from cervical cancer around the world – especially in the world's poorest countries," said Thomas C. Wright Jr., M.D., principal investigator of the study and professor of pathology, Columbia University College of Physicians & Surgeons. "We found that conducting HPV DNA or VIA protocols in South Africa were not only much more cost-effective than traditional cytology-based approaches, but were similar in overall cost to other well-accepted health interventions, such as childhood vaccines."
Published in the Nov. 2, 2005 issue of the Journal of the American Medical Association, the randomized clinical trial included 6,555 nonpregnant women, aged 35 to 65 years, between June 2000 and December 2002 at three ambulatory women's health clinics in Khayelitsha, South Africa. All women were screened using HPV DNA and VIA testing. Women were subsequently randomized to one of three groups: cryotherapy if the woman had a positive HPV DNA test; cryotherapy if the woman had a positive VIA test; or to a delayed evaluation group.
The women returned after six and 12 months for follow-up exams. Both the HPV DNA and VIA testing followed by cryotherapy reduced the prevalence of cervical cancer precursor lesions, or CIN 2+. After six months, a 77 percent lower prevalence of CIN 2+ was found among the HPV group compared with the delayed evaluation group and a 37 percent lower prevalence among the VIA group compared with the delayed evaluation group.
"This novel approach to cervical cancer prevention is highly acceptable to the women in the community," said Lynette Denny, M.D., MPH of the University of Cape Town in South Africa who directed the clinical activities in Cape Town. "Ninety-nine percent of participants said they would recommend this type of screening program to friends and family."
"The next step is to conduct large-scale public health intervention projects to better define the operational needs and challenges of these programs," said Dr. Wright.
Each year nearly half a million cases and nearly a quarter million deaths occur from cervical cancer, of which 80 percent occur in less-developed countries that have access to less than 5 percent of global cancer treatment resources. The lifetime risk of a woman developing cervical cancer in a low-resource setting is approximately 2 percent to 4 percent
Health experts have long been frustrated by the high incidence and mortality rates of cervical cancer – a common and easily preventable cancer in women – in developing areas. The cytology-based screening programs, which have significantly reduced the incidence of cervical cancer in the United States and Europe and other developed parts of the world, have not been feasible for many low-resource settings because of the complex health infrastructure they require. Low-resource settings are not able to provide the advanced and lengthy training needed for cytology laboratories, used to examine Pap smears; nor are they set up for the extensive evaluation used for women with abnormal cytological results, which typically involves a colposcopy, where a doctor uses a specially designed microscope to look at the surface of the cervix.
The study, intended to combat these financial and systematic hurdles, was approved by the institutional review boards of Columbia University Medical Center and the University of Cape Town (Cape Town, South Africa).
The international group included researchers from Columbia University Medical Center: Dr. Wright and Louise Kuhn, Ph.D. of the Gertrude H. Sergievsky Center at Columbia's College of Physicians & Surgeons and the Department of Epidemiology at Columbia's Mailman School of Public Health. Researchers from the University of Cape Town included Lynette Denny, M.D., Ph.D. and Michelle De Souza, M.D., both in the Department of Obstetrics and Gynaecology. The team also included Amy E. Pollack, M.D., MPH from EngenderHealth in New York, NY and William Dupree, M.D. from HealthNetwork Laboratory in Allentown, Pa.
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