Evaluation of CA 15-3 serum levels in breast cancer patients.

The usefulness of post operative serum CA 15-3 determination was evaluated in a group of 57 breast cancer patients. CA 15-3 was assayed at baseline and every 3 months for a median follow-up of 34 months. Recurrence-free survival probability for patients with elevated serum CA 15-3 levels before surgery was 53.5% versus 88% for patients with normal serum CA 15-3 levels (p < 0.201). In 12 of the 15 patients with increased trend for CA 15-3 during follow-up, elevated CA 15-3 levels preceded (10 patients) coincided (2 patients) with the clinical detection of tumour recurrence, providing a predictive value of an increased trend of 80%. In the group of 10 patients who showed elevated serum CA 15-3 levels prior to the detection of recurrence, the median load-time was 5 months/(range 3-11 months). We concluded that CA 15-3 had prognostic value in breast cancer. Serial determinations of CA 15-3 was consistent with the treatment results.