Secondary myeloma in patients with chronic lymphoblastic leukemia: A case report and analysis of data from SEER database

Both chronic lymphocytic leukemia (CLL) and multiple myeloma (MM) are common hematological malignancies originating from mature B cells of different differentiation stage. However, it is quite rare that MM could develop after CLL diagnosed. We reported a 66-year-old female progressed forward myeloma 3 years after she was diagnosed as CLL and conducted an analysis to investigate the epidemiology and clinical features among these patients based on the Surveillance, Epidemiology, and End Results (SEER) database. Our data demonstrated that CLL patients were 19% less likely to develop myeloma than general U.S. population (standardized incidence ratio 0.81; 95% confidence interval 0.62-1.03), although without statistical difference. The median overall survival from CLL diagnosed was 90 (58.1-121.9) months, which was the same as general CLL patients according to historical data. But the outcomes of secondary MM was much poorer than general MM patients. Age and gender were independent factors that impact the survival among these patients.