Impact of tomosynthesis on the evolution of the cancer detection rate in the French National Breast Cancer Screening Program

Abstract

Objectives: This study aims to evaluate the cancer detection rate in French National Breast Cancer Screening Program, especially the cancer detection rate during second reading session (Reading 2) based on digital technologies used in radiology centres.

Study design: This was an analytical and descriptive study.

Methods: Cancer detection rate was estimated by the ratio between the number of cancers detected and the number of women screened. The positive predictive value (PPV) was estimated as cancer detection rate among abnormal Reading 2. The relationship between Reading 2's PPV and the predictive factors was evaluated using multilevel mixed-effects logistic regression.

Results: A total of 1,380,006 digital mammograms were retained in the analysis between 2010 and 2019. Cancer detection rate represented 7.8‰ at first reading session (Reading 1) and 0.5‰ at Reading 2. Cancer detection rate is significantly associated with the use of tomosynthesis (P < 0.001) at Reading 1, and differences appear within different tomosynthesis brands (P = 0.007). Reading 2's PPV differs significantly according on technologies used by first Reader (P < 0.004). Nevertheless, Reading 2 has 1.9 (1.5-2.4) more likely to predict a cancer with the presence of previous mammogram compared with those without previous images.

Conclusion: Using tomosynthesis technology improves cancer detection rate at Reading 1, even if differences are noticeable between brands. Using tomosynthesis technology at Reading 1 reduces Reading 2's PPV and cancer detection rate at Reading 2.

Keywords: Breast cancer screening; Digital breast tomosynthesis; Mammogram double reading; Population screening.