Tumor Lysis Syndrome in a Patient with BRAF Mutated Colon Cancer Treated with Cetuximab and Encorafenib.

Tumor lysis syndrome (TLS) is a fatal complication associated with chemotherapy. We herein report a case of TLS in a 73-year-old woman with metastatic BRAF mutated colon cancer after she received combined treatment with cetuximab and encorafenib. The serum uric acid, urea nitrogen, and creatinine levels were elevated on day four of the first cycle. The fibrin degradation product (FDP) and D-dimer levels were also high. Diuresis and rasburicase were initiated for TLS, and the laboratory data all normalized on day 8. Thus, the possibility of TLS being induced by targeted drugs in patients with solid tumors, including colorectal cancer, must not be overlooked.