Serum C-reactive Protein Level Predicts Overall Survival for Clear Cell and Non-Clear Cell Renal Cell Carcinoma Treated with Ipilimumab plus Nivolumab

SIMPLE SUMMARY: Elevated serum C-reactive protein (CRP) level is one of the most established markers of systemic inflammation, potentially affecting tumor immune-microenvironmental status. Thus, we assessed the predictive value of serum CRP level for metastatic renal cell carcinoma (mRCC) treated with first-line ipilimumab and nivolumab using our real-world clinical dataset including non-clear cell RCC (nccRCC). Treatment record of 74 patients treated with ipilimumab and nivolumab for intermediate or poor-risk RCC defined by IMCD (international metastatic RCC database consortium). The one-year overall survival (OS) rate and objective response rate were 65% and 41% for all 74 mRCC patients, respectively. The receiver operating characteristic curve identified 1.0 mg/dL of serum CRP level as an ideal cut-off for predicting overall survival (OS). OS for patients with CRP > 1 mg/dL was significantly shorter than those with CRP < 1 mg/dL in both ccRCC (58 patient: p = 0.009) and nccRCC (16 patients: p = 0.008). The present study suggested that serum CRP level is a prognostic indicator for OS. ABSTRACT: Serum C-reactive protein (CRP) is known to be a biomarker for systemic inflammatory reactions. In the present study, we sought to measure the predictive value of serum CRP level for metastatic renal cell carcinoma (mRCC) treated with first-line ipilimumab and nivolumab using our real-world clinical dataset including non-clear cell RCC (nccRCC). The clinical record of patients who underwent the first-line ipilimumab plus nivolumab treatment for mRCC including ccRCC and nccRCC from 2018 to 2021 was retrospectively analyzed. All patients were diagnosed with either intermediate or poor-risk group defined by IMCD (international metastatic RCC database consortium). In total, 74 patients were involved. The median age was 68 years and 24 (32.4%) patients deceased during the follow-up. Forty-five (61%) and 29 (39%) patients were classified into intermediate and poor-risk groups. The one-year overall survival (OS) rate and objective response rate were 65% and 41% for all 74 mRCC patients, respectively. The receiver operating characteristic curve identified 1.0 mg/dL of serum CRP level as an ideal cut-off for predicting overall survival (OS). Serum CRP > 1.0 mg/dL and nccRCC were the independent predictors for OS in 74 mRCC patients. OS for patients with CRP > 1 mg/dL was significantly shorter than those with CRP < 1 mg/dL in both ccRCC (58 patient: p = 0.009) and nccRCC (16 patients: p = 0.008). The present study indicated that serum CRP level is a prognostic indicator for OS in both ccRCC and nccRCC patients treated with the first-line ipilimumab plus nivolumab treatment.