How can treatment response be measured in breast cancer patients?

Serum TPS, CA 15-3 and CEA levels were measured in 31 women when progressive metastatic disease was established according to UICC criteria. A method was developed to apply these serum tumor markers in order to measure the short-term effect of the treatment. Using strict criteria, whereby an increase of the markers of more than 25% indicated progressive disease and a decrease of more than 50% indicated a positive effect of the treatment, TPS (which measures tumoral activity) was shown to be a more sensitive and earlier marker for measuring treatment response than CA 15-3 and CEA (which measure tumor mass).