Mammography screening is less accurate in women who have already had breast cancer compared with other women, according to the results of a recent study.
Women with prior breast cancer are at high risk for developing the disease again, and are advised to have screening mammograms. To examine the accuracy and outcomes of this testing in such patients, researchers used Breast Cancer Surveillance Consortium data to evaluate 58,870 screening mammograms from 19,078 women with a history of early-stage (in situ or stage I-II invasive) breast cancer and 58,870 screening mammograms from 55,315 women without a personal history of breast cancer.
Cancer rates measured 10.5 per 1,000 screenings in women who had had breast cancer, compared with 5.8/1,000 in the other group. Rates of cancer, cancer detection, and interval cancer (the number of false-negative results among 1,000 mammograms) were 1.3 to 2.6 times higher for prior-cancer screens than for matched screens.
Screening sensitivity was lower in the women with prior breast cancer (65.4% vs. 76.5%), particularly for detection of invasive cancer. Sensitivity in the initial five years from first cancer was lower than sensitivity after five years. Specificity of screening also was lower among women with prior cancer: 98.3% vs. 99.0%.
The authors noted that based on these findings, a more tailored screening strategy than currently recommended might be warranted for women with prior breast cancer (JAMA. 2011;305:790-799).