Combination treatment with tyrosine kinase inhibitors (TKIs) and immunotherapies has shown efficacy in the treatment of multiple cancers, but the immunomodulatory effect of TKIs on the tumor cell phenotype remains unknown in hepatocellular carcinoma (HCC). Given that human lymphocyte antigen class I (HLA-I) is essential for tumor antigen presentation and subsequent antitumor immunity, we examined the effects of regorafenib, as well as other TKIs (sorafenib, lenvatinib and cabozantinib) on HLA-I expression in HCC cell lines. Regorafenib increased cell surface HLA-I and β2-microglobulin protein expression in the presence of interferon γ (IFNγ). The expressions of various genes associated with the HLA-I antigen processing pathway and its transcriptional regulators were also upregulated by regorafenib. Furthermore, we found that regorafenib had an activating effect on signal transducers and activators of transcription 1 (STAT1), and that regorafenib-induced HLA-I expression was dependent on the augmented IFNγ/STAT1 signaling pathway. Trametinib, an inhibitor of the extracellular signal-regulated kinase (ERK) kinase MEK, also activated IFNγ/STAT1 signaling and increased HLA-I expression, whereas the phosphatidylinositol 3-kinase (PI3K) inhibitor buparlisib did not. Given that regorafenib directly inhibits Raf/MEK/ERK signaling, the downregulation of the MEK/ERK pathway appears to be one of the mechanisms by which regorafenib promotes STAT1 activation. Sorafenib, lenvatinib, and cabozantinib also showed the same effects as regorafenib, while regorafenib had most potent effects on HLA-I expression, possibly dependent on its stronger inhibitory activity against the MEK/ERK pathway. These results support the clinical combination of TKIs with immunotherapy for the treatment of HCC.
Copyright © 2021 Takahashi, Umemura, Yano, Okishio, Kataoka, Okuda, Seko, Yamaguchi, Moriguchi, Okanoue and Itoh.

A 54-year-old woman was referred to our hospital with a cervical tumor. CT revealed a cervical tumor extending to the upper mediastinum, tracheal deviation and tumor infiltration in the cervical vessels. She was followed-up because no diagnosis of malignancy was made by cytology. However, 2 months later, a CT scan showed enlargement of the tumor and tracheal stenosis, and a surgical biopsy was performed and she was diagnosed with anaplastic thyroid cancer (ATC). The tracheal tube with tracheal stenosis could not be removed due to the rapid growth of the tumor, necessitating management by mechanical ventilation. Due to the difficulty of surgical resection, she was treated with lenvatinib. A lenvatinib solution was made and administered via a nasogastric tube. After lenvatinib treatment, the tumor volume decreased and the tracheal stenosis improved. The tracheal tube was removed and oral intake became possible. She was discharged and received ambulatory lenvatinib therapy. The tumor was significantly reduced in size, but gradually grew and was exposed through the cervical wound 6 months later. Esophageal perforation occurred 10 months after the start of treatment. Lenvatinib was re-administered via a nasogastric tube. Eleven months later, the patient died of massive bleeding from the exposed cervical tumor. Patients with advanced ATC may require management with mechanical ventilation for airway stenosis or with a nasogastric tube for esophageal stenosis and perforation. We experienced a case in which lenvatinib was safely administered via a nasogastric tube while performing mechanical ventilation.
An anaplastic thyroid cancer patient under mechanical ventilator management was treated with lenvatinib via a nasogastric tube. The lenvatinib solution can easily be prepared and administered via a nasogastric tube. The lenvatinib solution was effective for a patient with difficulty in oral intake. Lenvatinib could also improve the prognosis of an anaplastic thyroid cancer patient with severe airway and esophageal trouble.