- Breast density is a measure of the amount of fibroglandular tissue in the breast.
- Currently about 43.3% of US women have dense breasts age 40-74 years while this is seen in only 28% of women aged 75 or older.
- There is a positive association between high breast density and breast cancer risk for women aged 75 years or older.
- The decision as to when to stop screening mammography is a very personalized decision between women and their providers and breast density should be considered in decision making.
Advani SM, Zhu W, Demb J, et al.
Association of Breast Density With Breast Cancer Risk Among Women Aged 65 Years or Older by Age Group and Body Mass Index.
JAMA Netw Open. Aug 02 2021;4(8):e2122810.
Breast density is a measure of the amount of fibroglandular tissue in the breast. Currently about 43.3% of US women have dense breasts age 40-74 years while this is seen in only 28% of women aged 75 or older. Prior studies have shown that breast density decreases with increasing age with a sharp decrease in breast density during the postmenopausal period. Previously it has been shown that breast density is associated with breast cancer among women aged 40 to 74 years, however the association between breast density and breast cancer risk is not known for women 75 years and older.
Advani et al looked at the 221,714 screening mammograms for which 38% of the population was aged 75 years or older. These mammograms were collected from the Breast Cancer Surveillance Consortium from 1996- 2012. Women were followed on average for 6.3 years. The main outcome from this study was the incidence of invasive breast cancer by level of breast density and age. This study found that breast density was associated with increased breast cancer risk among women aged 65 to 74 years regardless of their body mass index (BMI). In addition, women aged 75 or older had increased risk of breast cancer with increasing breast density only if they have a BMI > 25. There was no interaction between BMI and breast density in either age group.
This study finds a positive association between breast density and breast cancer risk for women aged 75 years or older. Based on this data, it is suggested that women discuss breast density and life expectancy when discussing the need to continue with potential benefits mammography beyond age 75, weighing risks and benefits. The decision as to when to stop screening mammography is a very personalized decision between women and their providers. Factors to be considered are age, comorbidities, life expectancy, risk of breast cancer and breast density.