Clinical Characteristics and Prognostic Factors of Primary Bone Diffuse Large B-Cell Lymphoma: A Retrospective Study.

BACKGROUND

Primary bone diffuse large B-cell lymphoma (PB-DLBCL) is a rare extranodal lymphoma with heterogeneous clinical features and survival outcomes. Although most patients respond favorably to modern immunochemotherapy, reliable baseline prognostic indicators remain insufficiently defined.

METHODS

We retrospectively analyzed 424 patients with histologically confirmed PB-DLBCL. Clinical characteristics, treatment patterns and survival outcomes were evaluated. Overall survival (OS) and progression-free survival (PFS) were estimated using the Kaplan-Meier method. Prognostic factors were assessed by univariate and multivariate Cox regression analyses.

RESULTS

With a median follow-up of 36 months, the 3 year OS and PFS rates were 81.3% and 63.3%, respectively. In multivariate analysis, high-risk International Prognostic Index (IPI; score 3-5) was independently associated with inferior OS (HR 2.06, 95% CI 1.24-3.43, p = 0.006). For PFS, hypoalbuminemia (< 40 g/L) emerged as an independent predictor (HR 1.44, 95% CI 1.03-2.02, p = 0.035). Although failure to achieve complete remission and high Deauville score were associated with worse outcomes in univariate analyses, these post-treatment variables were not included in multivariable models.

CONCLUSION

PB-DLBCL often presents with advanced disease but demonstrates generally favorable survival in the rituximab era. Baseline IPI remains a robust predictor of OS, while hypoalbuminemia independently predicts disease progression.