Taxanes Versus Androgen Receptor Therapy as Second-Line Treatment for Castrate-Resistant Metastatic Prostate Cancer After First-Line Androgen Receptor Therapy.

The optimal therapeutic sequence for metastatic castrate-resistance prostate cancer (mCRPC) is still debated. This study aimed to compare activity of taxanes (TAX) versus that of androgen-receptor therapy (ART) in men with mCRPC treated with first-line ART.

This retrospective study included all consecutive chemo-naive mCRPC patients who have received first-line ART treatment. Progression-free survival (PFS) and overall survival (OS) were compared between patients treated with second-line ART or TAX.

Overall, 175 patients treated with first-line enzalutamide (ENZA, n = 75) or abiraterone (ABI, n = 100) were evaluated. Among them, 69 (39%) and 30 (17%) patients received second-line TAX and ART, respectively, while 76 (43%) patients did not receive further treatment. From the start of first-line therapy, the median PFS and OS were 13 months (95% CI: 11-15) and 34 months (95% CI: 29-39), respectively, without any significant difference between ENZA and ABI. From the start of second-line therapy, the median PFS and OS were 6 months (95% CI: 5-7) and 18 months (95% CI: 14-21), respectively. Compared with ART, docetaxel was associated with significantly higher prostate-specific antigen (PSA, ≥ 50%) (29% vs. 0%, P < .001) and radiological responses (21% vs. 0%, P < .001). PFS was longer in TAX than in ART (6.7 months vs. 4 months, HR: 0.63, 95% CI: 0.41-0.96, P = .034), but there was no significant difference in OS (19 months vs. 12 months, P = .1). After propensity score adjustment, PFS (P = .2) and OS (P = .1) were similar between second-line TAX and ART.

In the second-line setting, TAX provides higher PSA and radiological responses than does ART for mCRPC patients who received first-line ART, but the PFS and OS are similar. This study provides new elements to help deciding the best treatment sequence.

Clinical genitourinary cancer. 2023 Feb 16 [Epub ahead of print]

Antonin Broyelle, Nicolas Delanoy, André-Michel Bimbai, Marie-Cécile Le Deley, Nicolas Penel, Arnauld Villers, Loïc Lebellec, Stéphane Oudard

Medical Oncology Department, Centre Oscar Lambret, Lille, France. Electronic address: ., Medical Oncology Department, Hopital Européen Georges Pompidou, Paris, France; Paris Cité University, Medical School, Paris, France., Methodology and Biostatistics Unit, Centre Oscar Lambret, Lille, France., Medical Oncology Department, Centre Oscar Lambret, Lille, France; Lille University, Medical School, Lille, France., Urology Department, Hopital Claude Huriez, Lille University Hospital, Lille, France; Lille University, Medical School, Lille, France., Medical Oncology Department, Centre Oscar Lambret, Lille, France.