[Clinical value of the estimation of growth kinetics of primary ovarian cancer recurrences by CA125 doubling time].

The aim of this retrospective work was to study the clinical importance of growth rate determination for ovarian cancer primary recurrence in term of CA125 doubling time (dt). Fifty-one patients with epithelial ovarian carcinoma stage III or IV who developed a recurrence were included. 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 clinical and/or radiological diagnosis of recurrence. No early treatment of the recurrence has permitted a drop in CA125 level. We applied exponential regression models to CA125 individual kinetics in order to calculate dt values. Individual dt values vary from 5 to 375 days. Spontaneous and apparent dt medianes (respectively 64 and 39 days) are not significantly different. Among all early clinical, histological, biological and therapeutic parameters, the initial CA125 half-life calculated during the third courses of the first-line chemotherapy is the unique predictive parameter of dt (relative risk (RR) = 78; p < 0.01). The prognostic impact was more important in spontaneous dt values than in apparent ones. Being spontaneous or apparent dt was the major predictive parameter of the delay between the initial CA125 increase and clinical and/or radiological signs of recurrence (RR = 0.3; p < 0.0001). Its prognostic impact is superior to the T1/2 one (RR = 2.9; p = 0.0010). For equivalent treatments, dt (RR = 0.4; 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 parameter of ovarian epithelial tumor recurrences.