Mast Cells in the Solid Tumor Microenvironment: Multiple Roles and Targeted Therapeutic Potential

The tumor microenvironment (TME) is a complex network composed of non-tumor cells, extracellular matrix, blood vessels, and various molecular signals that surround and profoundly influence tumor progression. As one of the key immune effector cells within the TME, mast cells (MCs) exhibit functional complexity, and their specific roles remain widely debated. Depending on the cancer type, spatial distribution, and interactions with other TME components, MCs can demonstrate dual regulatory capabilities-either promoting or inhibiting tumor growth. This characteristic has made them an important focus in current tumor immunology research. This review aims to systematically review the current understanding of MCs in the TME, with emphasis on their characteristics and functional differences across various tumor types, pathological status, and species. In recent years, advances in the understanding of MC markers, activation mechanisms, and biological functions have made targeting specific MC subsets an emerging therapeutic strategy. By comprehensively examining the origin, activation mechanisms, cellular interactions, and therapeutic regulation of MCs, this review provides new perspectives and a basis for future directions in tumor research and treatment.