Reduced expression of α-catenin, β-catenin, and γ-catenin is associated with high cell proliferative activity and poor differentiation in non-small cell lung cancer

Aims—To investigate the expression of catenins (α, β, and γ) in non-small cell lung carcinoma (NSCLC) and its relation to clinicopathological factors and prognosis. Methods—The expression of catenins was analysed immunohistochemically in 261 patients with resected NSCLC, diagnosed between 1978 and 1996 in eastern Finland. The cell proliferation index of the tumours was analysed by means of an image analyser. The staining results were compared with clinicopathological characteristics and survival. Results—Normal catenin staining was found significantly more often in adenocarcinomas than in squamous cell carcinomas or anaplastic/large cell carcinomas. Reduced staining of α-catenin, β-catenin, and γ-catenin was related to poor differentiation of the tumour. The tumours with reduced staining of β-catenin or γ-catenin often had higher cell proliferation activity. Nuclear staining of β-catenin and γ-catenin was found in 16 (7%) and 29 (13%) cases, respectively. This nuclear staining correlated directly with increased cell proliferation and inversely with membranous staining. In survival analyses the predictors of overall and disease free survival were stage and tumour type. The expression of catenins did not affect survival. Conclusions—The expression of α-catenin, β-catenin, and γ-catenin is related to histological type and differentiation in NSCLC, although catenins have no independent prognostic value. However, this study supports the important role of the nuclear accumulation of β-catenin and γ-catenin in highly proliferative cells.