ASCO 2017: Chemotherapy for Metastatic Castration-Resistant Prostate Cancer: Which Patient? Which Time?

Chicago, IL (OncToday.com) At 2017 ASCO annual meeting session on “How to Integrate Multimodal Therapy Into the Management of Castration-Resistant Prostate Cancer CRPC”, Dr. Aparicio discussed the role of chemotherapy, specifically aspects regarding which patient to treat and when to treat. 

The first case Dr. Aparicio presented was a 69 y/o man who underwent a prostatectomy in 2004 for Gleason 4+5, pT2cN0M0R0, preop-PSA 4.6 ng/mL. In 2006 he had a biochemical recurrence, underwent salvage radiotherapy and then was treated with intermittent ADT in 2007 when his PSA reached 17.6 ng/mL. In 2010, he developed bone metastasis and early CRPC so was treated with chronologic bicalutamide, bicalutamide withdrawal, nicalutamide, Sipuleucel-T, diethylstilbestrol, and abiraterone. In 2014 when his PSA reached 14.3 ng/mL he was treated with six cycles of radium-223. 

With a further PSA rise to 26.4 ng/mL, Dr. Aparicio then prompted the audience for what they would do next for treatment, with the correct answer being enzalutamide 1600 mg PO daily. The patient did have a slight response to enzalutamide, however he then developed bone disease progression with a PSA of 52.8 ng/mL. Another prompt for the audience demonstrated that the next line of therapy was docetaxel 75 mg/m2 every 3 weeks for up to 10 cycles, or progression, or Grade ≥3 adverse events. This resulted in a 12-month durable response, however in 2016 he subsequently had worsening disease with PSA 57.4 ng/mL, which prompted second-line cabazitaxel 20 mg/m2 plus prednisone 5 mg PO BID every 3 weeks. As Dr. Aparicio notes, this case highlights the >10 year survivability of aggressive disease at the outset with appropriate and timely management decisions.

The second case was a 77 y/o man who in 2010 presented with back pain, PSA 14.1 ng/mL, Gleason 5+4 disease, cT3bN1M1b de novo metastatic prostate cancer to bone and lymph nodes. An MRI of the thoracic spine demonstrated a bone metastasis without spinal cord compromise. A poll of the audience demonstrated widespread opinions for modality of ADT, however Dr. Aparicio argued that degarelix 240 mg SQ injection every month would allow for rapid stabilization of the disease and resolution of symptoms. 

Based on level 1 data (CHAARTED and STAMPEDE), she also argued that docetaxel 75 mg/m2 IV every three weeks x 6 cycles was also appropriate management. With subsequent disease progression, Dr. Aparicio noted that the next appropriate management would be cabazitaxel 25 mg/m2 IV every three weeks plus carboplatin plus prednisone plus growth factor support based on level 2 evidence. Ultimately, this patient did have disease progression and eventually opted for hospice care. In conclusion, Dr. Aparicio highlights that chemotherapy is an integral part of the treatment of mCRPC patients with appropriate timing and agents to maximize quality and quantity of life.

Presented by: Ana Aparicio, The University of Texas MD Anderson Cancer Center, Houston, TX, USA

Written by: Zachary Klaassen, MD, Urologic Oncology Fellow, University of Toronto, Princess Margaret Cancer Centre
Twitter: @zklaassen_md

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