A Case of Resistance to Systemic Therapy in Hypermutation of Colorectal Cancer

• Published in: Gan to kagaku ryoho Vol. 45; no. 13; p. 2476
• Main Authors: Tanaka, Kana, Shimada, Yoshifumi, Tajima, Yosuke, Yamada, Saki, Hotta, Shinnosuke, Nakano, Mae, Nakano, Masato, Kameyama, Hitoshi, Miura, Kohei, Ichikawa, Hiroshi, Nagahashi, Masayuki, Nogami, Hitoshi, Maruyama, Satoshi, Takii, Yasumasa, Wakai, Toshifumi
• Format: Journal Article
• Language: Japanese
• Published: Japan 01-12-2018
• Subjects: Aged; Antineoplastic Combined Chemotherapy Protocols - therapeutic use; Colorectal Neoplasms; Fluorouracil; Humans; Leucovorin; Liver Neoplasms - drug therapy; Liver Neoplasms - secondary; Male; Mutation; MutS Homolog 2 Protein - genetics; Organoplatinum Compounds; Rectal Neoplasms - drug therapy; Rectal Neoplasms - genetics; Rectal Neoplasms - pathology; Retrospective Studies
• ISSN: 0385-0684

A 78-year-old man was admitted with diarrhea. Colonoscopy and computed tomography(CT)revealed rectal cancer with multiple liver metastases. Low anterior resection was performed for local control. After the operation, 5 courses of mFOLFOX6 plus bevacizumab chemotherapy were administered as first-line systemic therapy, but CT showed progressive disease with liver metastases. After the first-line systemic therapy, 2 courses of FOLFIRI plus bevacizumab chemotherapy were performed as second-line systemic therapy, but CT also revealed progressive disease with liver metastases. We retrospectively performed comprehensive genomic sequencing with a 415-gene panel and found that the patient had a hypermutation subtype. Interestingly, the panel also revealed that he had mismatch-repair(MMR)deficiency with MSH2 mutation, which is reported as a possible cause of resistance to 5-fluorouracil in colorectal cancer.