Many women will have an abnormal mammogram if they do regular screening exams.
The probability of having a normal result if a woman decides to mammography screening depends on the age of the patient.
If a woman of 40 years is detected every year for 10 years, the probability of having a normal result is 30%, or one in three.
If a woman of 50 years or 60 years is screened every year for 10 years, the probability of having a normal result is 25%, or one in four.
Among women who have an abnormal result, the majority does not have breast cancer. All patients with an abnormal result, must undergo further testing to determine whether they have cancer or not.
References:
Kerlikowske K, J. Barclay Outcomes of modern screening mammography. Monogr Natl Cancer Inst 1997; 22:105-111
Elmore JG, Barton MB, Moceri VM, Polk S, Arena PH, Fletcher SW. Ten-year risk of false-positive screenning mammograms and clinical breast examinations. NEJM 1998; 338:1089-1096.
C. Christiansen, Wang F, Barton MB, W. Kreuter, Elmore JG, Gelfand AE, Fletcher SW. Predicting the risk of cumulative false-positive mammograms. J Natl Cancer Inst. 2000; 92:1657-66.
