# Automated calculation of background parenchymal enhancement as a biomarker of treatment responses and recurrence-free survival in breast cancer

## TL;DR

This study shows that automated MRI analysis of breast tissue can predict cancer treatment response and survival outcomes.

## Contribution

The paper introduces an automated method to quantify background parenchymal enhancement (BPE) as a predictive imaging biomarker in breast cancer.

## Key findings

- Automated BPE quantification strongly correlates with radiologist-defined BPE categories.
- Baseline BPE is independently associated with improved overall survival in breast cancer patients.
- Reduction in BPE after chemotherapy predicts pathological complete response in high and low baseline BPE groups.

## Abstract

To determine whether automated quantification of background parenchymal enhancement (BPE) from dynamic contrast-enhanced MRI (DCE-MRI) can serve as an imaging biomarker for clinical outcomes including overall survival (OS), recurrence-free survival (RFS), and pathological complete response (pCR) in breast cancer.

The multi-institutional data consisted of 922 biopsy-confirmed invasive breast cancer patients from the Duke-Breast-Cancer-MRI dataset and 152 patients with whole-breast pre- (T0) and/or post (T3) DCE-MRI from the I-SPY2 dataset for validation. Automated fibroglandular tissue (FGT) segmentation and BPE quantification were performed on DCE-MRI. The optimal intensity enhancement threshold by volume-based method was established against four radiologist-defined BPE categories. The area under the curve (AUC) was obtained for classification of BPE categories. Cox proportional hazards models were used to predict OS and RFS. Logistic regression was used to predict pCR.

Peak-contrast BPE showed strong correlation with radiologist-defined BPE, achieving the best performance at a 55% signal enhancement threshold (AUC 0.70–0.86). The calculated BPE decreased after neoadjuvant chemotherapy. A reduction in calculated BPE grade after neoadjuvant chemotherapy was predictive of pCR for the high baseline BPE group (adjusted odds ratio = 5.88 [1.03, 33.33]) and for the low baseline BPE group (adjusted odds ratio = 6.54 [1.26, 33.94]). Baseline BPE was independently associated with improved OS (adjusted hazard ratio 0.58 [0.34, 0.99]) but not associated with RFS.

Automated quantification of BPE from DCE-MRI provides an objective and reproducible imaging biomarker associated with treatment response and overall survival in breast cancer. These results support its potential utility for individualized risk stratification and therapeutic decision-making.

The online version contains supplementary material available at 10.1007/s10549-026-07941-5.