# Immune Infiltration Correlates with Transcriptomic Subtypes in Primary ER+ Invasive Lobular Breast Cancer

## TL;DR

This study finds that immune cell presence in a specific type of breast cancer correlates with different genetic patterns, which could help predict patient outcomes.

## Contribution

The study identifies novel transcriptomic subtypes and immune infiltration patterns specific to ER+/HER2- invasive lobular breast cancer.

## Key findings

- Two transcriptomic subtypes and five immune infiltration patterns were identified in ER+/HER2- invasive lobular breast cancer.
- A TAM-Low signature correlates with lower infiltration of pro-inflammatory TAM and better patient outcomes in ER+ tumors.

## Abstract

Understanding interplay of breast cancer and microenvironment is critical. Here, we
identified two transcriptomic subtypes and five immune infiltration patterns from
RNA-seq and multiplex immunohistochemistry from 21 ER+/HER2- invasive lobular breast
cancers. The proliferative subtype associated with increased immune infiltration
especially by immunosuppressive regulatory T-cells and macrophages. We also defined a
TAM-Low signature, which associated with lower infiltration of proliferative,
pro-inflammatory TAM, and improved outcome in patients with ER+ tumors.