Li, JCzene, KBrauch, HSchroth, WSaladores, PLi, YHumphreys, KHall, PSURGERY2020-11-102020-11-102013Li, J, Czene, K, Brauch, H, Schroth, W, Saladores, P, Li, Y, Humphreys, K, Hall, P (2013). Association of CYP2D6 metabolizer status with mammographic density change in response to tamoxifen treatment. Breast Cancer Research 15 (5) : R93. ScholarBank@NUS Repository. https://doi.org/10.1186/bcr349514655411https://scholarbank.nus.edu.sg/handle/10635/183197Introduction: Not all breast cancer patients respond to tamoxifen treatment, possibly due to genetic predisposition. As tamoxifen-induced reductions in percent mammographic density (PMD) have been linked to the risk and prognosis of breast cancer, we conducted a candidate gene study to investigate the association between germline CYP2D6 polymorphisms and PMD change.Methods: Baseline and follow-up mammograms were retrieved for 278 tamoxifen-treated subjects with CYP2D6 metabolizer status (extensive (EM), heterozygous extensive/intermediate (hetEM/IM) or poor metabolizer (PM)). Logistic regression analyses were conducted comparing subjects who experienced >10% reduction in PMD to those who experienced ?10% reduction or increase.Results: After multivariate adjustment, PMD change was found to be significantly associated with the degree of CYP2D6 enzyme functionality (Ptrend = 0.021). Compared with EM, hetEM/IM and PM were 72% (95% confidence interval (CI): 0.10 to 0.79) and 71% (0.03 to 2.62) less likely to experience a >10% reduction, respectively.Conclusions: Tamoxifen-induced change in PMD appears to have a genetic component. © 2013 Li et al.; licensee BioMed Central Ltd.Attribution 4.0 Internationalhttp://creativecommons.org/licenses/by/4.0/cytochrome P450 2D6tamoxifenantineoplastic hormone agonists and antagoniststamoxifenadultagedarticlebody massbreast cancerenzyme polymorphismfemalefollow upgenetic variabilityhumanmajor clinical studymammographic densitymammographyquantitative traittreatment responsebreast tumorcongenital malformationgenetic polymorphismgeneticsgenotypemammary glandmammographic densitymetabolismmiddle agedpathologyprognosisrisk factortreatment outcomeAgedAntineoplastic Agents, HormonalBreast NeoplasmsCytochrome P-450 CYP2D6FemaleGenotypeHumansMammary Glands, HumanMiddle AgedPolymorphism, GeneticPrognosisRisk FactorsTamoxifenTreatment OutcomeArticle