[A case-control study of multiple myeloma patients with central nervous system involvement]

Objective: To investigate the treatment options for multiple myeloma patients with central nervous system involvement (CNS-MM) , as well as their clinical characteristics and prognostic factors. Methods: Between January 2011 and January 2022 our center diagnosed 18 people with CNS-MM. A retrospective analysis was done on the clinical information from the initial diagnosis and central nervous system involvement, and it was compared to 1∶3 matched newly diagnosed MM from the same period. Analysis was done on the clinical characteristics and survival rates of the two groups. Results: In patients with CNS-MM, the median time of onset was 14.2 (0.9-79.6) months and the median overall survival (OS) was 30.5 months from initial diagnosis and only 3.8 months in patients after CNS involvement. The CNS-MM patients showed more IgD type (P=0.010) , severer anemia (P=0.014) , a higher proportion of bone marrow plasma cells (P=0.013) , more extramedullary lesions (P=0.001) , and increased lactic dehydrogenase (LDH) (P=0.009) when compared to the control group. Lenalidomide or pomalidomide-based combinations had higher rates of hematology and CNS remission than bortezomib or daratumumab-based regimens (75.0% vs 16.7% , P=0.019) . Patients who received IMiD-based regimens and had 2 high-risk factors at initial diagnosis (high LDH and extramedullary lesions) had a significantly lower incidence of CNS-MM (P=0.026) . At the initial diagnosis, LDH (P=0.008, HR=7.319, 95% CI 1.663-32.219) and extramedullary lesions (P=0.006, HR=8.054, 95% CI 1.828-35.486) were independent risk factors for the occurrence of CNS-MM. Conclusion: Patients with CNS-MM had a poor prognosis. Patients with high LDH or extramedullary lesions at the time of the initial diagnosis are more likely to have CNS-MM. The prognosis of this patient may be improved by immunoregulator-based therapy.