BACKGROUND: Some evidence suggests a role for HER-2/neu overexpression in prostate carcinoma progression. Reported rates of HER-2/neu overexpression in patients with prostate carcinoma vary greatly. METHODS: The authors studied radical prostatectomy specimens from 38 patients who had biochemical failure after undergoing radical prostatectomy for prostate carcinoma. Immunohistochemistry for HER-2/neu overexpression using the HercepTest kit (Dako Corporation, Carpenteria, CA) was employed. Two different antigen-retrieval techniques were used: 1) the standard U.S. Food and Drug Administration (FDA)-approved HercepTest assay and 2) a modified HercepTest, which employed an alkaline citrate buffer, pH 9.0, for antigen retrieval and a 1-hour primary antibody incubation time. The level of HER-2/neu expression was evaluated on a scale from 0 (no staining) to 3+ according to the published guidelines. Fluorescent in situ hybridization for gene amplification was performed on all specimens. RESULTS: With the standard technique, only one specimen had 2+ staining, and no specimens had 3+ staining. With the modified technique, 10 specimens (26%) had 2+ staining, and 9 specimens (24%) had 3+ staining. There was a significant association between the level of HER-2/neu expression shown with the modified technique and tumor stage (P = 0.03) as well as Gleason grade (P = 0.01). None of the specimens had HER-2/neu gene amplification. CONCLUSIONS: The authors report a simple modification of the HercepTest that resulted in an increased rate of HER-2/neu expression, which was correlated with poor-risk pathologic findings. The findings suggest that adenocarcinoma of the prostate should be evaluated for HER-2/neu expression with a prostate specific immunohistochemical procedure that differs from the FDA-approved standard procedure. Copyright 2002 American Cancer Society.
BACKGROUND: Some evidence suggests a role for HER-2/neu overexpression in prostate carcinoma progression. Reported rates of HER-2/neu overexpression in patients with prostate carcinoma vary greatly. METHODS: The authors studied radical prostatectomy specimens from 38 patients who had biochemical failure after undergoing radical prostatectomy for prostate carcinoma. Immunohistochemistry for HER-2/neu overexpression using the HercepTest kit (Dako Corporation, Carpenteria, CA) was employed. Two different antigen-retrieval techniques were used: 1) the standard U.S. Food and Drug Administration (FDA)-approved HercepTest assay and 2) a modified HercepTest, which employed an alkaline citrate buffer, pH 9.0, for antigen retrieval and a 1-hour primary antibody incubation time. The level of HER-2/neu expression was evaluated on a scale from 0 (no staining) to 3+ according to the published guidelines. Fluorescent in situ hybridization for gene amplification was performed on all specimens. RESULTS: With the standard technique, only one specimen had 2+ staining, and no specimens had 3+ staining. With the modified technique, 10 specimens (26%) had 2+ staining, and 9 specimens (24%) had 3+ staining. There was a significant association between the level of HER-2/neu expression shown with the modified technique and tumor stage (P = 0.03) as well as Gleason grade (P = 0.01). None of the specimens had HER-2/neu gene amplification. CONCLUSIONS: The authors report a simple modification of the HercepTest that resulted in an increased rate of HER-2/neu expression, which was correlated with poor-risk pathologic findings. The findings suggest that adenocarcinoma of the prostate should be evaluated for HER-2/neu expression with a prostate specific immunohistochemical procedure that differs from the FDA-approved standard procedure. Copyright 2002 American Cancer Society.
Authors: Noelia Perez; Mireia Castillo; Yolanda Santos; David Truan; Rafael Gutierrez; Agustin Franco; Antonio Palacin; Josep Antoni Bombi; Elias Campo; Pedro L Fernandez Journal: Virchows Arch Date: 2005-04-09 Impact factor: 4.064