# Magnesium and Cancer Immunotherapy: A Narrative Practical Review

## TL;DR

This review explores how magnesium may influence cancer immunotherapy by affecting immune function and patient outcomes.

## Contribution

The paper provides a narrative review of magnesium's role in cancer immunotherapy and suggests potential future therapeutic applications.

## Key findings

- Preclinical studies show Mg2+ regulates immune function, especially in cytotoxic cells.
- Maintaining normal Mg2+ levels may improve responses to immunotherapy and survival outcomes.
- Injectable gels and metal-based biomaterials are emerging as new modulators of immunotherapy response.

## Abstract

Magnesium (Mg2+) has garnered the attention of oncologists due to its wide range of biological functions and frequent use as a complementary or integrative agent. In this study, a concise narrative review of the complex relationships between Mg2+ and immunotherapy for human malignancies is presented, in addition to a possible future therapeutic scenario. Pertinent full-text articles were thoroughly examined, and the most relevant ones were selected for inclusion in this review. A significant body of preclinical studies highlights the role of Mg2+ in regulating immune function, particularly in cytotoxic effector cells, underscoring the importance of maintaining adequate Mg2+ homeostasis mainly when immune-modulating agents are used in clinical practice. Whether serum Mg2+ levels influence the clinical outcomes of cancer patients treated with immune checkpoint blocker treatment remains to be fully elucidated. However, over the last decade, an increasing amount of data suggests that maintaining normal or slightly elevated serum levels of Mg2+ may enhance the response to immune therapy and even improve survival outcomes. New potential modulators of the tumor microenvironment and response to immunotherapy, such as injectable gels and metal-based biomaterials, are discussed.