EVIDENCE OF ASSOCIATIONS BETWEEN NEUROTRANSMITTER CANDIDATE GENES AND PERSISTENT ARM PAIN SEVERITY FOLLOWING BREAST CANCER SURGERY

Persistent arm pain, a distinct syndrome from persistent breast pain, is a considerable clinical problem following breast cancer surgery. The roles of neurotransmitters and neurotransmitter genes have been examined in persistent neuropathic pain; however, genetic associations have not been examined in the setting of breast cancer surgery. In this study, associations between previously identified arm pain classes (i.e., No Arm Pain vs. Mild Arm Pain and No Arm Pain vs. Moderate Arm Pain) and single nucleotide polymorphisms (SNPs) over 30 candidate neurotransmitter genes were evaluated. After multivariate logistic regression analyses for phenotypic characteristics, 4 SNPs and 1 haplotype remained significant between the No Arm Pain and Mild Arm Pain classes: 1 SNP in BDNF (i.e., rs11030102), 1 SNP in COMT (i.e., rs4633), 1 haplotype in HTR2A (i.e., Haplotype B02), 1 SNP for HTR3A (i.e., rs1985242), and 1 SNP in TH (i.e., rs2070762). Between the No Arm Pain and Moderate Arm Pain classes, 9 SNPs remained significant: 1 SNP in BDNF (i.e., rs2049046), 1 SNP in COMT (i.e., rs165656), 2 SNPs in HTR2A (i.e., rs2770298 and rs9534511), 1 SNP in HTR3A (i.e., rs1985242), 1 SNP in NOS2A (i.e., rs2248814), 1 SNP in NPY (i.e., rs16148), 1 SNP in SLC6A1 (i.e., rs2601126), and 1 SNP in TACR1 (i.e., rs4439987). These findings suggest meaningful impact of neurotransmitter genes on the development of persistent arm pain following breast cancer surgery