The role of preoperative immune cell metrics in renal cell carcinoma with a tumor thrombus

Introduction: The objective of this study was to stratify preoperative immune cell counts by cancer specific outcomes in patients with renal cell carcinoma (RCC) and a tumor thrombus after radical nephrectomy with tumor thrombectomy. Methods: Patients with a diagnosis of RCC with tumor thrombus that underwent radical nephrectomy with thrombectomy across an international consortium of seven institutions were included. Patients who were metastatic at diagnosis and those who received preoperative medical treatment were also included. Retrospective chart review was performed to collect demographic information, past medical history, preoperative lab work, surgical pathology, and follow up data. Neutrophil counts, lymphocyte counts, monocyte counts, neutrophil to lymphocyte ratios (NLR), lymphocyte to monocyte ratios (LMR), and neutrophil to monocyte ratios (NMR) were compared against cancer-specific outcomes using independent samples t-test, Pearson's bivariate correlation, and analysis of variance. Results: One hundred forty-four patients were included in the study, including nine patients who were metastatic at the time of surgery. Absolute lymphocyte count preoperatively was greater in patients who died from RCC compared to those who did not (2 vs 1.4; p < 0.001). Patients with tumor pathology showing perirenal fat invasion had a greater neutrophil count compared to those who did not (7.5 vs 5.5; p = 0.010). Patients with metastatic RCC had a lower LMR compared to those without metastases after surgery (2.5 vs 3.2; p = 0.041). Tumor size, both preoperatively and on gross specimen, had an interaction with multiple immune cell metrics (p < 0.05). Conclusions: Preoperative immune metrics have clinical utility in predicting cancer-specific outcomes for patients with RCC and a tumor thrombus. Additional study is needed to determine the added value of preoperative serum immune cell data to established prognostic risk calculators for this patient population.