ass="h4">Purpose
To identify potenti
al bio
markers for the prognosis of non-s
mall cell lung c
ancer (NSCLC) p
atients by using bronchi
al brushing speci
mens.
ass="h4">Methods
The expression of MCM7, Ki67 and EGFR was evaluated in 494 NSCLC tissues and 174 bronchial brushings using immunohistochemical and immunocytochemical techniques. Associations between protein expression and clinico-pathologic parameters were assessed, and the impact on overall survival (OS) was analyzed.
ass="h4">Results
High expression of MCM7, Ki67 and EGFR was detected in 33.3%, 23.5%and 12.7%of tissues and in 52.4%, 52.7%and 20.6%of bronchial brushings, respectively. Expression of MCM7 and Ki67 was associated with squamous cell carcinoma (SCC) in both tissues and bronchial brushings (MCM7: m>Pm> = 0.0007, 0.00003; Ki67: m>Pm> < 0.00001, 0.00001). Overexpression of MCM7 in tumor tissues was detected more frequently in poorly differentiated tumors (m>Pm> = 0.0120) and non-bronchioloalveolar carcinomas (non-BACs) (m>Pm> = 0.0238). EGFR overexpression was observed in tissues of larger tumors (m>Pm> = 0.00004) and in bronchial brushings at later stage (m>Pm> = 0.0262). Kaplan-Meier curves indicated that patients with overexpression of MCM7 or Ki67 had a poorer OS compared to those with low expression for all stages (m>Pm> < 0.00001, 0.0233) and early-stages (m>Pm> < 0.00001, 0.0032). In particular, the patients with MCM7 overexpression in bronchial brushings had a poorer prognosis (m>Pm> = 0.0045). Multivariate Cox regression analysis showed that MCM7 was an independent prognostic indicator both in tissue samples and bronchial brushings.
ass="h4">Conclusions
Our data suggest that MCM7 and Ki67 in tumor tissues may be potential markers of a poor prognosis for NSCLC patients. MCM7 in bronchial brushings also showed an independent prognostic value, which may be useful when biopsies are unavailable.