This therapy is selected when treatment (surgery or isotope therapy) that has been used for advanced thyroid cancer has been significantly ineffective. Molecular targeted drugs are administered orally every day, in principle. At present, 3 molecular targeted drugs (sorafenib [Nexavar®], lenvatinib [Lenvima®] and vandetanib [Caprelsa®]) for thyroid cancer are covered by health insurance.
Cancer cells encourage the growth new feeder blood vessels to obtain nutrients. Molecular targeted drugs mainly inhibit the growth of blood vessels, thereby exerting antitumor effects (effects to shrink tumors).
Types of drugs that can be used vary depending on the type of thyroid cancer.
Sorafenib; Papillary carcinoma, follicular carcinoma and medullary carcinoma
Lenvatinib; All types of thyroid cancer
Vandetanib; Only medullary carcinoma
*In principle, papillary carcinoma and follicular carcinoma are indications for this therapy, if resistant to radioactive iodine isotope therapy.
Each drug has its own adverse reactions. Oral treatment should be continued with as high a dose as possible, with the drug being withdrawn or the dose reduced depending on the extent of the adverse reactions, typical reactions being as follows:
Sorafenib: Hand and foot syndrome, hypertension, diarrhea, etc.
Lenvatinib: Hypertension, diarrhea, proteinuria, anorexia, thrombocytopenia, etc.
Vandetanib: Eruption, diarrhea, corneal opacity, electrocardiographic abnormalities, etc.
In our hospital, patients are hospitalized for approximately 1 week when starting oral treatment to receive an explanation of the management of oral treatment, precautions, etc. and to monitor for adverse reactions. After that, patients receive outpatient care.
Because the drugs are expensive, we recommend patients to use the high-cost medical care benefit system, etc.