Role of ERCC1, XRCC3, Aurora A and TGFBR1 single-nucleotide polymorphisms (SNP) and CHFR and 14–3-3σ methylation in a customized cisplatin (cis) trial based on ERCC1 mRNA levels in stage IV non-small cell lung cancer (NSCLC) patients (pts)

Abstract

7687 Background: The primary aim of this trial was response. In both the control arm and in the genotypic arm with low tumor ERCC1 mRNA levels, pts received docetaxel (doc)/cis; in the genotypic arm with high tumor ERCC1 mRNA levels, pts received doc/gemcitabine. Response was significantly higher in the genotypic arms. We examined 324 pts for genetic markers that could influence response, including ERCC1 118 C/T, ERCC1 C8092A, XRCC3 241 (Thr to Met), Aurora A 91 T>A, Aurora A 169G>A, a SNP within intron 7 of the TGFBR1 gene (Int7G24A), and an in-frame germline deletion (TGFBR1*6A). Methylation of 14–3-3s and CHFR were also analyzed. Methods: DNA from peripheral lymphocytes was used for genotyping (Taqman assay) and methylation-specific PCR was used for 14–3- 3s and CHFR in pretreatment serum DNA. Results: There were no differences in clinical characteristics among the different SNP types, except that pts with Aurora A 91 AA had higher tumor ERCC1 mRNA levels (P=0.005). No relationship was found between ERCC1 SNPs and tumor ERCC1 mRNA levels. A strong correlation was found between the Int7G24A and XRCC3 241 SNPs (P=0.03). The Int7G24A GA type had a higher odds ratio (OR) of response (OR 2.32) than the AA type (OR 3.15) (P=0.02). XRCC3 241 MetMet had a lower probability of response (OR 0.23) (P=0.04). No other differences in response were observed according to any of the other SNPs or methylation. In the multivariate model, the best response was observed in pts with performance status (PS) 0, low ERCC1 levels, and XRCC3 241 SNP ( Table ). Conclusions: Further research is warranted to define the role of theTGFBR1 Int7G24A gene in customized treatments. No significant financial relationships to disclose. [Table: see text]