Scheel JR, et al. - Experts ascertained the accuracy of preoperative measurements for detecting the pathologic complete response (CR) and evaluating residual disease following neoadjuvant chemotherapy (NACT) in patients with locally advanced breast cancer. They noted greater efficacy of measurement of longest diameter by MRI than by mammography and clinical examination for preoperative assessment of tumour residua after NACT and could improve surgical planning.

Methods

• Women with ≥ 3 cm invasive breast cancer receiving NACT, were prospectively enrolled in the American College of Radiology Imaging Network 6657 Trial.
• Longest diameter by mammography, MRI, and clinical examination and functional volume on MRI were included in the preoperative measurements of residual disease.
• Authors assessed the accuracy of preoperative measurements for detecting pathologic CR and the association with final pathology size for all lesions, separately for single masses and nonmass enhancements (NMEs), multiple masses, and lesions without ductal carcinoma in situ (DCIS).

Results

• As per data, in the 138 women with all 4 preoperative measures, longest diameter by MRI demonstrated the highest accuracy for detecting pathologic CR for all lesions and NME (AUC = 0.76 and 0.84, respectively).
• Findings suggested that in the accuracy of detecting pathologic CR for single masses, there was little difference across preoperative measurements (AUC = 0.69–0.72).
• Results demonstrated that moderate ability for detecting pathologic CR for multiple masses was demonstrated with longest diameter by MRI and longest diameter by clinical examination (AUC = 0.78 and 0.74), and longest diameter by MRI and longest diameter by mammography demonstrated moderate ability for detecting pathologic CR for tumors without DCIS (AUC = 0.74 and 0.71).
• In subjects with residual disease, the strongest association of longest diameter by MRI with pathology size for all lesions and single masses was seen (r=0.33 and 0.47).
• Researchers noted no significant influence of tumor subtype or maphic densimmograty on associations between preoperative measures and pathology results.