Relationship between toxicities and clinical benefits of newly approved tyrosine kinase inhibitors in thyroid cancer: A meta-analysis of literature.

Background: The aim of this meta-analysis was to analyze the relationship of toxicities and clinical benefits of newly approved lenvatinib and sorafenib to thyroid cancer (TC) in patients.

Materials And Methods: Three major medical databases, PubMed, EMBASE, and ISI web of science were systematically searched to identify all studies on lenvatinib and sorafenib in TC. A meta-analysis was performed to clarify the toxicities and clinical benefits of newly Food and Drug Administration (FDA) approved lenvatinib and sorafenib to thyroid cancer.

Results: Ten studies (n = 749) were included which evaluated the toxicities and clinical benefits of newly FDA approved lenvatinib and sorafenib to thyroid cancer. 537 (71.7%) of the 749 patients bearing TC (radioiodine-refractory, differentiated thyroid cancer) clinical benefits from lenvatinib or sorafenib, and serious adverse events occurred in 430 (57.4%) of the 749 patients ([risk ratio (RR) = 1.27, 95% confidence interval (CI) = (1.05-1.53), P = 0.01]). While 31 (4.1%) of the 749 patients died due to various reasons, that mainly accounts for severe bleeding events and cardiac arrest. The clinical benefit is obvious compared to deaths ([RR = 17.06, 95% CI = (12.08-24.11), P < 0.001]). Subgroup analyses were then conducted according to cancer type (radioiodine-refractory thyroid cancer [RR-TC] and TC). We found that in treating RR-TC, the clinical benefits are close to toxicities. While in treating TC, the clinical benefits are better than toxicities. And we found that sorafenib and lenvatinib might be proper to deal with TC (benefits rate 79.7%) compared to RR-TC (benefits rate 69.5%), taking consider of toxicities.

Conclusions: Lenvatinib and sorafenib are useful in the treatment of TC. Although, their toxicities remain high (57.4%) in the patients, the death rate is controlled (4.1%). Take consider of toxicities, lenvatinib, and sorafenib are more useful for TC compared to RR-TC.