Can Mid-Treatment MRI Help Predict Neoadjuvant Chemotherapy Response for Patients with Breast Cancer?

The use of mid-treatment magnetic resonance imaging (MRI) may provide a pertinent glimpse of neoadjuvant chemotherapy outcomes in patients with triple-negative breast cancer (TNBC).

In a new retrospective study, recently presented at the American Society of Clinical Oncology (ASCO) conference, researchers reviewed pre-, post- and mid-treatment MRI data and pathological outcomes for 154 patients treated with neoadjuvant chemotherapy for breast cancer. The cohort included patients with TNBC, the human epidermal growth factor receptor 2 (HER2) subtype and the hormone receptor-positive (HR+) subtype, according to the study.

For eight patients achieving an imaging complete response (iCR) at the mid-treatment breast MRI, the researchers noted a 100 percent positive predictive value (PPV) for pathologic complete response (pCR).

New research presented at the American Society of Clinical Oncology (ASCO) conference found that at least a partial response to neoadjuvant chemotherapy on mid-treatment MRI preceded pathologic complete response (pCR) in greater than 50 percent of patients with triple negative and HER2+ breast cancer subtypes.

The study authors also found at that at least a partial response on the mid-treatment MRI preceded pCR in 61.5 percent of women with TNBC.

“Mid-point breast MRI may serve as an early predictor of pathological response, particularly in patients with iCR,” wrote lead study author Ahmed Yahya, M.D., who is affiliated with the Mayo Clinic in Jacksonville, Fla., and colleagues.

Less than a partial response on mid-treatment MRI led to a significantly lower rate of pCR in women with TNBC (38.9 percent) and HR+ tumors (16.7 percent), according to the study authors.

“These findings highlight the importance of considering additional therapies for these subgroups of patients to improve the treatment outcomes, as they are less likely to achieve pCR with the current standard neoadjuvant chemotherapy regimen,” emphasized Yahya and colleagues.

The researchers noted mixed results with the use of mid-treatment MRI in patients with HER2+ and HR+ tumors. While partial response preceded pCR in greater than 50 percent of patients with TNBC and HER2+ subtypes (59.5 percent), this only occurred in 26.7 percent of patients with HR+ tumors.

The study authors also acknowledged that among women with HER2+ breast cancer, 65.2 percent achieved pCR despite having less than a partial response to neoadjuvant chemotherapy on the mid-treatment MRI.

(Editor’s note: For related content, see “Can Abbreviated Breast MRI Have an Impact in Assessing Post-Neoadjuvant Chemotherapy Response?,” “Breast MRI Quantification of Intra-Tumoral Heterogeneity May Help Predict Response to Neoadjuvant Chemotherapy” and “Imaging-Based Treatment Modifications Only Used in 15 Percent of Neoadjuvant Systemic Therapy Trials for Breast Cancer.”)

Reference

1. Yahya A, Chumsri S, Maimone IV S, et al. Midpoint MRI as an early predictor of responses to neoadjuvant chemotherapy in patients with breast cancer. Presented at the American Society of Clinical Oncology (ASCO) conference, May 30-June 3, Chicago. Available at: https://meetings.asco.org/abstracts-presentations/244698