Papers of the Week

Persistent arm pain is a common problem following breast cancer surgery. Little is known about genetic factors that contribute to this type of postsurgical pain. Study purpose was to explore associations between persistent arm pain phenotypes and genetic polymorphisms among fifteen genes involved in catecholaminergic and serotonergic neurotransmission. Women (n=398) rated the presence and intensity of arm pain monthly for six months following breast cancer surgery. Three distinct latent classes of patients were identified (i.e., No Arm Pain (41.6%), Mild Arm Pain (23.6%), and Moderate Arm Pain (34.8%). Logistic regression analyses were used to evaluate for differences between genotype or haplotype frequencies and the persistent arm pain classes. Compared to the No Arm Pain class, three SNPs and one haplotype, in four genes, were associated with membership in the Mild Arm Pain class: COMT rs4633, HTR2A haplotype B02 (composed of rs1923886 and rs7330636), HTR3A rs1985242, and TH rs2070762. Compared to the No Arm Pain class, four SNPs in three genes were associated with membership in the Moderate Arm Pain class: COMT rs165656, HTR2A rs2770298 and rs9534511, and HTR3A rs1985242. Findings suggest that variations in catecholaminergic and serotonergic genes play a role in the development of persistent arm pain. PERSPECTIVE – Limited information is available on genetic factors that contribute to persistent arm pain following breast cancer surgery. Genetic polymorphisms in genes involved in catecholaminergic and serotonergic neurotransmission were associated with two persistent arm pain phenotypes. Findings may be used to identify patients are higher risk for this common pain condition.