- Approximately 28 million women ages 40 to 76 in the United States have dense breasts:
- This represents approximately 40% of all women
- Breast density:
- Refers to the relative quantities of fat (radiolucent) versus epithelium and stroma (radiodense) in breast tissue
- Higher breast density:
- Is associated with decreased mammographic sensitivity and increased breast cancer risk
- While there are no clinical guidelines for women with dense breasts:
- The data support a discussion of this risk and consideration of additional screening
- Supplemental screening can be considered in this population:
- Although there is no consensus on the optimal additional screening modality used for women with dense breast tissue:
- Often ultrasound or contrast-enhanced mammography (or tomosynthesis if not part of patient’s standard screening regimen) are selected
- Although there is no consensus on the optimal additional screening modality used for women with dense breast tissue:
- The American College of Radiology Imaging Network (ACRIN) 6666 trial:
- Investigated screening breast ultrasound in women with dense breast tissue and at least one additional breast cancer risk factor:
- Incremental detection rate:
- Was four cancers per 1000 patients when screening ultrasound was added to mammography
- Incremental detection rate:
- Investigated screening breast ultrasound in women with dense breast tissue and at least one additional breast cancer risk factor:
- MRI has the highest incremental cancer detection rate:
- Reported in the high-risk population to be 4 to 14 per 1000 women following a negative mammogram
- The majority of MRI detected cancers:
- 67% to 80% are invasive
- This benefit, though, needs to be balanced with the false positive rates:
- Which range from 14% to 38% at time of baseline MRI and 8% to 18% for subsequent MRI screening
- Additionally, breast MRI requires intravenous gadolinium contrast and is an expensive test
- The American Cancer Society reports there is insufficient evidence:
- To recommend for or against MRI in women with heterogeneously or extremely dense breasts on mammography as their only risk factor
- The Dutch DENSE trial:
- Is currently investigating the value of MRI screening in this population, but these data are not yet available
- Optimal screening regimens for women with dense breasts require a thorough discussion with the patient regarding the risks and benefits of supplemental screening, including:
- The potential for false positives, additional biopsies and increased cost
- Risk models will often help guide individual screening recommendations but even in the absence of family history, breast density may justify supplemental screening:
- Insurance reimbursement is variable
- References:
- Throckmorton AD, Rhodes DJ, Hughes KS, Degnim AC, Dickson-Witmer D. Dense breasts: what do our patients need to be told and why? Ann Surg Oncol. 2016;23(10):3119-3127.
- Melnikow J, Fenton JJ, Whitlock EP, Miglioretti DL, Weyrich MS, Thompson JH, et al. Supplemental screening for breast cancer in women with dense breasts: a systematic review for the U.S. Preventive Services Task Force. Ann Intern Med. 2016;164(4):268-278.
- Berg WA, Zhang Z, Lehrer D, Jong RA, Pisano ED, Barr RG, et al. Detection of breast cancer with addition of annual screening ultrasound or a single screening MRI to mammography in women with elevated breast cancer risk. JAMA. 2012;307(13):1394-1404.
- Mann RM, Kuhl CK, Moy L. Contrast-enhanced MRI for breast cancer screening. J Magn Reson Imaging. 2019;50(2):377-390.
- Breast Cancer Screening With MRI in Women Aged 50-75 Years With Extremely Dense Breast Tissue: the DENSE Trial. ClinicalTrials.gov Identifier: NCT01315015. https://clinicaltrials.gov/ct2/show/NCT01315015 Accessed November 8, 2019.
Rodrigo Arrangoiz MS, MD, FACS, FSSO 