OBJECTIVETo investigate the clinical characteristics, outcomes and prognostic factors of primary bone lymphoma (PBL).

METHODSWe retrospectively analyzed 31 consecutive patients with the diagnosis of PBL initially treated at our hospital between 1992 and 2010. Kaplan-Meier method was used for survival analysis and Cox regression model used for analyzing the prognostic factors.

RESULTSThe median age of the patients was 46 years. The most common sites of involvement were the femur (29%) and the spine (29%). Sixteen (52%) patients underwent chemoradiotherapy, and the other 15 (48%) received chemotherapy. With a median follow-up of 49 months, the patients showed an overall response rate of 94% (including a complete response rate of 68% and a partial response rate of 26%). The median overall survival (OS) of the patients was 71 months (95% CI: 36-106 months) with a median progression-free survival (PFS) of 47 months (95% CI: 30-64 months). Univariate analysis identified the use of rituximab, radiotherapy, and an international prognostic index (IPI) score of 0-2 as the favorable prognostic factors for OS and PFS. Multivariate analysis showed that the use of rituximab and IPI score were independent prognostic factors of the OS and PFS, and radiotherapy was the predicting factor for PFS but not for OS.

CONCLUSIONThe use of rituximab can improve the OS or PFS of patients with PBL, and radiotherapy offers additional benefits for PFS but not for OS.