MUC1 expression in prostate carcinoma: Correlation with grade and stage

Mucins have been implicated in the biologic behavior and progression of sev eral types of cancer. The aims of this study were to define the expression pattern of one particular mucin, MUC1, in benign and malignant human prosta te tissue and to determine if MUC1 expression correlates with tumor grade a nd stage. Immunohistochemical staining utilizing an anti-MUC1 monoclonal an tibody was performed on 4 fetal prostates, 4 specimens of benign prostatic hyperplasia (BPH), and 34 radical prostatectomy specimens. In human fetal a nd BPH specimens, there was an apical pattern of MUC1 expression, similar t o that reported in other normal and benign tissues. Ninety-four percent of the prostate cancers were MUC1 positive. A high percentage of prostate canc er specimens (62%) demonstrated a diffuse, cytoplasmic staining pattern. Th ere was a statistically significant correlation between diffuse MUC1 staini ng and Gleason pattern, with a diffuse/total staining percentage of 9% in G leason 2, 64% in Gleason 3, 80% in Gleason 4, and 100% in Gleason 5, More d iffuse staining was also seen in samples from patients with high pathologic stage: 21% in T-2, 75% in T-3, and 67% in N-1 disease. These data indicate that MUC1 expression is prevalent in prostate cancer and that diffuse cyto plasmic staining correlates with advanced Gleason pattern and advanced path ologic stage.