Positive Tests: A Risk Assessment and Pathway Analysis for the Use of Screening LaboratoriesFalse Positive Tests: A Risk Assessment and Pathway Analysis for the Use of Screening Laboratories
Last update: September 3, 2017
While the incidence of ovarian cancer is relatively low, it is a leading cause of gynecologic cancer-related death (Jemal, et al. (2010) CA Cancer J. Clin. 60(1):4–25). Detection and treatment of ovarian cancer in the early stages results in an 87% survival rate and 82% of patients are diagnosed in the early stages (Jemal, et al. (2010) CA Cancer J. Clin. 60(1):4–25).
The American Cancer Society estimates that more than 22,000 women will be diagnosed with ovarian cancer and approximately 14,000 will die from the disease in the United States in 2012. Currently, the FDA-approved diagnostic tests for early detection of ovarian cancer include serum tumor markers, transvaginal ultrasound, and computerized tomography (CT) and magnetic resonance imaging (MRI). Computerized tomography (CT) is used to image the large intestine and to assess the extent of a colon cancer. However, it is expensive and not recommended for use as an initial test in asymptomatic patients without symptoms. In addition, CT and MRI are limited in their ability to identify non-ovarian tumors, such as tumors of the stomach, uterus, fallopian tube, and brain.
While screening for cervical cancer has been made available to most women, there is a screening gap for ovarian cancer. Despite the increased screening in ovarian cancer, the 5-year survival rate for women diagnosed with stage I and II ovarian cancer remains at 60% or less (Siegel, et al. (2007) J. Clin. Oncol. 25(33):6867–6874). Hence, there is an urgent need for early diagnosis of ovarian cancer.
Consequently, there is an unmet need for cost-effective and non-invasive screening tests for ovarian cancer.
Transvaginal ultrasound (TVU) is widely used as an initial screening test for detecting ovarian cancer, although it has low sensitivity and specificity, and in some cases may yield false positive results. The sensitivity of TVU in detecting early-stage disease is limited to 55–70% and specificity is only 60–70% (NCCN Guidelines, 2014; NCCN Guidelines, 2014). However, some studies reported that TVU can detect ovarian tumors as small as 2 mm in diameter with 100% sensitivity. As mentioned above, tumor markers have been used as an alternative test to detect ovarian cancer in patients with positive results on TVU. Despite the fact that a recent study suggested that tumor markers such as CA125 are not appropriate for the early detection of ovarian cancer, CA125 and CA19-9, the most commonly used tumor markers 0b46394aab