The association of atrophy in baseline prostate biopsy and lower prostate cancer grade in radical prostatectomy specimens.

Introduction: To evaluate whether the presence of prostate atrophy (P.A.) in negative prostate biopsy is associated with prostate cancer (P.C.a) grade at surgical pathology among men who are ultimately diagnosed with P.C.a and undergo radical prostatectomy (R.P.).
Methods: A retrospective analysis was performed of 136 men from the placebo arm of the Reduction by Dutasteride of P.C.a Events (R.E.D.U.C.E.) trial who had a baseline prostate biopsy negative for P.C.a, and were later diagnosed with P.C.a on biopsy and underwent radical prostatectomy over the 4-year study period. The association of baseline P.A. (present/absent) with P.C.a grade (W.H.O./I.S.U.P. grade group 1 or ≥2) at surgical pathology was evaluated with logistic regression in uni- and multivariable analyses, controlling for baseline patient characteristics.
Results: P.A. was observed in 74 prostate biopsies (54%). P.A. was not associated with baseline characteristics (age, body mass index, prostate-specific antigen level, prostate volume, race, family history of P.C.a, and digital rectal exam), except for chronic inflammation (p = 0.001). The presence of P.A. in baseline prostate biopsies was associated with lower risk of W.H.O./I.S.U.P. grade group ≥2 P.C.a in R.P. specimens on both univariable (O.R. = 0.39, 95% C.I. = 0.19-0.78, p = 0.008) and multivariable (O.R. = 0.43, 95% C.I. = 0.20-0.92, p = 0.029) analyses.
Conclusions: Among men with a baseline prostate biopsy negative for P.C.a who were later found to have P.C.a and underwent R.P., baseline P.A. is independently associated with lower risk of W.H.O./I.S.U.P. grade group ≥2 P.C.a on surgical pathology. P.A. may be used to identify subjects at lower risk for W.H.O./I.S.U.P. ≥ 2 P.C.a and select optimal candidates for active surveillance.