title: Comparison of mammographic density assessed as volumes and areas among women undergoing diagnostic image-guided breast biopsy.
abstract: BACKGROUND
  Mammographic density (MD), the area of non-fatty-appearing tissue divided by total breast area, is a strong breast cancer risk factor. Most MD analyses have used visual categorizations or computer-assisted quantification, which ignore breast thickness. We explored MD volume and area, using a volumetric approach previously validated as predictive of breast cancer risk, in relation to risk factors among women undergoing breast biopsy.
  
  
  METHODS
  Among 413 primarily white women, ages 40 to 65 years, undergoing diagnostic breast biopsies between 2007 and 2010 at an academic facility in Vermont, MD volume (cm(3)) was quantified in craniocaudal views of the breast contralateral to the biopsy target using a density phantom, whereas MD area (cm(2)) was measured on the same digital mammograms using thresholding software. Risk factor associations with continuous MD measurements were evaluated using linear regression.
  
  
  RESULTS
  Percent MD volume and area were correlated (r = 0.81) and strongly and inversely associated with age, body mass index (BMI), and menopause. Both measures were inversely associated with smoking and positively associated with breast biopsy history. Absolute MD measures were correlated (r = 0.46) and inversely related to age and menopause. Whereas absolute dense area was inversely associated with BMI, absolute dense volume was positively associated.
  
  
  CONCLUSIONS
  Volume and area MD measures exhibit some overlap in risk factor associations, but divergence as well, particularly for BMI.
  
  
  CONCLUSIONS
  Findings suggest that volume and area density measures differ in subsets of women; notably, among obese women, absolute density was higher with volumetric methods, suggesting that breast cancer risk assessments may vary for these techniques.
authors.affiliation: Hormonal and Reproductive Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, NIH, Bethesda, Maryland. gierachg@mail.nih.gov.
authors.forename: Gretchen L
authors.initials: GL
authors.lastname: Gierach
authors.affiliation: University of Vermont, Burlington, Vermont.
authors.forename: Berta M
authors.initials: BM
authors.lastname: Geller
authors.affiliation: University of California, San Francisco, San Francisco, California.
authors.forename: John A
authors.initials: JA
authors.lastname: Shepherd
authors.affiliation: Hormonal and Reproductive Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, NIH, Bethesda, Maryland.
authors.forename: Deesha A
authors.initials: DA
authors.lastname: Patel
authors.affiliation: University of Vermont, Burlington, Vermont.
authors.forename: Pamela M
authors.initials: PM
authors.lastname: Vacek
authors.affiliation: University of Vermont, Burlington, Vermont.
authors.forename: Donald L
authors.initials: DL
authors.lastname: Weaver
authors.affiliation: University of Vermont, Burlington, Vermont.
authors.forename: Rachael E
authors.initials: RE
authors.lastname: Chicoine
authors.affiliation: Biostatistics Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, NIH, Bethesda, Maryland.
authors.forename: Ruth M
authors.initials: RM
authors.lastname: Pfeiffer
authors.affiliation: University of California, San Francisco, San Francisco, California.
authors.forename: Bo
authors.initials: B
authors.lastname: Fan
authors.affiliation: University of California, San Francisco, San Francisco, California.
authors.forename: Amir Pasha
authors.initials: AP
authors.lastname: Mahmoudzadeh
authors.affiliation: University of California, San Francisco, San Francisco, California.
authors.forename: Jeff
authors.initials: J
authors.lastname: Wang
authors.affiliation: University of Vermont, Burlington, Vermont.
authors.forename: Jason M
authors.initials: JM
authors.lastname: Johnson
authors.affiliation: University of Vermont, Burlington, Vermont.
authors.forename: Sally D
authors.initials: SD
authors.lastname: Herschorn
authors.affiliation: Hormonal and Reproductive Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, NIH, Bethesda, Maryland.
authors.forename: Louise A
authors.initials: LA
authors.lastname: Brinton
authors.affiliation: Breast and Gynecologic Cancer Research Group, Division of Cancer Prevention, National Cancer Institute, NIH, Bethesda, Maryland.
authors.forename: Mark E
authors.initials: ME
authors.lastname: Sherman
mesh_terms: D000367:Age Factors; D000368:Aged; D015992:Body Mass Index; D001940:Breast / Q000473:pathology*; D000071060:Breast Density; D001943:Breast Neoplasms / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000473:pathology*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D061705:Image-Guided Biopsy; D042361:Mammary Glands, Human / Q000002:abnormalities* / Q000473:pathology; D008593:Menopause; D008875:Middle Aged; D009929:Organ Size; D011446:Prospective Studies; D011859:Radiography; D012307:Risk Factors; D012907:Smoking