From the Guidelines
For a 79-year-old patient with recurrent metastatic prostate cancer affecting the ribs, sacrum, and spine with rising PSA despite Bicalutamide therapy, the next steps should focus on transitioning to a second-generation androgen receptor antagonist such as Enzalutamide (160mg daily), as it has shown to improve survival and reduce the risk of skeletal-related events compared to Bicalutamide 1. The patient should discontinue Bicalutamide and start Enzalutamide, combined with androgen deprivation therapy (ADT) using a GnRH agonist like Leuprolide or antagonist like Degarelix. Key considerations for this patient include:
- Bone-targeted therapy with zoledronic acid (4mg IV every 3-4 weeks) or denosumab (120mg subcutaneous monthly) to reduce skeletal-related events
- Optimization of pain management
- Consideration of radiation therapy for painful bone metastases
- Regular monitoring with PSA tests every 1-3 months, periodic imaging studies, and assessment for treatment side effects This approach is supported by studies such as the TERRAIN and STRIVE trials, which demonstrated the superiority of Enzalutamide over Bicalutamide in terms of progression-free survival and overall survival in patients with metastatic castration-resistant prostate cancer 1. Additionally, the PROSPER trial showed that Enzalutamide improved metastasis-free survival and delayed pain progression, symptom worsening, and decrease in functional status compared to placebo in patients with nonmetastatic castration-resistant prostate cancer 1. Given the patient's age and disease status, it is essential to prioritize treatments that improve survival, reduce symptoms, and maintain quality of life, as evidenced by the patient's rising PSA and metastatic progression despite Bicalutamide therapy.
From the Research
Next Steps for a 79-Year-Old Patient with Recurrent Prostate Cancer
The patient has recurrent prostate cancer with metastases in the ribs, sacrum, and spine, and a rising Prostate-Specific Antigen (PSA) level, currently on Bicalutamide (Casodex). Considering the patient's condition, the following points are relevant:
- The patient has started Bicalutamide for a week and PSA dropped to .1, indicating a positive response to the treatment 2, 3.
- Bicalutamide is a nonsteroidal pure antiandrogen given at a dosage of 150 mg once daily as monotherapy for the treatment of early (localised or locally advanced) nonmetastatic prostate cancer 2.
- The choice of the 50-mg dose of bicalutamide when used in combined androgen blockade is supported by four main arguments, including receptor affinity, potency, and favorable plasma concentration profile 4.
- Increasing the dosage to 150 mg/day has improved its efficacy in patients with non-metastatic disease: combined data from 2 trials demonstrate similar survival with bicalutamide in this dosage compared with castration 3.
- Bicalutamide dose intensification may benefit a subset of patients with castrate-resistant prostate cancer (CRPC) 5.
Potential Treatment Options
Some potential next steps for the patient could be:
- Continuing Bicalutamide treatment and monitoring PSA levels to assess the response to treatment 2, 3.
- Considering a dose escalation of Bicalutamide to 150 mg/day, as some studies suggest that this may improve efficacy in patients with non-metastatic disease 3, 5.
- Evaluating the patient's response to treatment using PSMA PET/CT scans, as changes in PSMA expression may be associated with response to treatment 6.
Key Considerations
Key considerations for the patient's treatment plan include:
- The patient's age and overall health status, as these may impact the tolerability of treatment 2, 3.
- The presence of metastases in the ribs, sacrum, and spine, which may require additional treatment considerations 6.
- The patient's PSA level and response to treatment, which will inform future treatment decisions 2, 3.