Analysis of clinical and laboratory characteristics and survival with hairy cell leukemia

OBJECTIVE: To explore the clinical and laboratory characteristics and survival of Chinese patients with hairy cell leukemia (HCL). METHODS: A total of 30 HCL patients from August 1990 to March 2012 were retrospectively analyzed. RESULTS: There were 22 cases with classical HCL (HCL-C) and 8 with variant HCL (HCL-V). Splenomegaly was the most common physical finding. Leukocytosis was found in all cases of HCL-V. But pancytopenia only accounted for 36.4% (8/22) in HCL-C. And 3/5 of HCL-V had abnormal chromosome karyotypes. Ribosomal-lamellae complexes (RLC) were found only in about 3/12 of HCL cases. Chemotherapy regimens including purine nucleoside analogues achieved a better complete remission (CR) rate than other regimens (3/4 vs 1/18, P = 0.012) in HCL-C. The median follow-up period was 27 (1 - 142) months. There was no follow-up loss. Eleven cases progressed and 6 died. The median overall survival (OS) was not reached. And the 1, 3, 6-year OS rates were 84%, 78% and 58% respectively. The median progression-free survival (PFS) was (63 ± 24) months and the 1, 2, 5-year PFS rates were 86%, 72% and 44% respectively. The median PFS of HCL-V was significant shorter than HCL-C ((23 ± 3) vs (78 ± 12) months, P = 0.014). In HCL-C group, fever (P = 0.038) and anemia (P = 0.000) at diagnosis were poor prognostic factors. But purine nucleoside analogues made no significant difference in PFS. CONCLUSIONS: Pancytopenia is infrequent in Chinese HCL patients. And classical RLC is rare under electron microscope. Purine nucleoside analogues may achieve a better CR rate, but fail to improve PFS rate. As compared with HCL-C, HCL-V is common with genetic abnormalities and has a worse prognosis with a shorter PFS.