Demographics and Survival in Primary Effusion Lymphoma: SEER Database Analysis

Background: Primary effusion lymphoma (PEL) is one of the least common of the AIDS-related lymphomas, accounting for less than 4% of cases. The optimal treatment for primary effusion lymphoma (PEL) remains unclear and there is a paucity of data regarding this neoplasm, which carries a uniformly poor prognosis. Antiretroviral therapy in addition to chemotherapy has shown to improve survival in a few small retrospective studies.

Methods: Between 2002 and 2014, all cases of PEL were extracted from the population-based cancer registries of the Surveillance Epidemiology and End Results program (SEER). Instances of PEL were identified with the ICD-O-3 (9678) histological code. Frequency, demographics, and survival data were assessed using SPSS statistical software.

Results: A total of 117 cases of PEL were identified. PEL was significantly more prevalent in men (89.7%) and in Caucasians (77.8%) with median age at diagnosis of 49 years. Median overall survival in the entire cohort was 6 months; CI, 3.7 to 8.2 months. Of all PEL cases, 62.4% received chemotherapy and 37.6% did not. Those who received chemotherapy had a median overall survival of 10 months vs less than one month when compared to subjects who did not receive chemotherapy (p = 0.002). PEL was the cause of death in 40.2% of the cases. PEL-specific median overall survival was markedly higher (29.000 months) than that of the entire cohort. Multivariable analysis demonstrated that age and race were not associated with mortality. Chemotherapy was associated with decreased mortality risk (HR, 0.45; CI, 0.28 -0.74; p = 0.002)

Conclusions: In confirmation of previously published data, the highest incidence of PEL was found in Caucasian males. Subjects who received chemotherapy were found to have improved overall survival outcome. Other factors not related to PEL were associated with early mortality in this population.