Microsatellite Instability-high Intrahepatic Cholangiocarcinoma with Portal Vein Tumor Thrombosis Successfully Treated with Pembrolizumab
Atsushi Naganuma, Takayoshi Sakuda, Tatsuma Murakami, Kosuke Aihara, Yuta Watanuki, Yuhei Suzuki, Erina Shibasaki, Tomoyuki Masuda, Sanae Uehara, Hidetoshi Yasuoka, Takashi Hoshino, Tomohiro Kudo, Hiroshi Ishihara, Tetsushi Ogawa, Yoshizumi Kitamoto, Akira Ogawa
Abstract
A 60-year-old man presented with postoperative recurrence of intrahepatic cholangiocarcinoma with right portal vein tumor thrombosis (PVTT). After failure of standard chemotherapy, a liver biopsy showed that his microsatellite instability (MSI) status was high. Treatment with the immune checkpoint inhibitor (ICI) pembrolizumab was commenced, which resulted in a partial response and resolution of the PVTT. There were no significant immune-related adverse events. According to recently published reports, the frequency of MSI-high biliary tract cancer (BTC) is about 0-2.1%, which is extremely rare. However, ICIs may be effective in patients with MSI-high BTC, such as the present patient.