The Association of Breast Density Changes, Plasma Hormone Changes, and Breast Cancer Recurrence: A Companion Study to NCIC CTG MA.27

OBJECTIVES:

Primary

• Assess the change in percent breast density and dense area in response to aromatase inhibitor therapy from pretreatment to 1 year, 1 year to 2 years, and pretreatment to 2 years in women with invasive breast cancer.
• Determine the changes in percent breast density and dense area in response to aromatase inhibitor therapy from pretreatment to 1 year and correlate the changes with changes in plasma hormones (e.g., estrone, estrone-sulfate, estradiol, and sex hormone binding globulin) and drug levels (anastrozole or exemestane) over the same period in women with invasive breast cancer.
• Determine the change over time in percent breast density and dense area (from pretreatment to the time period prior to local recurrence) in the contralateral breast in correlation to local recurrence of breast cancer.

Secondary

• Determine the change over time in percent breast density and dense area in the contralateral breast in correlation to the development of contralateral breast cancer.
• Determine whether women with high pretreatment percent density (upper tertile) experience greater decreases in percent breast density at 1 and 2 years of aromatase inhibitor therapy than women with low pretreatment percent density (lower tertile).
• Determine whether women with high pretreatment dense area (upper tertile) experience greater decreases in dense area at 1 and 2 years of aromatase inhibitor therapy than women with low pretreatment dense area (lower tertile).
• Correlate haplotype tagged single nucleotide polymorphisms in genes in the aromatase pathway (identified thorough the Mayo Clinic and Indiana University Pharmacogenomics Research Network Projects) with changes in percent and area breast density, plasma hormone levels, and 1-year drug levels.