Is Repetition Of The Contralateral Mammogram Of Patients Referred From Breast Cancer Screening For Unilateral Findings Necessary?

Abstract Introduction - The Netherlands started a nationwide breast cancer screening program in 1989, including women from the age of 50 until 75. Screening mammograms are performed two yearly in a mobile unit and consist of a bilateral two-view mammogram of the breast (mediolateral oblique and craniocaudal views). If indicated, patients are referred to a breast clinic for diagnostic analysis. This work-up consist of among others repeating the bilateral two-view mammogram. Since the screening is digitalized, repeating of at least the mammogram of the non suspicious side might be unnecessary. The aim of this study is to determine the additional value of repeating the contralateral mammogram in patients referred for a suspicious unilateral lesion. Material and methods – 395 patients were referred from breast screening program to our institution for unilateral findings between October 2009 and August 2011. In all patients a bilateral mammogram was repeated and analyzed by an experienced breast radiologist. In the case of breast cancer a breast magnetic resonance imaging (MRI) was performed for preoperative staging. Anonymised data concerning the date of registration of the screening mammogram, the referred side (left/right or bilateral), age, screening's BI-RADS classification, breast density, biopsy results and breast MRI results were collected. Results - Of the 395 patients referred for a suspicious unilateral finding, a malignancy on the referred side was observed in 144 patients (36.5%). In five patients bilateral breast cancer was detected. In one patient no malignancy was detected on the referred side, though on the contralateral side. Three of these six contralateral malignancies were directly mammographically detected. All six malignancies were detected with preoperative breast MRI. Conclusion - Repetition of the two-view mammogram of the contralateral side in patients referred with a unilateral suspicious finding seems unnecessary, since all contralateral malignancies were depicted on the preoperative staging breast MRI recommended according to the EUSOBI-guidelines. Omission of the contralateral mammogram could lead to reduction of associated health care costs, radiation exposure, and patient discomfort caused by the exam. Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P3-02-08.