False-Negative Rates of Breast Cancer Screening with and without Digital Breast Tomosynthesis.

Background Screening with digital breast tomosynthesis (DBT) improves breast cancer detection and recall rates compared with those obtained with digital mammography (DM); however, the impact of DBT on patient survival has not been established. False-negative (FN) screening examinations can be a surrogate for long-term outcomes, such as breast cancer morbidity and mortality. Purpose To determine if screening with DBT is associated with lower FN rates, detection of cancers with more favorable prognoses, and improved performance outcomes versus DM. Materials and Methods This retrospective study involved 10 academic and community practices. DM screening examinations 1 year prior to DBT implementation and DBT screening examinations from the start date until June 30, 2013, were linked to cancers through June 30, 2014, with data collection in 2016 and analysis in 2018-2019. Cancers after FN examinations were characterized by presentation, either symptomatic or asymptomatic. FN rates, sensitivity, specificity, cancer detection and recall rates, positive predictive values, tumor size, histologic features, and receptor profile were compared. Results A total of 380 641 screening examinations were included. There were 183 989 DBT and 196 652 DM examinations. With DBT, rates trended lower for overall FN examinations (DBT, 0.6 per 1000 screens; DM, 0.7 per 1000 screens; P = .20) and symptomatic FN examinations (DBT, 0.4 per 1000 screens; DM, 0.5 per 1000 screens; P = .21). Asymptomatic FN rates trended higher in women with dense breasts (DBT, 0.14 per 1000 screens; DM: 0.07 per 1000 screens; P = .07). With DBT, improved sensitivity (DBT, 89.8% [966 of 1076 cancers]; DM, 85.6% [789 of 922 cancers]; P = .004) and specificity (DBT, 90.7% [165 830 of 182 913 examinations]; DM, 89.1% [174 480 of 195 730 examinations]; P < .001) were observed. Overall, cancers identified with DBT were more frequently invasive (P < .001), had fewer positive lymph nodes (P = .04) and distant metastases (P = .01), and had lower odds of an FN finding of advanced cancer (odds ratio, 0.9 [95% CI: 0.5, 1.5]). Conclusion Screening with digital breast tomosynthesis improves sensitivity and specificity and reveals more invasive cancers with fewer nodal or distant metastases. © RSNA, 2020 Online supplemental material is available for this article. See also the editorial by Schattner in this issue.

Validation of the breast cancer surveillance consortium model of breast cancer risk.

PURPOSE: In order to use a breast cancer prediction model in clinical practice to guide screening and prevention, it must be well calibrated and validated in samples independent from the one used for development. We assessed the accuracy of the breast cancer surveillance consortium (BCSC) model in a racially diverse population followed for up to 10 years. METHODS: The BCSC model combines breast density with other risk factors to estimate a woman's 5- and 10-year risk of invasive breast cancer. We validated the model in an independent cohort of 252,997 women in the Chicago area. We evaluated calibration using the ratio of expected to observed (E/O) invasive breast cancers in the cohort and discrimination using the area under the receiver operating characteristic curve (AUROC). RESULTS: In an independent cohort of 252,997 women (median age 50 years, 26% non-Hispanic Black), the BCSC model was well calibrated (E/O = 0.94, 95% confidence interval [CI] 0.90-0.98), but underestimated the incidence of invasive breast cancer in younger women and in women with low mammographic density. The AUROC was 0.633, similar to that observed in prior validation studies. CONCLUSIONS: The BCSC model is a well-validated risk assessment tool for breast cancer that may be particularly useful when assessing the utility of supplemental screening in women with dense breasts.

Impact of a False-Positive Screening Mammogram on Subsequent Screening Behavior and Stage at Breast Cancer Diagnosis.

Background: Experiencing a false positive (FP) screening mammogram is economically, physically, and emotionally burdensome, which may affect future screening behavior by delaying the next scheduled mammogram or by avoiding screening altogether. We sought to examine the impact of a FP screening mammogram on the subsequent screening mammography behavior.Methods: Delay in obtaining subsequent screening was defined as any mammogram performed more than 12 months from index mammogram. The Kaplan-Meier (product limit) estimator and Cox proportional hazards model were used to estimate the unadjusted delay and the hazard ratio (HR) of delay of the subsequent screening mammogram within the next 36 months from the index mammogram date.Results: A total of 650,232 true negative (TN) and 90,918 FP mammograms from 261,767 women were included. The likelihood of a subsequent mammogram was higher in women experiencing a TN result than women experiencing a FP result (85.0% vs. 77.9%, P < 0.001). The median delay in returning to screening was higher for FP versus TN (13 months vs. 3 months, P < 0.001). Women with TN result were 36% more likely to return to screening in the next 36 months compared with women with a FP result HR = 1.36 (95% CI, 1.35-1.37). Experiencing a FP mammogram increases the risk of late stage at diagnosis compared with prior TN mammogram (P < 0.001).Conclusions: Women with a FP mammogram were more likely to delay their subsequent screening compared with women with a TN mammogram.Impact: A prior FP experience may subsequently increase the 4-year cumulative risk of late stage at diagnosis. Cancer Epidemiol Biomarkers Prev; 26(3); 397-403. ©2017 AACR.