The Tumor Immune Microenvironment in Breast Cancer Progression

Area of Science:

• Oncology
• Immunology
• Cancer Biology

Background:

• The tumor microenvironment critically impacts breast cancer development, progression, and metastasis.
• Immune cells like T cells, B cells, NK cells, and myeloid cells play varied roles, supporting or hindering anti-tumor responses across breast cancer subtypes.

Purpose of the Study:

• To review predominant immune cell populations in breast cancer subtypes.
• To elucidate the suppressive and prognostic effects of immune cells.
• To outline the immune microenvironment's role from normal tissue to metastasis.

Main Methods:

• A comprehensive literature review was performed.
• Analysis focused on immune cell involvement throughout breast cancer progression.

Main Results:

• Breast tumors show increased immune cell infiltration compared to normal tissue.
• Triple-negative and HER2+ breast cancers exhibit higher immune infiltration linked to better survival.
• Estrogen receptor-positive (ER+) tumors have lower immune infiltration, associated with poorer outcomes, and metastatic sites often present a more immunosuppressive environment.

Conclusions:

• Understanding tumor-immune cell interactions is crucial for advancing breast cancer research.
• This knowledge is essential for developing effective immune-based therapies and improving patient outcomes.