Figure 5.

(A) A 34-year-old man presented at age 31 years with a serum prostate-specific antigen (PSA) level of 3.4 ng/mL, leading to biopsy showing 1 mm of adenocarcinoma with a Gleason score of 6. Prostate cancer antigen 3 (PCA3) scores were low (6.6 initially, 2.5 at 2-year follow-up). Serial biopsy showed no evidence of progression over the next 3 years. During that time, PSA values ranged from 3.4 ng/mL to 0.8 ng/mL (current level). Active surveillance continues.

(B) A 64-year-old man with a serum PSA level of 5.2 ng/mL. His PCA3 score was 27.2. Biopsy showed 2 mm of adenocarcinoma with a Gleason score of 6. Active surveillance was considered, but the patient elected radical prostatectomy; the 60-g prostate contained tiny foci (< 1% of volume) of adenocarcinoma with a Gleason score of 6, an unlikely threat. Thus, the low PCA3 score accurately predicted insignificant disease. The cancer specificity of PCA3 may allow gene scores to be used as a marker of disease severity and a guide for active surveillance.²⁵,²⁶