Abstract
Objective: Neoadjuvant chemotherapy (NACT) has been used more frequently in the treatment of non-metastatic breast cancer. Achieving a pathological complete response (pCR) after NACT provides us with information about the prognosis of the disease. We aimed to investigate the diagnostic accuracy of preoperative magnetic resonance imaging (MRI) in predicting pCR in patients with breast cancer.
Method: The charts of patients who received NACT for breast cancer between 2018 and 2024 were retrospectively analyzed. Factors associated with radiologic complete response (rCR) and pCR were analyzed in univariate and multivariate settings. The correlation between rCR and pCR according to MRI interpretation was analyzed.
Results: A total of 153 patients were included in this study; 26 (17%) of these patients achieved rCR, and 39 (25.5%) achieved pCR. A statistically significant correlation was found between pCR and rCR assessed on MRI. Sensitivity, specificity, accuracy, pCR predictive value (PPV) and non-pCR predictive value were estimated at 51.3%, 94.7%, 83.7%, 76.9% and 85%, respectively. Statistically significant correlations between rCR and pCR were found in Luminal A (p<0.05), Luminal B (p<0.05), HER2- positive (p<0.05), but not in triple negative subtypes (p>0.05). In univariate and multivariate analysis, tumor characteristics significantly associated with both rCR and pCR were tumor size, lymph node metastasis and molecular subtypes.
Conclusion: MRI evaluation varies according to the subtype and after NACT showed a correlation between rCR and pCR.