Combination of total length of Gleason pattern 4 and number of Gleason score 3 + 4 = 7 cores detects similar outcome group to Gleason score 6 cancers among cases with ≥5% of Gleason pattern 4.

Expanding the inclusion criteria for active prostate cancer surveillance to include cases with a Gleason score (GS) of 3 + 4 = 7 has been discussed. GS 3 + 4 = 7 cases with a percentage of Gleason pattern 4 (%GP4) <5% were shown to be associated with similar outcomes with those of GS 6 cases. We examined the clinicopathological significance of %GP4 ≥5% with a limited amount of GP4. A total of 315 radical prostatectomy cases with GS 6 or 3 + 4 = 7 in a prior biopsy, were reviewed. The cases with the highest %GP4 ≥5% were subcategorized using the total length of GP4 (GP4-TL) and number of GS 3 + 4 = 7 cores. As outcome measures, the frequency of adverse pathology (AP) and the risk of biochemical recurrence (BCR) were compared between the GS 6 and 3 + 4 = 7 subgroups. In the %GP4 ≥5% subgroup, only cases with both GP4-TL <0.5 mm and 1 core of GS 3 + 4 = 7 showed similar outcome measures with those of GS 6 cancers. However, all other subgroups showed a higher frequency of AP and/or risk of BCR than GS 6 cancers. Our results suggest that cases with %GP4 ≥5% with a limited amount of GP4 should be considered for inclusion in the active surveillance category.