Women with dense breasts have a significantly increased risk of breast cancer. Is the yearly mammogram often enough for adequate for tumor detection?
Because dense tissue increases the risk of breast cancer, one may wonder if a woman with dense breasts should have mammograms more often than women without this feature.
“Annual mammogram starting at the age of 40 saves the most lives and is appropriate for women of all breast densities,” says Anjali Malik, MD, a board certified diagnostic radiologist with Washington Radiology in Washington, DC. She interprets mammograms, breast MRIs and ultrasounds, and performs biopsies.
“Breast tomosynthesis [3D mammogram] has improved the detection of small, invasive breast cancers and decreased the ‘false positive’ call-backs,” continues Dr. Malik.
A report in JAMA Internal Medicine (March 2013) says that a study involving over 900,000 women concludes that mammograms once every two years are just as beneficial as annual screenings—even for patients with dense breasts.
The every-two-year screening results in fewer false positives, meaning, fewer indications of malignancy that turn out to be benign.
The researchers (UC San Francisco and Seattle-based Group Health Research Institute) say these recommendations apply to women 50 to 74.
Dr. Malik explains, “In 2013 (the time of the JAMA report), breast tomosynthesis (3D mammography) was not in routine use.
“The 2013 JAMA report was based on 2D analog mammography and prospective data from 1994-2008.
“Currently, 3D digital mammography is in use, and most centers use fellowship trained breast imaging radiologists, where this was not as widespread in the ‘90s and early 2000s. Therefore, this data is near obsolete in 2019.”
What about women in their 40s with dense breasts?
“For women, particularly for those women ages 40-49, who are also more likely to have dense breast parenchyma, nine per 10,000 breast cancer deaths are prevented by annual screening mammograms,” says Dr. Malik.
This data comes from a study by Nelson et al (Annals of Internal Medicine, 164(4):244-55, 2016).
A woman with dense breasts may wonder if more of an important screening tool means better: twice a year mammograms, whether they’re 3D or 2D.
But here’s the problem (other than the extra radiation exposure): Biannual screening increases the call-back rate and the rate of false positives.
This creates tremendous anxiety and sometimes unnecessary biopsies.
Though biannual screening via mammogram has been shown by limited research to result in more cancers detected, it has not been shown to increase survival rates.
Women with dense breasts (as determined mammographically) should ask their doctor about annual 3D mammograms supplemented with annual ultrasounds.