Accuracy of clinical evaluation of locally advanced breast cancer in patients receiving neoadjuvant chemotherapy.

Background: Physical examination (PE), mammography (MG), breast magnetic resonance imaging (MRI), fluorodeoxyglucose positron emission tomography (PET), and pathologic evaluation are used to assess primary breast cancer. To the authors' knowledge, their accuracy has not been well studied in patients receiving neoadjuvant chemotherapy. Accuracies of each modality in tumor and lymph node assessment in patients with T3/T4 tumors receiving neoadjuvant chemotherapy were compared.

Methods: Forty-five patients of a prospective clinical trial studying T3-T4M0 tumors were included. Patients received neoadjuvant chemotherapy: docetaxel/carboplatin with or without trastuzumab before and/or after surgery (depending on HER-2/neu status and randomization). Tumor measurements by PE, MG, and MRI and lymph node status by PE and PET were obtained before and after neoadjuvant chemotherapy. Concordance among different clinical measurements was assessed and compared with the tumor and lymph node staging by pathology. Spearman correlation (r) and root mean square error (RMSE) were used to measure the accuracy of measurements among all modalities and between modalities and pathologic tumor size.

Results: Compared with the tumor size measured by PE, MRI was more accurate than MG at baseline (r=0.559, RMSE=35.4% vs r=0.046, RMSE=66.1%). After neoadjuvant chemotherapy, PE correlated better with pathology than MG or MRI (r=0.655, RMSE=88.6% vs r=0.146, RMSE=147.1% and r=0.364, RMSE=92.6%). Axillary lymph node assessment after neoadjuvant chemotherapy demonstrated high specificity but low sensitivity by PET and PE.

Conclusions: Findings suggested that MRI was a more accurate imaging study at baseline for T3/T4 tumor, and PE correlated best with pathology finding. PET and PE both correctly predicted positive axillary lymph nodes but not negative lymph nodes.