The landscape of angiogenesis subtypes for breast cancer: a comprehensive analysis based on the Cancer Genome Atlas.

Abstract

Purpose: Breast cancer is a common malignant tumor in women with a poor prognosis. This study aimed to investigate angiogenesis subtypes of breast cancer and unveil the etiology and molecular features of breast cancer.

Methods: Based on the angiogenesis gene set derived from AmiGO2, and breast cancer data in the Cancer Genome Atlas (TCGA), we define a novel cluster of angiogenesis subtypes for patients by consensus clustering. The gene regulation, immune landscape, molecular characteristics, and clinical features as well as enrichment pathways were explored in the angiogenesis subtypes of breast cancer.

Results: Two angiogenesis subtypes were established through consensus clustering, among which subtype1 included 275 patients and subtype2 included 813 patients. A total of 643 differential expressed genes and 109 miRNAs were found between the two subtypes. The gene set enrichment analysis showed that the enriched hallmark pathways in subtype2 were related to the cancer tumorigenesis and breast cancer progression, including estrogen response early estrogen response late, epithelial-mesenchymal transition (EMT), especially angiogenesis. The mutant-allele tumor heterogeneity and tumor mutation burden of non-angiogenesis subtype were significantly higher than that in the angiogenesis subtype. The stroma score, immune score and ESTIMATE score were significantly higher in angiogenesis subtype, while the tumor purity in angiogenesis subtype was considerably lower. Finally, most immune checkpoints were expressed higher in the angiogenesis subtype.

Conclusions: The omics analysis has established a novel angiogenesis subtype of breast cancer and identified the characteristics of the immune microenvironment and genomic alteration of breast cancer. Thus, this angiogenesis subtype might provide new evidence for inhibiting the progression and immunotherapy response in breast cancer.