There are women for whom a screening breast MRI is clinically recommended, but not feasible either due to patient factors (body habitus, pacemaker or other implant, claustrophobia) or access (cost, other constraints). Contrast-enhanced mammography (CEM) is a potential alternative to MRI for screening that uses updated standard mammography equipment to obtain low- and high-energy images after intravenous injection of iodinated contrast (as used in CT scanning). The investigators seek to validate screening CEM as an alternative to screening MRI.

This is a prospective study designed to evaluate the role of contrast enhanced mammography (CEM) in screening for breast cancer. The overarching goal of the research program is to improve cancer detection on screening, particularly in women with dense breasts. MRI depicts more cancers than other screening methods, including ultrasound. MRI is proven to both improve cancer detection and reduce clinically detected cancers ("interval cancers") after a negative screening mammogram in women with dense breasts. PA Senate Bill 595, signed into law June 30, 2020, requires insurance carriers to provide coverage for supplemental screening with MRI or ultrasound for a variety of indications. Relative to the number of women who may benefit from screening MRI, there is a shortage of equipment/capacity. Further, nearly half of women cannot have an MRI for medical or other reasons, such as claustrophobia, implanted devices, body habitus, or cost (deductible and copay apply even with the new legislation). Contrast-enhanced mammography (CEM) appears to have similar performance to MRI but has not been widely validated, particularly for screening. In order to lay the foundation for improved screening of women with dense breasts, the investigators seek to offer screening CEM as an alternative to MRI for women who meet guidelines for screening MRI but are unable to have MRI.

Inclusion Criteria:

1. Asymptomatic women under age 75 who are recommended for annual screening MRI and mammography based on current criteria:

   1. Women known to be at high risk for breast cancer because of known or suspected pathogenic mutation, prior chest radiation therapy at least 8 years earlier and before age 30, or estimated lifetime risk of at least 20% based on family history/prior biopsy history (22), between age 30 and 75.
   2. Women with extremely dense breasts age 40-75 (about 7% of the screening population (1)) (12).

2. Women with lobular carcinoma in situ (1% of women biopsied each year; about 0.06% of our screening population) beginning the year after diagnosis.

3. Women with a personal history of breast cancer diagnosed by age 50 or with dense breasts (21), beginning the year after diagnosis (will be recruited under separate ongoing TOCEM protocol).

4. Women with heterogeneously dense breasts and any family history of breast cancer (about 36% of the screening population has dense breasts and about 20% have a family history of breast cancer) who do not meet current high-risk criteria, beginning at age 40 or ten years prior to the age of the youngest relative but not before age 30.

Participants are expected to have medical or other reasons that they are not able to have screening breast MRI.

Exclusion Criteria:

1. Under age 30 or over age 75.
2. Pregnant or breast feeding.
3. Breast implants.
4. Breast surgery within the prior 12 months.
5. Breast signs or symptoms (lump, nipple discharge, nipple retraction, or being followed for breast abnormality on prior imaging).
6. Currently undergoing any type of systemic chemotherapy for cancer (excludes oral endocrine therapy such as aromatase inhibitors or tamoxifen).
7. Reduced kidney function with eGFR < 45 mL/min.

Images may be shared with secondary investigators, including commercial companies after removal of all identifiers. All patient identification (name, patient number, birth date) will be removed from the DICOM headers of the images.

after publication

secondary investigators for image analysis. Sharing via Box

All participants were assigned to screening contrast enhanced mammography with standard of care tomsynthesis (DBT).

1.5 years

All participants were assigned to screening contrast enhanced mammography (CEM) with standard of care tomosynthesis (DBT).