Objective: To review the prevalence of various conditions associated with serum CA-125 values > 65 U/mL, to calculate the odds ratios of different ranges of high CA-125 in predicting cancer and to study the effect of menopause and the presence of a mass on the predictive value of high serum CA-125.
Study design: A retrospective review of the diagnoses in 313 consecutive women seen at the Cleveland Clinic Foundation whose serum CA-125 was > 65 U/mL was performed. Statistical analysis was performed using crosstabulation, chi 2, Fisher's exact test and the odds ratio.
Results: In patients with serum CA-125 > 65 U/mL, gynecologic cancers, nongynecologic cancers and non-malignant conditions constituted 74.3%, 10.2% and 13.1% of diagnoses, respectively. In patients with serum CA-125 > or = 1,000 U/mL, the same conditions were responsible for 89%, 7% and 3% of diagnoses, respectively. Endometriosis and metastatic breast cancer were the most common benign condition and nongynecologic cancer associated with serum CA-125 > 65 U/mL. The presence of an abdominopelvic mass significantly increased the risk of malignancy (P < .00005). Approximately 90% of patients with CA-125 > 65 U/mL and no mass had nonmalignant disease. The diagnoses of serum CA-125 values > 65 U/mL varied significantly in premenopausal versus postmenopausal patients. Postmenopausal patients had a higher incidence of gynecologic (P = .002) and nongynecologic (P = .0008) cancers and lower incidence of benign conditions (P < .0005). The odds ratio that CA-125 levels were associated with cancer increased as the level of CA-125 increased. The odds ratio of malignant versus benign disease was significantly higher in post-menopausal patients for all intervals of CA-125 levels until the level of > or = 1,000 U/mL was reached.
Conclusion: In patients seen at a tertiary center, serum CA-125 measurements > 65 U/mL were associated with nonmalignant conditions in 13% of patients. Although higher serum CA-125 levels were more associated with gynecologic malignancies, no level of CA-125 occurred exclusively with gynecologic cancers. In postmenopausal patients with serum CA-125 values > 65 U/mL and in patients with serum CA-125 values > 65 U/mL and an abdominopelvic mass, subspecialty consultation should be considered before proceeding to surgery.