Serum markers TPS, TPA and CA 15-3 as monitors of chemotherapy in patientswith metastatic breast cancer

The serum markers TPS, TPA and CA 15-3 have been applied in monitoring the clinical course of 63 patients with metastatic breast cancer. To evaluate t he clinical usefulness of these markers, we investigated the relationship b etween the initial marker levels and the changes of the marker levels durin g chemotherapy. All three markers demonstrated high sensitivity for detecti ng visceral and bone metastases (89-94%) compared to soft tissues and local ly advanced disease in the patients (45-50%). The marker combination, TPS a nd CA15-3, showed the highest sensitivity for detecting bone/visceral metas tases (98%) and soft tissues/locally advanced metastases (75%). The patients were followed for an extended time period and in total, 126 cl inical events (CR, PR, SD, PD) were recorded. Median 7 serum samples per pa tient were analyzed. TPA showed the highest sensitivity (85%) to the clinic ally confirmed events PR/CR compared to TPS (68%) or CA 15-3 (54%). In the case of clinical confirmed progressive disease (PD), TPS and TPA showed the highest sensitivity with increased marker levels (>25%) in 77-78% of the e vents compared to CA 15-3 (58%). On the other hand, in patients with increa sed marker levels (>25%), the formal evaluation could verify a PD in 90% an d 94% of the events for TPS and TPA compared to 78% for CA 15-3. Analogous the correlation between decreasing (>50%) marker levels and clinical PR/CR was 72% for CA 15-3 compared to 65-66% for the cytokeratin markers. Overall , TPS and TPA tend to be superior to CA 15-3 for follow-up of metastatic br east cancer patients. TPS, TPA and CA 15-3 marker increase preceded the cli nical and/or radiological signs of PD in most of the patients; 1.5, 1.5 and 1.1 months, respectively. The cytokeratin markers TPS and TPA tended to be the most useful tumor mark ers for monitoring treatment and the simultaneous determination of two mark ers provided additive diagnostic information in advanced breast cancer pati ents.