||2x higher risk of adverse side-effect if taking aromatase inhibitor
||4x higher risk of adverse side-effect if taking aromatase inhibitor
rs7158782 is one of 4 SNPs found on chromosome 14 near a gene known as T-cell leukemia/lymphoma 1A (TCL1A). This gene appears to be estrogen dependent.
In a study of ~300 patients with early-stage estrogen receptor–positive (ER+) breast cancer who were treated with the aromatase inhibitor (AI) anastrozole or exemestane and who developed musculoskeletal toxicity severe enough to prompt discontinuation, rs7158782(G) allele carriers were at ~2x higher risk for toxicity (CI: 1.5 - 2.9, p < 10e-6). The population attributable risk (i.e., the fraction of such adverse events that could be due to this allele) was estimated to be 11%. 10.1200/JCO.2010.28.5064
An editorial accompanying this article downplays the clinical utility of this finding, since testing for this allele, given its frequency and (mere) doubling of risk, has about equal odds of yielding a true positive and a false positive. 10.1200/JCO.2010.31.2926
||Genome-Wide Associations and Functional Genomic Studies of Musculoskeletal Adverse Events in Women Receiving Aromatase Inhibitors
[PMID 25035853] Genotype, allele and haplotype frequencies of four TCL1A gene polymorphisms associated with musculoskeletal toxicity in the South Indian descent