Association of baseline inflammatory biomarkers and clinical outcomes in patients with advanced renal cell carcinoma treated with immune checkpoint inhibitors.

Background: Immune checkpoint inhibitors (ICIs) have become the mainstay treatment of metastatic kidney cancer, demonstrating enhanced outcomes and durable responses in select patient subgroups. However, identifying reliable prognostic biomarkers for treatment outcomes remains challenging.

Objectives: This study aimed to assess the correlation between baseline inflammatory markers and overall survival (OS), progression-free survival (PFS), and clinical benefit (CB) in metastatic kidney cancer patients receiving ICIs. CB was defined as patients achieving stable disease, partial response, or complete response.

Design: Retrospective, single-center study.

Methods: A retrospective analysis was conducted on 401 adult patients with advanced kidney cancer treated with ICIs at Emory Winship Cancer Institute between 2018 and 2023. Modified Glasgow Prognostic Score (mGPS), neutrophil-to-lymphocyte (NLR), monocyte-to-lymphocyte (MLR), platelet-to-lymphocyte (PLR), and neutrophil-to-eosinophil ratios (NER) were collected from baseline blood samples.

Results: Among 401 patients (median age, 66; 71% male; 21% Black/African American), median follow-up was 43.0 months (95% CI, 36.6-51.4). Patients with mGPS scores of 0 had longer OS than those with a score of 1 (hazard ratio (HR), 0.38; 95% CI, 0.23-0.62; p < 0.001) and 2 (HR, 0.37; 95% CI, 0.20-0.67; p = 0.001), and longer PFS compared to patients with mGPS scores of 1 (HR, 0.66; 95% CI, 0.44-0.98; p = 0.039) and 2 (HR, 0.44; 95% CI, 0.29-0.67; p < 0.001). Low baseline NLR was associated with longer PFS (HR, 0.73; 95% CI, 0.54-0.97; p = 0.032). Low baseline MLR correlated with improved OS (HR, 0.60; 95% CI, 0.44-0.83; p = 0.002) and PFS (HR, 0.73; 95% CI, 0.55-0.97; p = 0.031). Similarly, low baseline PLR was associated with higher CB likelihood (odds ratio (OR), 2.20; 95% CI, 1.31-3.69; p = 0.003), and low baseline NER was linked to improved OS (HR, 0.63; 95% CI, 0.46-0.87; p = 0.004), PFS (HR, 0.67; 95% CI, 0.51-0.88; p = 0.003), and higher CB (OR, 2.04; 95% CI, 1.20-3.46; p = 0.008).

Conclusion: Lower levels of systemic inflammatory markers are associated with more favorable clinical outcomes with ICI treatment. Prospective studies are needed for further validation.