Frequency and prognostic significance of the PSA flare-up phenomenon in men with castration-resistant prostate cancer (CRPC) who undergo docetaxel-based chemotherapy.
92 Background: Chemotherapy with docetaxel and prednisone represents the guideline-recommended first-line therapy in men with metastatic CRPC. Until now there is a lack of information with regard to the oncological efficacy, survival and treatment-associated toxicity in patients who are treated in the community beside clinical trials. Methods: 487 patients were prospectively recruited according to a standardized questionnaire within a 1-year time interval. Patients were treated in 144 institutions who contributed between 2 and 48 patients. The mean age was 73.4 (41 – 85) years, the mean PSA level was 135.9 (2.1 – 1.895) ng/ml. 445 (91.5%) patients had bone metastases and/or lymph node metastases. Cardiovascular, pulmonary, neurological or endocrinological comorbidities were present in 157 (27.5%) patients. Results: The mean follow-up was 24 (15-36) months. A mean of 6.6 (1-21) cycles docetaxel were delivered. 101 (20.7%) patients received 1-3 cycles, 222 (45.6%) patients received 4-6 cycles and 167 (34.3%) patients underwent 7-10 cycles. 29 (5.9%) and 295 (61.4%) patients achieved a complete or partial remission, respectively; 95 (19.5%) and 19 (3.9%) patients demonstrated stable disease or progression, respectively. An immediate, delayed (flare-up) or no PSA response was achieved in 40.9%, 29.9% and. 21.8%, respectively. During follow-up 192 (40.6%) patients developed progressive disease. 49 (10.4%) patients died, 37 (7.8%) died due to cancer progression. The mean and median progression-free survival was 256.6 ± 14.8 and 216 days, respectively. The mean and median overall survival was 394 ± 10.7 and 476 days, respectively. Significant Grad 3/4 toxicities were identified in 46 (9.4%) patients with predominantly hematotoxicity and gastrointestinal toxicity. Conclusions: We were able to reproduce the therapeutic response rate of clinical studies with a selected pool of patients. We verified the efficacy of docetaxel in general in patients with CRPC. A flare-up phenomenon within the first three cycles was observed in 30% of patients, which suggest to continue therapy for at least that period of time.