Prognostic significance of immunohistochemical Rac1 expression in survival in early operable non-small cell lung cancer.
BACKGROUND
The small GTPases are involved in the regulation of critical cellular functions, such as transcription control, cell cycle, and organization of actin cytoskeleton. Although a number of investigations have established the significance of Rho-family GTPases in several human tumors, there is still little information available on the clinical significance of Rac1 expression in non-small cell lung cancer (NSCLC). Therefore, immunohistologic expression of Rac1 was studied in a tissue microarray of 111 Stage I-II NSCLCs and correlated with clinicopathologic parameters and clinical outcome.


METHODS
For this retrospective study 111 tissue samples, obtained from anonymized patients with early operable NSCLC (stage I-II), were used to construct a tissue microarray for immunohistochemical study.


RESULTS
Rac1 showed a cytoplasmic pattern of expression in tumor cells, while normal lung components showed negative or weak cytoplasmic staining. Rac1 expression increased significantly with the advancement of the T stage (P<0.01) and the TNM stage (P<0.05). Analysis of overall survival showed that Rac1 expression was related to poor outcome (P=0.012), even in the group of stage I patients (P=0.023). Multivariate analysis showed that Rac1 overexpression was an independent marker for overall survival after adjusting for other prognostic factors (P=0.023).


CONCLUSIONS
We found a positive prognostic value of immunohistologically determined Rac1 protein expression and presents Rac1 as a potential unfavorable prognosis biomarker in patients with early operable NSCLC.
Yuan
Kai
K
Department of Thoracic Surgery, ZhongShan Hospital, Fudan University, Shanghai, PR China.
Qian
Chen
C
Zheng
Ruheng
R
D000328:Adult; D000368:Aged; D002289:Carcinoma, Non-Small-Cell Lung / Q000175:diagnosis* / Q000378:metabolism / Q000473:pathology / Q000601:surgery*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D053208:Kaplan-Meier Estimate; D008175:Lung Neoplasms / Q000175:diagnosis* / Q000378:metabolism / Q000473:pathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D016016:Proportional Hazards Models; D020830:rac1 GTP-Binding Protein / Q000378:metabolism*
D020830:rac1 GTP-Binding Protein