Systematic review determining the characteristics of primary bone lymphoma.

Abstract

e19543 Background: Primary Bone Lymphoma (PBL) is defined as a lymphoma originating in an osseous site with no systemic disease. It is rare, constituting around 1% of all lymphomas. Due to its rarity, ascertaining natural history and standard of care treatments are based primarily on small case series but there have been no systematic reviews, randomized control trials or meta-analysis to establish optimal treatment strategies. Methods: We searched MEDLINE, Embase, Scopus and other sources, from each database's inception to September 2022. Outcomes of interest included mortality and progression at different time points, as well as complete response and partial response. Meta-analysis was conducted using the random-effects model. Results: The number of studies matching our inquiry was 51 ranging from 1955 to 2019. Total patients studied were 5,847 of which 3,055 were male and the dominant histology was diffuse large B cell lymphoma with 3,816. Treatment primarily consisted of radiation therapy, chemotherapy, or a combination of the two. Overall mortality at 2, 5 and 10 years was 17%, 29% and 39% respectively. Complete response to initial treatment was noted in 73% of patients. Disease progression at 2 and 5 years was 26% and 29% respectively. Patients aged older than 60 years and multiple sites of disease in the skeleton (such as axial and spine etc.) had worse outcomes with RR 1.76 (P value 0.0027) and 1.133 (P value 0.0167) respectively. Additionally, patients who underwent chemotherapy with radiation vs radiation alone had improved outcomes with a relative risk of 0.38 (P value of 0.0001). Patients who underwent radiation treatment in addition to chemotherapy tended to have improved outcomes with a relative risk of 0.60 but this was not statistically significant with a P value of 0.068. Conclusions: We performed a systematic review to determine the characteristics and current treatment of PBL. The analysis demonstrates the rarity and heterogenicity of the disease. The current standard of care is for chemoradiation, but this is based primarily on old case studies. Our study confirms the utility of multimodal treatment with a tendency for improved outcomes. However, further prospective trials are needed to determine the necessity of multimodal treatment given this hypothesis generating study. [Table: see text]