Undifferentiated carcinoma has the worst outcome of all types of thyroid cancer. Although it accounts for only about 2% of all thyroid malignancies, it is very difficult to treat. The ideal treatment is radical surgery with comprehensive postoperative radiotherapy. However, nearly half of patients with undifferentiated cancer have distant metastases at the time of diagnosis. In addition, most patients also have locally advanced primary cancer sites that invade surrounding organs and are inoperable. Even after radical surgery and postoperative systemic therapy, recurrence or distant metastasis often occurs within a short period of time.
Immunotherapy of tumors has been a hot topic of research in recent years. Immune checkpoint inhibitors such as CTLA-4 inhibitors (eprilimumab, also known as Ipilimumab), PD-1 inhibitors (Nivolumab, Chinese name nabulizumab; Pembrolizumab, Chinese name pablizumab), and PD-L1 inhibitors (Atezolizumab, Chinese name atezolizumab) have been shown to be effective in different tumors. monotherapy), all of which have shown improved outcomes in different tumors and are available in the United States. Among them, nabolutumab and pablizumab were also launched in China in 2018. The response rates for these drugs are around 20% to 40%, depending on the results of different studies.
Although there are no immunotherapies and drugs for undifferentiated thyroid cancer, scholars have turned to explore immunotherapy in the field of undifferentiated cancer in the current situation where conventional treatments are helpless. Existing studies have confirmed that undifferentiated thyroid cancer can express some immune indicators and receive modulation by cytokines, thus making immunotherapy possible. The current studies in this field are relatively few, mostly animal models and case reports. Nonetheless, these cases still show the potential of immunotherapy in undifferentiated thyroid cancer.
Co-written by Dr. Jiaqian Hu, Cancer Hospital of Fudan University