The Intratumoral Microbiota in Breast Cancer: Roles in Progression, Immunity, and Therapy

Area of Science:

• Oncology
• Microbiology
• Genomics

Background:

• Breast cancer (BC) is a major cause of cancer mortality globally.
• The tumor-associated microbiota is increasingly recognized for its role in BC heterogeneity.
• Advances in multi-omics reveal distinct intratumoral microbiome patterns in BC.

Purpose of the Study:

• To review the composition, function, and clinical relevance of the BC intratumoral microbiome.
• To highlight challenges in low-biomass microbiome profiling.
• To propose a framework for clinical translation of microbiome findings.

Main Methods:

• Systematic review of current literature on the breast cancer microbiome.
• Analysis of sequencing and multi-omics data.
• Evaluation of experimental evidence on microbial function in the tumor microenvironment (TME).

Main Results:

• Reproducible intratumoral microbiome signatures in BC correlate with molecular subtypes and outcomes.
• Microbial alterations impact tumor immunity, metastasis, and response to therapies.
• Intratumoral microbes are functionally active, influencing tumor progression via immune modulation and metabolic reprogramming.

Conclusions:

• The BC intratumoral microbiome plays a significant role in pathogenesis and treatment response.
• Addressing methodological challenges is crucial for reliable microbiome profiling.
• Translating microbiome research into clinical practice holds promise for improved BC management.