CA 125 - A VALID MARKER IN OVARIAN-CARCINOMA PATIENTS TREATED WITH PACLITAXEL

BACKGROUND. Changes in serum CA 125 from baseline do not reflect respo nse to paclitaxel in relapsed ovarian carcinoma patients. Our study ai med to determine whether CA 125 changes relate to tumor response and o verall survival during paclitaxel salvage treatment. METHODS. Response data and CA 125 values of 77 platinum pretreated ovarian carcinoma pa tients were included in the study. Patients received 496 courses of pa clitaxel in total (median 6; range: 2-18 courses). RESULTS. Response g roup numbers on the basis of World Health Organization (WHO) criteria were: 7 partial response, 22 stable disease, and 48 progressive diseas e. CA 125 values at the moment of clinical response allocation, the me dian survival duration, and the 5-year survival rate did not differ am ong WHO defined response groups. For both the stable disease group and the responders, the slopes of the exponential CA 125 regression curve s during paclitaxel treatment were negative. Response groups, as defin ed by CA 125 changes, i.e., halving or doubling of baseline values, af ter 4 courses were concordant with WHO defined response groups in only 27%, but predicted survival far better. CONCLUSIONS. This study confi rms that CA 125 changes in patients receiving paclitaxel treatment do not correlate with response allocations according to WHO criteria. In particular, patients with clinically and radiologically defined progre ssion will often not show an increase in CA. 125 concentrations from b aseline. Those patients who do show doubling of CA 125 values, however , have a very poor prognosis. The CA 125 ratio, as determined after 4 courses of paclitaxel treatment, may be a better indicator of response than WHO defined response status. (C) 1996 American Cancer Society.