Potential Antihuman Epidermal Growth Factor Receptor 2 Target Therapy Beneficiaries: The Role of MRI‐Based Radiomics in Distinguishing Human Epidermal Growth Factor Receptor 2‐Low Status of Breast Cancer

Abstract

BackgroundMultiparametric MRI radiomics could distinguish human epidermal growth factor receptor 2 (HER2)‐positive from HER2‐negative breast cancers. However, its value for further distinguishing HER2‐low from HER2‐negative breast cancers has not been investigated.PurposeTo investigate whether multiparametric MRI‐based radiomics can distinguish HER2‐positive from HER2‐negative breast cancers (task 1) and HER2‐low from HER2‐negative breast cancers (task 2).Study TypeRetrospective.PopulationTask 1: 310 operable breast cancer patients from center 1 (97 HER2‐positive and 213 HER2‐negative); task 2: 213 HER2‐negative patients (108 HER2‐low and 105 HER2‐zero); 59 patients from center 2 (16 HER2‐positive, 27 HER2‐low and 16 HER2‐zero) for external validation.Field Strength/SequenceA 3.0 T/T1‐weighted contrast‐enhanced imaging (T1CE), diffusion‐weighted imaging (DWI)‐derived apparent diffusion coefficient (ADC).AssessmentPatients in center 1 were assigned to a training and internal validation cohort at a 2:1 ratio. Intratumoral and peritumoral features were extracted from T1CE and ADC. After dimensionality reduction, the radiomics signatures (RS) of two tasks were developed using features from T1CE (RS‐T1CE), ADC (RS‐ADC) alone and T1CE + ADC combination (RS‐Com).Statistical TestsMann–Whitney U tests, the least absolute shrinkage and selection operator, receiver operating characteristic (ROC) curve, calibration curve, and decision curve analysis (DCA).ResultsFor task 1, RS‐ADC yielded higher area under the ROC curve (AUC) in the training, internal, and external validation of 0.767/0.725/0.746 than RS‐T1CE (AUC = 0.733/0.674/0.641). For task 2, RS‐T1CE yielded higher AUC of 0.765/0.755/0.678 than RS‐ADC (AUC = 0.706/0.608/0.630). For both of task 1 and task 2, RS‐Com achieved the best performance with AUC of 0.793/0.778/0.760 and 0.820/0.776/0.711, respectively, and obtained higher clinical benefit in DCA compared with RS‐T1CE and RS‐ADC. The calibration curves of all RS demonstrated a good fitness.Data ConclusionMultiparametric MRI radiomics could noninvasively and robustly distinguish HER2‐positive from HER2‐negative breast cancers and further distinguish HER2‐low from HER2‐negative breast cancers.Evidence Level3.Technical EfficacyStage 2.