Novel screening strategies for early ovarian cancer by transabdominal ultrasonography.

Data collected during a prospective study to assess the efficacy of detecting early ovarian cancer by transabdominal ultrasonography have been used to refine and extend the screening procedure. The analysis was based on results from 5479 self-referred asymptomatic women, who were scheduled to undergo three annual screens consisting of one or more ultrasound scans. A positive result (based mainly on the presence of abnormal morphology) was obtained at 338 screens (326 women). Five patients with primary ovarian cancer (four stage 1a, one stage 1b; two at screen 1, three at screen 2) were identified (prevalence 0.09%). The apparent detection rate was 100% and the false-positive rate (FPR) was 3.5% at screen 1 and 2.3% overall. The use of abnormal morphology, or the maximum ovarian volume (MOV) greater than 96th centile as alternative criteria for a positive screen result, together with a defined volume change at rescan (VC) would give a FPR of 3.1% at screen 1 and 2.0% overall. The use of abnormal morphology alone at scan 1 and VC at rescan would give an overall FPR of 1.6%. The odds that a positive screen result would indicate the presence of an ovarian mass, a benign tumour, any ovarian cancer or primary ovarian cancer would be about 4 to 1, 2 to 1, 1 to 26, and 1 to 50 respectively. The results provide a more rational basis for the application and development of screening procedures for early ovarian cancer in both pre- and post-menopausal women.