Risk of diagnosis of ovarian cancer after raised serum CA 125 concentration: a prospective cohort study.

OBJECTIVE: To determine the risk of invasive epithelial ovarian cancer and fallopian tube cancer associated with a raised concentration of the tumour marker CA 125 in asymptomatic postmenopausal women. DESIGN: Serum CA 125 concentration was measured annually in study participants for one to four years. Participants with a concentration > or = 30 U/ml were recalled for abdominal ultrasonography. Follow up was by annual postal questionnaire. SETTING: General practice, occupational health departments, ovarian cancer screening unit in a teaching hospital. SUBJECTS: 22,000 volunteers, all postmenopausal women > or = 45 years of age; recruited between 1 June 1986 and 1 May 1990. INTERVENTION: Surgical investigation if the ultrasound examination was abnormal. MAIN OUTCOME MEASURES: Cumulative and relative risk of developing an index cancer (invasive epithelial cancer of the ovary or fallopian tube) after a specified CA 125 result. RESULTS: 49 index cancers developed in the study population during a mean follow up of 6.76 years. The overall cumulative risk of developing an index cancer was 0.0022 for the entire study population and was lower for women with a serum CA 125 concentration < 30 U/ml (cumulative risk 0.0012) but was appreciably increased for women with a concentration > or = 30 U/ml (0.030) and > 100 U/ml (0.149). Compared with the entire study population the relative risk of developing an index cancer within one year and five years was increased 35.9-fold (95% confidence interval 18.3 to 70.4) and 14.3-fold (8.5 to 24.3) respectively after a serum CA 125 concentration > or = 30 U/ml and 204.8-fold (79.0 to 530.7) and 74.5-fold (31.1 to 178.3) respectively after a concentration > or = 100 U/ml. CONCLUSION: CA 125 is a powerful index of risk of ovarian and fallopian tube cancer in asymptomatic postmenopausal women.

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 ovarian cancer screening strategy. DESIGN: Prospective ovarian cancer screening trial between December 1986 and June 1993. SETTING: General practice, occupational health departments and an ovarian cancer screening clinic at a London teaching hospital. POPULATION: Postmenopausal women, > or = 45 years with a raised CA125. METHODS: Volunteers with a CA125 > or = 30 U/mL underwent a pelvic ultrasound. Scans were classified as normal, abnormal (ovarian volume > or = 8.8 mL) or equivocal (normal volume with abnormal morphology). Abnormal ovarian morphology was subclassified as simple cyst (single, thin walled cyst with no septa or papillary projections) or complex (all other abnormalities). Volunteers with abnormal scans were referred for a gynaecological opinion. Follow up was via the cancer registry and postal questionnaires. MAIN OUTCOME MEASURES: Sensitivity, specificity and positive predictive value of different ultrasound criteria for detection of index cancer (e.g. primary invasive epithelial carcinoma of the ovary and fallopian tube). RESULTS: Seven hundred and forty-one women underwent 1,219 scans and 20 index cancers occurred during a median follow up of 6 x 8 years. The sensitivity for detection of ovarian cancer of different ultrasound criteria was 100% for abnormal morphology, 89 x 5% for abnormal volume and 84% for complex morphology. The highest specificity (97%) and positive predictive value (37 x 2%) was achieved using complex morphology. CONCLUSION: A variety of ultrasound criteria can achieve high sensitivity, specificity and positive predictive value for index cancers in postmenopausal women with an elevated CA125. Use of ovarian morphology to interpret ultrasound may increase sensitivity and use of complex ovarian morphology may increase the positive predictive value.