Expression of Kª²ras oncoprotein in human nonª²small cell lung cancer and its clinical significance

    CHEN Jian1, YANG Zeng1, LIANG Jingª²Ren1, WANG Hongª²Yan2

    1Department of Thoracic Surgery, 2Department of Pathology, First Hospital, Xi¬ðan Jiaotong University, Xi¬ðan 710061, China

    ¡¾Abstract¡¿ AIM: To investigate the role of Kª²ras oncoprotein in the occurrence, development and prognosis of nonª²small cell lung cancer (NSCLC). METHODS: Thirtyª²seven specimens of resected, paraffin embedded NSCLC and 9 cases of normal lung tissues were examined by immunohistochemical technique(SABC methods)for the expression of Kª²ras oncoprotein. RESULTS: Overexpression rate of Kª²ras oncoprotein was 56.8%. Only histological type (r=0.529, P=0.021), smoking (r=0.582, P=0.003), tumour size (r=0.506, P=0.049) and lymph node involvement (r=0.521, P=0.018) had significantly positive correlation with the overexpression of Kª²ras oncoprotein. The mean survival time was significantly shorter in patients with Kª²ras high expression than in patients with Kª²ras low expression (11.29 vs 34.31 mo, P<0.01). The estimated increased relative risk for patients with Kª²ras overexpression was 4.107. The results of the proportional hazards regression model (Cox model) showed that Kª²ras was independental factor that had correlation with prognosis (P=0.004). CONCLUSION: The overexpression of Kª²ras oncoprotein was closely related to the the occurrence¡¢development and prognosis of NSCLC. The overexpression of Kª²ras oncoprotein was found more frequently in smokers and patients suffering from the adenocarcinoma of lung or lymph node involvement. Kª²ras, which is important prognostic cellular factor, may play an important role in early diagnosis for patients with NSCLC. ......