Clinical characterization and outcome of primary bone lymphoma: a retrospective study of 61 Chinese patients

Primary bone lymphoma(PBL) is a rare disease. To assess the clinical characteristics, outcome, and prognostic factors of this entity in Chinese population, we retrospectively analyzed 61 PBL patients initially treated in our institution between 1997 and 2014. The median age was 45 years. The most common histological subtype was diffuse large B-cell lymphoma (DLBCL) (55.7%), followed by T-cell lymphoma (18.0%). All patients underwent systemic chemotherapy as initial treatment while 24 patients (39.3%) were additionally treated with radiotherapy. The 5-year overall survival (OS) and the 5-year progression-free survival (PFS) rates of 57 cases with completed follow-up were 52.3% and 40.1%, respectively. In further analysis of the primary bone DLBCL (PB-DLBCL) subgroup, the 5-year OS and PFS rates were 53.0% and 47.0%, and a multivariable analysis revealed that baseline Eastern Cooperative Oncology Group (ECOG) score and response to initial treatment (complete remission versus no complete remission) were independent prognostic factors for both OS and PFS. The proportion of T-cell lymphoma is higher in China than in western populations. High baseline ECOG scores (≥2) and unachieved CR in initial therapy were factors for poor PB-DLBCL prognosis. The role of radiotherapy and rituximab in PLB therapy remains to be confirmed in further investigation.