Abstract：
Hairy cell leukemia (HCL) and HCL-like disorders have to be distinguished because of their different biology and treatment response. Thus, we conducted a retrospective study on patients with HCL and hairy cell leukemia variant (HCLv) to assess diagnostic algorithms and treatment outcomes in a real-world setting. We analyzed 225 HCL and 26 HCLv patients with median follow-up of 67.9 months (HCL) and 20.1 months (HCLv). Median age at diagnosis was 56.2 (HCL) and 69.5 years (HCLv), male predominance was observed in both groups (76.0% vs. 73.1%). Diagnostics was mostly based on morphological evidence of hairy cells in the peripheral blood and bone marrow. At diagnosis, BRAF V600E mutation was detected in 94.7% of examined HCL patients and in no HCLv patient. Front-line treatment was indicated in 205 (91.1%) HCL and 18 (69.2%) HCLv patients. The majority of HCL patients were administered a cladribine-based regimen (91.2%). Overall response rate (ORR) was higher in cladribine-treated patients compared to those given other treatments (97.7% vs. 81.3%), the same applied with achieving Complete remission (CR) (91.2% vs. 62.5%). HCLv treatment was heterogeneous, but cladribine remained the most frequent option (44.4%) with ORR 81.3% and CR rates 43.8%. Second-line treatment was indicated in 52 HCL and 8 HCLv patients, 25.4% and 44.4% of those treated in first-line. In the whole HCL group, median time to next treatment (TTNT) was not reached and 10-year TTNT was estimated at 74.1%. HCLv patients who underwent first-line treatment had a median TTNT of 56 months. The median overall survival (OS) in HCL patients was not reached compared to HCLv with a median OS of 9.5 years. These data confirm an excellent prognosis for HCL patients treated with cladribine-based therapy. On the contrary, HCLv with its aggressive behavior represents a group of patients in whom novel treatment approaches are needed.
摘要：
毛状细胞白血病（HCL）和HCL样疾病由于其不同的生物学和治疗反应而必须加以区分。因此，我们对HCL和毛细胞白血病变异型(HCLv)患者进行了一项回顾性研究,以评估真实世界中的诊断算法和治疗结局.我们分析了225例HCL和26例HCLv患者，中位随访时间为67.9个月（HCL）和20.1个月（HCLv）。诊断时的中位年龄为56.2岁（HCL）和69.5岁（HCLv），两组男性占主导地位(76.0%vs.73.1%）。诊断主要基于外周血和骨髓中毛细胞的形态学证据。诊断时,在94.7%的受检HCL患者和无HCL患者中检测到BRAFV600E突变。205（91.1％）HCL和18（69.2％）HCLv患者需要一线治疗。大多数HCL患者采用基于克拉屈滨的方案(91.2%)。与接受其他治疗的患者相比，接受克拉屈滨治疗的患者的总体反应率（ORR）更高（97.7%vs.81.3%），同样适用于实现完全缓解(CR)(91.2%vs.62.5%）。HCLv治疗是异质的，但克拉屈滨仍然是最常见的选择(44.4%)，ORR为81.3%，CR率为43.8%。在52例HCL和8例HCLv患者中进行了二线治疗，一线治疗者的25.4%和44.4%。在整个HCL组中，未达到下一次治疗的中位时间(TTNT),10年TTNT估计为74.1%.接受一线治疗的HCLv患者的中位TTNT为56个月。与中位OS为9.5年的HCLv相比，未达到HCL患者的中位总生存期（OS）。这些数据证实了使用克拉屈滨治疗的HCL患者的良好预后。相反,HCLv的攻击行为代表了一组需要新治疗方法的患者。
