Neoadjuvant chemotherapy with MRI monitoring for breast cancer

Neoadjuvant chemotherapy (NACT) is increasingly being offered to patients with breast cancer. No survival benefit has been demonstrated for NACT, but it may serve to reduce tumour size and improve prognosis through the attainment of a pathological complete response (pCR). The role and mode of MRI monitoring during NACT remain unclear.

Patients managed with NACT at a UK centre over 7 years were studied using a prospectively maintained database, which also included details of MRI. Clinicopathological and radiological predictors of NACT response were analysed in a univariable setting and survival analysis was undertaken using the Kaplan-Meier method.

A total of 278 patients underwent surgery following NACT, of whom 200 (71·9 per cent) had residual invasive disease and 78 (28·1 per cent) achieved a pCR. Attaining a pCR improved survival significantly compared with that of patients with residual invasive disease (mean 77·1 versus 66·0 months; P = 0·004) and resulted in significantly fewer recurrences (6·0 versus 24·3 per cent; P = 0·001). The pCR rate varied significantly among molecular subgroups of breast cancer (P < 0·001): luminal A, 6 per cent; luminal B/human epidermal growth factor 2 receptor (Her2)-negative, 21 per cent; luminal B/Her2-positive, 35 per cent, Her2-positive/non-luminal, 72 per cent; and triple-negative breast cancer (TNBC), 32 per cent. High-grade disease (G3) correlated with an increased rate of pCR. A radiological response seen on the mid-treatment MRI was predictive of pCR (sensitivity 77·6 per cent, but specificity only 53·3 per cent), as was complete radiological response at final MRI (specificity 97·6 per cent, but sensitivity only 32·2 per cent).

NACT allows identification of patient subgroups within TNBC and Her2-positive cohorts with a good prognosis. MRI can be used to identify patients who are responding to treatment.