Inflammatory biomarkers predict outcomes of patients with radioactive iodine refractory thyroid cancer treated with sorafenib.

[BACKGROUND] The objective of this multicenter, retrospective cohort study was to evaluate the ability of inflammatory biomarkers representing the host immune system to predict outcomes in 70 patients with progressive radioactive iodine (RAI)-refractory thyroid cancer who were treated with sorafenib.

[METHOD] Patients were divided into low and high inflammatory biomarker groups based on median values. Progression-free survival (PFS) and overall survival (OS) were assessed based on the lymphocyte-to-monocyte ratio (LMR), neutrophil-to-lymphocyte ratio (NLR), and platelet-to-lymphocyte ratio (PLR).

[RESULTS] The median LMR, NLR, and PLR values were 3.4, 2.2, and 140.1, respectively. No significant differences were observed in baseline characteristics of high and low LMR, NLR and PLR groups. Median PFS values were 6.6 and 19.5 months in the low and high LMR groups, respectively (P < 0.001). Compared with the high NLR and PLR groups, PFS was significantly prolonged in the low NLR and PLR groups (P = 0.003 and P = 0.041 respectively). In the multivariate analysis, low LMR and high NLR were associated with poor PFS after adjusting for multiple confounding factors including age, sex, pathology, disease-related symptoms, serum thyroglobulin level, lung-only metastasis, cumulative RAI dose, time from diagnosis, and longer diameter of the target lesion (hazard ratio, HR = 2.42; 95% confidence interval, CI 1.25-4.71; P = 0.009, and HR = 2.09; CI, 1.06-4.14; P = 0.033, respectively). High LMR, low NLR, and low PLR were significantly associated with prolonged OS (P = 0.011, P = 0.023, and P = 0.007, respectively). Patients with at least one risk factors for inflammatory biomarkers presented a significantly lower PFS (HR 2.29; CI, 1.36-3.84; P = 0.003) and OS (HR 2.95; CI, 1.49-5.81; P = 0.006) than patients without any risk factor.

[CONCLUSION] Baseline inflammatory biomarkers successfully predicted PFS and OS in patients with progressive RAI-refractory thyroid cancer treated with sorafenib. These prognostic biomarkers might help arrive at appropriate clinical decisions regarding the use of sorafenib.