Histologic findings on prostate needle core biopsies following cryotherapy as monotherapy for prostatic adenocarcinoma

Abstract

The histologic features seen in the prostate following cryotherapy can be highly variable. However, most previous studies were performed on specimens following salvage cryotherapy, which introduces additional confounding variables of the histologic changes after the other primary treatment modalities. We examined prostate needle core biopsies from a cohort of patients following cryotherapy as monotherapy for prostatic adenocarcinoma, to evaluate the true spectrum of morphologic changes in the prostate. Cases that had prior radiation therapy or androgen-deprivation therapy were excluded from the study. Thirty cases were identified. The average patient age was 69 years (range, 51-81 years), and the average time interval between cryotherapy and repeat biopsy was 19.2 months (range, 2-60 months). The original Gleason scores were as follows: 3 + 3 = 6 in 14 (46%) of 30 cases, 3 + 4 = 7 in 8 (27%) of 30 cases, 4 + 3 = 7 in 2 (7%) of 30 cases, 4 + 4 = 8 in 3 (10%) of 30 cases, 4 + 5 = 9 in 2 (7%) of 30 cases, and 5 + 4 = 9 in 1 (3%) of 30 cases. Postcryotherapy, 11 of 30 cases (37%) had recurrent/residual prostatic adenocarcinoma, which showed no therapy-related changes, similar to the residual benign glands. Gleason scores were higher in 5 (46%) of 11 cases, same in 4 (36%) of 11 cases, and lower in 2 (18%) of 11 cases. Multiple additional histologic findings were documented. Unlike other nonsurgical therapeutic modalities, cases with recurrent/residual prostatic adenocarcinoma and benign glands showed therapy-related changes predominantly involving the stroma. It is therefore conceivable that benign or malignant prostatic glands are either completely destroyed during cryotherapy or left unaltered if not in the direct field of cryoablation.