Development and validation of ultrasound-based radiomics model to predict germline BRCA mutations in patients with breast cancer

Background Identifying breast cancer (BC) patients with germline breast cancer susceptibility gene (g BRCA ) mutation is important. The current criteria for germline testing for BC remain controversial. This study aimed to develop a nomogram incorporating ultrasound radiomic features and clinicopathological factors to predict g BRCA mutations in patients with BC. Materials and methods In this retrospective study, 497 women with BC who underwent g BRCA genetic testing from March 2013 to May 2022 were included, including 348 for training (84 with and 264 without a g BRCA mutation) and 149 for validation(36 patients with and 113 without a g BRCA mutation). Factors associated with g BRCA mutations were identified to establish a clinicopathological model. Radiomics features were extracted from the intratumoral and peritumoral regions (3 mm and 5 mm) of each image. The least absolute shrinkage and selection operator regression algorithm was used to select the features and logistic regression analysis was used to construct three imaging models. Finally, a nomogram that combined clinicopathological and radiomics features was developed. The models were evaluated based on the area under the receiver operating characteristic curve (AUC), calibration, and clinical usefulness. Results Age at diagnosis, family history of BC, personal history of other BRCA -related cancers, and human epidermal growth factor receptor 2 status were independent predictors of the clinicopathological model. The AUC of the imaging radiomics model combining intratumoral and peritumoral 3 mm areas in the validation set was 0.783 (95% confidence interval [CI]: 0.702—0.862), which showed the best performance among three imaging models. The nomogram yielded better performance than the clinicopathological model in validation sets (AUC: 0.824 [0.755—0.894] versus 0.659 [0.563—0.755], p = 0.007). Conclusion The nomogram based on ultrasound images and clinicopathological factors performs well in predicting g BRCA mutations in BC patients and may help to improve clinical decisions about genetic testing.