Magnetic resonance imaging in comparison to clinical palpation in assessing the response of breast cancer to epirubicin primary chemotherapy.

PURPOSE: To investigate whether magnetic resonance imaging (MRI) is superior to clinical palpation in the assessment of response of breast cancer to primary chemotherapy (PC). PATIENTS AND METHODS: Seventy-three patients with T2-4, N0, M0 breast cancer were treated with 3-4 cycles of single agent epirubicin before definitive surgery. MRI was performed at baseline condition and at the end of chemotherapy. RESULTS: According to the WHO criteria, 20 (27.4%) patients attained a complete response (CR) by clinical palpation and 41 (56.2%) a partial response. The corresponding response rate by MRI was 11 (15.1%) and 34 (46.6%), respectively. Residual tumor assessed by MRI better correlated with pathologic measurements (Spearman r : 0.72) than residual tumor assessed by clinical palpation (Spearman r : 0.58). Post-chemotherapy histology evaluation revealed pathologic CR in three cases, only one of them was considered as complete responder by MRI. Residual disease consisted in in situ carcinoma in four cases, one of them was complete responder at MRI, the remaining three showed residual abnormal contrast enhancement indistinguishable from that of invasive tumors. CONCLUSIONS: As compared to pathology specimens, MRI is able to represent the extent of cancer more accurately than clinical palpation. It constitutes a promising technique in assessing the BC response to PC. The current limit of MRI is the scarce specificity in predicting the nature of residual disease.