Stylianos Drisis MD, Presenter: Nothing to Disclose

Konstantinos Stathopoulos MD, Abstract Co-Author: Nothing to Disclose

Marta Capelan MD, Abstract Co-Author: Nothing to Disclose

Shi-Li Chao DIPLPHYS, PhD, Abstract Co-Author: Nothing to Disclose

Marc Paul Lemort MD, Abstract Co-Author: Nothing to Disclose

To evaluate if the stratification of patients receiving neoadjuvant chemotherapy (NAC) for locally advanced breast cancer into groups of breast cancer subtypes, could improve the performance of DCE-MRI as a surrogate marker

A retrospective study was performed, including 91 patients who received NAC and underwent two DCE-MRI examinations, one before (EX1) and one during NAC (EX2). The maximum diameter of the tumor (Dmax) and pharmacokinetic parameters from DCE-MRI such as Ktrans (permeability), Ve (extravascular volume) and Vp (plasmatic volume) were measured at both examinations. Post operative pathological examination was used as the golden standard for the evaluation of tumour response with a binary model: responders and non responders according to the presence of residual vital tumour. Moreover, patients were classified in four subgroups according to their receptor status: i) the whole population, ii) triple negative, iii) HER2 positive and iv) ER-positive/ HER2-negative. Statistical analysis was performed using receiver operator curves (ROC), Delongs’ and Hanley JA method for comparison of ROC

From the 91 patients 75 were non responders (82.5%) and 16 showed complete pathological response (17.5%). The ROC curve analysis showed the best performance for Ktrans at EX1, for Dmax at EX2 and for % decrease of Ve between EX1 and EX2. This means that responders and non responders could be differentiated with Ktrans in the first examination, with Dmax the second examination and with % decrease of Ve when the change of each pharmacological parameter between EX1 and EX2 was concerned. For the abovementioned parameters, no significant difference was found between the performances of ROC curves of the whole population group and the groups of breast cancer subtypes. However, the ER positive/HER2 negative group showed no significant difference for any parameter neither at EX1 or EX2 neither between EX1 and EX2.

DCE-MRI could have a potential predictive and monitoring role in the triple negative and HER2 positive groups but a weak performance was observed for the ER positive/HER2 negative group

DCE-MRI can differentiate responders from non responders and is recommended for the evaluation of neoadjuvant treatement for locally advanced breast cancer.

Drisis, S, Stathopoulos, K, Capelan, M, Chao, S, Lemort, M, The Impact of Breast Cancer Subtypes on DCE-MRI as a Surrogate Marker for Locally Advanced Breast Cancer.  Radiological Society of North America 2012 Scientific Assembly and Annual Meeting, November 25 - November 30, 2012 ,Chicago IL. http://archive.rsna.org/2012/12029023.html