Treatment Recommendation for 74-Year-Old Male with Enlarged Prostate
For this 74-year-old patient with PSA 1.89 ng/mL, prostate volume 120 mL, and normal uroflowmetry, medical therapy with a 5-alpha reductase inhibitor (finasteride 5 mg daily) is the appropriate treatment to reduce prostate volume and prevent disease progression, while no further cancer workup is needed given the low PSA level. 1
Rationale for No Cancer Workup
PSA 1.89 ng/mL is well below the concerning threshold for this age group. The age-specific PSA reference range for men aged 70-79 years is 0-6.5 ng/mL, and the median PSA for men in their 70s is approximately 1.5 ng/mL. 2
Men aged 75 years or older with PSA less than 3.0 ng/mL are unlikely to die from prostate cancer and may safely discontinue screening. 1 This patient's PSA of 1.89 ng/mL places him in a very low-risk category for clinically significant prostate cancer.
At age 74 with PSA <3.0 ng/mL, further cancer testing is not recommended due to very low risk of clinically significant disease. 1 The ratio of harm to benefit from further investigation is extremely unfavorable in this population.
Primary Treatment: Medical Management of BPH
Indication for 5-Alpha Reductase Inhibitor
The prostate volume of 120 mL is substantially enlarged (normal is approximately 20-30 mL), making this patient an ideal candidate for finasteride therapy, which specifically targets prostate volume reduction. 3
Finasteride reduces prostate volume by approximately 20% within three months and reduces serum DHT concentration by approximately 70% with daily dosing at 5 mg/day. 3
Despite the large prostate volume (120 mL), the normal uroflowmetry suggests the patient is not yet experiencing significant obstructive symptoms, making this an optimal time to initiate preventive medical therapy before symptoms worsen. 3
Specific Treatment Protocol
Start finasteride 5 mg once daily. This is the FDA-approved dose for BPH treatment. 3
Counsel the patient that PSA levels will decrease by approximately 50% within six months of treatment. Establish a new PSA baseline at least six months after starting treatment. 3
For future PSA interpretation after six months of finasteride therapy, double the PSA value for comparison with normal ranges in untreated men. This adjustment preserves the utility of PSA to detect prostate cancer. 3
Any confirmed increase from the lowest PSA value while on finasteride may signal the presence of prostate cancer and should be evaluated, even if PSA levels remain within the normal range for men not taking a 5-alpha reductase inhibitor. 3
Expected Outcomes and Monitoring
Maximum finasteride plasma concentration is reached 1-2 hours post-dose, with steady-state achieved after approximately 17 days of dosing. 3
Prostate volume reduction of approximately 20% should be expected within three months, which may help prevent future urinary obstruction as the patient ages. 3
Monitor for potential adverse effects including decreased libido (10% incidence), impotence (18.5% incidence), and abnormal ejaculation (7.2% incidence). 3 These effects are dose-dependent and may improve with continued therapy.
Important Caveats
The patient should be carefully monitored for obstructive uropathy given the large prostate volume (120 mL) and post-void residual (PVU) of 120 mL. Patients with large residual urinary volume should be carefully monitored, as they may not be ideal candidates for finasteride monotherapy if obstruction worsens. 3
Consider adding an alpha-blocker (such as doxazosin or tamsulosin) if the patient develops lower urinary tract symptoms, as combination therapy has been shown to be more effective than monotherapy for preventing BPH progression. 3
Reassess in 6-12 months with repeat uroflowmetry, post-void residual measurement, and symptom assessment to determine if the current therapy is adequate or if additional interventions are needed. 3
Do not proceed with prostate biopsy based solely on prostate size. The PSA level is the primary determinant of cancer risk, and at 1.89 ng/mL, this patient has very low risk. 1, 4