Purpose: There are no robust data on hemoglobin (Hb), lactate dehydrogenase (LDH), and calcium variability for overall survival (OS) in patients with metastatic renal cell carcinoma (mRCC) treated with vascular endothelial growth factor (VEGF)-targeted therapy. We aim to evaluate prognostic implications of Hb, LDH, and calcium variability and establish a novel risk stratification model in RCC patients receiving targeted therapies.
Methods: We retrospectively studied an unselected cohort of patients with mRCC, who were treated with tyrosine kinase inhibitors. We assessed LDH variability, Ca variability, and Hb variability with various methods using standard deviation and fluctuation across thresholds. Kaplan-Meier and log-rank analyses were employed on OS and multivariate Cox proportional hazard model analyzed clinical parameters for their prognostic relevance.
Results: A total of 59 patients intermediate-risk group according to the Memorial Sloan-Kettering Cancer Center with mRCC who had early progressed after first-line therapy with interferon-α were included in this retrospective single-center study conducted between February 2008 and December 2011. The mean Hb was 12.4 g/dl (min-max 9.1-15.2) throughout the study. Multivariable-adjusted Cox regression showed that patients in the consistently low-Hb group and patients in the low-amplitude and high-amplitude groups had a statistically significant increase in risk compared with patients who were consistently on target (HR 4.1; 95 % CI 1.3-12.9 and HR 2.9; 95 % CI 1.05-8.1 and HR 4.4; 95 % CI 1.7-11.1, respectively). On the other hand, the higher mean LDH (LDH more than 1 >upper limit of normal) was associated with OS. LDH variability and Ca variability were not associated with mortality.
Conclusions: In patients with mRCC treated with VEGF-targeted therapy, Hb variability and mean LDH level might be associated with OS. This should be investigated prospectively.