Abstract 5489: A genome-wide association study identifies novel loci associated with taxane-related sensory neuropathy in breast cancer patients enrolled in a cooperative group clinical trial (SWOG S0221)
Authors: Sucheston-Campbell Lara , Clay Alyssa , Barlow William E. , Budd G Thomas , Stram Dan , Haiman Chris , Yan Li , Zirpoli Gary , Yao Song , Hershman Dawn , Albain Kathy S. , Hayes Daniel F. , Moore Halle , Hobday Timothy J. , Stewart James A. , Isaacs Claudine , Salim Muhammad , Gralow Julie R. , Hortobagyi Gabriel N. , Livingston Robert B. , Sheng Xin , Kroetz Deanna L. , Ambrosone Christine B. 
Published: August 2015

Introduction: The use of multi-drug regimens, including taxanes (T), has increased survival for breast cancer patients. However, T-induced neuropathy, one of the most common side effects, cannot be predicted, prevented or effectively treated. Using genome wide analyses (GWA), we sought to identify common genetic variants that infer susceptibility to clinical and self-reported neuropathy.

Methods: Women with high risk breast cancer were enrolled in SWOG 0221, a trial of dosing schedules for AC and T. Genotyping was performed using the Illumina 1M chip and SNPs examined in relation to CTCAE grade 3 and 4 neurotoxicity and self-reported symptoms (FACT-TAXANE) among women providing blood samples. Significant associations were tested for replication in CALGB40101.

Results: Among 1269 European Americans (EA) and 139 African Americans (AA) in S0221, there were 147 and 31 grade 3+ neuropathies, respectively. In CALGB40101, grade 3 toxicity was less frequent (59/855 EA and 15/117 AA).  In S0221 EA patients, loci on chromosomes 7, 10, 16 and 17 showed associations with grades 3 and 4 neuropathy at p&lt;5×10e-06, with the most significant genetic association on chromosome 17, rs910920, p = 6.8×10e-08, odds ratio (OR) = 0.44 (95% confidence interval (CI), 0.32-0.61); this SNP is a cis eQTL, thought likely to affect transcription factor binding and linked to expression of VPS53 in lymphoblastoid cell lines. While the rs910920 association was specific to EA, the A allele in rs1858826 on chromosome 7 was associated with reduced odds of neuropathy in both EA (p = 7×10e-07) and AA (p = .02) groups. The S0221 associations at p&lt;5×10e-06 did not replicate in CALGB40101.

A subset of patients (n = 677 EA and n = 42 AA) completed the FACT-TAXANE. The most significant associations with this neuropathy phenotype (p&lt;5×10e-07) were on chromosomes 2 (rs4267555 and rs4443044) and 3 (rs2421468). Of the 168 SNPs tested for association with neuropathy in previous studies, rs1695 in GSTP1 (p = 0.0009) and rs228591 in ATM (p = 0.0006), showed some evidence of association with FACT-TAXANE scores; the latter SNP was significant at p = .005 in ordinal regression analysis of neuropathy grades 0-4 in CALGB40101. None of these SNPs were significantly associated with grade 3 CTCAE neuropathy at p&lt;.05, nor were the top CTCAE associations in relation to FACT-TAXANE scores. Replication of the most significant S0221 FACT-TAXANE findings in CALGB40101 is ongoing.

Conclusions: Failure to replicate S0221 in CALGB40101, and the lack of coherence between self-report and clinical grade in S0221 could be attributable to differences in trial designs as well as differences in defining a complex phenotype. Larger homogeneous trials with similar dosing and criteria for defining neuropathy are needed to assess the relationship of genetics and the neuropathy symptom spectrum.

Citation Format: Lara Sucheston-Campbell, Alyssa Clay, William E. Barlow, G Thomas Budd, Dan Stram, Chris Haiman, Li Yan, Gary Zirpoli, Song Yao, Dawn Hershman, Kathy S. Albain, Daniel F. Hayes, Halle Moore, Timothy J. Hobday, James A. Stewart, Claudine Isaacs, Muhammad Salim, Julie R. Gralow, Gabriel N. Hortobagyi, Robert B. Livingston, Xin Sheng, Deanna L. Kroetz, Christine B. Ambrosone. A genome-wide association study identifies novel loci associated with taxane-related sensory neuropathy in breast cancer patients enrolled in a cooperative group clinical trial (SWOG S0221). [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 5489. doi:10.1158/1538-7445.AM2015-5489