Abstract: Objective To investigate the clinical characteristics, outcomes and prognostic factors of primary bone lymphoma
(PBL). Methods We 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. Results The 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.
Conclusion The use of rituximab can improve the OS or PFS of patients with PBL, and radiotherapy offers additional benefits
for PFS but not for OS.