IntroductionSystemic inflammation is associated with prognosis in solid tumors. The neutrophil-to-lymphocyte ratio (NLR) is a marker for the general immune response to various stress stimuli. Studies have shown correlation of NLR to outcomes in immune checkpoint blockade, peripheral neutrophil count to intratumor neutrophil population, and NLR to intratumoral levels of myeloid-derived suppressor cells. Studies have shown elevated peripheral blood regulator T cells accompanied by elevated NLR are associated with poor outcomes further highlighting the importance of inflammation in the prognosis of cancer patients.MethodsWe performed a meta-analysis of published articles on the utility of baseline NLR in predicting outcomes in patients treated with immune checkpoint inhibitors (ICIs) using Review Manager, version 5.3. Seven studies on the prognostic utility of NLR in ICI treatment were included in this analysis. For outcomes of interest, the hazard ratios (HRs) were computed. Subgroup analyses were planned based on type of malignancy and type of immune checkpoint inhibitor.Results/discussionA high NLR resulted in worse overall survival (OS) (HR, 1.92; 95% CI, 1.29–2.87; p=0.001) and progression-free survival (PFS; HR, 1.66; 95% CI, 1.38–2.01; p<0.00001) across types of malignancies studied (melanoma, non-small-cell lung cancer, and genitourinary cancer). Subgroup analysis across different types of malignancies treated with ICI showed similar results for OS and PFS. The single study on genitourinary cancers also showed worse OS and PFS (OS: HR, 1.82; 95% CI, 1.29–2.87; p=0.001 and PFS: HR, 1.83; 95% CI, 0.97–3.44; p=0.06). A high NLR also showed worse OS and PFS across all ICIs (ipilimumab, nivolumab, and unspecified or pooled pembrolizumab and nivolumab; OS: HR, 1.92; 95% CI, 1.29–2.87; p=0.001 and PFS: HR, 1.66; 95% CI, 1.38–2.01; p<0.00001). Subgroup analysis by type of ICI showed similar results.ConclusionA high NLR is associated with poorer outcomes across studies. This shows that NLR has the potential as a readily available prognostic indicator for patients receiving ICI based on available studies. Studies utilizing more stringent design may serve to better determine the utility of this tool.

Background Convalescent plasma has been widely used to treat COVID-19 and is under investigation in numerous randomized clinical trials, but results are publicly available only for a small number of trials. The objective of this study was to assess the benefits of convalescent plasma treatment compared to placebo or no treatment and all-cause mortality in patients with COVID-19, using data from all available randomized clinical trials, including unpublished and ongoing trials (Open Science Framework, https://doi.org/10.17605/OSF.IO/GEHFX). Methods In this collaborative systematic review and meta-analysis, clinical trial registries (ClinicalTrials.gov, WHO International Clinical Trials Registry Platform), the Cochrane COVID-19 register, the LOVE database, and PubMed were searched until April 8, 2021. Investigators of trials registered by March 1, 2021, without published results were contacted via email. Eligible were ongoing, discontinued and completed randomized clinical trials that compared convalescent plasma with placebo or no treatment in COVID-19 patients, regardless of setting or treatment schedule. Aggregated mortality data were extracted from publications or provided by investigators of unpublished trials and combined using the Hartung–Knapp–Sidik–Jonkman random effects model. We investigated the contribution of unpublished trials to the overall evidence. Results A total of 16,477 patients were included in 33 trials (20 unpublished with 3190 patients, 13 published with 13,287 patients). 32 trials enrolled only hospitalized patients (including 3 with only intensive care unit patients). Risk of bias was low for 29/33 trials. Of 8495 patients who received convalescent plasma, 1997 died (23%), and of 7982 control patients, 1952 died (24%). The combined risk ratio for all-cause mortality was 0.97 (95% confidence interval: 0.92; 1.02) with between-study heterogeneity not beyond chance (I2 = 0%). The RECOVERY trial had 69.8% and the unpublished evidence 25.3% of the weight in the meta-analysis. Conclusions Convalescent plasma treatment of patients with COVID-19 did not reduce all-cause mortality. These results provide strong evidence that convalescent plasma treatment for patients with COVID-19 should not be used outside of randomized trials. Evidence synthesis from collaborations among trial investigators can inform both evidence generation and evidence application in patient care.

Evasion of immune destruction is considered one of the hallmarks of cancer. Chronic inflammation can enable immune escape by suppressing immune surveillance and permitting the development of tumors and creating a tumor microenvironment that sustains cancer. This includes generating mechanisms that prevent the effectiveness of anti-tumor treatment including immune checkpoint inhibitor therapy. In this review, we explore the interplay of inflammation and immunosuppression, their effects on the tumor microenvironment, and their implications for immune checkpoint inhibitor therapy particularly in the context of predictive biomarkers for their use.

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