The Role of Spleen Volume Change in Predicting Immunotherapy Response in Metastatic Renal Cell Carcinoma.

Resistance to immune checkpoint inhibitors (ICI) is a significant issue in metastatic renal cell carcinoma (mRCC), as it is in the majority of cancer types. An important deficiency in immunooncology today is the lack of a predictive factor to identify this patient group. Myeloid-derived suppressor cells (MDSC) are a type of cell that contributes to immunotherapy resistance by inhibiting T cell activity. While it accumulates in the tumor microenvironment and blood, it can also accumulate in lymphoid organs such as the spleen and cause splenomegaly. Therefore we aimed to evaluate the effect of increase in splenic volume, which can be considered as an indirect indicator of increased MDSC cells, on survival outcomes in mRCC patients. We analyzed 45 patients with mRCC who received nivolumab as a second-line or subsequent therapy. Splenic volume was analyzed from baseline imaging before starting nivolumab and from control imaging performed within the first 6 months of treatment initiation. Additionally, we analyzed how patients’ body mass index (BMI), IMDC risk score, ECOG performance status, nephrectomy status, neutrophil-lymphocyte ratio (NLR), Platelet-to-lymphocyte ratio (PLR) and sites of metastasis. Median splenic volume change was 10