Prospective Evaluation of Contrast-enhanced Mammography for Early Prediction of Pathologic Response after Neoadjuvant Therapy

Purpose To assess whether changes in contrast-enhanced mammography (CEM)-derived lesion measurements after the first cycle of neoadjuvant therapy (NAT) can predict pathologic complete response (pCR) in individuals with breast cancer. Materials and Methods This prospective single-center pilot study enrolled consecutive participants with breast cancer treated with NAT who underwent CEM at baseline (May 2018 to December 2018). CEM was performed before and after the first cycle of NAT. Two breast radiologists independently evaluated the percentage change in the longest dimension of the lesion (CLD) and Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 criteria at CEM. Multivariable logistic regression was used to identify independent predictors of pCR, and predictive performance was assessed using area under the receiver operating characteristic curve (AUC). Results Thirty-six participants (mean age ± SD, 48 years ± 10.3) were included; 11 (30.5%) participants achieved pCR. A CLD of at least 20.93% independently predicted pCR (odds ratio, 9.52; 95% CI: 1.34, 67.23; <i>P</i> = .02), achieving a sensitivity of 73% (eight of 11) and a specificity of 88% (22 of 25). Response according to RECIST 1.1 criteria was not associated with pCR (odds ratio, 3.22; 95% CI: 0.46, 22.53; <i>P</i> = .24). In participants with hormone-receptor negative breast cancer, a CLD of at least 20.93% was associated with a higher likelihood of pCR (odds ratio, 40.00; 95% CI: 2.01, 794.27; <i>P</i> = .005) and had an AUC of 0.86 (95% CI: 0.65, >0.99; <i>P</i> = .005). Conclusion CLD at CEM after the first cycle of NAT may be an early predictor of pCR in individuals with breast cancer. <b>Keywords:</b> Breast, Tumor Response, Mammography, Oncology, Neoadjuvant Therapy, Radiographic Image Enhancement, Pathologic Complete Response, Breast Tumor <i>Supplemental material is available for this article.</i> © RSNA, 2025.