Clinicopathological significance of expression of CD133 protein in neuroendocrine lung carcinoma tissues

OBJECTIVE: To investigate the expression of CD133 protein in neuroendocrine lung carcinoma,and evaluate its clinicopatholigical significance.METHODS: Expression of CD133 protein was detected by immunohistochemistry in 90 cases of the neuroendocrine lung carcinoma,and the relationship between expression of CD133 protein and clinicopathological indices was analyzed by statistics.RESULTS: The positive staining of CD133 protein was mainly localized on the membrane and in the cytoplasm of tumor cells,and the positive rate for expression of CD133 protein in carcinoid,atypical carcinoid,large cell neuroendocrine carcinoma and small cell lung cancer were 14.3%(2/14),45.0%(9/20),55.6%(10/18) and 60.5%(23/38),respectively.There was a significant difference between the histological types(P=0.005).CD133 protein was expressed in 21.1%(4/19) of stage Ⅰ,56.0%(14/25) of stage Ⅱ,54.8%(23/42) of stage Ⅲ and 75.0%(3/4) of stage Ⅳ(P=0.015);in 39.2%(20/51) of tumors 5 cm and 61.5%(24/39) of cancers ≥5 cm(P=0.035);in 56.3%(40/71) of tumors with metastasis and in 21.1%(4/19) of those without(P=0.009).The expression of CD133 protein was not related to age(P=0.191) and sex(P=0.242).The median survival in patients with CD133 negative tumors was 55 months,whereas that in those with CD133 positive carcinomas 13 months.There was a greatly significant difference between carcinomas with CD133 expression and those without(Log-rank=35.91,P=0.000 1).CONCLUSION: CD133 protein expression appears to play an important biological and clinical role in the development and evolution of neuroendocrine lung carcinoma,and may become a useful molecular marker to predict the prognosis of patients.