Fatima Jimenez Aragon, Presenter: Nothing to Disclose

Celia Bernal Lafuente MD, Abstract Co-Author: Nothing to Disclose

Carmen Garcia Mur, Abstract Co-Author: Nothing to Disclose

Margarita Beltrán Marín, Abstract Co-Author: Nothing to Disclose

Ricardo Gómez-Pereda, Abstract Co-Author: Nothing to Disclose

Luis Martinez Comín, Abstract Co-Author: Nothing to Disclose

To analyze the role of Magnetic Resonance Imaging (MRI) predicting response to neoadjuvant chemotherapy (NAC) in the three molecular subtypes of breast cancer (BC): Luminal, HER2 and Triple Negative (TN). To determine the impact of the molecular classification of BC in the response to NAC and patients survival.  

The study includes a total of 168 consecutive women with a histologically confirmed diagnosis of invasive breast cancer who were treated with neoadjuvant intention. All patients underwent two breast MRI, prior to beginning NAC and before surgical excision. Inmunohistochemistry studies were used to classify tumors, according to the molecular classification, into three subtypes: Luminal, HER2 or TN. Based on the MRI findings there was established the radiological response (RR), and patients were divided into four groups: complete response, major partial response, minor partial response and no response. The pathological response (pR) was based on the Miller & Payne Scale. A Pearson correlation was used for comparing MRI response and pathological response, p<0.05 was considered significant. <0> It was examined the relationship between neoadjuvant response and long-term end points, including distant disease-free survival and overall survival.  

Of the 168 patients, 92 were into the luminal subtype, 44 HER2 and 32 TN. The MRI results showed 47,7% of complete RR in the HER2 subtype and 43,8% in the TN. The pathological complete response (pCR) prediction accuracy was much higher in the HER2 (81%) and TN (92%) subtypes. The correlation index between the pR and RR was bigger in the TN (0,903 Pearson coefficient, p<0,0001). The TN subtype showed the biggest rates of relapse (28%) and death (22,6%), in front of the HER2 or luminal subtypes. Between patients with pathological complete response, only 4 patients relapsed and 1 died, and MRI diagnosed correctly all of them  

There is a high correlation between pathological and radiological response in all molecular BC subtypes, mainly in TN. HER2 and TN showed the best rates of pCR to NAC. Despite inicial chemosensitivity, patients with the TN subtype had the worse overall survival.  

The high accuracy that Breast MRI has shown to predict pCR after NAC made of it an important issue in the presurgical patient management and a relevant tool to estimate patient survival.

Jimenez Aragon, F, Bernal Lafuente, C, Garcia Mur, C, Beltrán Marín, M, Gómez-Pereda, R, Martinez Comín, L, Role of Magnetic Resonance Imaging in Predicting Pathological Response of Breast Cancer Molecular Subtypes to Neoadjuvant Chemotherapy and Its Impact in Patients Survival.  Radiological Society of North America 2009 Scientific Assembly and Annual Meeting, November 29 - December 4, 2009 ,Chicago IL. http://archive.rsna.org/2009/8006049.html