Epithelial ovarian cancer: role of pegylated liposomal Doxorubicin in prolonging the platinum-free interval and cancer antigen 125 trends during treatment.

BACKGROUND Epithelial ovarian cancer's response to platinum retreatment depends on the duration of response to first-line platinum therapy. Platinum-free interval predicts subsequent platinum sensitivity and is a prognostic factor. Little has been published on the effect of pegylated liposomal doxorubicin (PLD) in the prolongation of treatment-free interval. METHODS Patients treated with PLD were reviewed to assess response to platinum retreatment after PLD and to establish the use of cancer antigen 125 (Ca125) trends. All patients treated with PLD had progressed within 12 months of prior platinum therapy. Cancer antigen 125 fluctuations were categorized as the variances from the baseline (+/-10%, +/-10%-25%, and >25%). The response to chemotherapy was defined as Ca125 reduction from the baseline of more than 50%, clinical, or radiological response. RESULTS Fifty-nine women were identified. The response rate (RR) to PLD was 28.9%, and the median overall survival from PLD initiation was 62 weeks. The number of women demonstrating more than 25% reduction in Ca125 from the baseline increased progressively with each cycle; at cycle 2, 11%; cycle 3, 18%; cycle 4, 22%; and cycle 5, 27% (trend significant between cycles 2 and 4, P = 0.004). Fifteen patients were re-treated with platinum after progression after PLD with 80% (12/15) of the patients responding. The RR to platinum retreatment after PLD compares favorably with the historical data on the response to second-line platinum retreatment. CONCLUSIONS The sole use of early Ca125 trends in PLD treatment before cycle 4 may result in an erroneous discontinuation of PLD in potential responders. Retreatment with platinum after PLD may yield a good RR in selected patients even those with disease progression within 12 months after prior platinum treatment.