Ovarian cancer screening.

Background: Despite advances in evaluation and treatment, ovarian cancer mortality has decreased minimally during the past two decades. Most patients have advanced-stage disease at diagnosis, and the prognosis is poor. As a result, there has been increasing interest in the development of methods for the early detection of ovarian cancer. To benefit from screening, a disease should (1) be a significant cause of mortality, (2) have a high prevalence in the screened population, (3) have a preclinical phase that can be detected by screening, and (4) be amenable to therapy, such that the survival rate of patients with early-stage disease is significantly higher than that of patients with advanced-stage disease. Ovarian cancer fulfils all of these criteria.
Methods: An optimal screening method should be safe, easy to do, time efficient, and acceptable to the patients being screened. Most importantly, it should have a high sensitivity and specificity.
Results: Currently, the most effective screening methods for ovarian cancer are serum CA 125 levels and transvaginal sonography (TVS). In screening studies, the serum CA 125 level has had a reasonably high specificity but a low sensitivity. Currently, approximately 8000 asymptomatic women have been screened with TVS. Ten primary ovarian cancers were detected, and all were Stage I lesions. Patients whose tumors were detected by TVS all have been cured by conventional treatment. TVS screening has resulted in a significant reduction in stage at detection and in the case-specific death rate from ovarian cancer. In these studies, TVS has had a high sensitivity but only a moderate specificity. CA 125 level, Doppler flow sonography, and the use of a morphology index are being evaluated as methods to increase the specificity of TVS.
Conclusions: A large multiinstitutional study is indicated to determine if annual TVS screening will cause a significant decrease in site-specific mortality from ovarian cancer.