Description of the Evidence
Evidence of Benefit or Lack of Benefit Associated With Different Screening Modalities
Potential screening tests for ovarian cancer include transvaginal ultrasound (TVU) and the serum cancer antigen 125 (CA-125) assay, often performed in combination. Several biomarkers with potential application to ovarian cancer screening are under development but have not yet been validated or evaluated for efficacy in early detection and mortality reduction.
Manual pelvic examination is a part of the routine pelvic examination. The sensitivity and specificity of the pelvic examination are not characterized, but examination generally detects advanced disease.[6,7] There is no evidence for the benefit of this test for the early detection of and decreased mortality from ovarian cancer and it is not further considered.
The focus in this summary is on asymptomatic screening for ovarian cancer. Ovarian cancer often presents with persistent but vague symptoms and some investigators have proposed the use of symptom indices as a method for screening for ovarian cancer.[8,9] Because this is not, by definition, asymptomatic screening, it is not considered further in this summary.
Transvaginal ultrasonography (or transvaginal sonography)
TVU (or transvaginal sonogram [TVS]) has been proposed as a screening method for ovarian cancer because of its ability to reliably measure ovarian size and detect small masses.
TVU as an independent screening modality is being evaluated in one arm of the United Kingdom Collaborative Trial of Ovarian Cancer Screening (UKCTOCS) (NCT00058032). The UKTOCS is an ongoing randomized controlled trial of 202,638 postmenopausal women recruited in 13 trial centers across the United Kingdom. Women were randomly assigned to receive multimodality screening with CA-125 as a primary test and TVS as a secondary screen (multimodal group); an ultrasound only (ultrasound group); or no routine screening (control group). Of the 50,639 women randomly assigned to receive ultrasound screening, 48,230 attended the first year screening, with 48,053 women with data to evaluate ovarian morphology. Of these, 9.1% (4,367) had an abnormal adnexal scan. Among women with an abnormal scan, the absolute risk of epithelial ovarian cancer in the next 3 years was 1.08%. Thus, most of these abnormal scans represented a false-positive test result. In the ultrasound group, 11,982 women had both ovaries visualized and normal scans at all UKCTOCS annual visits during the 3-year study period. Among this group, eight women were diagnosed with epithelial ovarian cancer within 3 years of the first scan.