Relevant Research About Expression Level Of ERCC1and BRCA1in Prognosis Of NSCLC Patients Receiving Postoperative Adjuvant Chemotherapy

Objective：Lung cancer is a frequently-occurring and common disease. Surgerycombined with chemotherapy is primary therapeutic method for patients with lungcancer, but curative effect is poor. Now many researches suggest that excision repaircross-complementing1(ERCC1) and breast cancer susceptibility gene1(BRCA1) notonly reflect the sensitivity of patients using chemotherapy drugs but also predictpatients’ survival time. In this paper, we aim at studying the relationship betweenexpression level of ERCC1and BRCA1in non-small cell lung cancer and prognosisof patients who received postoperative platinum-based chemotherapy.Methods：Paraffin specimens of lung cancer tissues from100patients who wereeventually diagnosed with NSCLC by surgery between2007and2011were collected.Protein expressions of ERCC1and BRCA1in lung caner tissues of100NSCLC casesand in adjacent normal lung tissues of20cases were detected byimmunohistochemisty. All tissues came from patients with NSCLC who received atleast two cycles of Platinum-based postoperative adjuvant chemotherapy. Theexpressions of two genes were combined analyzed in relation to chemotherapy anddisease-free survival times(DFS) and overall survival time(OS).Results：（1）ERCC1protein and BRCA1protein expressed both in non-small celllung cancer tissues and adjuvant normal lung tissues, but expression level of ERCC1and BRCA1were significantly higher in lung cancer tissues than in adjuvant normallung tissues, among them the high expression rate of ERCC1protein in lung cancertissues and adjuvant normal lung tissues respectively were40%and15%withstatistical differences(P=0.033); the high expression rate of BRCA1protein in lungcancer tissues and adjuvant normal lung tissues respective were46%and20%withstatistical differences(P=0.031).（2）Expressions of ERCC1protein and BRCA1protein were not correlated with patients’ age, sex, clinical stages, pathological classification and degree ofdifferentiation of tumor cells in non-small lung cancer tissues(P>0.05).（3）The disease-free survival time of patients in lower ERCC1expressiongroup was two months longer than patients in high ERCC1expression group, theoverall survival time was one point seven months longer than patients in high groupand the differences were statistically significant(P=0.002,P=0.001); similarconclusion was drawn concerning expressions of BRCA1(P=0.004,P=0.005).（4）Patients with ERCC1and BRCA1low expressions had a significantlylonger DFS and OS(P=0.001,P=0.000) than those with high expressions in non-smallcell lung cancer.（5）Expression of ERCC1were positively related to expression of BRCA1inthe NSCLC (r=0.199,P=0.047).（6）Patients in lower ERCC1and BRCA1expression group benefited mostlyfrom cisplatin-based chemotherapy.Conclusions:（1）The expression levels of ERCC1and BRCA1are significantly higher inNSCLC than that in adjacent normal lung tissues, which prompt they are associatedwith the pathogenesis of NSCLC.（2）Patients in lower ERCC1expression and BRCA1expression groups havelonger disease-free survival time and overall survival time than those in higherexpression groups, which show they could effectively estimate prognosis of NSCLCpatients receiving postoperative adjuvant chemotherapy, and higher expression ofERCC1and BRCA1may be predictior of patients with NSCLC who have adverseoutcomes after postoperative adjuvant chemotherapy.（3）Expression of ERCC1are positively related to expression of BRCA1inthe NSCLC, which point out they might play synergistic roles in occurrence anddevelopment of NSCLC.