Objectives: To assess the changes in the concordance rate of prostate biopsy and radical prostatectomy (RP) Gleason score (GS) over 15 years.
Methods: We reviewed 1670 consecutive patients who underwent RP between 1992 and 2006. We excluded patients who underwent neoadjuvant hormone therapy or salvage RP, or who had incomplete data. Patients who had RP during 1992 through 1996, 1997 through 2001, and 2002 through 2006 were assigned to groups 1, 2, and 3, respectively. All clinical and pathological data were collected retrospectively. We defined overgrading as a biopsy GS higher than the RP Gleason score. Undergrading was a biopsy GS less than the RP Gleason score. The GS concordance between biopsy and RP was evaluated by kappa coefficient.
Results: A total of 1363 patients satisfied the inclusion criteria. Biopsy and RP Gleason score categories correlated exactly in 937 (69%) men. Gleason undergrading occurred in 361 (26%) men and overgrading in 65 (5%). The exact correlation of GS between biopsy and RP was 58%, 66%, and 75% in groups 1, 2, and 3, respectively. The most common discordant finding was undergrading of the biopsy specimen. The number of cases with exact correlation was highest in GS 7 (78%). Undergrading was more in GS 6 or less (35%) and overgrading was more in the GS 8 through 10 (35%) category.
Conclusions: This large, single institutional study confirms increasing concordance of Gleason scores in prostate needle biopsies and surgical specimens. This is reassuring for patients assessing various treatment options for prostate cancer.