EGFR Genomic CA-simple Sequence Repeat Polymorphism In NSCLC Patients Treated With Tyrosine Kinase Inhibitor Therapy:a Meta-analysis And Systematic Review

Objective:The NSCLC patients were treated with single agent epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) generally. The objective of this analysis was to examine the relationship between EGFR CA-simple sequence repeat polymorphism and clinical outcomes in these studies. We also want to find out the CA-SSR could be a biomarkers.Methods:Searching the MEDLINE/Pubmed, Elsevier ScienceDirect and Cochra-ne Library databases and reference lists of retrieved studies, we systematically identified articles in patients with advanced or recurrent NSCLC treated with the TKIs (erlotinib or gefitinib) investigating EGFR gene CA-simple sequence repeat polymorphism(last search date:29, February2012). The study should provided enough data for analysis. We performed a meta-analysis of the results by the Review Manager5.0.Results:Eleven studies included1135asymptomatic participants met inclusion criteria. Compared with long CA-simple sequence repeats(LRCA), the patients with short CA-simple sequence repeats(SRCA) got a higher response rate(39.4%vs27.8%; OR1.81,95%CI1.20-2.74, P<0.01) and a disease control rate(76.9%vs50.0%; OR3.64,95%CI2.06-6.33, P<0.01) when treated with EGFR-TKIs. The skin rash occurrence (59.1%vs50.0%; OR1.68,95%CI0.59-4.76, P=0.33) was no difference in the two groups. The average of median survival time was14.36months(95%CI10.55-18.17months) in SRCA group. It is higher than LRCA group, but there was no difference with statistical sense(P=0.34). Also, CA ploymorphism was no difference from both EGFR mution rate (37.9%vs32.9%; OR0.94,95%CI0.5-1.77, P=0.84) and EGFR expression positive rate(48.2%vs38.3%; OR1.30,95%CI0.51-2.96, P=0.53). Furthermore, the response rate and survival time in the first subgroup analysis coincide with the overall.Conclusions:The clinical effect in the SRCR group was higher than the LRCR grouping in the near future, which would be a molecular predictors. But the CA-SSR mean little for long-term therapeutic effects. The CA ploymorphism and EGFR mution may be independent prognostic factors in TKI-treated patients.