Correlation between late gadolinium enhancement sequences in magnetic resonance imaging (MRI) and pathologic response after neoadjuvant chemotherapy in breast cancer

Abstract

Objectives To study the correlation between radiologic response observed by late enhancement sequences in MRI and pathologic response after neoadjuvant chemotherapy in patients with breast cancer.

Material and methods Retrospective observational study of 132 patients with 136 tumors (4 with bilateral disease), treated consecutively with neoadjuvant chemotherapy at our institution between 2011 and 2017. In all cases, we performed 3 breast MRI's, using late enhancement gadolinium sequences: the first prior to neoadjuvant chemotherapy, the second half way through treatment, and the third at the completion of therapy. Following treatment, contrast medium uptake in tumor bed was evaluated based on the Response Evaluation Criteria for Solid Tumors (RECIST).

All patients underwent conservative or radical surgery. We compared the radiologic response estimated by MRI, with the pathologic response observed in the surgical specimen, according to Miller and Payne grading system. We calculated the sensitivity, specificity, and predictive values of the test, and used the Spearman correlation coefficient to stablish correlations between the parameters analyzed.

Results Complete pathologic response (pCR) was observed in 58.1% (79/136). The percentage of global radio-pathologic correlation was 88.97%. MRI showed a sensitivity of 78.9%, a specificity of 79.7%, a positive-predictive value (PPV) of 73.8% and a negative-predictive value (NPV) of 84%. In patients with partial response, the Spearman correlation was positive (rho = 1, P < .001). According to surrogate subtypes of breast cancer, we observed moderate correlation for luminal tumors (rho = 0.63, P < .001) and poor correlation for non-luminal types (rho = 0,4, P < .01).

Conclusions Breast MRI, using late enhancement sequences, accurately predicts tumor response to neoadjuvant chemotherapy, especially in cases of partial response to therapy and in luminal surrogate tumoral subtypes.