Impact of ABCG2 polymorphisms on the clinical outcome of TKIs therapy in Chinese advanced non-small-cell lung cancer patients.

Objective: The primary purpose of this study was to investigate the correlation between single nucleotide polymorphisms (SNPs) of ATP binding cassette superfamily G member 2 (ABCG2) and outcome of tyrosine kinase inhibitions (TKIs) therapy in Chinese advanced non-small-cell lung cancer (NSCLC) patients. The secondary objective was to identify biomarkers to evaluate the response to treatment and outcome of the targeted therapy.

Methods: SNP genotyping (34 G/A, 421 C/A, 1143 C/T and -15622 C/T) of ABCG2 gene in 100 patients was performed using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The clinical characteristics of 100 patients were collected. A total of 70 patients were treated with TKIs (gefitinib, erlotinib and icotinib). The association between ABCG2 polymorphisms and clinical characteristics was evaluated. Kaplan-Meier survival curves were plotted for overall survival (OS) and analyzed with the log-rank test.

Results: The three polymorphisms of the ABCG2 34 G/A, 421 C/A and 1143 C/T occurred more frequently compared with -15622 C/T in Chinese advanced NSCLC patients. There was no association between ABCG2 polymorphisms and clinical characteristics (p > 0.05). The median OS of patients with GG genotype at position 34 of the ABCG2 gene was significantly shorter than those with GA or AA genotype (p < 0.05). No significant difference of OS was found in 421 C/A and 1143 C/T polymorphisms (p > 0.05).

Conclusion: ABCG2 34 G/A may be a possible predictor of the clinical outcome of TKIs therapy in NSCLC patients.