Is it really possible to cure hairy cell leukemia patients only with frontline therapy?

Hairy cell leukemia (HCL) patients could have an excellent prognosis with adequate treatment. Treatments are not generally curative but are extremely effective in inducing long-lasting clinical remissions. An observational retrospective study was conducted on a single-center registry of 144 patients with a median follow-up of 11.5 years, focusing on long-lasting continuous first complete remissions (CR) wondering if patients can be cured only with front-line approach. CR for more than 5 years after first-line therapy were found in 22.2 \% cases. The median duration of response was 9.8 years, while for relapsed patients, the first response had a median duration of 2.4 years. Three different subsets of long-lasting first CR were identified: 15 patients are between 5 and 10 years with a median duration of CR of 6.5 years; 7 patients are between 10 and 15 years with a median duration of CR of 12.3 years; and 10 patients present a follow-up superior to 15 years with a median duration of CR of 20.0 years. There is a need for continuous study in this field to better define the optimal therapeutic regimen and, in particular, the biological issues since at least 20-25 \% of HCL patients can be cured with only one treatment.