ASCO 2017: Real-world outcomes in second-line treatment of metastatic castration-resistant prostate cancer: The Prostate Cancer Registry

Chicago, IL ( In this multi-institutional study, the authors utilize the Prostate Cancer Registry, to examine outcomes of patients with metastatic castration-resistant prostate cancer (mCRPC) who have undergone second-line therapy. The Prostate Cancer Registry is a prospective, international observational study that began in June 2013. It is the first prospective international registry for metastatic prostate cancer. Its goal is to assess the characteristics and management of > 3000 mCRPC patients (pts) in routine clinical practice for ≤ 3 years.

In this interim publication, the authors report a descriptive summary of this unique patient population. Baseline characteristics, treatments and outcomes of patients with ≥ 12-month follow-up receiving second-line mCRPC treatment (following docetaxel chemotherapy as the only prior mCRPC treatment) are reported.

As of August 2016, there were 2517 evaluable patients with >= 12 months of follow-up data (median follow-up 15 months). This group was then narrowed to patients who had received docetaxel as the only prior treatment for mCRPC. 

The most commonly initiated second-line mCPRC treatments were abiraterone acetate + prednisone (AAP, n = 177), enzalutamide (ENZ, n = 94) and cabazitaxel (CAB, n = 70). Characteristics and outcomes were summarized in the table provided in the abstract. In each of the three groups above, approximately 62% had Gleason >= 8 at diagnosis. However, patients treated with CAB tended to be slightly younger (68 vs. 71/72) and more likely to have > 5 bone metastases (61% vs. 47-50%).  Of note, PSA was 42-87 ng/dL, which seems inappropriate for patients 

Time to progression (TTP) was not significantly different for AAP vs ENZ, AAP vs CAB or ENZ vs CAB (propensity score adjusted p = 0.5954, p = 0.5888 and p= 0.4808, respectively). PSA response was highest in the ENZ treated group. In terms of quality of life (QOL), improvement was more predominant in the AAP and ENZ arms than in the CAB arm.

While this is a real-world study, it was started as AAP and ENZ were just becoming commonplace. In fact, many of these agents are now used prior to docetaxel chemotherapy, so to some degree, this is already outdated data.

However, what the authors do touch upon is that determining appropriate sequencing of therapies matters. It would appear that AAP, ENZ and CAB after docetaxel have similar clinical outcomes (TTP), while QOL outcomes were best in AAP and ENZ treated patients, suggesting these may better than CAB in this situation. 

Ultimately, sequencing of these therapies to maximize clinical response, minimize QOL insults and maximize cost efficacy will be critical.

Presented By: Simon Chowdhury, MD, Guy's Hospital, London, United Kingdom;

Co-Author(s): Alison J. Birtle, Anders Bjartell, Luis Costa, Susan Feyerabend, Luca Galli, Ewa Kalinka-Warzocha, Gero Kramer, Nicolaas Lumen, Pablo Maroto, Vsevolod B Matveev, Thomas Paiss, Salvatore Pisconti, Dominique Spaeth, Francisco Gomez Veiga, Laurent Antoni, Edwin Klumper, Robert Wapenaar, Erik van den Berg, Emma Lee

Institution(s): Rosemere Cancer Centre, Royal Preston Hospital, Preston, United Kingdom; Skane University Hospital, Malmo, Sweden; Hospital de Santa Maria, Lisbon, Portugal; Studienpraxis Urologie, Nurtingen, Germany; Azienda Ospedaliero-Universitaria Pisana, Pisa, Italy; Wojewodzki Szpital Specjalistyczny im Kopernika, Lodz, Poland; Department of Urology, Medical University Vienna, Vienna, Austria; Ghent University Hospital, Ghent, Belgium; Sant Pau Hospital, Barcelona, Spain; N. N. Blokhin Cancer Research Center, Russian Academy of Medical Sciences, Moscow, Russia; Urologieteam Ulm, Ulm, Germany; S.G. Moscati Hospital of Taranto, Taranto, Italy; Centre d'Oncologie de Gentilly, Nancy, France; Salamanca University Hospital, Salamanca, Spain; EMEA Medical Affairs, Janssen Pharmaceutica, Beerse, Belgium; SMS-Oncology BV, Amsterdam, Netherlands; Janssen-Cilag BV, Breda, Netherlands

Written By: Thenappan Chandrasekar, MD, Clinical Fellow, University of Toronto
Twitter: @tchandra_uromd

at the 2017 ASCO Annual Meeting - June 2 - 6, 2017 - Chicago, Illinois, USA