The Correlation Between iNKT Cells and Malignant Tumors: A Meta-Analysis

Cancer is one of the major global health problems, with increasing numbers of new cases and deaths each year. This highlights the urgency of effective treatment. The iNKT cells act as a special subset of T cells with potent anti-tumor effects. Therefore, the correlation between iNKT cells and cancer will be evaluated in terms of frequency, prognosis, and efficacy in this study. A total of 62 studies involving 1076 healthy controls and 2453 cancer patients were included in this meta-analysis. The meta-analysis showed that the number of circulating iNKT cells was significantly higher in healthy controls than in cancer patients, as well as the frequency of iNKT cells in circulating T cells and mononuclear cells. At the same time, the frequency of iNKT cells in T cells was significantly higher in non-tumor tissues than in tumor tissues. In terms of prognosis, the higher frequency of iNKT cells in peripheral blood or tumor tissues of cancer patients was associated with improved overall survival (OS) and relapse-free survival (RFS). Regarding the efficacy of iNKT cell-related therapies, the objective response rate was 3%, and the disease control rate was 49%. In conclusion, iNKT cells were significantly reduced in cancer patients, and the higher frequency of iNKT cells was associated with a favorable prognosis in these patients.