Plasma cell leukemia: Updates on demographics and prognostication.

Abstract

e19555 Background: Plasma cell leukemia (PCL) is an uncommon and highly aggressive form of multiple myeloma characterized by the presence of ≥5% circulating plasma cells in the peripheral blood smear. It is classified into primary PCL and secondary PCL. Secondary PCL stems from the transformation of previously diagnosed Multiple Myeloma (MM) and occurs in 0.5-4% patients. The aggressive nature of the neoplasm requires immediate treatment initiation post-diagnosis. The treatment usually involves induction chemotherapy followed by HSCT and maintenance therapy in transplant eligible patients or mere maintenance therapy in transplant ineligible patients. Methods: Data was collected from Surveillance, Epidemiology and End Result database Research Plus Data, 17 Registries, Nov 2023 Sub (2000-2021). Plasma cell leukemia cases were extracted using the ICD Code 9733/3. The data was further stratified based on age, gender, race, treatment options including chemotherapy, and radiation, and median annual household income inflation adjusted to 2022. Survival curves were compared using the GraphPad Prism software. Results: A total of 300 cases of plasma cell leukemia were identified, of which 48% were males and 52% were females. The median age of diagnosis was 66 years. Racial distribution was notable for: White (63.7%), Black (20.67%), Hispanic (10.67%), Asian/Pacific Islander (4.67%) and American Indian/Alaskan (0.33%). 90% of the patients were residents of metropolitan areas, while only 10% were from non-metropolitan areas. The overall median of survival (MoS) was 6 months, with a 1-year survival of 37.9% (CI 95%, 32.4-43.2%), 3-year survival of 18.1% (CI 95%, 14-22.1%), and 5-year survival of 11% (CI 95%, 8-15%). 80% of the patients had expired by the time of data compilation. Patients who received chemo had an overall survival of 10 months. The median of survival (MoS) based on gender was statistically significant for females vs males (8 months vs 5 months) (p 0.0193, Gehan-Breslow-Wilcoxon test). The survival analysis based on age, race, radiation therapy, median household income, and geographic location was not statistically significant. Conclusions: Plasma cell leukemia is an ultra-rare malignancy, with only 300 patients identified in SEER database over a period of 21 years. Superior survival was associated with female gender and treatment involving chemotherapy. The median overall survival was not influenced by age, race, radiotherapy, income or geographical disparities.