BACKGROUND.
Changes in serum CA 125 from baseline do not reflect response to paclitaxel in relapsed ovarian carcinoma patients. Our study aimed to determine whether CA 125 changes relate to tumor response and overall survival during paclitaxel salvage treatment.
METHODS.
Response data and CA 125 values of 77 platinum pretreated ovarian carcinoma patients were included in the study. Patients received 496 courses of paclitaxel in total (median 6; range: 2-18 courses).
RESULTS. Response group numbers on the basis of World Health Organization
(WHO) criteria were: 7 partial response, 22 stable disease, and 48 progressive disease. CA 125 values at the moment of clinical response allocation, the median survival duration, and the 3-year survival rate did not differ among WHO defined response groups. For both the stable disease group and the responders, the slopes of the exponential CA 125 regression curves during paclitaxel treatment were negative. Response groups, as defined by CA 125 changes, i.e., halving or doubling of baseline values, after 4 courses were concordant with WHO defined response groups in only 27%, but predicted survival far better.
CONCLUSIONS.
This study confirms that CA 125 changes in patients receiving paclitaxel treatment do not correlate uith response allocations according to WHO criteria. In particular, patients with clinically and radiologically defined progression will often not show an increase in CA 125 concentrations from baseline. 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. Cancer 1996; 78118-27.