Breast Tumor Heterogeneity Quantification using 3D Ultrasound Texture

Breast tumors are heterogeneous disease that can vary among individuals (intertumor heterogeneity) and within a patient’s tumor (intratumor heterogeneity). Intratumor heterogeneity indicates the existence of varied cellular groups within a tumor, potentially influencing tumor progression and impacting therapy response. Ultrasound, a primary imaging modality for breast tumors, can offer valuable insights into the subtle texture characteristics throughout the entire tumor, particularly when employed in a three-dimensional mode. In this study, our objective is to quantitatively assess the intratumor heterogeneity using three-dimensional B-mode ultrasound texture to enhance our understanding of tumor heterogeneity in treatment-naïve breast tumor patients. The results of our study underscore the presence of varied textural characteristics within the tumor across different spatial locations. These observations suggest the potential for non-invasive biomarkers that can offer insights into the tumor microenvironment, behavior, and progression.

I. Introduction

Breast cancer (BC), one of the most prevalent cancers and the leading cause of women’s mortality worldwide, is categorized by histological and molecular subtypes. Histologically, BC is categorized into invasive carcinoma-invasive ductal carcinoma (IDC), invasive lobular carcinoma (ILC), mucinous, tubular, medullary carcinoma, and in situ carcinoma-ductal carcinoma in situ (DCIS), and lobular carcinoma in situ (LCIS) [1]. Molecularly, it is classified as luminal A (ER-positive/PgR positive, HER2 negative, Ki%), luminal B (varying ER/PgR expression, HER2 positive, Ki%), HER2 enriched (ER and PgR negative, HER2 positive) and triple-negative breast cancer (TNBC- ER-negative, PgR negative, HER2 negative) [2]. These subtypes play a significant role in devising therapeutic regimens and predicting survival outcomes. Breast tumor heterogeneity due to the tumor microenvironment can vary across the tumor volume or between different tumor types. Intratumor heterogeneity is the coexistence of distinct subpopulations of tumor cells within the primary tumor [3].