The prognosis for hairy cell leukemia is excellent if the patient is treated with a drug such as cladribine or pentostatin, according to the Leukemia and Lymphoma Society. Eighty-five percent of patients treated with cladribine go into remission, while 10 percent go into partial remission. Remission means there is no evidence of the cancer in the body.
It is possible for a patient with hairy leukemia to recover completely and live a normal life span if he is treated with pentostatin or cladribine, says the Leukemia and Lymphoma Society.
There are some patients with hairy cell leukemia who still have a small number of leukemia cells in their bodies even after treatment, says the Leukemia and Lymphoma Society. This is known as minimal residual disease, or MRD. These patients appear to be in full remission.
Though the cancer cells in MRD can't be detected with regular diagnostic tools, the doctor can find them through such tests as polymerase chain reaction or flow cytometry, according to the Leukemia and Lymphoma Society. In flow cytometry, cells are found by passing them through the laser beam of a flow cytometer. The doctor detects the cancer cells when their antibody-specific characteristics light up. In a polymerase chain reaction, the cancer's DNA can be replicated millions of times within a few hours, says the National Institutes of Health.