Comparative Characterization of Lymphoid Infiltration in Different Molecular-Biological Subtypes of Invasive Breast...

Area of Science:

• Oncology
• Immunology
• Pathology

Background:

• Invasive breast cancer (BC) exhibits diverse molecular subtypes.
• The tumor microenvironment, including immune cell infiltration, plays a critical role in BC progression.
• Understanding the interplay between BC subtypes and immune responses is crucial for diagnosis and prognosis.

Purpose of the Study:

• To investigate the morphometric characteristics of lymphoid structures and leukocytic infiltrates in different molecular-biological subtypes of invasive breast cancer.
• To correlate the presence and type of immune cell infiltrates with specific BC subtypes and clinicopathological features.

Main Methods:

• Morphometric analysis of mammary gland tissue from women with invasive breast cancer.
• Immunohistochemical characterization of lymphoid cells, including B cells (CD20+), T helper cells (CD4+), cytotoxic lymphocytes (CD8+), macrophages, and plasma cells.
• Assessment of tumor proliferation index (Ki-67) and presence of necrosis and fibrosis.

Main Results:

• High lymphoid infiltration with nodule formation was characteristic of Luminal B (LumB) and triple-negative BC subtypes, especially those with high Ki-67.
• Extensive necrosis and stromal fibrosis were observed in these aggressive BC subtypes.
• Lymphoid nodules were rich in B cells (CD20+) and T helper cells (CD4+), while cytotoxic lymphocytes (CD8+) were in interstitial infiltrates. Macrophages and plasma cells were near tumor cells.

Conclusions:

• Dense lymphoid infiltrates and lymphoid nodules in invasive breast cancer can serve as an unfavorable prognostic indicator.
• The immune cell profile associated with specific BC subtypes offers insights into tumor behavior and patient outcomes.
• Further research into the role of immune cell clusters may improve BC diagnosis and treatment strategies.