# MRI for Predicting Response and 10-Year Outcome of Neoadjuvant Chemotherapy with or Without Additional Bevacizumab Treatment in HER2-Negative Breast Cancer

## TL;DR

This study explores whether MRI can predict treatment response and long-term survival in breast cancer patients receiving chemotherapy with or without bevacizumab.

## Contribution

The study introduces a novel approach using MRI parameters to assess treatment response and survival in HER2-negative breast cancer patients.

## Key findings

- MRI parameters like tumor size, ADC, and KTRANS changed significantly with treatment.
- Baseline KTRANS predicted pathological complete response in the bevacizumab group.
- No MRI parameters predicted 10-year survival or benefit from bevacizumab.

## Abstract

Breast cancer is a heterogeneous disease and treatment response and prognosis can be difficult to predict. Medical treatment prior to surgery is increasingly used to prevent tumour spread and improve survival for women with large breast cancers. Treatment aimed at tumour blood supply, such as bevacizumab, has been studied and some data support that it may benefit a selected subgroup of patients. There are, however, no tools for selecting these patients. In this study, we use MRI to compare tumours in patients treated with chemotherapy and patients treated with bevacizumab, in addition to chemotherapy, aiming to explore if any findings can help to predict treatment effect or survival. Patients in this study have been clinically followed for 10 years after treatment, giving valuable information relative to longtime survival.

Objectives: To explore if MRI can monitor treatment and predict outcome in patients with human epidermal growth factor 2 (HER2)-negative breast cancer receiving neoadjuvant chemotherapy (NACT) with or without bevacizumab. Methods: Multiparametric MRI was performed at baseline and after 12 and 25 weeks of NACT. MRI assessment included tumour size, apparent diffusion coefficient (ADC) from diffusion-weighted imaging (DWI), and signal intensity–time curves and vascular volume transfer constant (KTRANS) from dynamic contrast-enhanced MRI (DCE). The reference standards were pathological complete response (pCR) at the time of surgery, and 10-year recurrence-free survival. Receiver operating characteristics analyses were performed to assess the predictive value of the MRI parameters. MRI findings and outcomes were compared between the treatment groups. Results: Seventy women were included from November 2008 to July 2012, with a median age of 49.5 years and median tumour diameter of 47 mm. Fourteen patients (20.0%) achieved pCR, while eleven (15.7%) had recurrence during the 10-year follow-up. The treatment significantly reduced tumour size, increased ADC, decreased KTRANS, and shifted the signal intensity–time curves towards more benign shapes. The DCE parameters changed significantly more in the bevacizumab group. In the bevacizumab group, baseline KTRANS predicted pCR (Area under curve (AUC) = 0.73), but the difference in pCR-rates between the treatment groups was not significant (p = 0.07). Only tumour size and shrinkage at 12 weeks predicted pCR (AUC = 0.71–0.85) regardless of size measuring method. No MRI parameters predicted survival. Conclusions: All MRI parameters reflected treatment response, but no parameter predicted survival or benefit from adding bevacizumab to chemotherapy.