Comparing docetaxel to abiraterone in patients with metastatic castration-sensitive prostate cancer

This study compared the effectiveness of docetaxel (DOC; Taxotere) to abiraterone (ABI; Zytiga) and assessed possible predictive markers of progression-free survival (PFS) in patients with metastatic castration-sensitive prostate cancer (mCSPC). The authors concluded that under real-world conditions, ABI was associated with better PFS in these patients.

In mCSPC, the growth of prostate cancer cells depends on male hormones known as androgens such as testosterone. In these patients, hormonal treatment such as androgen deprivation therapy (ADT) that decreases androgens is recommended. The addition of DOC chemotherapy or androgen receptor signaling inhibitors (ARSIs) like ABI to ADT is the present standard of care for mCSPC.

However, no real-world comparisons on the effectiveness of this approach have been done. There is also a need to identify predictive biomarkers of response to ABI or DOC to optimize treatment options in patients with mCSPC.

This study included 121 patients with mCSPC on ADT. Patients had testosterone levels of 1.7 nmol/L or less. 79 patients received DOC at 75 mg/m² without prednisone, every 3 weeks for a maximum of 6 cycles. 42 patients received once-daily ABI at 1,000 mg, combined with 5 mg of prednisone, until disease progression or intolerance. The average follow-up was 39.6 months for DOC and 25.1 months for ABI treatments.

At 12 months, 78% of patients that received ABI were alive without disease progression compared to 67.1% of patients that had DOC. The average PFS was 18.5 months for the DOC group and 32 months for the ABI group. 

Factors such as older age at diagnosis of mCSPC, the lowest prostate-specific antigen (PSA; a protein made by the prostate that is high in prostate cancer) of 0.2ng/ml or lower after 6 months were associated with a longer PFS.

At 12 months, 98.7% in the DOC group and 92.7% in the ABI group were alive.

The study suggests that adding DOC or ABI to ADT is effective for patients with mCSPC under real-world conditions and that ABI was associated with longer PFS.

The number of patients in the study was small. Also, this study was based on data from medical records. Information might have been missing.