Clinical Significance of PTEN and Ki-67 Expression in Prostate Cancer

ABSTRACT

PURPOSE: Phosphatase and tensin homolog (PTEN) is a novel tumor suppressor gene located at chromosome 10q23. Ki-67 antigen is a human nuclear protein that is expressed in all active parts of the cell cycle. We evaluated the significance of PTEN and Ki-67 expression in prostate cancer and investigated the relation of this expression with clinico-pathological factors in prostate cancer. MATERIALS AND METHODS: Initially, we did two kinds of immunohistochemical staining for PTEN and Ki-67. Immunohistochemical staining was performed on 75 formalin-fixed paraffin-embedded cancer specimens. Staining on paraffin blocks from prostate carcinomas was compared with that for adjacent normal prostate. Stainings were considered positive if nuclear staining was seen. Positive stainings were analyzed with the patient's clinico-pathological findings. Statistical analysis was performed by using chi-square test with p0.05). PTEN expression was negatively correlated with lymph node or distant metastases (p<0.05). Ki-67 was positively correlated with the serum PSA level, the Gleason score, and metastases (p<0.05). CONCLUSIONS: PTEN and Ki-67 staining correlated well with Gleason score and PSA level in prostate cancer. These could be a possible predictor of prostatic neoplasms.