Calcium Specks on Mammograms
Most women associate mammograms with screening for tumors or other abnormal masses (such as cysts) in the breast. These can be benign (noncancerous) or malignant (cancerous). If a mass is suspicious on a mammogram, the doctor will further evaluate it using breast ultrasound or a biopsy technique to remove some tissue for examination under a microscope.
However, small white specks called calcifications can also appear on mammogram films. Calcifications are tiny mineral deposits within the breast tissue or breast arteries. They are usually benign, but a number of recent studies are focusing on these calcifications as indicators of not only cancer, but also of a higher risk for heart disease.
Calcifications appear as white specks on mammograms. They are divided into two categories: macrocalcifications and microcalcifications.
Macrocalcifications are coarse and somewhat larger calcium deposits that most likely represent changes in the breast due to aging of the breast arteries, old injuries, or inflammations. These deposits are associated with benign (noncancerous) conditions and do not require a biopsy. Macrocalcifications are found in about 50 percent of women over the age of 50, and in about 10 percent of women under the age of 50.
Microcalcifications are tiny (less than 1/50 of an inch) specks of calcium in the breast. The shape and arrangement of these microcalcifications help the radiologist judge the likelihood of cancer being present.
According to a study presented at the recent International Congress on Anti-Aging and Biomedical Technologies, calcium deposits that appear in arteries in the breast—called breast arterial calcifications or BACs—can be directly linked to the likelihood of additional calcium deposits in coronary (heart) arteries. This could serve as an important early warning sign for heart disease.
Dr. Marion Jabczenski of the Breast Evaluation Center in Phoenix, Arizona studied mammograms from 40 patients that showed breast artery calcifications. He wanted to see if additional calcifications would also be present in the patients’ coronary arteries. (In patients aged 50 and older, 49 percent had breast artery calcifications that were visible on mammograms.)
Using electron beam computed tomography, Jabczenski found "a positive correlation" between calcifications in breast arteries and also in coronary arteries. "The more calcification in the breast, the more in the heart," he noted. Importantly, most of these patients did not have any apparent symptoms for heart disease. Therefore, the information gleaned from studying the calcium specks on their mammograms provided a crucial early warning.
In those patients who had known heart disease, Jabczenski also found a correlation between breast artery calcifications and elevated lipid (fat) levels—a further risk factor for heart disease.
Jabczenski’s study builds on earlier research that also linked the presence of calcifications in breast arteries with coronary heart disease. For example, a 1998 Dutch study of 12,200 women aged 50 to 68 found that the presence of calcifications in breast arteries was an independent risk factor for cardiovascular death, particularly in diabetic women.
Writing in the American Journal of Epidemiology, Jeanet M. Kenmeren of the Utrecht University in Utrecht, the Netherlands, suggested that mammograms may therefore provide important information that clinicians can use to predict cardiovascular disease.
"This would open the possibility that mammograms might also contribute to an earlier detection of vascular damage, thus allowing for secondary prevention of vascular-related disease, particularly when detected in women with diabetes," she wrote. She added that previous studies have shown that women with calcifications in their breast arteries are more likely to also have hypertension or diabetes.
Dr. Beverly Hashimoto of the Virginia Mason Medical Center in Seattle wanted to see if ultrasonography could be used to help determine whether calcifications found on a mammogram were indicative of cancer. Ultrasonography uses high-frequency sound waves to evaluate suspicious masses.
In a presentation at the Scientific Assembly and Annual Meeting of the Radiological Society of North America, Hashimoto reported on her study of 200 abnormal mammograms, 86 of which revealed clusters of calcifications visible on the mammogram but with no accompanying tumors.
Ultrasonography was able to detect 58 of these 86 calcifications (67 percent) as well as malignant (cancerous) calcifications in 20 of the 24 women in whom a subsequent biopsy confirmed breast cancer. Importantly, ultrasonography detected 12 cancerous masses associated with calcifications that were not found on the initial mammogram.
In a similar study, Dr. Wendie Berg of the University of Maryland in Baltimore used a technique called stereotactic biopsy to evaluate "amorphous" breast calcifications (those having no apparent shape or form).
A stereotactic biopsy uses a mammogram and a computer to guide a needle into a lump or area of abnormal tissue that has been detected by a mammogram. The procedure is performed by using a stereotactic biopsy machine.
In a presentation at the Annual Meeting of the American Roentgen Ray Society, Berg said she used the stereotactic biopsy technique for 113 women whose mammograms showed such clustered amorphous calcifications. The areas of calcification were generally subtle, powdery calcifications that might not have been seen with older equipment, Berg said. Their size ranged from 2 mm to 70 mm in size.
Overall, 30 stereotactic biopsies of these amorphous calcifications indicated the presence of cancer, and 30 others gave high-risk diagnoses. Furthermore, the technique detected cancers in 17 percent of the women who otherwise had no identifiable risk factor.
Berg also found that as many as two-thirds of those women with a family history of breast cancer, precancerous conditions, or who had breast cancer previously, also had amorphous calcifications that were associated with malignancy.
New studies such as these mentioned above are proving that a closer look at breast calcifications may provide an important early warning—not only for cancer but also for heart disease. However, the fact remains that the vast majority of calcium specks that appear on mammograms are benign (noncancerous).
The American Cancer Society (www.cancer.org)
Eighth International Congress on Anti-Aging and Biomedical Technologies, December 18, 2000, Las Vegas, Nevada
American Journal of Epidemiology, 1998; 147:333-41)
100th Annual Meeting of the American Roentgen Ray Society, May 10, 2000, Washington, DC
The Susan G. Komen Breast Cancer Foundation (www.komen.org)
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