Yes. Mammography is the first step in screening for most women. While additional screening may be recommended for women with dense breasts and/or high risk for developing breast cancer, there are still some cancers and precancerous changes that will show on a mammogram better than on ultrasound or MRI. Whenever possible, women with dense breasts should have digital mammography rather than film mammography, and preferably with DBT (tomosynthesis) due to slightly improved cancer detection using digital mammography . About half of cancers seen on mammography have calcifications (white dots like salt crystals), and calcifications can be seen even in dense areas of the breast (Figure below). It is important to know that at least a few calcifications can be seen in nearly all breasts and that the vast majority of calcifications seen on a mammogram are not due to cancer. Some calcifications require special magnification mammography views to be adequately evaluated. A biopsy may be recommended for calcifications which are new or increasing and have a concerning appearance on magnification views. Even when a biopsy is recommended for calcifications, only about 1 in 4 or 5 are shown to be due to cancer. When there are no calcifications, some masses due to cancer can be seen in dense breasts because they distort (pucker) the tissue around them. Some masses due to cancer are seen in dense breasts because at least a portion of the mass is in an area where the breast is more fatty.
Women who are pregnant may want to defer screening mammography until after the pregnancy. (For women who are pregnant with a lump or other breast problem, diagnostic ultrasound is performed first, and mammography can be used safely and effectively performed if needed with abdominal shield protection.) For women who are breastfeeding, if they will only be nursing for a short time (3-5 months), they might defer screening mammography until 2-3 months after the baby is weaned. For those planning on breastfeeding 6 months or longer, mammography screening can be performed while nursing but probably best to schedule it after the first 3 months when the breasts are less likely to be engorged. Patients who are breastfeeding will almost certainly have dense breasts during that time.
Mammography Shows Some Early Breast Cancers Not Seen on Ultrasound. Magnification of mammographic images of heterogeneously dense breasts show new grouped calcifications (white specks like salt crystals within yellow circles). These are difficult or impossible to see with ultrasound. Most calcifications seen on mammograms are not due to cancer; however, biopsy showed these to be due to ductal carcinoma in situ (DCIS), a noninvasive cancerous change which, if left untreated, can progress to invasive breast cancer.
1. Pisano ED, Gatsonis C, Hendrick E, et al. Diagnostic performance of digital versus film mammography for breast-cancer screening. N Engl J Med 2005; 353:1773-1783