Extraosseous/extramedullary disease (EMD) plays an important role in the development of relapsed and refractory multiple myeloma (RRMM). However, the molecular biology of EMD development has not been well-described and could be important for prognosis and treatment.
Rie Nakamoto-Matsubara, MD, PhD and colleagues analyzed nucleic acid samples from 443 patients with MM seen at Massachusetts General Hospital between 2013 and 2021 to identify specific mutations. The development of EMD in sample patients was diagnosed via imaging and in some instances confirmed by biopsy.
Results showed that patients with KRAS/NRAS/BRAF mutations who developed EMD had a poorer prognosis than those with the same mutations who did not develop EMD. For each mutation, overall survival was lower for patients with EMD than those without.