Barcelona, Spain ( Multiple studies have shown the efficacy of docetaxel in metastatic hormone-sensitive and castration-resistant prostate cancer, though there is ongoing debate regarding the impact that metastatic disease burden has on docetaxel use in the hormone-sensitive setting. The STAMPEDE group has previously presented data suggesting that docetaxel is also beneficial with regards to failure free-survival1 in the non-metastatic patients who are beginning long-term hormonal therapy.  However, data for metastatic progression-free survival (mPFS), a surrogate for overall survival, was not mature until recently.

In this poster, Dr. James and colleagues present data for metastatic progression-free survival for patients who received docetaxel in addition to the STAMPEDE standard-of-care therapy of androgen-deprivation +/- radiation to the prostate for non-metastatic hormone-sensitive prostate cancer. A total of 460 men received the standard of care therapy, and 230 patients received standard of care plus docetaxel at standard dosing. At a median follow-up of 6.5 years with 142 events of metastatic progression, there was no evidence of advantage to adding docetaxel therapy with regards to mPFS (HR 0.89, 95% CI 0.66-1.19, P = 0.425) or overall survival (HR 0.88, 95% CI 0.64-1.21, P = 0.442). Adding docetaxel did not increase long-term toxicity to patients. In an exploratory analysis of the effect of adding radiotherapy to androgen deprivation therapy in this cohort, radiotherapy appears to improve both failure-free and progression-free survival in patients, but this improvement disappears with the addition of docetaxel therapy.

ESMO 2019 summary of all outcomes

ESMO 2019 failure free survival graphs

Although docetaxel in addition to androgen deprivation therapy improves short term outcomes such as failure-free survival for non-metastatic hormone-sensitive prostate cancer, this does not appear to translate into an improvement in metastatic progression-free survival or overall survival benefit. Interestingly, in patients who receive radiation therapy in this context, docetaxel appears to eliminate the additive benefit seen from radiotherapy. The reasons for this are unclear. Though the authors have previously published that improved failure-free survival translates into greater quality-adjusted life years in this context, it is not clear that docetaxel should be incorporated into care at this disease state given both the unclear impact on patients who have received radiotherapy as well as lack of survival benefit.

Presented by: Nicholas James, MBBS, PhD, Professor of Clinical Oncology at University Hospitals Birmingham, United Kingdom

Written by: Alok Tewari, MD, PhD, Medical Oncology Fellow at the Dana-Farber Cancer Institute, at the 2019 European Society for Medical Oncology annual meeting, ESMO 2019 #ESMO19, 27 Sept – 1 Oct 2019 in Barcelona, Spain

1. Woods BS, Sideris E, Sydes MR, et al. Addition of Docetaxel to First-line Long-term Hormone Therapy in Prostate Cancer (STAMPEDE): Modelling to Estimate Long-term Survival, Quality-adjusted Survival, and Cost-effectiveness. Eur Urol Oncol. 2018;1(6):449–458. doi:10.1016/j.euo.2018.06.004