Docetaxel-rechallenge in castration-resistant prostate cancer: defining clinical factors for successful treatment response and improvement in overall survival

The purpose of the study was to define clinical factors for successful treatment response and re-exposure to docetaxel in metastatic castration-resistant prostate cancer (mCRPC).

An mCRPC database of patients receiving first-line docetaxel and rechallenge courses was established. Several clinical factors were evaluated for prediction of treatment response. Multivariate cox-regression analysis was used to define pre-treatment and treatment factors for survival.

Between 2005 and 2013, 94 patients with mCRPC were treated with docetaxel. Full data set and follow-up were available for 62 patients. Median follow-up was 84 m [interquartile range (IQR) 64-104 m]. Median biochemical progression-free survival (bPFS) and overall survival under docetaxel were 9 m (IQR 5-16 m) and 20 m (IQR 16-26 m), respectively. Partial PSA-response at first docetaxel-sequence (n = 62), rechallenge (n = 32), and third-sequence (n = 22) docetaxel was 48.4%, 31.6%, and 34.8%, respectively. Time from start of primary androgen deprivation to CRPC > 47 m was the only independent pre-treatment parameter to predict improved overall survival (Hazard Ratio 0.48, p = 0.015). Interestingly, there was a strong trend for improved overall survival in patients with high Gleason Score (Hazard Ratio 0.58; p = 0.08). Partial PSA-response at docetaxel-rechallenge (Hazard Ratio 0.31; p = 0.008) and treatment-free interval > 3 m (Hazard Ratio 3.49; p = 0.014) were the only independent predictive factors under taxane treatment for overall survival.

Despite novel hormonal drugs, docetaxel still plays an important role in the treatment of mCRPC. Patients with partial-PSA-response at rechallenge or a treatment-free interval > 3 m benefit most from docetaxel re-exposure.

International urology and nephrology. 2018 Aug 17 [Epub ahead of print]

Christian Thomas, Maximilian P Brandt, Stephanie Baldauf, Igor Tsaur, Sebastian Frees, Hendrik Borgmann, Wolfgang Jäger, Georg Bartsch, Meike Schneider, Robert Dotzauer, Andreas Neisius, Axel Haferkamp

Department of Urology, University of Mainz, Langenbeckstraße 1, 55131, Mainz, Germany. ., Department of Urology, University of Mainz, Langenbeckstraße 1, 55131, Mainz, Germany.