Final results of 4-monthly screening in the UK Familial Ovarian Cancer Screening Study (UKFOCSS Phase 2).

5507^ Background: Annual transvaginal ultrasound (TVS) and serum CA125 screening for women at high-risk of Ovarian/Fallopian tube cancer (OC/FTC) in Phase 1 of UKFOCSS lacked sensitivity for early stage disease but downstaged disease volume and may have improved optimal debulking rates. More frequent screening might provide greater benefits. Here we report the final results of 4-monthly screening in one of the largest such trials worldwide. Methods: Between 14/06/2007 and 29/03/2012, 4,531 women at an estimated ≥10% lifetime risk of OC/FTC were recruited and screened by 42 UK centres for 14,263 women screen years. Screening comprised 4-monthly CA125 tests analysed by a risk of ovarian cancer algorithm, adjusted for menopausal status. TVS was annual in those with normal algorithm results, but was triggered sooner if results were non-normal. Women with suspicious scan and/or algorithm results were referred for consideration of surgical intervention. Participants were followed prospectively by centres, quest...