Comparison of mammography results from individual and organized screening for breast cancer

In France, the coexistence of individual screening (IS) and organized screening (OS) for breast cancer induces difficulties for primary care practitioners to position themselves. This study assessed whether the risk of having a mammography with a high risk of malignancy (BI-RADS 4 or 5) was different between patients aged from 50 to 74year performing it as part of an IS or of the OS.

This cross-sectional multicenter study included women aged 50-74, with no personal history of breast cancer, performing mammography in radiology centers in Paris (France). The nature of the screening (OS or IS), breast cancer risk (high risk: BI-RADS 4 or 5), risk factors and clinical breast examination (CBE) abnormalities were collected. Patients in the IS and OS group were matched on age, breast density, history of benign lesions and family history of breast cancer using a propensity score. The association between the nature of screening and the risk of malignancy was evaluated by conditional logistic regression.

Among 2190 included patients, 77 % performed a mammography with the IS and had more CBE abnormalities (23 % vs 11 %, p<0,001), a history of benign lesion (15 % vs 11 %, p=0.01) and a family history of breast cancer (42 % vs 29 %, p<0,001). After matching 503 OS patients with 941 IS patients, the risk of malignancy and the nature of the screening were not associated (OR=0.72 [0.35-1.47], p=0.50).

The risk of malignancy was not different whether the mammography was performed as part of the OS or IS.