Reduced expression of alpha-catenin, beta-catenin, and gamma-catenin is associated with high cell proliferative activity and poor differentiation in non-small cell lung cancer

Aims-To investigate the expression of catenins (alpha, beta, and gamma) in non-small cell lung carcinoma (NSCLC) and its relation to clinicopathologic al factors and prognosis. Methods-The expression of catenins was analysed immunohistochemically in 26 1 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 clinicopathol ogical characteristics and survival. Results-Normal catenin staining was found significantly more often in adeno carcinomas than in squamous cell carcinomas or anaplastic/large cell carcin omas. Reduced staining of alpha -catenin, beta -catenin, and gamma -catenin was related to poor differentiation of the tumour. The tumours with reduce d staining of beta -catenin or gamma -catenin often had higher cell prolife ration activity. Nuclear staining of beta -catenin and gamma -catenin was f ound in 16 (7%) and 29 (13%) cases, respectively. This nuclear staining cor related directly with increased cell proliferation and inversely with membr anous staining. In survival analyses the predictors of overall and disease free survival were stage and tumour type. The expression of catenins did no t affect survival. Conclusions-The expression of alpha -catenin, beta -catenin, and gamma -cat enin is related to histological type and differentiation in NSCLC, although catenins have no independent prognostic value. However, this study support s the important role of the nuclear accumulation of beta -catenin and gamma -catenin in highly proliferative cells.