Table Significant Differences in Demographic Clinical
Table 2. Significant Differences in Demographic, Clinical, and Surgical Characteristics Between Women in the No Arm Pain (n = 164) and Moderate Arm Pain (n = 137) Classes
NO PAIN MODERATE PAIN
Body mass index, kg/m
Severity of worst postoperative pain
Total annual household income
Occurrence of anemia
Ever breast fed
Stage of disease
IIA and IIB
IIIA, IIIB, IIIC, and IV
Type of surgery
Intercostobrachial nerve sacrificed .6 (1)
Placement of surgical drain
Only in the breast
Only in the axilla
Abbreviations: FE, Fisher’s exact; U, Mann-Whitney U test.
NOTE. Values are mean § standard deviation or percentage (number).
placed; had an axillary lymph node dissection; and had the intercostobrachial nerve sacrificed. Women in the moderate arm pain class reported higher average and worst postoperative pain severity scores, were more likely to have had physical therapy and received biological therapy within the 6 months after surgery, and had more postoperative complications.
Candidate Gene Analyses: No Arm Pain Versus Mild Arm Pain Classes
Genotype distributions differed between the no arm pain and mild arm pain LY-294002 for 5 SNPs and 2
Multivariate logistic regression models were fit to determine the phenotypic and genotypic predictors for membership in the mild arm pain class. In addition to self-reported race/ethnicity and AIMs, the significant covariates included in these analyses were functional status (KPS), pain in the affected breast before surgery, and having had an axillary lymph node dissection.
Three SNPs and 1 haplotype in 4 different genes remained significant in the multivariate analyses: COMT rs4633, HTR2A haplotype B02, HTR3A rs1985242, and TH
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6 The Journal of Pain Genetic Associations With Persistent Arm Pain
Table 3. Multiple Logistic Regression Analyses for COMT, HTR2A, HTR3A, and TH Candidate Genes and Membership in the No Arm Pain (n = 129) Versus Mild Arm Pain (n = 78) Classes
PREDICTOR ODDS RATIO STANDARD ERROR 95% CI Z P VALUE
Abbreviations: CI, confidence interval; COMT, catechol-O-methyltransferase; KPS, Karnofsky Performance Status; ALND, axillary lymph node dissection; HTR2A, 5-hydroxytryptamine receptor 2A, G protein coupled; HTR3A, 5-hydroxytryptamine receptor 3A, ionotropic; TH, tyrosine hydroxylase.
NOTE. Multiple logistic regression analyses of candidate gene associations with no arm pain versus mild arm pain classes. For each model, the first 3 principal compo-nents identified from the analysis of ancestry informative markers, as well as self-reported race/ethnicity, were retained in all models to adjust for potential confound-ing owing to race/ethnicity (data not shown). Predictors evaluated in each model included genotype (COMT rs4633: CC+CT vs TT; HTR2A HapB02 composed of the rs1923886 common T allele and the rs7330636 rare T allele; HTR3A rs1985242: TT+TA vs AA; TH rs2070762: TT vs TC+CC), functional status (KPS score in 10 unit increments), pain in the affected breast before surgery, and underwent an axillary lymph node dissection.
rs2070762 (Table 3). Figures 1A through 1D illustrate the differences between the no arm pain and mild arm pain classes in the percentage of patients who were homozygous for the common allele or heterozygous or homozygous for the rare allele for each of the signifi-cant polymorphisms or dose of the haplotype. For COMT rs4633, carrying 2 doses of the rare T allele (ie, CC+CT vs TT) was associated with a 68% decrease in the odds of belonging to the mild arm pain class. For HTR2A haplotype B02 (composed of rs1923886 [com-mon T allele], rs7330636 [rare T allele]), each additional dose of the haplotype was associated with a 51% decrease in the odds of belonging to the mild arm pain class. For HTR3A rs1985242, carrying 2 doses of the rare A allele (ie, TT+TA vs AA) was associated with a 90% decrease in the odds of belonging to the mild arm pain class. For TH rs2070762, carrying 1 or 2 doses of the rare C allele (ie, TT vs TC+CC) was associated with a 2.39-fold increase in the odds of belonging to the mild arm pain class.
Candidate Gene Analyses: No Arm Pain Versus Moderate Arm Pain Classes
Genotype distributions differed between the no arm pain and moderate arm pain classes for 2 SNPs and 2 haplotypes in ADRA1D, 1 SNP in ADRBK2, 5 SNPs and 4 haplotypes in COMT, 1 SNP in HTR1A, 7 SNPs and 3 hap-lotypes in HTR2A, 1 SNP and 1 haplotype in HTR3A, 3 SNPs in SLC6A2, 1 SNP in SLC6A4, and 1 SNP in TPH2 (Supplementary Table 1).
Multivariate logistic regression models were fit to determine the phenotypic and genotypic predictors for membership in the moderate arm pain class. In addition to self-reported race/ethnicity and AIMs, the significant covariates included in these analyses were functional status (ie, KPS), pain in the affected breast before sur-gery, number of breast biopsies in the past year, place-ment of a surgical drain, and receipt of physical therapy in the 6 months after surgery.