Myeloid-derived suppressor cells in peripheral blood as predictive biomarkers in patients with solid tumors undergoing immune checkpoint therapy: systematic review and meta-analysis.

Background: Immunotherapeutic approaches, including immune checkpoint inhibitor (ICI) therapy, are increasingly recognized for their potential. Despite notable successes, patient responses to these treatments vary significantly. The absence of reliable predictive and prognostic biomarkers hampers the ability to foresee outcomes. This meta-analysis aims to evaluate the predictive significance of circulating myeloid-derived suppressor cells (MDSC) in patients with solid tumors undergoing ICI therapy, focusing on progression-free survival (PFS) and overall survival (OS). Methods: A comprehensive literature search was performed across PubMed and EMBASE from January 2007 to November 2023, utilizing keywords related to MDSC and ICI. We extracted hazard ratios (HRs) and 95% confidence intervals (CIs) directly from the publications or calculated them based on the reported data. A hazard ratio greater than 1 indicated a beneficial effect of low MDSC levels. We assessed heterogeneity and effect size through subgroup analyses. Results: Our search yielded 4,023 articles, of which 17 studies involving 1,035 patients were included. The analysis revealed that patients with lower levels of circulating MDSC experienced significantly improved OS (HR=2.13 [95% CI 1.51-2.99]) and PFS (HR=1.87 [95% CI 1.29-2.72]) in response to ICI therapy. Notably, heterogeneity across these outcomes was primarily attributed to differences in polymorphonuclear MDSC (PMN-MDSC) subpopulations and varying cutoff methodologies used in the studies. The monocytic MDSC (M-MDSC) subpopulation emerged as a consistent and significant prognostic marker across various subgroup analyses, including ethnicity, tumor type, ICI target, sample size, and cutoff methodology. Conclusions: Our findings suggest that standardized assessment of MDSC, particularly M-MDSC, should be integral to ICI therapy strategies. These cells hold the promise of identifying patients at risk of poor response to ICI therapy, enabling tailored treatment approaches. Further research focusing on the standardization of markers and validation of cutoff methods is crucial for integrating MDSC into clinical practice. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42023420095, identifier CRD42023420095.

Malnutrition and vitamin deficiencies after surgery for esophageal and gastric cancer: A metanalysis.

BACKGROUND & AIMS: Patients receiving oncological esophagectomy or gastrectomy are known to be at high risk for vitamin and micronutrient deficiency before, during and after surgery. However, there are no clear guidelines for these cancer patients regarding postoperative vitamin supplementation. METHODS: We conducted a metanalysis consisting of 10 studies regarding vitamin and micronutrient deficiencies after oncological gastric or esophageal resection. 5 databases were searched. RESULTS: Data was sufficient regarding Vitamins B12 and 25-OH D3 as well as calcium. We were able to show deficiencies in 25-OH Vitamin D3 levels (p < 0.001) and lower levels of Vitamin B12 and calcium (bit p < 0.001) when compared to the healthy population. CONCLUSIONS: Patients from these groups are at risk for vitamin deficiencies. A guideline on postoperative supplementation is needed.