: Hairy cell leukemia (HCL) is a rare lymphoproliferative disease with an excellent prognosis after treatment with cladribine (2CDA), although relapse may occur during follow-up. The aim of the study is to review the efficacy, safety, long-term remission rate, and overall survival (OS) in those patients who received 2CDA as first-line treatment. We retrospectively reviewed data of HCL patients treated with 2CDA between March 1991 and May 2019 at 18 Italian Hematological centers: 513 patients were evaluable for study purpose. The median age was 54 years (range 24-88) and ECOG was 0 in 84.9% of cases. A total of 330 (64.3%) patients received 2CDA intravenously and 183 (35.7%) subcutaneously. ORR was 91.8%: CR was obtained in 335 patients (65.3%), PR in 96 (18.7%), and hematological response in 40 (7.8%) patients; in 42 (8.2%) no response was observed. Hemoglobin value (p = 0.044), frequency of circulating hairy cells (p = 0.039), recovery of absolute neutrophil count (p = 0.006), and normalization of spleen (p ≤ 0.001) were associated with CR compared to PR in univariable analysis. At a median follow-up of 6.83 years (range 0.04-28.52), the median time to relapse was 12.2 years. A significant difference in duration of response was identified between patients that obtained a CR and PR (19.4 years versus 4.8 years, p < 0.0001). Non-hematological grade 3 or higher early toxicity was reported in 103 (20.1%) patients. Median OS was not reached: 95.3%, 92.4%, and 81.8% of patients were estimated to be alive at 5, 10, and 15 years, respectively. Forty-nine patients died (9.5%), following an infection in 14 cases (2.7%), natural causes in 14 (2.7%), cardiovascular events in 13 (2.5%), a second neoplasm in 6 (1.2%), and progression of HCL in 2 cases (0.4%). Following treatment of HCL with 2CDA, 80% of patients are estimated to be alive 15 years after diagnosis.
Long-term follow-up of cladribine treatment in hairy cell leukemia: 30-year experience in a multicentric Italian study / Pagano, Livio; Criscuolo, Marianna; Broccoli, Alessandro; Piciocchi, Alfonso; Varettoni, Marzia; Galli, Eugenio; Anastasia, Antonella; Cantonetti, Maria; Trentin, Livio; Kovalchuk, Sofia; Orsucci, Lorella; Frustaci, Annamaria; Spolzino, Angelica; Volpetti, Stefano; Annibali, Ombretta; Storti, Sergio; Stelitano, Caterina; Marchesi, Francesco; Offidani, Massimo; Casadei, Beatrice; Nizzoli, Maria Elena; De Luca, Maria Lucia; Fianchi, Luana; Motta, Marina; Guarnera, Luca; Simonetti, Edoardo; Visentin, Andrea; Vassallo, Francesco; Deodato, Marina; Sarlo, Chiara; Olivieri, Attilio; Falini, Brunangelo; Pulsoni, Alessandro; Tiacci, Enrico; Zinzani, Pier Luigi. - In: BLOOD CANCER JOURNAL. - ISSN 2044-5385. - 12:7(2022), p. 109. [10.1038/s41408-022-00702-9]