Research progress in restrained immunotherapy efficacy for melanoma with liver metastasis and its countermeasures

Abstract

Melanoma is a common malignant tumor, characterized by high fatality rate and poor prognosis. Early phase melanoma can be successfully treated by surgical resection, while targeted therapy or immunotherapy is mostly recommended for advanced melanoma. Advanced melanoma is often accompanied with multiple organ metastases, and most common in the liver. Numerous clinical studies show that in contrast to metastasis to other organs, the efficacy of immunotherapy is significantly reduced in melanoma patients with liver metastasis. This review discusses this interesting clinical phenomenon and its possible treatment strategies. The discrepancy in the efficacy of immunotherapy for liver metastatic melanoma may be related to the special anatomical structure and immune components of the liver. Liver metastasis can lead to the apoptosis or decreased activity of tumor antigen-specific CD8+ T cells, which are crucial for killing tumor cells. Immunotherapy combined with liver-targeted radiotherapy, adoptive cell therapy, or targeted elimination of Treg cells may offer opportunities to correct the immune imbalance caused by liver metastasis. However, the optimal treatment plan remains to be further explored.

Keywords

• melanoma
• liver metastasis
• immunotherapy
• immune checkpoint inhibitor
• radiotherapy