The risks and benefits of different cervical cancer prevention approaches may aid women to work with their physicians to implement the appropriate screening strategies, as analyzed by a model, reported in an article released on September 22, 2008 in Archives of Internal Medicine, one of the JAMA/Archives journals.
Women in the United States have a 0.7% risk of experiencing cervical cancer at some point in their lives. The Pap smear, the routine screening technique that tests a cell sample from the cervix, has been credited with significantly reducing the number of new cases of cervical cancer by detecting abnormal cells earlier than previous detection methods. Additionally colposcopy is a process in which the doctor directly examines the cervix through a microscope. Recently, more sensitive DNA testing for human papillomavirus (HPV), a contributing risk factor for cervical cancer, has become available, as have vaccines against HPV. As a result of the advances, women and physicians have many prevention options available which must be carefully considered.
To explore these options, Natasha K. Stout, Ph.D., and colleagues at the Harvard School of Public Health, Boston, created a computerized model to simulate incidence of cervical cancer in the United States. Various screening strategies were applied to the model, with different primary screening tests, abnormal result processing plans, and frequency of screening. The authors point out that they sought out positive and negative aspects of each combination: “These strategies pose trade-offs between minimizing cancer risk (already small with regular screening) and minimizing the risk of false-positive test results and excessive diagnostic procedures.”
The lifetime risk of developing cancer did not vary significantly using different screening strategies. However, a strategy offering more referrals for colposcopy significantly reduced cancer incidence. In a hypothetical representative group of 1,000 women at the age of 20 undergoing annual screening for 10 years, implementing combined cell examination and HPV testing would lead to an estimated 1,795 colposcopy and other follow-up procedures, 1,788 of which would not be on a woman with cancer. The same group of women, using a screening test beginning with cytologic testing and followed by triage HPV testing for those showing abnormalities, would receive 403 referrals, 396 of which would be excessive. When cytologic testing alone was simulated, this led to 333 referrals, 326 of which were excessive. Finally, when HPV testing was followed by triage cytologic testing, they would receive 223 referrals, 216 of which were excessive.
The authors explain that this means each woman should take personal circumstances into account when determining the best screening method with her physician. “For women who experience short-term anxiety around screening and diagnostic workup, quality of life could be an important criterion for decision making if several screening options associated with similar cancer risk reduction are available,” they say. “Using cytologic testing followed by triage testing in younger women minimizes both diagnostic workups and positive HPV test results, whereas in older women diagnostic workups are minimized with HPV DNA testing followed by cytologic triage testing.”
They conclude that effective screening methods can be implemented to optimize cancer detection. “There is great promise in the availability of accurate HPV diagnostics, new screening technology and HPV vaccination for successful cervical cancer prevention in the United States. From both an individual and population perspective, the range of new options for prevention will ideally be assembled in such a way as to improve cancer outcomes, reduce disparities and minimize the risk of overdetection of abnormalities likely to resolve on their own.”
“These results provide an initial step toward a comprehensive set of clinically relevant information highlighting trade-offs among screening policies to ultimately better inform women’s decisions and provide additional dimensions for the construction of clinical guidelines.”
Trade-offs in Cervical Cancer Prevention: Balancing Benefits and Risks
Natasha K. Stout, PhD; Jeremy D. Goldhaber-Fiebert, PhD; Jesse D. Ortendahl, BS; Sue J. Goldie, MD, MPH
Arch Intern Med. 2008;168(17):1881-1889.
Written by Anna Sophia McKenney