Impact of systemic therapy on circulating leukocyte populations in patients with metastatic breast cancer

Area of Science:

• Immunology
• Oncology
• Pharmacology

Background:

• Tumors significantly impact the immune system, influencing patient prognosis and disease progression.
• Conventional antitumoral therapies possess immunomodulatory effects, altering circulating immune cell populations.
• Existing data on treatment effects on immune cells primarily come from animal or in vitro studies, necessitating patient-based research.

Purpose of the Study:

• To investigate the dynamic changes in circulating immune cell populations in patients with metastatic breast cancer undergoing standard antitumoral therapies.
• To assess the impact of endocrine therapy and chemotherapy on specific immune cell subsets over time.
• To explore the potential for reversing systemic immunosuppression through standard treatments.

Main Methods:

• A pilot study involving ten patients with metastatic breast cancer.
• Longitudinal evaluation of a wide panel of circulating immune cells for up to six months.
• Analysis of immune cell population shifts in response to standard antitumoral regimens (endocrine therapy and chemotherapy).

Main Results:

• Endocrine therapy was associated with an enrichment of natural killer (NK) and natural killer T (NKT) cells in circulation.
• Both chemotherapy and endocrine therapy led to a reduction in circulating monocytic myeloid-derived suppressor cells (Mo-MDSCs).
• Systemic immunosuppressive profiles showed a tendency to revert during the course of therapy.

Conclusions:

• Standard antitumoral therapies, including endocrine therapy and chemotherapy, modulate circulating immune cell populations in metastatic breast cancer patients.
• Therapy-induced changes suggest a potential reversal of systemic immunosuppression.
• These findings support future investigations into combination treatments involving standard therapies and immunotherapy.