title: Prognostic significance of mammographic density change after initiation of tamoxifen for ER-positive breast cancer.
abstract: BACKGROUND
  A prior analysis of postmenopausal breast cancer patients linked a decline in mammographic density (MD) following the initiation of tamoxifen treatment with improved survival, but excluded premenopausal women, for whom tamoxifen is the primary anti-endocrine therapy. Therefore, we evaluated change in MD after tamoxifen and breast cancer death among patients age 32 to 87 years.
  
  
  METHODS
  This case-control study included 349 estrogen receptor (ER)-positive breast cancer patients who were treated with tamoxifen at Kaiser Permanente Northwest (1990-2008): 97 who died from breast cancer (case patients) and 252 who did not (control patients), matched on age and year at diagnosis and disease stage. Percent MD in the unaffected breast was measured at baseline (mean six months before tamoxifen initiation) and follow-up (mean 12 months after initiation). Associations between change in MD and breast cancer death were estimated using conditional logistic regression.
  
  
  RESULTS
  Patients in the highest tertile of MD decline had a lower risk of breast cancer death when compared with women in the lowest tertile (odds ratio [OR] = 0.44, 95% confidence interval [CI] = 0.22 to 0.88); results were similar after adjustment for baseline MD (OR = 0.49, 95% CI = 0.23 to 1.02). Reductions in death were observed only among patients in the middle and upper tertiles of baseline MD. Associations did not differ by age, tamoxifen use duration, estrogen and/or progestin use, body mass index, or receipt of chemotherapy or radiotherapy.
  
  
  CONCLUSIONS
  These data suggest that younger and older ER-positive breast cancer patients who experience large reductions in MD following tamoxifen initiation have an improved prognosis.
authors: Division of Cancer Epidemiology and Genetics (SJN, MES, RMP, ABdG, LAB, RNH, GLG) and Division of Cancer Prevention (MES), National Cancer Institute, Bethesda, MD; Group Health Research Institute, Seattle, WA (EJAB); Kaiser Permanente Northwest Center for Health Research, Portland, OR (AG).Current affiliation: SJN is currently affiliated with the Radiology Department, University of North Carolina at Chapel Hill, Chapel Hill, NC.
authors: Sarah J
authors: SJ
authors: Nyante
authors: Division of Cancer Epidemiology and Genetics (SJN, MES, RMP, ABdG, LAB, RNH, GLG) and Division of Cancer Prevention (MES), National Cancer Institute, Bethesda, MD; Group Health Research Institute, Seattle, WA (EJAB); Kaiser Permanente Northwest Center for Health Research, Portland, OR (AG).Current affiliation: SJN is currently affiliated with the Radiology Department, University of North Carolina at Chapel Hill, Chapel Hill, NC.
authors: Mark E
authors: ME
authors: Sherman
authors: Division of Cancer Epidemiology and Genetics (SJN, MES, RMP, ABdG, LAB, RNH, GLG) and Division of Cancer Prevention (MES), National Cancer Institute, Bethesda, MD; Group Health Research Institute, Seattle, WA (EJAB); Kaiser Permanente Northwest Center for Health Research, Portland, OR (AG).Current affiliation: SJN is currently affiliated with the Radiology Department, University of North Carolina at Chapel Hill, Chapel Hill, NC.
authors: Ruth M
authors: RM
authors: Pfeiffer
authors: Division of Cancer Epidemiology and Genetics (SJN, MES, RMP, ABdG, LAB, RNH, GLG) and Division of Cancer Prevention (MES), National Cancer Institute, Bethesda, MD; Group Health Research Institute, Seattle, WA (EJAB); Kaiser Permanente Northwest Center for Health Research, Portland, OR (AG).Current affiliation: SJN is currently affiliated with the Radiology Department, University of North Carolina at Chapel Hill, Chapel Hill, NC.
authors: Amy
authors: A
authors: Berrington de Gonzalez
authors: Division of Cancer Epidemiology and Genetics (SJN, MES, RMP, ABdG, LAB, RNH, GLG) and Division of Cancer Prevention (MES), National Cancer Institute, Bethesda, MD; Group Health Research Institute, Seattle, WA (EJAB); Kaiser Permanente Northwest Center for Health Research, Portland, OR (AG).Current affiliation: SJN is currently affiliated with the Radiology Department, University of North Carolina at Chapel Hill, Chapel Hill, NC.
authors: Louise A
authors: LA
authors: Brinton
authors: Division of Cancer Epidemiology and Genetics (SJN, MES, RMP, ABdG, LAB, RNH, GLG) and Division of Cancer Prevention (MES), National Cancer Institute, Bethesda, MD; Group Health Research Institute, Seattle, WA (EJAB); Kaiser Permanente Northwest Center for Health Research, Portland, OR (AG).Current affiliation: SJN is currently affiliated with the Radiology Department, University of North Carolina at Chapel Hill, Chapel Hill, NC.
authors: Erin J
authors: EJ
authors: Aiello Bowles
authors: Division of Cancer Epidemiology and Genetics (SJN, MES, RMP, ABdG, LAB, RNH, GLG) and Division of Cancer Prevention (MES), National Cancer Institute, Bethesda, MD; Group Health Research Institute, Seattle, WA (EJAB); Kaiser Permanente Northwest Center for Health Research, Portland, OR (AG).Current affiliation: SJN is currently affiliated with the Radiology Department, University of North Carolina at Chapel Hill, Chapel Hill, NC.
authors: Robert N
authors: RN
authors: Hoover
authors: Division of Cancer Epidemiology and Genetics (SJN, MES, RMP, ABdG, LAB, RNH, GLG) and Division of Cancer Prevention (MES), National Cancer Institute, Bethesda, MD; Group Health Research Institute, Seattle, WA (EJAB); Kaiser Permanente Northwest Center for Health Research, Portland, OR (AG).Current affiliation: SJN is currently affiliated with the Radiology Department, University of North Carolina at Chapel Hill, Chapel Hill, NC.
authors: Andrew
authors: A
authors: Glass
authors: Division of Cancer Epidemiology and Genetics (SJN, MES, RMP, ABdG, LAB, RNH, GLG) and Division of Cancer Prevention (MES), National Cancer Institute, Bethesda, MD; Group Health Research Institute, Seattle, WA (EJAB); Kaiser Permanente Northwest Center for Health Research, Portland, OR (AG).Current affiliation: SJN is currently affiliated with the Radiology Department, University of North Carolina at Chapel Hill, Chapel Hill, NC. gierachg@mail.nih.gov.
authors: Gretchen L
authors: GL
authors: Gierach
mesh_terms: D000328:Adult; D000368:Aged; D018931:Antineoplastic Agents, Hormonal / Q000008:administration & dosage*; D001943:Breast Neoplasms / Q000737:chemistry / Q000000981:diagnostic imaging / Q000188:drug therapy* / Q000473:pathology*; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008327:Mammography; D008875:Middle Aged; D015205:Northwestern United States; D017697:Premenopause; D011379:Prognosis; D011960:Receptors, Estrogen / Q000032:analysis*; D020845:Selective Estrogen Receptor Modulators / Q000008:administration & dosage*; D013629:Tamoxifen / Q000008:administration & dosage*
chemical_list: D018931:Antineoplastic Agents, Hormonal; D011960:Receptors, Estrogen; D020845:Selective Estrogen Receptor Modulators; D013629:Tamoxifen