Extramedullary Intracranial Localization of Multiple Myeloma and Treatment with Novel Agents: a Retrospective Survey of 50 Patients

Background: Intracranial involvement in multiple myeloma is extremely rare. The effect of new drugs (eg, thalidomide, bortezomib, lenalidomide) with respect to old drugs (eg, alkylators, steroids) has not been reported.

Methods: We collected clinical and biological data of patients presenting with an osteo-dural or primary dural multiple myeloma (OD-DMM) or a central nervous system myelomatosis (CNS-MM) by sending a questionnaire to the centers of the Gruppo Italiano Malattie Ematologiche dell'Adulto (GIMEMA).

Results: A total of 50 patients were registered. New therapies were used in 35 patients, whereas 15 patients received old treatments. Twenty-five out of 50 patients obtained a complete remission or a very good partial remission (CR+VGPR). Overall survival (OS) for CNS-MM was 6 months, for OD-DMM 25 months. OS was 25 months for patients treated with new agents versus 8 months with old agents. Improved OS and progression-free survival were predicted by response (CR+VGPR) and by patients who underwent stem cell transplantation versus chemotherapy. β2-Microglobulin >5 mmol/L was a poor prognostic factor. Multivariate analysis showed poor survival for patients with β2-microglobulin >5 mmol/L and better survival for patients achieving CR+VGPR.

Conclusions: The overall data highlight the relevance of therapy with new drugs in intracranial myeloma, providing a framework for future clinical trials.