PSA Doubling Time (PSADT) Calculator

Why Use

In patients with biochemical recurrence, PSADT: Predicts risk of metastasis and risk of dying of prostate cancer when combined with other factors such as the Gleason Score and length of time to biochemical recurrence. Helps identify patients more likely to develop clinically significant disease. Helps guide patient selection for salvage local therapy or androgen deprivation therapy. Helps guide utilization and timing of imaging studies. For patients with M0 castration resistant disease, PSADT helps guide patient selection for observation, second generation antiandrogen, androgen metabolism inhibitor, or other secondary hormone treatments. Used in assessment of eligibility for clinical trials.

When to Use

Patients with prostate cancer who have undergone radical prostatectomy or definitive radiation therapy and have biochemical recurrence, defined as confirmed PSA ≥0.2 ng/mL if radical prostatectomy or confirmed PSA rise of ≥2 ng/mL above the nadir PSA level if radiation therapy. PSADT has limited value in prostate cancer screening or diagnosis.

Formula

Pearls / Pitfalls

For patients with biochemical recurrence of prostate cancer, optimal PSADT calculation should include all PSA values of the individual within two years of initially documented PSA recurrence. Entering more values improves accuracy of estimation. Shorter PSADT reflects faster increase in PSA levels, while longer PSADT reflects a slower increase in PSA levels over time.

Advice

Further management should be individualized based on age, comorbidities, life expectancy, patient preferences, and other relevant factors. More detailed information can be found in the National Comprehensive Cancer Network (NCCN) Guidelines .