Traditional medical treatment is mainly chemotherapy, while targeted therapy and immunotherapy are new systemic treatments that have emerged in recent years. For DTC and MCT, chemotherapy is ineffective, and targeted therapy has some efficacy. The main medical treatment for ATC is chemotherapy, and targeted therapy has certain efficacy.
(i) Molecular targeted therapy.
Differentiated thyroid cancer has high expression of vascular endothelial growth factor and its receptor, as well as genetic alterations such as BRAFV600E mutation, RET rearrangement and RAS point mutation. Multikinase inhibitors acting on these targets may prolong median progression-free survival and result in tumor shrinkage in some patients.
For patients with more rapidly progressing, symptomatic advanced radioiodine-refractory differentiated thyroid cancer, the multikinase inhibitor sorafenib may be considered. The approved indications for sorafenib in China are: progressive radioiodine-refractory differentiated thyroid cancer with local recurrence or metastasis.
For advanced MTC that is rapidly progressing and inoperable, the approved targeted therapy in China is anlotinib.
(ii) Chemotherapy.
For stage IVA and IVB ATC, chemotherapy can be considered in addition to radiotherapy. Chemotherapy can be used simultaneously with radiotherapy or can be given adjuvantly after radiotherapy. The drugs used include paclitaxel, anthracyclines, and platinum, and the specific regimens are shown in Table 9. For concurrent chemoradiotherapy, the chemotherapy regimen is recommended as a weekly regimen.
For stage IVC undifferentiated thyroid cancer, systemic chemotherapy may be considered. Recommended regimens for stage IVC undifferentiated thyroid cancer include paclitaxel combined with platinum, doxorubicin combined with doxorubicin, paclitaxel alone, and doxorubicin alone. The specific regimens are shown in Table 10.
(iii) Immunotherapy.
It is still in the clinical research stage. For patients with thyroid cancer who have failed other treatments and whose disease is still progressing, it is recommended to participate in clinical studies related to immunotherapy.
(iv) Indications for targeted therapy.
According to the results of current clinical studies, targeted therapy may prolong the progression-free survival of patients, but most of them cannot improve the overall survival. After the start of targeted therapy, once the disease progresses, it may show accelerated progression. Therefore, it is recommended to strictly control the indications for targeted therapy. Especially for DTC, it is recommended to consider targeted therapy when surgical treatment and 131I therapy are not effective and the disease still progresses significantly.