Resonancia magnética en el cáncer de mama tratado con neoadyuvanciacorrelación radiopatológica de la respuesta

Abstract

. ABSTRACT Introduction: The treatment of breast cancer (BC) is aimed at healing with a high rate of success. Advances in the development of magnetic resonance imaging (MRI), have made this technique very important for the assessment of tumor response to neoadjuvant chemotherapy (QTN) treatment, leaving behind methods such as mammography and ultrasound. There are four relevant aspects that have undergone variations. First, the MRI indications are wider than initially. Second, we have studied biomarkers in the MRI, that behave as predictive factors for the tratment response. Third, the impact of QTN on treatment, through the knowledge of tumor biology according to the observed responses. Finally, molecular classification and genetic testing allow better predictive stratification. Thus, the present is a review of the results of different QTN responses of breast tumors evaluated with MRI. Objectives: To analyze the radiological and pathological response of patients with BC undergoing QTN by MRI, and to know the variables related to it. To analyze the variables in morphology and dynamic of MRI, prior to the QTN in the prediction of the radiological and pathological response, as well as the concordance between both the breast and axilla. Material and Methods: This is a cross-sectional observational study undertaken in the Clinic University Hospital "Virgen de la Arrixaca" in the period of 2008-2016. The study includes 63 women with breast cancer treated with QTN, to evaluate the response to this treatment by MRI, and study the pathological response after surgery. Results: The response rates were 52.4 % for RR (12.7 % rRC), 63.5 % for local RP and 57.2% for axillary RP. The overall pRC rate in the breast and axilla was 22.2%. When the radiological response (RR) was studied in the multivariate logistic regression analysis, the presence of BRCA + (OR: 319.40, 95% CI: 2.6-388338.08) and the type of curve post-QTN in MRI (OR: 140.49, 95% CI: 4.7-4143.54), were independent predictor factors of the response. The tumor size in the post QTN in MRI, the type of lesion in ultrasound at the moment of diagnosis and axillary involvement, also explain the RR. We found a non-significant association with a higher RR in the CLI histological subtype (87.5%). The only independent predictor of pathologic response (PR) in the breast was tumor enhancement in post-QTN in MRI (OR: 12.38; CI: 3.1-49.04). In the axilla, the independent predictors were biopsy of centinella gland (OR: 42.5; 95% CI: 3.5-506.18), negativity of hormonal receptor (HR) and high Ki 67. There is a non-significant correlation between RR and RP, higher in the axilla compared to the brast. The pathological response in the breast and axilla had a significant correlation between both. The subtype HER-2 + showed the highest radiological and pathological response rate. Conclusions: MRI is an excellent method for the evaluation of the response to QTN treatment. The presence of BRCA mutation, ultrasound lesions, tumor size, kinetic curve in the post-QTN in MRI, and axillary involvement were independent predictors of the radiological response. The only independent predictor of PR in MRI was post-QTN tumor enhancement variable as a function of immunophenotype. The concordance between radiological and pathological responses was greater at the axillary level. Keywords: Breast cancer; Neoadjuvant chemotherapy; Magnetic resonance; Radiological response; Pathological response;