EAU 2019: Comparison of Docetaxel and Androgen Receptor Axis Targeted (ARAT) Agents mCRPC Patients with Intraductal Carcinoma of the Prostate

Barcelona, Spain (UroToday.com) Intraductal carcinoma of the prostate is recognized as a poor prognostic risk factor. However, there are no data available on the optimal sequence of multiple new agents for metastatic castrate-resistant prostate cancer (mCRPC). The authors of this study aimed to investigate the efficacy of docetaxel and androgen receptor axis-targeted (ARAT) agents in mCRPC patients with intraductal carcinoma.

This was a retrospective study of 311 mCRPC identified patients, who were diagnosed between 2007 and 2016. All patients underwent prostate biopsy at 7 affiliated institutions and were diagnosed with advanced prostate cancer. All patients received androgen deprivation therapy (ADT), followed by docetaxel, and then ARAT (abiraterone or enzalutamide) after progressing to mCRPC. The primary outcome of this study was overall survival from the time of CRPC status and progression-free survival from the time of administration of docetaxel or ARAT. The intraductal carcinoma was defined by the criteria established by McNeal and Yemoto.1

Basic clinical data are shown in Table 1, stratified by whether the patients had intraductal carcinoma or not. The study demonstrated that intraductal carcinoma at initial diagnosis was a strong prognostic factor in mCRPC patients. In these patients, the overall survival was longer for patients treated with ARAT than for those treated with docetaxel as first line treatment. However, the overall survival was not longer than in patients without intraductal carcinoma. The survival comparisons between these groups can be seen in figure 1. The survival curves in figure 1 demonstrate a clear survival advantage in patients with no intraductal carcinoma. The figure also shows that patients with intraductal carcinoma who were treated with ARAT have improved survival compared to those treated with docetaxel. Lastly, table 2 is a multivariable analysis showing the factors that are harbor increased association with worse overall survival.

Table 1: Basic clinical data on analyzed patients:

EAU 2019 ARAT 1

Figure 1 – Comparison of survival curves between negative and positive intraductal carcinoma, and comparisons of various treatments in patients with and without intraductal carcinoma:

EAU 2019 ARAT 2
Table 2 – Univariate and multivariable analysis of factors predicting overall survival:

EAU 2019 ARAT 3a

In conclusion, despite the retrospective nature of this study and all its associated limitations, the present study shows an association between intraductal carcinoma and worse overall survival and progression-free survival in mCRPC patients. In these specific patients, improved oncological outcomes may be expected with ARAT agents, rather than with docetaxel as initial treatment.

Presented by: Masashi Kato, Nagoya University Graduate School of Medicine, Department of Urology, Nagoya, Japan

Written by: Hanan Goldberg, MD, Urologic Oncology Fellow (SUO), University of Toronto, Princess Margaret Cancer Centre @GoldbergHanan at the 34th European Association of Urology (EAU 2019) #EAU19 conference in Barcelona, Spain, March 15-19, 2019. 

1. Mcneal JE et al. Am J Surg Pathol 1996