Increased levels of tumor markers in the follow-up of 400 patients with breast cancer without recurrence or metastasis: interpretation of false-positive results.

PURPOSE: To analyze, study and interpret the increased levels of tumor markers in breast cancer patients without recurrence or metastasis. PATIENTS AND METHODS: We studied a series of 400 patients with stage 1 breast cancer during a 3-year follow-up after primary treatment. Follow-up included frequent serum estimation of CEA, CA 15.3, CA 125, CA 27-29, TPA and TPS tumor markers.
RESULTS: Of 358 patients being continuously disease-free, 18 (5%) cases showed false-positive levels of tumor markers, associated with benign conditions and not to cancer recurrence or metastasis. These conditions included ovarian cysts, thyroid disorders, hepatitis, renal stone and sarcoidosis.
CONCLUSION: The value of increased tumor markers should be interpreted cautiously because it doesn't always imply disease recurrence. Tumor markers may increase in many benign conditions.