ABCL-256: Role of Radiotherapy Differs Between Stages for Primary Bone Large B-Cell Lymphoma in the Rituximab Era: A Real-World Study

Abstract

Background: Owing in large part to the rarity of primary bone DLBCL (PB-DLBCL), whether radiotherapy (RT) should be omitted in the rituximab era is still under debate. Methods: We included adult patients with PB-DLBCL diagnosed from 2002 to 2016 from SEER 18. The effect of RT on overall survival (OS) using univariate (UVA) and multivariate (MVA) Cox proportional regression and propensity score matching (PSM) was assessed for the entire cohort and subgroups by stages. We included adult patients diagnosed from 2002 to 2016 from SEER 18. The short- and long-term risk for second primary malignancies (SPM) were calculated from 2002 to 2016 in SEER 18 and 1983 to 2016 in SEER 9. Results: A total of 1320 patients were identified, including 856 with early-stage (ES) and 464 with advanced-stage (AS). A decreasing trend was observed in the ES cohort after 2002, while the rate of RT utilization remained stable in the AS cohort over the past three decades. Most patients in ES (63.9%) underwent RT, whereas only 42.2% of AS patients received it. RT significantly improved survival both in UVA and MVA (P Conclusion: This population-based analysis is the largest PB-DLBCL dataset to date and demonstrates a significant survival benefit associated with RT in early stages, rather than advanced stages. In the absence of randomized controlled trials, RT should be considered in ES disease with cautions of second cancers in specific subsets of patients. Funding: National Natural Sciences Foundation of China (No. 81302043, 81500109, 81500168) and the Major International Joint Research Project of China (No.31620103909).