Use of multikinase inhibitors/lenvatinib concomitant with antiresorptive therapy for bone metastases from radioiodine‐resistant differentiated thyroid cancer

Bone is the second most common distant metastasis site in differentiated thyroid cancer (DTC) and is normally associated with the presence of other metastases, which are usually radioiodine-resistant. The presence of bone metastasis (BM) determines low survival and greater morbidity due to the frequency of skeletal-related events (SREs), which can be a serious complication of BM. There is evidence that antiresorptive therapy (AT) reduces SREs in other solid tumors, but not yet in DTC BM, for which data are scant. The same is true for systemic therapy with multikinase inhibitors (MKIs). In general, the results for MKI use are well known, although the effect on BM has rarely been evaluated. While MKIs are indicated in current clinical practice guidelines, studies evaluating the benefits and risks of concomitant treatment with MKIs and AT are lacking, and the available data come from small samples in retrospective studies. The objective of this article is to review the latest evidence for concomitant MKIs and AT.