CLINICAL INTEREST OF ESTIMATION OF THE GROWTH-KINETICS OF OVARIAN PRIMARY RECURRENCES BY CA125 DOUBLING TIME

The aim of this retrospective work was to study the clinical importanc e of growth rate determination for ovarian cancer primary recurrence i n term of CA125 doubling time (nit). Fifty-one patients with epithelia l ovarian carcinoma stage III or IV who developped a recurrence were i ncluded. Eighteen spontaneous dt values were calculated in non-treated patients during follow-up and 33 apparent dt values were estimated in patients undergoing treatment during CA125 increase before the clinic al and/or radiological diagnosis of recurrence. No early treatment of the recurrence has permitted a drop in CA125 level. We applied exponen tial regression models to CA125 individual Kinetics in order to calcul ate dt values. Individual dt values vary from 5 to 375 days. Spontaneo us and apparent dt medianes (respectively 64 and 39 days) are not sign ificantly different. Among all early clinical histological, biological and therapeutic parameters, the initial CA125 half-life calculated du ring the third courses of the first-line chemotherapy is the unique pr edictive parameter of dt (relative risk (RR) = 78; p < 0,01). The prog nostic impact was more important in spontaneous dt values than in appa rent ones. Being spontaneous or apparent dt was the major predictive p arameter of the delay between the initial CA125 increase and clinical and/or radiological signs of recurrence (RR = 0,3;p < 0,0001). Its pro gnostic impact is superior to the T1/2 one (RR = 2,9; p = 0,0010). Far equivalent treatments, dt (RR = a,4; p < 0,0001) and T1/2 (RR = 4, 0; p < 0,0001) are the only predictive parameters of the survival after CA125 increase This work shows that dt was an essential predictive par ameter of ovarian epithelial tumor recurrences.