AUA 2018: Is PSA Density Useful in Predicting Low-Risk Prostate Cancer in African American Men?

San Francisco, CA ( In African-American (AA) men the incidence of prostate cancer is almost 60% higher, and the mortality rate is two- to three-times greater than that of Caucasian men. Over the last 10 years, there has been a significant push to offer active surveillance to patients who are diagnosed with low-risk prostate cancer. PSA density (PSAD) has been one of the main criteria utilized to help differentiate patients at low risk for prostate cancer progression. The current recommendation is that patients with group 1 disease (Gleason 3+3=6) and a PSADT < 0.15 ng/ml/gm have a low potential for prostate cancer progression. However, this value was derived from historical cohorts of mostly Caucasian (CA) men, and the PSAD remains to be validated in an AA cohort. Dr. Babaian, from LSU Shreveport, presents data validating the role of PSAD in identifying men with low-risk prostate cancer.  

The study performed a retrospective review of 82 African American men who underwent a radical prostatectomy between 2008 and 2017. PSA at diagnosis, prostate volume (PV) estimated by transrectal ultrasound (TRUS), pathologic T Stage (pT), pathologic Gleason Score (pGS), prostate weight at radical prostatectomy, and percentage of the prostate involved with cancer (%PCa) were collected from the record. PSAD was defined as the PSA at the time of surgery divided by the prostate volume obtained during TRUS evaluation. Low-risk prostate cancer was defined as a (1) Stage pT2, pGS 6, and ≤5%PCa and (2) Stage pT2, ≤pGS 3+4, and ≤5%PCa. They then utilized a receiver operator (ROC) curve to assess the ideal PSAD cut-off that identifies low-risk disease in AA men.  

The median age for the cohort was 59 years, with median PSA, PV, and PSAD of 8.7 ng/mL,39 ccc , and 0.22 ng/mL/g, respectively. With low risk defined as Stage pT2 + pGS 6 + ≤5%PCa, ROC curve analysis demonstrated a PSAD cut off score of 0.118 ng/mL/gm, which had a sensitivity of 88.0% and specificity of 85.7%. With low risk defined as Stage pT2 + ≤pGS 3+4 + ≤5%PCa, the ROC curve demonstrated a PSAD cut off score of 0.133 ng/mL/gm, which had a sensitivity of 86.1% and specificity of 80.0%. AUC was 0.892 (p<0.001, 95% CI 0.813 - 0.970).

In summary, on a limited sample set PSAD appears to be a good discriminator for low-risk prostate cancer in African American men undergoing radical prostatectomy. A PSAD cut off score of 0.118 ng/mL/gm can be used to predict low risk prostate cancer with good sensitivity and specificity. The lack of a comparator group of non-AA men, and lack of any other oncological measures (biochemical recurrence rates) were significant limitations of the presentation.  

Presented By: Kara Babaian, MD, Louisiana State University Shreveport

Written by: Andres F. Correa, Urologic Oncology Fellow , Fox Chase Cancer Center, Philadelphia, PA, Twitter: @UroCorrea, the 2018 AUA Annual Meeting - May 18 - 21, 2018 – San Francisco, CA USA