The treatment of hairy cell leukemia (HCL) has considerably changed over years. Purine analogues, namely cladribine, now represent the treatment of choice. One hundred and eighty-four patients were followed between 1986 and 2018 and treated according to era-specific guidelines. Responses were classified by combining Consensus Resolution criteria and marrow immunohistochemistry. Patients were grouped according to the number of treatment lines they received. Patients treated first line responded in 86% of cases, with complete response (CR) in 44% of cases. Response rates remained high throughout the first four lines (84%, 81%, 79% for the second line onward, with CR in 38%, 37%, 15% of cases respectively). One hundred and twenty-two patients received cladribine as first line treatment, with a response rate of 86% and a CR rate of 54%. Among the 66 CR patients, 45 (68%) have never received further therapy: 11 patients are in continuous CR between 5 and 10 years after treatment, 14 between 10 and 20 years and three patients at more than 20 years. Median time-to-next treatment (TTNT) for frontline cladribine-treated patients was 8.2 years: partial responders had a significantly shorter median TTNT than CR patients (5.3 years vs median not reached at 25.8 years, p < 0.001). Patients with HCL require subsequent lines of therapy in more than 50% of cases. Purine analogues allow significant response rates when applied first line and upon retreatment. Some patients may enjoy long lasting treatment-free intervals after one course of cladribine.

中文翻译：

---

毛细胞白血病的治疗重点是对克拉屈滨的长期反应：30 年的经验

多年来，毛细胞白血病 (HCL) 的治疗发生了很大变化。嘌呤类似物，即克拉屈滨，现在代表了治疗选择。1986 年至 2018 年期间，对 184 名患者进行了随访，并根据特定时代的指南进行了治疗。通过结合共识决议标准和骨髓免疫组织化学对反应进行分类。患者根据他们接受的治疗线数进行分组。接受一线治疗的患者在 86% 的病例中有反应，在 44% 的病例中有完全反应 (CR)。前四线的反应率仍然很高（第二线以后的反应率分别为 84%、81%、79%，CR 分别为 38%、37%、15%）。122 名患者接受克拉屈滨作为一线治疗，反应率为 86%，CR 率为 54%。在 66 名 CR 患者中，45 名 (68%) 从未接受过进一步治疗：11 名患者在治疗后 5 至 10 年之间持续 CR，14 名患者在 10 至 20 年之间，3 名患者在 20 年以上。一线克拉屈滨治疗患者的中位至下次治疗时间 (TTNT) 为 8.2 年：部分反应者的中位 TTNT 明显短于 CR 患者（5.3 年 vs 中位未达到 25.8 年，p  < 0.001)。超过 50% 的 HCL 患者需要后续治疗。嘌呤类似物在一线应用和再治疗时具有显着的反应率。一些患者可能会在一个疗程的克拉屈滨后享受长期的无治疗间隔。