informed of the limitations of mammography. Mammography will not detect all breast cancers, and some breast cancers detected by screening still have poor prognosis. Mammography screening may also lead to overdiagnosis. That is, some breast tumors or lesions detected by mammography, particularly DCIS, would not have progressed or otherwise been detected without screening. Estimates of the prevalence of overdiagnosis vary widely because it cannot be directly measured.180 Mammography may also result in falsepositive results, which lead to follow-up examinations, including biopsies, when there is no cancer; false positives are more likely when women have their first screening. About 12% of women screened with modern digital mammography require follow-up imaging or biopsy, but most (95%) of these women do not have cancer.181 Cummulative radiation exposure from repeated mammograms may slightly increase the risk of breast cancer;182 however, the dose of radiation during a mammogram is relatively small and the benefit of screening likely outweighs any harm. Reducing radiation exposure through more effective imaging is an area of current research. The Affordable Care Act requires that Medicare and all new private health insurance plans fully cover screening mammograms without any out-of-pocket expense for patients. There are also programs, such as the CDC’s National Breast and Cervical Cancer Early Detection Program, that offer mammography services for low-income, uninsured, and underserved women. For help locating a free or low-cost screening mammogram in your area, contact the American Cancer Society at 1-800-227-2345. Digital breast tomosynthesis (DBT) In 2011, the FDA approved the use of DBT (also referred to as 3D mammography) for breast cancer screening. DBT takes multiple breast images, in combination with digital 2D mammography, which can be used to construct a 3D image of the breast. Some studies have found that DBT may be more sensitive (i.e., detect more cancers) and have Breast Cancer Facts & Figures 2019-2020 21 lower recall rates than 2D mammography alone;183, 184 however, when 2D images are produced separately from DBT, women receive about twice the dose of radiation. The FDA has approved the use of tomographic images to produce synthetic 2D images, which reduces the radiation dose levels similar to conventional digital mammography, although this practice is not yet widespread. DBT is not yet available in all communities and may not be fully covered by health insurance. Prevalence of mammography • In 2018, the prevalence of up-to-date mammography according to American Cancer Society recommendations was lower among Hispanic and Asian (55%-60%) women than NH black (66%), NH white, and AIAN (both 64%) women (Table 5).185 However, studies have documented that self-reported survey data overestimate mammography screening prevalence, particularly among black and Hispanic women.34- 36, 186 • Only 30% of uninsured women were up to date with breast cancer screening in 2018, compared to 64% of insured women. • The prevalence of up-to-date breast cancer screening was 70% or higher among lesbian women, college graduates, and those ages 55-74 years. • In 2016, by state, the prevalence of up-to-date mammography among women ages 45 and older ranged from 57% in Wyoming to 79% in Rhode Island (Table 6).187 American Cancer Society Guideline for Breast Cancer Screening, 2015174 The recommendations below are for women at average risk of breast cancer (i.e., women without a personal history of breast cancer, a suspected or confirmed pathogenic genetic variation [e.g., BRCA1 or BRCA2], a strong family history, or a history of previous radiotherapy to the chest at a young age). All women should become familiar with the potential benefits, limitations, and harms associated with breast cancer screening. • Women should have the opportunity to begin annual screening between the ages of 40 and 44. • Women ages 45 to 54 should be screened annually. • Women ages 55 and older should transition to biennial screening or have the opportunity to continue screening annually. • Women should continue screening mammography as long as their overall health is good and they have a life expectancy of 10 years or more. Table 5. Mammography (%), Women 45 and Older, US, 2018 Up to date* (≥ 45 years) Within the past 2 years (50-74 years) Overall 63 73 Age (years) 45-54 53 – 55-64 73 – 50-64 – 72 65-74 75 75 75+ 51 – Race/Ethnicity Non-Hispanic White 64 73 Non-Hispanic Black 66 74 Non-Hispanic Asian American 55 71 Non-Hispanic American Indian and Alaska Native 64 66 Hispanic 60 71 Sexual orientation Gay/Lesbian 70 79 Straight 63 73 Bisexual † † Education Less than high school 52 63 High school diploma or GED 61 69 Some college/associates degree 64 72 College graduate 70 81 Health insurance status (age ≤64 years) Uninsured 30 39 Insured 64 75 Immigration Born in US 64 73 Born in US territory 68 † In US fewer than 10 years 43 54 In US 10 or more years 61 74 GED = General Educational Development high school equivalency. *According to American Cancer Society recommendations: mammogram within the past year (ages 45-54 years) or past two years (ages ≥55 years). †Estimate not provided due to