Stage Information for Hairy Cell Leukemia
No generally accepted staging system is useful for both prognosis and therapy.
For the purpose of treatment decisions, it is best to consider this disease in the following two broad categories:
- Untreated hairy cell leukemia.
- Progressive hairy cell leukemia, either postsplenectomy or postsystemic therapy.
Untreated hairy cell leukemia
Untreated hairy cell leukemia is characterized by splenomegaly, varying degrees of leukopenia (occasionally leukocytosis) and/or pancytopenia, and bone marrow infiltration by an atypical cell with prominent cytoplasmic projections (i.e., hairy cells). The bone marrow is usually fibrotic and is not easily aspirated. Bone marrow biopsies are, therefore, required for diagnosis and evaluation of the degree of hairy cell infiltration.
Progressive hairy cell leukemia
Progressive hairy cell leukemia, postsplenectomy (or following any systemic therapy) is characterized by progressive bone marrow replacement by hairy cells with pancytopenia refractory to treatment. For patients with advanced hairy cell leukemia treated with cladribine (2-chlorodeoxyadenosine, 2-CdA), pentostatin, or interferon-alpha, the survival rate appears to be more than 85% at 5 years following the initiation of any one of these therapies.[1,2]
- Frassoldati A, Lamparelli T, Federico M, et al.: Hairy cell leukemia: a clinical review based on 725 cases of the Italian Cooperative Group (ICGHCL). Italian Cooperative Group for Hairy Cell Leukemia. Leuk Lymphoma 13 (3-4): 307-16, 1994. [PUBMED Abstract]
- Kurzrock R, Strom SS, Estey E, et al.: Second cancer risk in hairy cell leukemia: analysis of 350 patients. J Clin Oncol 15 (5): 1803-10, 1997. [PUBMED Abstract]