RATIONALE: Studying mammograms for breast density changes over time may help doctors predict breast cancer risk.

PURPOSE: This natural history study is looking at changes in breast density and gathering health information over time to assess breast cancer risk in women with breast cancer and in healthy women.

OBJECTIVES:

• Characterize each woman's individual mammographic density (MD) longitudinal change trajectory in women with breast cancer and in healthy female participants to assess within-individual MD longitudinal change and breast cancer risk.
• Examine whether these patients or healthy participants manifest different patterns of within-individual change in MD and evaluate predictors of across-individual differences.
• Determine whether the developmental profile of MD differs systematically between these patients and healthy participants.

OUTLINE: This is a prospective, retrospective, controlled study. Patients and healthy participants are frequency-matched by age (± 2 years) and ethnicity.

• Questionnaire: Patients and healthy participants complete a self-administered questionnaire providing detailed information on breast cancer risk factors, including demographics, behavioral and lifestyle factors, reproductive history, family history of breast cancer, comorbidities, medication and hormone replacement therapy use, and breast cancer screening history. This information is then cross-validated with documented data abstracted from medical records to provide a longitudinal and historical framework for assessing individual risk.
• Mammographic density (MD) assessment: Patients and healthy participants are evaluated for patterns of longitudinal change in MD and subsequent breast cancer risk by retrospective review of screening mammograms performed prior to breast cancer diagnosis.

PROJECTED ACCRUAL: A total of 1500 patients and 1500 healthy participants will be accrued for this study.

Inclusion Criteria:

• Patient at the University Hospitals Breast Center and primary care clinics within the University Hospitals system
• Have at least 3 screening mammograms since 1994
• for cases, diagnosis with breast cancer between 2004-2006

Exclusion criteria:

• having had irregular screening (less than 3 mammorgrams since 1994)
• Having breast implants
• Known carriers of BRCA1/BRCA2 genes
• Unable to give written consent

Breast cancer cases diagnosed after 1994 and equal number of frequency-matched (by age within 2 years and ethnicity) controls. Cases and eligible controls with at least 3 screening mammograms since 1994 will be recruited through the University Hospitals Breast Center, and primary care clinics within the University Hospitals Health System (UHHS). The restriction of 3 or more screening mammograms will allow us to adequately model the longitudinal change patterns.