Prognostic significance of OCT4 expression in adenocarcinoma of the lung.

OBJECTIVE: The purpose of this study was to detect the presence of cancer stem-like cells with bronchioalveolar stem cells (BASCs) properties and investigate the clinicopathological role of expression of OCT4 as well as the correlation with clinical outcomes in adenocarcinoma of the lung.

METHODS: Specimens of 112 cases of Stage IB-IIIA lung adenocarcinoma after radical surgery were collected from June 1999 to June 2002. The putative cancer stem cells in tumor sections were visualized immunofluorescently by using the antibodies against three bronchioalveolar stem cells markers: surfactant protein C (SPC), Clara cell secretary protein (CCSP) and Octamer-4 (OCT4). Cancer stem-like cells with bronchioalveolar stem cell properties in human lung adenocarcinoma were subdivided into two phenotypes: OCT4(+)BASC (SPC(+)CCSP(+)OCT4(+)) and OCT4(-)BASC (SPC(+)CCSP(+)OCT4(-)).

RESULTS: Cancer cells with CCSP(+)SPC(+)BASC phenotype were detected in 107 cases, 80 cases with OCT4(+)BASC phenotype (SPC(+)CCSP(+)OCT4(+)) and 27 cases with SPC(+)CCSP(+)OCT4(-). There was a correlation between differentiation and OCT4 expression (P = 0.047). The pattern of survival curves shows the expected trend of decreasing survival with increasing stage at diagnosis (P = 0.015) and with OCT4(+)BASC expression (P = 0.019). Multivariate Cox's analysis reveals that pathological stages of TNM (P = 0.008) and bronchioalveolar stem cells phenotypes (P = 0.015) are the independent prognostic factors.

CONCLUSIONS: The cancer cells with bronchioalveolar stem cells phenotype are detectable in adenocarcinoma of the lung and the expression of self-renewal regulatory gene OCT4 in these cells indicated the worse clinical outcomes.