Epidemiological characteristics and cause-specific survival analysis of plasmablastic lymphoma (PBL) using the SEER database.

Abstract

e19546 Background: Plasmablastic lymphoma (PBL), a variant of diffuse large B-cell lymphoma, is a rare and aggressive malignancy. Minimal guidelines exist for its diagnosis and standard of care. Hence, we studied the epidemiological characteristics and survival variables of PBL patients by using the SEER 20 database. Methods: A total of 229 cases of PBL (WHO ICD-O-3 codes 9735/3) were identified between 2000 and 2015, after excluding 66 cases with unknown survival time or no microscopic confirmation. The epidemiological characteristics and the survival variables included were age, gender, ethnicity, Ann Arbor stage, B-symptoms, and site. The overall 5-year survival (OS), cause-specific 5-year survival (CSS), and cause-specific survival plots across different strata were plotted using the Kaplan Meier Method. The analysis was done using the Cox proportional hazard regression model (p < 0.05). Results: The incidence of PBL was 0.03 per 100,000 cases. It was more common in adults less than 60 years (61.57%), males (79.04%), and White ethnicity (72.49 %). There were more cases of patients with advanced Ann Arbor stages (3 or 4) PBL (52.84%), although some patients (5.68%) had unknown staging. There were 55.02% of extranodal cases, and 28.38% of patients had B-symptoms. The OS was 36.55%, and the CSS was 46.5%. CSS did not differ significantly based on age, race, or gender. However, the absence of B-symptoms was associated with better CSS (HR: 0.654, 95% CI: 0.455-0.941, p: 0.022). Nodal involvement (HR: 1.553, 95% CI: 1.135-2.124, p: 0.006) and advanced stages 3 or 4 (HR: 1.414, 95% CI: 1.018-1.962, p: 0.038) were also linked to a poor CSS. Conclusions: PBL patients with a primary nodal involvement and advanced staging (3 or 4) had poor CSS, and the absence of B-symptoms was associated with a better outcome. Age, gender, and ethnicity had no discernible effects on survival. We did not include therapeutic options in our study, and hence, further studies analyzing the impact of treatment options on PBL survival can be conducted.[Table: see text]