Anemia Before and after Tyrosine Kinase Inhibitors Treatment Indicate A Poor Prognosis in Patients with Metastatic Renal Cell Carcinoma: A Systematic Review and Meta-Analysis

Abstract

Aim: It was reported that metastatic renal cell carcinoma (mRCC) patients with anemia had a poor prognosis after cytokine therapy. However, it is still unknown in the tyrosine kinase inhibitors (TKIs) era. This study aimed to evaluate the role of hemoglobin levels in predicting the prognosis of mRCC patients receiving TKIs treatment.

Materials and methods: We searched Pubmed, Web of Science, EMBASE, and Cochrane Library databases until February 1, 2022, for studies comparing outcomes of mRCC patients who had different hemoglobin levels before and after TKIs therapy. The hazard ratios (HRs) and their 95% confidence interval (CIs) of overall survival (OS) and progression-free survival (PFS) were extracted to evaluate the prognostic value of hemoglobin.

Results: 37 studies were included. Patients with mRCC had poor OS (HR = 1.83, 95% CI: 1.52-2.21, P < 0.001, I2 = 89.0%) and poor PFS (HR = 1.59, 95% CI: 1.42-1.79, P < 0.001, I2 = 47.2%) if they were diagnosed with anemia before the administration of TKIs. The OS (HR = 1.92, 95% CI: 1.57-2.34, P < 0.001, I2 = 0) and PFS (HR = 1.66, 95% CI: 1.19-2.33, P = 0.003, I2 = 0) of patients getting anemia after TKIs treatment were worse than those of patients without anemia. The increase in hemoglobin level after TKIs treatment was not associated with longer OS (HR = 0.91, 95% CI: 0.25-3.27, P = 0.883, I2 = 86.9%) or PFS (HR = 0.67, 95% CI: 0.39-1.12, P = 0.128, I2 = 63.8%).

Conclusions: Pre-treatment and post-treatment anemia were predictors of poor outcomes in mRCC patients who received TKIs therapy. The post-treatment increase in hemoglobin levels was not associated with a better prognosis in these patients.

Funding Information: The authors did not receive any funding.

Declaration of Interests: The authors declare that they have no conflict of interest.

Keywords: metastatic renal cell carcinoma, tyrosine kinase inhibitors, anemia, hemoglobin, prognosis