Assessing Breast Density's Value in Imaging - A Comparative Effectiveness Study

Aim 1 Clinical Outcomes Inclusion criteria: * Women aged 40-79 undergoing screening mammography from 2010-2017 for comparisons with tomosynthesis and 2005-2017 for comparison with breast MRI at a facility that participates in one of six BCSC breast imaging registries * Digital mammography exams performed for screening and performed with or without supplemental screening with digital breast tomosynthesis from 2010-2017 or breast MRI from 2005-2017, at a facility that participates in one of seven BCSC breast imaging registries, and in women who meet inclusion criteria. Exclusion criteria: * Exams performed on women with a history of breast cancer, mastectomy, or breast augmentation. * Unilateral mammograms and mammograms performed within 9 months of a prior mammogram to avoid classifying diagnostic exams as screening * Exams without complete cancer capture during the follow-up period Aim 1 Patient Reported Outcomes Inclusion criteria: * Women aged 40-74 years undergoing screening mammography, with or without supplemental screening with digital breast tomosynthesis or breast MRI, at selected BCSC facilities * Women within 12 months of a digital screening mammogram with known breast density and no known breast cancer diagnosis * For MRI subgroup, we will include women with a screening MRI within the prior 24 months * Within strata defined by BCSC registry, breast density subgroup (dense vs. not dense), and race/ethnicity, women with supplemental screening with digital breast tomosynthesis or breast MRI will be matched to women without supplemental screening Aim 1 Focus Groups Inclusion criteria: * Women age 40-74 years undergoing screening mammography, with or without supplemental screening (defined as digital breast tomosynthesis or breast MRI) * Women within 12 months post-most recent screening examination with known dense breasts from most recent screening mammogram and no known breast cancer diagnosis * Women who are able to speak English and can travel to a nearby location for a discussion Subaim 1 Inclusion criteria: * Radiologists interpreting digital mammography and/or tomosynthesis for at least one year from 2010-2017 at a facility that participates in the BCSC * Digital mammography exams and digital breast tomosynthesis performed for screening and evaluated by a radiologist meeting inclusion criteria from 2010-2017 Exclusion criteria: * Exams performed on women with a history of breast cancer, mastectomy, or breast augmentation * Unilateral mammograms and mammograms performed within 9 months of a prior mammogram to avoid classifying diagnostic exams as screening * Exams without complete cancer capture during one year following the screening mammogram Aim 2 Clinical Outcomes Inclusion criteria: * Women at least 18 years of age with a first breast cancer diagnosis (DCIS or invasive) from 2005-2017 for whom there was a mammogram performed within the year prior to breast cancer diagnosis at one of the participating BCSC registry facilities * Women for whom we have pathologically-confirmed breast cancer (DCIS or invasive) with a pathology or biopsy record related to the incident cancer diagnosis in the BCSC data * MRI and mammography examinations performed for pre-operative work-up from 2005-2017 at one of the participating BCSC registry facilities in women meeting eligibility criteria Aim 2 Patient Reported Outcomes Inclusion criteria: * Women at least 18 years of age with a first pathology-confirmed breast cancer diagnosis (DCIS or stage I-III invasive) within 6-18 months * Known breast density at the time of breast cancer diagnosis Aim 2 Focus Groups Inclusion criteria: * Women age ≥18 with a first breast cancer diagnosis (DCIS or stage I-III invasive cancer) within 1-5 years and after completion of active breast cancer treatment who have undergone mammography or MRI pre-operatively. * Women who are able to speak English and can travel to a nearby location for a discussion COVID-19 Enhancement Focus Groups Inclusion criteria: * Women age 18-74 who were due for breast imaging services during the COVID pandemic and have either canceled their appointment, delayed their appointment, or kept their appointment * Women who are able to speak English and can attend calls virtually through Zoom or over the phone * In addition, for focus groups with women who have prior breast cancer: 1. First breast cancer diagnosis (DCIS or stage I-III invasive cancer) within 1-3 years prior to March, 2020. 2. Completed active cancer treatment (ongoing endocrine and Herceptin therapy acceptable) 3. No evidence of a second breast cancer event in cancer registry or pathology data before recruitment.