Presence of bone marrow fibrosis in multiple myeloma may predict extramedullary disease

Area of Science:

• Hematology
• Oncology

Background:

• Multiple myeloma (MM) is a hematologic malignancy characterized by plasma cell proliferation.
• Bone marrow fibrosis is a common finding in MM, but its clinical significance remains debated.

Purpose of the Study:

• To investigate the incidence of bone marrow fibrosis in newly diagnosed Japanese MM patients.
• To evaluate the impact of bone marrow fibrosis on clinical characteristics, biological features, and therapeutic outcomes in MM.

Main Methods:

• Analysis of bone marrow fibrosis grading in 91 newly diagnosed Japanese MM patients.
• Correlation of fibrosis with laboratory data, plasma cell percentage, cytogenetics, treatment response, stem cell transplantation outcomes, and survival.
• Investigation of MM cell biological characteristics, including CD49e expression.
• Re-evaluation of fibrosis grading after treatment in a subset of patients.

Main Results:

• 37% of patients exhibited grade 1 bone marrow fibrosis.
• Bone marrow fibrosis did not significantly affect laboratory data, plasma cell burden, cytogenetics, initial treatment response, stem cell engraftment, or overall survival.
• A significantly higher incidence of extramedullary disease was observed at diagnosis in patients with bone marrow fibrosis (p=0.006).
• CD49e expression was downregulated in MM cells from patients with bone marrow fibrosis (p=0.026).
• A reduction in fibrosis was observed in 71% of patients after treatment.

Conclusions:

• Bone marrow fibrosis in MM may not influence treatment outcomes or survival.
• The presence of bone marrow fibrosis might predict the development of extramedullary disease in MM patients.
• Further research is warranted to elucidate the role of fibrosis and CD49e in MM pathogenesis and progression.