Factors affecting mammogram breast cancer surveillance effectiveness in the ipsilateral and contralateral breast

Aim: Mammography is the mainstay of imaging surveillance after breast cancer (BC) treatment, but false negatives can occur. The objective of the study was to determine the factors that can predict poorer second breast cancer (SBC) mammogram detection of the ipsilateral and contralateral breast separately. Methods: A multicentre retrospective review was performed on female patients with a previous history of treated BC who developed a second breast cancer (SBC) in the ipsilateral (ISBC) or contralateral breast (CSBC) within 10 years from the first BC. SBC cases that occurred between January 2006 and October 2017 were included from the institutional database. The ISBC and CSBC mammogram-occult (MO) rates were correlated with mammographic breast density as well as various clinical, radiological and histological characteristics of the first BC. Results: 274 cases of SBC were evaluated. 39.4 % (108/274) of cases were ISBC and 60.6 % (166/274) were CSBC. 35 (32.4 %) of the ISBCs and 42 (25.3 %) of the CSBCs were MO (p = 0.218). On multivariate analysis, symptomatic first BC (p = 0.041), prevailing dense breast tissue at the time of SBC diagnosis (p = 0.003) and trabecular thickening on surveillance mammograms (p = 0.017) were associated with MO ISBC. MO first BC (p < 0.001) was the only factor found to correlate with MO CSBC. Conclusion: The study found various clinical, radiological and pathological factors associated with mammogram surveillance failure for the ipsilateral and contralateral breast. This information can provide additional guidance in the planning of a personalised surveillance program using adjunct imaging screening.