Clinical and prognostic significance of bone marrow involvement in patients with diffuse aggressive B-cell lymphoma

Purpose: We studied the effect of morphology and extent of bone marrow (BM) infiltrate on the survival of patients with diffuse aggressive B-cell non-Hodgkin's lymphoma (NHL), along with clinical features. Patients and Methods: Sixty adult patients with diffuse aggressive B-cell NHL and BM involvement at the time of presentation were studied. All patients were uniformly staged and treated with a curative high-dose chemotherapy regimen. BM involvement was assessed according to the cytology, pattern of infiltration, and extent of involvement, and was correlated with overall survival (OS) and failure-free survival (FFS). Results: Patients with BM involvement that consisted of ≥ 50% large cells or BM involvement of ≥ 70% had a poorer OS (P = .065 and P = .055, respectively). Those who presented with an infiltrate of less than 50% large cells and an international prognostic index (IPI) of ≤ 3 had a significantly longer postrelapse survival time (P = .003). A diffuse or interstitial pattern of BM involvement was predictive of both poor OS and FFS (P = .008 and .009, respectively). Multivariate analysis indicated that only IPI (P = .0005) and pattern of BM infiltration (P = .009) were independent predictors of OS, and only the former was predictive of FFS (P = .03). Conclusion: The IPI is predictive of OS and FFS, while BM involvement with a diffuse or interstitial pattern is associated with significantly poorer OS. Patients with BM infiltration that involved ≥ 70% of the marrow or contained ≥ 50% large cells had poor OS, but more patients need to be studied to determine the significance. Two parameters, IPI ≤ 3 and BM large cells less than 50%, identify a group of patients with long-term survival after relapse.