Is There a Taxane-Free Interval That Predicts Response to Taxanes as a Later-Line Treatment of Recurrent Ovarian or Primary Peritoneal Cancer?

Abstract

Taxanes have reported response rates of 20% to 40% in recurrent ovarian cancer (ROC) but are less well studied as a later-line treatment. We reviewed our experience with taxanes in ROC to determine (1) if a taxane-free interval is associated with response rates in women with ROC and (2) if the use of intervening therapy (IT) affects subsequent response rates to taxanes. We retrospectively identified women who received first- or second-line platinum-taxane therapy and later received a single-agent taxane. Demographics, intervening regimens, and follow-up and survival data were collected. Responses were characterized by cancer antigen 125 levels based on the Gynecologic Cancer InterGroup serologic response definitions. We identified 46 women who met the eligibility criteria. The median age was 57 years (range, 39-78 years). The median interval between taxanes was 25.8 months (range, 2.9-85.5 months), with 10 (21%) of the women were treated 12 months or less from their last taxane and 37 (79%) treated more than 12 months. The median number of IT was 2 (range, 0-5). Forty patients (87%) received paclitaxel; 6 (13%) received docetaxel. All patients treated 12 months or less from their last taxane responded (P = 0.02). The number of IT was associated with a better response; all women (100%) treated who had no IT, 7 (54%) of 13 women with 1 to 2 ITs, and 7 (39%) of 18 women with 3 ITs or more responded. The overall survival was 13.4 months in responders versus 10.6 months in nonresponders (P = 0.27). Taxanes maintain an activity as a later-line agent, even with 3 or more intervening therapies. However, the highest responses were seen if taxanes were used within 12 months of the last platinum-based combination. The lack of an increased response with aprolonged taxane-free interval is likely related to the number of IT, consistent with the emergence of multidrug resistance.