Ultrasound assessment of ovarian cancer risk in postmenopausal women with CA125 elevation

We have previously shown that, in asymptomatic post-menopausal women, serum CA125 elevation is associated with a 36-fold increase in risk of ovarian cancer. This study was undertaken to assess the value of pelvic ultrasound for further stratification of ovarian cancer risk. Of 22,000 post-menopausal women, aged ≥ 45 participating in an Ovarian Cancer Screening Trial, 741 with a CA125 ≥ 30 U ml-1 underwent pelvic ultrasonography. Twenty index cancers (primary invasive epithelial carcinomas of the ovary and fallopian tube) were diagnosed amongst these 741 women during a median follow-up of 6.8 years. Ultrasound results separated the women with CA125 elevation into two groups. Those with normal ovarian morphology had a cumulative risk (CR) of index cancer of 0.15% (95% confidence interval (CI) 0.02-1.12) which is similar to that of the entire population of 22,000 women (0.22%, 95% CI 0.18-0.30). In contrast, women with abnormal ovarian morphology had a CR of 24% (15-37) and a significantly increased relative risk (RR) of 327 (156-683). Ultrasound can effectively separate post-menopausal women with raised CA125 levels into those with normal scan findings who are not at increased risk of index cancer and those with abnormal findings who are at substantially increased risk of index cancer.