A211601 closed prematurely due to slow accrual.

This phase III trial evaluates mammographic breast density in participants with hormone receptor-negative breast cancer enrolled on study A011502. High breast density has been shown to be a strong risk factor for developing breast cancer and decreasing breast density may decrease the risk for breast cancer. Participants treated with aspirin may show reduced breast density on a mammogram.

PRIMARY OBJECTIVES I. To compare the 1-year mammographic breast density in the contralateral (unaffected) breast between the aspirin and placebo arms in patients with hormone receptor negative or positive breast cancer enrolled in A011502.

SECONDARY OBJECTIVES I. To compare the 2-year mammographic breast density in the contralateral (unaffected) breast between the aspirin and placebo arms in patients with hormone receptor negative or positive breast cancer enrolled in A011502.

OUTLINE:

Participants provide bilateral screening mammogram taken prior to all cancer treatment and within 8 weeks prior to registration to A011502 and an annual bilateral mammogram as near as possible to 1 year post-registration to A011502 and as near as possible to 2 years post-registration to A011502. Participants also undergo collection of blood sample and menstrual cycle data within 2 weeks after registration and at 1 and 2 years after registration to A011502.

After completion of study, participants are followed up annually until 10 years from registration to study A011502.

Inclusion Criteria:

• Must be either concurrently enrolling or previously enrolled to Alliance A011502. Eligible patients may be either pre- or post-menopausal.

• Patients must have either hormone receptor-negative breast cancer or be ER+ patients who have completed hormone therapy (e.g., tamoxifen, aromatase inhibitors) at least 6 months prior to registration to A011502.

• Patients must have baseline breast density measurement as defined by one of the following:

  • >= 25% breast density, or
  • Scattered areas of fibroglandular density, or
  • Breast composition category b, c, or d, per Breast Imaging Reporting and Data System (BI-RADS) 2013.

• Baseline digital screening mammogram (mediolateral [MLO] and craniocaudal [CC] views) taken prior to registration must be available for submission.

  • For patients enrolling concurrently with Alliance A011502: Baseline digital screening mammogram must be taken within 8 weeks prior to registration to A211601. If a baseline mammogram within 8 weeks is not available, a new screening mammogram must be performed prior to treatment on Alliance A011502
  • For patients enrolling retrospectively: The patient's previous routine mammogram on file must be within 1 year prior to registration to A011502.

• Contralateral unaffected breast in place (with no prior cancer or radiation, no implants and no plan for breast surgery on contralateral breast over the course of the study). Patients with a prior biopsy on the unaffected breast are eligible.

• Not pregnant and not nursing.

Participants with hormone receptor negative or positive breast cancer enrolled in Alliance A011502.