Cachexia index in predicting outcomes among patients receiving immune checkpoint inhibitor treatment for metastatic renal cell carcinoma

Abstract

Introduction: Immune checkpoint inhibitors (ICI) have transformed treatments for patients with metastatic renal cell carcinoma (mRCC). Although some patients benefit greatly from ICI treatments, an effective marker to determine which patients will benefit from these treatments is lacking. Moreover, chronic inflammation and sarcopenia have been associated with poor survival rates among cancer patients. Accordingly, in this study, we investigated how the cachexia index (CXI), used as a combined score for sarcopenia and chronic inflammation, affects the survival outcomes of patients with mRCC receiving ICI.

Methods: We retrospectively screened data from 52 mRCC patients who had followed up between October 2010 and October 2021 after receiving ICI as a second-line or later treatment. Patients' respective basal CXI score were calculated according to the following formula, based on their L3 vertebral skeletal musculoskeletal area (SMI), neutrophil-lymphocyte ratio (NLR), and albumin (Alb) levels: CXI = (SMI x Alb) / NLR. Additionally, we analyzed how patients' subcutaneous adipose tissue (SAT), body mass index (BMI), ECOG performance status, The International Metastatic Renal Cell Carcinoma Database Consortium (IMDC) risk score, nephrectomy status, sites of metastasis, and histological subtypes affected survival outcomes.

Results: Our univariate analysis significantly associated CXI score, NLR, nephrectomy status, and patient age with overall survival (OS). However, only CXI scores' significance was confirmed through multivariate analysis. The median OS (mOS) was 7 months for patients whose CXI score < the median value and 48 months for patients with a CXI score ≥ the median value. (HR 4.5, 95% CI [1.9-11], p = 0.001). Only CXI was significantly associated with progression-free survival (PFS) outcomes. The median progression-free survival (mPFS) was 4 months for patients whose CXI score < the median value and 17 months for patients with a CXI score ≥ the median value. (HR 2.6, 95% CI [1.3, 5.3], p = 0.007). Sarcopenia, sarcopenic obesity, and sarcopenia combined with NLR were not found to significantly affect OS.

Conclusion: Our findings suggest that CXI score, a combined indicator of sarcopenia and chronic inflammation parameters, may serve as a useful marker in predicting the outcomes of ICI-based treatments for mRCC patients.

Keywords: Biomarker; Cancer cachexia; Immune checkpoint inhibitor; Sarcopenia; Systemic inflammation; mRCC.