Global vs. individual scoring when prostate needle cores from a single systematic biopsy site show Gleason score heterogeneity.

It remains controversial how Gleason score/Grade Group (GG) should be reported when prostate needle cores from a single systematic biopsy site show different scores. One method is to grade globally, while another is to report multiple scores in the respective cores. To determine the optimal method for reporting, we assessed two sets of patients showing GG2 or GG3 cancer by global scoring in a single site of systematic sextant biopsy (typically two cores/site), along with their controls, all of whom underwent radical prostatectomy without neoadjuvant therapy. In the first set of patients (n = 50), one core showed GG3 and the other GG1-2. In the second set of patients (n = 35), one core showed GG4 and the other GG1-3. Control patients for the first (n = 72) or second (n = 45) set had GG2 or GG3 cancer, respectively, in both cores from a single biopsy site. Up-grading on prostatectomy occurred in 26 (52.0%) of GG3/GG1-2 (overall GG2) patients versus 12 (16.7%) of GG2/GG2 controls (P < 0.001), as well as in 19 (54.3%) of GG4/GG1-3 (overall GG3) patients versus 6 (13.3%) of GG3/GG3 controls (P < 0.001). Univariate (hazard ratio 3.442, 95% confidence interval 1.387-8.542, P = 0.005) and multivariable (hazard ratio 3.177, 95% confidence interval 1.180-8.551, P = 0.022) analyses further revealed that the presence of a GG3 core in cases with overall GG2 cancer (vs. GG2/GG2) was associated with a significantly higher risk of postoperative biochemical recurrence. Compared with global scoring, individual scoring within a single systematic biopsy site with multiple core involvement may provide more accurate risk stratification of prostate cancer.