Defective expression of transforming growth factor beta type II receptor (TGFBR2) in the large cell variant of non-small cell lung carcinoma.

Large cell carcinoma (LCC) of the lung is defined as an undifferentiated carcinoma without the characteristic features of squamous cell (SqC), small cell, or adenocarcinomas (AdC). In the present study, the expression level of the important tumor suppressor, transforming growth factor beta type II receptor (TGFBR2), was examined both in LCC and non-LCC tumors, which include AdC, SqC and adenosquamous carcinoma (Ad-SqC). Immunohistochemical staining with TGFBR2 antibody revealed statistically significant or near significant differences in the reduced expression in LCC (80% of cases) versus AdC (42.1% of cases, P=0.0288) and SqC (47.1% of cases, P=0.0589), or LCC versus non-LCC (45% of cases, P=0.02). The differences in the expression level of TGFBR2 between LCC and non-LCC were consistent with the histopathologic classification of these tumors, suggesting that the defective TGFBR2 expression might contribute to the carcinogenesis and/or development of LCC.