To analyze the stroma changes of benign and malignant human prostate tissues.For the identification of stroma cells phenotype in human prostate cancer and benign prostate hyperplasia tissues, Masson method and immunohistochemical analysis of α-smooth muscle actin (α-SMA), desmin, and vimentin were performed. The relative volume of intratumor stroma (0%, Grade 0; 1% - 33%, Grade 1; 34% - 66%, Grade 2; 67% - 100%, Grade 3) were quantified and analyzed in local and advanced prostate cancer tissues.Stroma myofibroblasts in prostate cancer were stained green by Masson staining and showed a co-expression of α-SMA and vimentin without an expression of desmin. It was significantly different from smooth muscle cells in benign prostate hyperplasia stained red and co-expressing a-SMA and desmin. Statistical analysis showed that high stroma volume (Grade 2/3) in advanced prostate cancer were significantly higher than that in an early stage of prostate cancer (83% vs 55%, P0.05).Significant phenotypic differences of stroma cells existed in benign and malignant human prostate tissues. A high expression of myofibroblasts in advanced prostate cancer may play an important role in cancer progression. And its clinical significance should raise a high alert.
