Performance of ultrasound as a second line test to serum CA125 in ovarian cancer screening

Objective To assess the performance of ultrasonography in a multimodal ovar ian cancer screening strategy. Design Prospective ovarian cancer screening trial between December 1986 and June 1993. Setting General practice, occupational health departments and an ovarian ca ncer screening clinic at a London teaching hospital. Population Postmenopausal women, greater than or equal to 45 years with a r aised CA125. Methods Volunteers with a CA125 greater than or equal to 30 U/mL underwent a pelvic ultrasound. Scans were classified as normal, abnormal (ovarian vol ume greater than or equal to 8.8 mL) or equivocal (normal volume with abnor mal morphology). Abnormal ovarian morphology was subclassified as simple cy st (single, thin walled cyst with no septa or papillary projections) or com plex (all other abnormalities). Volunteers with abnormal scans were referre d for a gynaecological opinion. Follow up was via the cancer registry and p ostal questionnaires. Main outcome measures Sensitivity, specificity and positive predictive valu e of different ultrasound criteria for detection of index cancer (e.g. prim ary invasive epithelial carcinoma of the ovary and fallopian tube). Results Seven hundred and forty-one women underwent 1219 scans and 20 index cancers occurred during a median follow up of 6.8 years. The sensitivity f or detection of ovarian cancer of different ultrasound criteria was 100% fo r abnormal morphology, 89.5% for abnormal volume and 84% for complex morpho logy. The highest specificity (97%) and positive predictive value (37.2%) w as achieved using complex morphology. Conclusion A variety of ultrasound criteria can achieve high sensitivity, s pecificity and positive predictive value for index cancers in postmenopausa l women with an elevated CA125. Use of ovarian morphology to interpret ultr asound may increase sensitivity and use of complex ovarian morphology may i ncrease the positive predictive value.