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Table 4 Results of tests of association between CYP2D6 metabolizer variants and change in percent mammographic density

From: Association of CYP2D6metabolizer status with mammographic density change in response to tamoxifen treatment

  PMD reduction Univariate Adjusted
  ≤10% >10% OR L95 U95 Ptrend OR L95 U95 Ptrend
+ Genotyped from whole blood
  EM 101 21 1.00 Reference 0.009 1.00 Reference 0.020
  hetEM/IM 127 9 0.34 0.15 0.78   0.28 0.10 0.79  
  PM 19 1 0.25 0.03 2.00   0.29 0.03 2.62  
  n = 278           
GOF           0.928
+ Genotyped from whole blood
+ Baseline PMD ≥10%           
  EM 63 21 1.00 Reference 0.010 1.00 Reference 0.021
  hetEM/IM 79 9 0.34 0.15 0.80   0.29 0.11 0.81  
  PM 13 1 0.23 0.03 1.87   0.29 0.03 2.57  
  n = 186           
GOF           0.609
  1. Results of tests of association between CYP2D6 metabolizer variants and change in percent mammographic density (PMD) in subjects treated with tamoxifen for at least six months. Mammograms were taken ≤1 year prior to initiation of tamoxifen, up to three years after treatment. The mammogram taken closest to the second year after tamoxifen treatment was selected for follow-up. Odds ratios (ODs) and 95% confidence intervals (CIs) (lower bound of a 95% confidence interval (L95), upper bound of a 95% confidence interval (U95)) were estimated by applying a logistic regression model, using the group with 10% reduction as a reference. Analyses were adjusted for baseline PMD, age at diagnosis (years), and body mass index (kg/m2) at baseline. The Wald test was used to determine the statistical significance of an overall linear trend for the association between CYP2D6 metabolizer status, treated as a semi-continuous variable, and PMD change (Ptrend). All statistical tests were two-sided. Statistical analyses were performed using R (version 2.15.1) [18]. EM, extensive metabolizer; hetEM/IM, heterozygous extensive/intermediate; PM, poor metabolizer; GOF, P value for Hosmer-Lemeshow goodness-of-fit test for logistic regression.