In all patients, the first two years after diagnosis have the highest risk for fatal outcome; generally, surviving five years predicts good control of the disease. After five years clinical remission, patients in the United States with normal blood counts can often qualify for private life insurance with some US companies.Accurately measuring survival for patients with the variant form of the disease (HCL-V) is complicated by the relatively high median age (70 years old) at diagnosis. However, HCL-V patients routinely survive for more than 10 years, and younger patients can likely expect a long life. Follow-up care
Despite decade-long remissions and years of living very normal lives after treatment, hairy cell leukemia is officially considered an incurable disease. While survivors of solid tumors are commonly declared to be permanently cured after two, three, or five years, people who have hairy cell leukemia are never considered cured. Relapses of HCL have happened even after more than twenty years of continuous remission. Patients will require lifelong monitoring and should be aware that the disease can recur even after decades of good health. While most oncologists consider Hairy Cell Leukemia to be incurable, there is some evidence that some patients are in fact cured after treatments. Of the original 358-patient cohort treated with cladribine at the Scripps Clinic, 9 of 19 in continuous CR for a median of 16 years were free of HCL MRD by flow cytometry and IHC.
Unlike most cancers, only one drug is normally given to a patient at a time. While monotherapy is normal, combination therapy—typically using one first-line therapy and one second-line therapy—is being studied in current clinical trials, and is used more frequently for refractory cases. Combining rituximab with cladribine or pentostatin may or may not produce any practical benefit to the patient. Combination therapy is almost never used with a new patient. Because the success rates with purine analog monotherapy are already so high, the additional benefit from immediate treatment with a second drug in a treatment-naïve patient is assumed to be very low. For example, one round of either cladribine or pentostatin gives the median first-time patient a decade-long remission; the addition of rituximab, which gives the median patient only three or four years, might provide no additional value for this easily treated patient. In a more difficult case, however, the benefit from the first drug may be substantially reduced, so a combination may provide some benefit. First-line therapy
Cladribine (2CDA) and pentostatin (DCF) are the two most common first-line therapies. They both belong to a class of medications called purine analogs, which have mild side effects compared to traditional chemotherapy regimens. Cladribine can be administered by injection under the skin, by infusion over a few hours into a vein (inravenous - IV), or by a pump worn by the patient that provides a slow drip into a vein, 24 hours a day for 7 days.