Background: This study aimed to determine the relationship between mammographic calcifications and magnetic resonance imaging (MRI) tumoral enhancement before and after neoadjuvant chemotherapy (NAC) and to assess the impact of these findings on surgical management.
Methods: This Institutional Review Board-approved, Health Insurance Portability and Accountability Act (HIPAA)-compliant retrospective study involved breast cancer patients who underwent NAC between 2009 and 2015. The study cohort comprised 90 patients with pre- and posttreatment MRI and mammograms demonstrating calcifications within the tumor bed either at presentation or after treatment. The data gathered included pre- and post-NAC imaging findings and post-NAC histopathology, particularly findings associated with calcifications. Comparisons were made using Fisher's exact test, with p values lower than 0.05 considered significant.
Results: Complete resolution of MRI enhancement occurred for 44% of the patients, and a pathologic complete response (pCR) was achieved for 32% of the patients. No statistically significant correlation between changes in mammographic calcifications and MRI enhancement was found (p = 0.12). Resolution of enhancement was strongly correlated with pCR (p < 0.0001). The majority of the patients with pCR demonstrated complete resolution of enhancement (79%, 23/29). No statistically significant relationship was found between changes in calcifications and rates of pCR (p = 0.06). A pCR was achieved most frequently for patients with resolution of enhancement and new, increasing, or unchanged calcifications (p < 0.0001).
Conclusions: Although calcifications seen on post-NAC mammography may be associated with benign disease, loss of MRI enhancement does not predict the absence of residual tumor with sufficient accuracy to leave calcifications in place. Complete excision of tumor bed calcifications remains standard practice and a substantial limitation to NAC use for downstaging patients to be eligible for breast conservation treatment.