The prognostic significance of cytopenia in chronic lymphocytic leukaemia/small lymphocytic lymphoma

The development of cytopenia in chronic lymphocytic leukaemia (CLL) patients can predict poor prognosis. All CLL patients seen in the Division of Hematology at Mayo Clinic Rochester from 1 January 1995 to 31 December 2004 (n = 1750) were evaluated for cytopenia, aetiology of cytopenia and clinical outcome. Cytopenia occurred in 423 (24.2%) patients and was attributable to CLL in 303 (17.3%) cases, with 228 (75%) of these having bone marrow (BM) failure and 75 (25%) having autoimmune disease (AID). Survival from onset of cytopenia was significantly better for patients with AID (median 9.1 years) compared to patients with BM failure (median 4.4 years, P < 0.001). Patients with AID diagnosed within 1 year of the diagnosis of CLL (n = 35) had similar survival from diagnosis compared to patients without CLL-related cytopenia (median 9.3 vs. 9.7 years, P = 0.881). Although cytopenia caused by BM failure predicted a poorer prognosis in CLL, cytopenia caused by AID was not an adverse prognostic factor. These findings suggest that patients with cytopenia due to AID cannot be meaningfully classified by the current clinical staging systems. Revisions of the National Cancer Institute Working Group 96 criteria should consider the aetiology of cytopenia in staging CLL patients.