Do Decreased Breast Microcalcifications After Neoadjuvant Chemotherapy Predict Pathologic Complete Response?

BACKGROUND: Clinical response evaluation by image examination after neoadjuvant chemotherapy for breast cancer is important for determining drug response and progression. Mammography is less correlated with pathologic response assessment than magnetic resonance imaging or ultrasonography. The present study clarified characteristics of breast cancer patients with decreased microcalcifications after neoadjuvant chemotherapy to increase the accuracy of mammographic assessment.

PATIENTS AND METHODS: Consecutive patients who received neoadjuvant chemotherapy for breast cancer at our hospital from January 2013 to June 2017 were retrospectively reviewed. Characteristics of cases of microcalcifications before neoadjuvant chemotherapy and those showing a reduction after were examined. Stromal tumor-infiltrating lymphocytes were evaluated in the biopsy. Pathologic complete response was also explored in patients exhibiting a decrease in microcalcifications by neoadjuvant chemotherapy.

RESULTS: Seventy breast cancer cases were included; 37 had no malignant microcalcifications before neoadjuvant chemotherapy and 33 did. Breast cancer with microcalcifications was significantly more positive for human epidermal growth factor receptor 2 than those without microcalcifications (48% vs. 22%, P = .018). Only 6 of 33 patients with microcalcifications before neoadjuvant chemotherapy showed a decrease after treatment. These patients tended to have high stromal tumor-infiltrating lymphocytes (50% vs. 17%), segmental microcalcifications (66% vs. 33%), and pleomorphic/linear microcalcifications (83% vs. 37%).

CONCLUSION: These results suggest that neoadjuvant chemotherapy is able to decrease malignant calcifications, particularly segmental and pleomorphic/linear microcalcifications. By clarifying the mechanisms of formation and disappearance of microcalcifications, a consensus can be reached on whether microcalcifications apparent by mammography are useful for evaluating response to neoadjuvant chemotherapy.