Expression and Clinical Significance of PTEN Protein in Non-small Cell Lung Cancer

Objective To evaluate expression levels of PTEN in primary non-small cell lung cancer(NSCLC) and to elucidate its clinical significance and prognostic value for patients with NSCLC.Methods Using 62 tumor tissue specimens and 20 noncancerous tissue specimens from 62 patients with NSCLC who underwent surgery,we investigated the expression of PTEN by immunohistochemical methods.Slides were scored semi-quantitatively based on staining intensity and distribution,and results were compared with clinical pathologic parameters.Results Thirty-one(50%) of 62 tumors had loss of PTEN protein expression.Two(10%) of 20 noncancerous tissue had loss of PTEN protein expression.There was significant difference between tumor tissues and noncancerous tissues(P0.05).Loss of PTEN expression was associated with tomor poorer differentiation,higher clinical stage and lymph node metastasis.Conclusion Loss of PTEN protein expression occurs commonly in NSCLC and closely correlated with oncogenesis,proliferation,invasion,and lymph node metastasis.Our results support the proposed role of PTEN as a candidate tumor suppressor in NSCLC and suggest a need for further study of this marker.