Nonpalpable breast lesions: impact of a second-opinion review at a breast unit on BI-RADS classification.

Objective: To compare BI-RADS classification, management, and outcome of nonpalpable breast lesions assessed both by community practices and by a multidisciplinary tumor board (MTB) at a breast unit.

Methods: All nonpalpable lesions that were first assigned a BI-RADS score by community practices and then reassessed by an MTB at a single breast unit from 2009 to 2017 were retrospectively reviewed. Inter-review agreement was assessed with Cohen's kappa statistic. Changes in biopsy recommendation were calculated. The percentage of additional tumor lesions detected by the MTB was obtained. The sensitivity, AUC, and cancer rates for BI-RADS category 3, 4, and 5 lesions were computed for both reviews.

Results: A total of 1909 nonpalpable lesions in 1732 patients were included. For BI-RADS scores in the whole cohort, a fair agreement was found (κ = 0.40 [0.36-0.45]) between the two reviews. Agreement was higher when considering only mammography combined with ultrasound (κ = 0.53 [0.44-0.62]), masses (κ = 0.50 [0.44-0.56]), and architectural distortion (κ = 0.44 [0.11-0.78]). Changes in biopsy recommendation occurred in 589 cases (31%). Ninety of 345 additional biopsies revealed high-risk or malignant lesions. Overall, the MTB identified 27% additional high-risk and malignant lesions compared to community practices. The BI-RADS classification AUCs for detecting malignant lesions were 0.66 (0.63-0.69) for community practices and 0.76 (0.75-0.78) for the MTB (p < 0.001).

Conclusion: Agreement between community practices and MTB reviews for BI-RADS classification in nonpalpable lesions is only fair. MTB review improves diagnostic performances of breast imaging and patient management.

Key Points: • The inter-review agreement for BI-RADS classification between community practices and the multidisciplinary board was only fair (κ = 0.40). • Disagreements resulted in changes of biopsy recommendation in 31% of the lesions. • The multidisciplinary board identified 27% additional high-risk and malignant lesions compared to community practices.