Carfilzomib-induced tumor lysis syndrome in relapsed multiple myeloma: a report of two cases

Background: Tumor lysis syndrome (TLS) is a potentially fatal complication of cancer therapy characterized by severe electrolyte and metabolic abnormalities such as hyperphosphatemia, hyperkalemia, and hypocalcaemia. TLS usually occurs in aggressive hematologic malignancies such as Burkitt lymphoma and acute leukemia. TLS has rarely been observed in multiple myeloma (MM). Case report: We present 2 patients with relapsed MM who developed TLS after the first cycle of carfilzomib treatment. Conclusion: Carfilzomib is a next-generation proteasome inhibitor with proven efficacy in relapsed/refractory MM. Recently, increasing frequency of TLS has been reported in MM, especially after treatment with proteasome inhibitors. The potential complications of TLS should be considered especially during the first cycle of carfilzomib treatment.