Tumor Microenvironment in Neuroblastoma and Immunotherapeutic Approaches: Towards More Effective Treatment.

Background/

Objectives

High-risk neuroblastoma (HR-NB) is a major cause of cancer-related death among children. The review aims to discuss various biochemical and genetic traits of neuroblastoma (NB) used for the potential of cell-based therapies.

Methods

A comprehensive search was performed through MEDLINE, PubMed, Scopus, and ScienceDirect using various combinations of "neuroblastoma", "tumor microenvironment (TME)", "immune cells", "non-immune cells", "hematopoietic stem cell transplantation (HSCT)", "autologous stem cell transplantation (ASCT)", "natural killer cells (NK)", "chimeric antigen receptor T cells (CAR-T)", "CAR-NKT", "tumor infiltrating lymphocytes (TIL)", "bioinformatics", and "neuro-antigens" in the published papers over the last decade. Reviews, systematic reviews, and clinical trials related to children's NB were selected. The final set included 106 articles of interest.

Results

Recent studies have shown that TME is crucial in determining the malignancy, immune evasion, and drug resistance of NB. Innate immune or non-immune cells play important roles in shaping the NB TME. Depleting or reprogramming TME factors can improve the effectiveness of immunotherapy. A number of clinical trials have studied and showed feasibility of using ASCT, NK cells, CAR-T, and CAR-NKT cells in the adoptive therapy for HR-NB. However, an unambiguous evaluation of the effectiveness of cell-based technologies in the HR-NB therapy is still complicated due to the lack of large randomized trials.

Conclusions

The reported small and non-randomized studies that demonstrated controversial results cannot prove, undoubtedly, the promising potential of the cell-based technologies including ASCT, NKs, CAR-T, and CAR-NKT cells. Further randomized clinical trials, using the same treatment, will help determine the role in the multimodal treatment for HR-NB.