Treatment for 81-Year-Old with Metastatic Prostate Cancer and Urinary Symptoms Only
Initiate continuous androgen deprivation therapy (ADT) with an LHRH agonist (such as goserelin) or LHRH antagonist, combined with a short course of antiandrogen for at least 7 days to prevent testosterone flare, and address urinary symptoms with alpha-blockers (tamsulosin) or anticholinergics (oxybutynin) as needed. 1, 2
Primary Systemic Treatment
ADT is the gold standard for metastatic prostate cancer and should be initiated immediately. 1 The evidence strongly supports early ADT over deferred therapy in metastatic disease, as it reduces catastrophic complications such as spinal cord compression and ureteral obstruction, even though survival benefit compared to waiting for symptoms is uncertain. 1, 3
ADT Options (Equally Effective):
- Medical castration: LHRH agonist (e.g., goserelin 3.6 mg subcutaneously every 28 days) or LHRH antagonist 1, 4
- Surgical castration: Bilateral orchiectomy 1, 2
Critical Flare Prevention:
An antiandrogen must precede or be coadministered with LHRH agonist therapy for at least 7 days to prevent testosterone flare, which can temporarily worsen urinary obstruction or cause spinal cord compression in patients with metastatic disease. 1, 4 This is particularly important given the patient's existing urinary symptoms.
Continuous vs. Intermittent ADT
Continuous ADT should be used rather than intermittent ADT in this metastatic setting. 1, 5 While intermittent ADT showed non-inferior survival in some contexts with better quality of life for erectile function, the only adequately powered phase III trial in metastatic disease (SWOG-9346) demonstrated that intermittent ADT was statistically inconclusive for non-inferiority and showed a 7% increase in prostate cancer deaths. 1, 5 Given the patient's age (81 years) and metastatic disease, the priority is disease control over quality of life benefits that intermittent therapy might provide.
Combined Androgen Blockade Consideration
Combined androgen blockade (CAB)—adding an antiandrogen to medical/surgical castration beyond the initial 7-day flare prevention period—provides modest to no survival benefit and is optional. 1 Meta-analyses suggest a small measurable prolongation in overall survival with CAB, but this must be weighed against increased adverse effects. 1, 5 For an 81-year-old, monotherapy with LHRH agonist alone after the initial antiandrogen course is reasonable.
Management of Urinary Symptoms
Address urinary symptoms directly with targeted medications while ADT takes effect:
- For slow urinary stream/difficulty emptying: Alpha-blockers such as tamsulosin 1
- For urgency, frequency, or nocturia: Anticholinergic medications such as oxybutynin 1
- For severe obstruction: Consider transurethral resection of the prostate (TURP) or palliative radiation to the prostate if urinary retention develops 1
The urinary symptoms may initially worsen during testosterone flare if antiandrogen coverage is inadequate, making flare prevention critical. 1, 4
Monitoring and Follow-Up
Verify achievement of castrate testosterone levels (<50 ng/dL) within 4 weeks of initiating ADT. 1 If adequate suppression is not achieved, consider additional hormonal manipulations, though clinical benefit is uncertain. 1
Monitor for ADT-related complications:
- Bone health: Baseline DEXA scan and FRAX score assessment, with bisphosphonates (alendronate 70 mg weekly or zoledronic acid 5 mg annually) if high fracture risk 1, 2
- Metabolic effects: Monitor blood glucose and HbA1c periodically for hyperglycemia/diabetes 4
- Cardiovascular risk: Monitor for myocardial infarction, stroke symptoms 4
- QT prolongation: Consider baseline ECG and electrolyte monitoring, especially if concurrent QT-prolonging medications 4
Important Caveats
Antiandrogen monotherapy should NOT be used as it is less effective than medical or surgical castration. 1
Triple androgen blockade (adding finasteride/dutasteride to CAB) has no supporting clinical data and should not be used. 1
For patients with very high metastatic burden or symptomatic disease, consider adding abiraterone plus low-dose prednisone to ADT, as this improved radiographic progression-free survival and delayed chemotherapy initiation in the pre-docetaxel setting (Category 1 recommendation). 1, 6 However, given this patient has only urinary symptoms and is 81 years old, starting with ADT alone is appropriate, reserving intensification for progression.
Neuroendocrine differentiation should be considered if the patient fails to respond to ADT, particularly if initial Gleason score was 9-10, requiring biopsy and potential switch to platinum-based chemotherapy. 1