Clinical significance of the Rb expression in adenocarcinoma of the lung.
BACKGROUND
Altered retinoblastoma gene expression has been found in various types of cancers including non-small cell lung cancer (NSCLC) and some reports have shown it also to be associated with a poor clinical prognosis in NSCLC.


METHODS
We evaluated the expression of Rb protein by immunohistochemistry in 90 patients with lung adenocarcinoma who underwent surgical resection and determined its prognostic significance. Also, the expression of p27 by immunohistochemistry and the mutations of the p53 gene by PCR-SSCP were evaluated.


RESULTS
Fifty-one out of 90 tumors (56.7%) had reduced expression of the Rb gene. There were no statistical differences between the Rb expression level and clinicopathological status. There was no correlation between the Rb expression level and the p53 mutations or the p27 expression level. The 5-year survival rate in the normal group was 55.1%, which was poorer than that of 73.0% in the reduced group, but showed no statistical difference (p=0.0981). In patients with a reduced Rb-expression, the survival rate of the p53 mutation group tended to show a poorer prognosis than that of the p53 normal group (p=0.0880). In addition, the survival rate of the negative p27 expression group tended to show a poorer prognosis than that of the positive p27 expression group (p=0.0537).


CONCLUSIONS
The Rb expression status was not significant as an individual factor for evaluating the prognosis in adenocarcinoma of the lung. Analyses of the accumulation of genetic alteration are necessary to identify the subset of patients with a poor prognosis.
Sugio
K
K
Department of Surgery and Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan. sugio@surg2.med.kyushu-u.ac.jp
Tsukamoto
S
S
Ushijima
C
C
Yamazaki
K
K
Kase
S
S
Yamaguchi
M
M
Ondo
K
K
Yano
T
T
Sugimachi
K
K
D000230:Adenocarcinoma / Q000378:metabolism*; D018797:Cell Cycle Proteins / Q000096:biosynthesis; D050760:Cyclin-Dependent Kinase Inhibitor p27; D018572:Disease-Free Survival; D005260:Female; D016158:Genes, p53 / Q000235:genetics; D006801:Humans; D007150:Immunohistochemistry; D008175:Lung Neoplasms / Q000378:metabolism*; D008297:Male; D009154:Mutation; D018807:Polymorphism, Single-Stranded Conformational; D011379:Prognosis; D016160:Retinoblastoma Protein / Q000096:biosynthesis*; D025521:Tumor Suppressor Proteins
D018797:Cell Cycle Proteins; D016160:Retinoblastoma Protein; D025521:Tumor Suppressor Proteins; D050760:Cyclin-Dependent Kinase Inhibitor p27