Risk of thyroid dysfunction in patients with solid tumors treated with VEGF receptor tyrosine kinase inhibitors: a critical literature review and meta analysis

We performed a systematic review and meta-analysis of thyroid function abnormalities associated with seven vascular endothelial growth factor receptor (VEGFR) targeted tyrosine kinase inhibitors (sorafenib, sunitinib, axitinib, cediranib, pazopanib, regorafenib and vandetanib). Eligible studies included randomized Phase II and III trials of patients with solid tumors on sorafenib OR sunitinib OR axitinib OR cediranib OR pazopanib OR regorafenib OR vandetanib; describing events of hypothyroidism or hyperthyroidism. Our search strategy yielded 195 potentially relevant citations on the seven agents from Pubmed/Medline, CENTRAL Cochrane registry and ASCO meeting library. After exclusion of ineligible studies, a total of 12 clinical trials were considered eligible for the meta-analysis, including six sunitinib studies, four cediranib studies and two axitinib studies. Patients treated with these agents had a significantly increased risk of all-grade hypothyroidism and the relative risk (RR) of all-grade hypothyroidism was 3.59 (95% CI = 2.40-5.38, p <= 0.0001). Exploratory subgroup analysis showed no effect of tumor types or agent used on the RR of hypothyroidism. Our meta-analysis has demonstrated that these three agents are associated with a significantly increased risk of all-grade hypothyroidism; with no difference - on subgroup analysis - between sunitinib and cediranib. Clinicians should be aware of these risks and perform regular thyroid function monitoring.