ASCO Provisional Clinical Opinion on Hormonal Therapy for Castration-Resistant Prostate Cancer
On April 25, ASCO issued a provisional clinical opinion on the use of second-line hormonal therapy for men with castration-resistant prostate cancer who have not yet received chemotherapy. The recommendations of this provisional clinical opinion were informed by evidence from a systematic review of the literature published from 1985 through October 2016, consensus opinion, and clinical experience. The Second-Line Hormonal Therapy for Men With Chemotherapy-Naive Castration-Resistant Prostate Cancer: American Society of Clinical Oncology Provisional Clinical Opinion was published by Virgo et al in the Journal of Clinical Oncology.1
Uncertainty Regarding Optimal Treatment
Katherine S. Virgo, PhD
“In the last few years, we have seen an unprecedented number of new systemic therapies showing improvements in survival and quality of life for men with [castration-resistant prostate cancer],” said Katherine S. Virgo, PhD, Co-Chair of the Expert Panel that developed the provisional clinical opinion. “However, due to lack of guidelines on second-line hormone therapy for chemotherapy-naive patients, there has been uncertainty regarding optimal treatment among clinicians.”
Many men with hormone-sensitive prostate cancer experience cancer recurrence or progression despite first-line androgen-deprivation therapy, meaning the cancer is castration-resistant. The provisional clinical opinion addresses the use of second-line hormonal therapy in chemotherapy-naive men with castration-resistant prostate cancer, ranging from asymptomatic men with only biochemical evidence of recurrence to those with measurable metastases but few symptoms.
Clinical trials have shown that second-line hormonal treatments such as abiraterone acetate (Zytiga) and enzalutamide (Xtandi) slow cancer growth, extend survival, and provide meaningful improvement in quality of life for men with castration-resistant prostate cancer.
Eric A. Singer, MD, MA, FACS
“To develop these recommendations, we used evidence from clinical trials as well as a formal consensus technique that relied on clinical experience, training, and judgment when evidence was limited,” said Eric A. Singer, MD, MA, FACS, Co-Chair of the Expert Panel that developed this provisional clinical opinion. “We hope this provisional clinical opinion will offer clinicians and patients timely direction to help inform treatment planning and shared decision making.”
- For men who develop castration-resistant prostate cancer despite castrate levels of testosterone, a castrate state should be maintained indefinitely.
- For chemotherapy-naive patients with M0 castration-resistant prostate cancer (no radiographic evidence of metastases) who are at high risk for developing metastases (defined as having rapid prostate-specific antigen [PSA] doubling time or velocity), second-line hormonal therapies may be offered, following a discussion with the patient about the limited scientific evidence, potential harms, benefits, cost, and patient preferences.
- Second-line hormonal therapy is not suggested for chemotherapy-naive men with M0 castration-resistant prostate cancer who are at a low risk for developing metastases (low risk defined as low PSA and slow PSA doubling time).
- For chemotherapy-naive men who develop castration-resistant prostate cancer and have radiographic evidence of metastases (M1a/M1s castration-resistant prostate cancer), second-line -hormonal treatment (abiraterone acetate plus prednisone or enzalutamide) should be offered, as these agents significantly increase radiographic progression-free and overall survival. Palliative care should also be offered.
- A PSA evaluation every 4 to 6 months should be performed for men with M0 castration-resistant prostate cancer who have a low risk of developing metastases and every 3 months for men with M0 castration-resistant prostate cancer who are at high risk for developing metastases or already have radiographic evidence of metastases (M1 castration-resistant prostate cancer).
- When imaging is performed for men with castration-resistant prostate cancer, a bone scan and either computed tomography or magnetic resonance imaging of the abdomen and pelvis should be offered. The appropriate frequency of imaging is variable and largely dependent on symptoms. Radiographic imaging is not indicated for men with castration-resistant prostate cancer and a rising PSA level, unless treatment selection would be altered based on radiographic findings or if symptoms potentially attributable to prostate cancer develop or worsen (eg, bone pain). Routine surveillance radiographic restaging is also not indicated, with the exception of for patients for whom PSA is not a reliable marker of disease.
1. Virgo KS, Basch E, Loblaw DA, et al: Second-line hormonal therapy for men with chemotherapy-naive, castration-resistant prostate cancer: American Society of Clinical Oncology provisional clinical opinion. J Clin Oncol. April 25, 2017 (early release online).