CA 125 in the early detection of metastatic breast cancer

Abstract

e12015 Background: Kinetics of CA 15–3 and CEA have a high specificity in the early detection (= asymptomatic patients) of metastatic breast cancer disease. However, this high specificity is associated with a lack of sensitivity (false-negative results). To decrease the number of false negative (FN) patients, the additional diagnostic potential of CA 125 kinetics was evaluated. Methods: We analysed 1,011 follow-up samples of 95 patients. Forty-seven of these patients showed metastatic recurrence during follow-up. Based on analyses, published previously, a reproducible increase of CA 125, CA 15–3, or CEA ≥100% based on the individual baseline value of each patient was selected as a reliable indicator for metastatic disease. Results: None of the 48 patients with NED had a reproducible increase of either CEA, CA 15–3, or CA125, i.e., all three tumor markers reached a specificity of 100%. At the time of first metastatic disease, the overall sensitivity was 29.8% for CA 125, 44.7% for CA 15–3, and 21.3% for CEA. In 7 patients (14.9%) only CA 125, in 14 patients (29.8%) only CA 15–3 and in 6 patients (12.8%) only CEA increased. In 8 patients (17.0%) more than one marker increased. The sensitivity of the CA 15–3/CEA combination was 59.6% (95%-CI: 45.5%-73.6%). With the additional use of CA 125, the sensitivity could be increased by 14.9% to 74.5% (95%-CI: 62.0–86.9%). The sensitivity of the marker combination was 66.6% for metastases in one site (n = 33) and 100% for metastases in more than one site (n = 14). Conclusions: This retrospective analysis indicates that CA 125 increased the sensitivity of the CA 15–3/CEA combination by 14.9% without loss of specificity. The combined use of CA15–3/CEA/CA125 may therefore be helpful for early detection of metastatic disease. The usefulness of this approach is presently verified in a prospective trial. [Table: see text]