Purpose of review This article reviews the current literature on tumor-infiltrating immune cells in gastrointestinal stromal tumor (GIST), and the current status and prospects of effective immunotherapeutic strategies. Recent findings Tumor-infiltrating immune cells populate the microenvironment of GISTs; the most numerous are tumorassociated macrophages (TAMs) and CD3+ T cells. TAMs have not been shown to have a relationship with the biological behavior of GISTs; however, the number of CD3+ T cells correlates with better outcomes. The prognostic significance of tumor-infiltrating neutrophils, natural killer cells, CD4+ T cells, CD8+ T cells, and Treg cells remains unknown. Imatinib mesylate achieves a clinical response in 80% of patients with GIST. Its antitumor mechanism is partially immune mediated. The combination of imatinib and interferon-a has been shown to be effective against GIST it eradicates tumor cells including those that are drug resistant. Preclinical trials including cytotoxic T lymphocyte-associated antigen 4 blockade, anti-KIT antibody, and the generation of designer T cells have shown promising therapeutic effect in animal models of GIST. Summary GIST contains many tumor-infiltrating immune cells and should be susceptible to immunotherapy; early clinical and preclinical trials have shown promising results that should lead to new investigations and effective forms of direct and synergistic therapies.
- Gastrointestinal stromal tumor
- Imatinib mesylate
- Immune cells
ASJC Scopus subject areas
- Cancer Research