Are there any potential risks to having a screening mammogram? (Part 3)

Yes, you should know about some possible problems with having routine mammograms.

3. Of women that have abnormal mammogram results, most do not have breast cancer.

Most of the time when a mammogram result is abnormal, there is no breast cancer. About 1 in 20 women who have mammograms are found to have some abnormality that needs further diagnostic tests.

Of 100 women under age 50 who have an abnormal mammogram result, about 3 turn out to have invasive breast cancer. The other 97 who had an abnormal mammogram result do not have breast cancer. This means that most women under age 50 who have an abnormal mammogram result do not have breast cancer.

Of 100 women age 50 and older who have an abnormal mammogram result, about 14 turn out to have invasive breast cancer. This means that most women over age 50 who have an abnormal mammogram result do not have breast cancer. However, because breast cancer is more common in older women, women with an abnormal mammogram result who are age 50 and older have a greater chance of having breast cancer than women under age 50.

References:
Kerlikowske K, Barclay J. Outcomes of modern screening mammography. Monogr Natl Cancer Inst 1997;22:105-111
Kerlikowske K, Grady D, Barclay J, Sickles EA, Eaton A, Ernster V. Positive predictive value of screening mammography by age and family history of breast cancer. JAMA 1993;270:2444-2450.
Brown ML, Hown F, Sickles EA, Kessler LG. Screening mammography in community practice: positive predictive value of abnormal findings and yield of follow-up diagnostic procedures. Am J Roentgenol 1995;273:1373-1377.
May DS, Lee NC, Nadel MR, Henson RM, Miller DS. The National Breast and Cervical Cancer Early Detection Program: report on the first 4 years of mammography provided to medically underserved women. Am J Roentgenol. 1998;170:97-104