The Use of Contrast-Enhanced Computed Tomography Before Neoadjuvant Chemotherapy to Identify Patients Likely to Be Treated Safely With Breast-Conserving Surgery

A large randomized clinical trial confirmed the efficacy of neoadjuvant chemotherapy (NAC) in downstaging breast carcinomas and permitting the increased use of breast-conserving treatment (BCT), although no survival advantage was demonstrated.1 The response rates of patients to NAC are generally high, ranging from 70 to 90%. Some patients, however, do not derive any benefit from NAC, and it would be advantageous to identify these patients before initiating NAC. In patients who were initially candidates for mastectomy but underwent BCT after NAC-mediated tumor downstaging, the incidence of ipsilateral breast tumor recurrence (IBTR) (14.5%) increased in comparison to patients undergoing BCT as initially planned (6.9%) (P = 0.04).1 This may be due to the wide mosaic satellites of residual viable tumor cells in the original tumor-bearing area, despite tumor downstaging following NAC administration.2,3 The reduction of a tumor into either a concentric circle or a wide mosaic-like pattern may be a critical factor for determining the suitability of BCT.4 The relationship between predictors of tumor shrinkage patterns and suitability of BCT has not been previously examined. Nakamura et al, however, reported in a small number of patients that papillotubular, estrogen receptor-positive, low nuclear grade, and negative c-erbB 2 tumors had a tendency to show mosaic-like patterns of residual tumor cells.6 The morphologic tumor type prior to NAC may be a strong predictor of tumor shrinkage pattern and suitability of BCT. In this study, we investigated whether classifying tumors into diffuse or localized types, through the use of diagnostic imaging, can predict the safety of BCT and the response to NAC.