[When do we have to treat chronic leukemia?].

The grounds for treating or not treating chronic lymphocytic leukemias (CLL) and chronic myelocytic leukemias (CML) are discussed in the light of results in recent years. In the case of CLL, objective evaluation of treatment benefits has hitherto been difficult due to the heterogeneity of this group of diseases. A recent classification, based on hematological and clinical parameters and apparently of prognostic value, will undoubtedly help to clarify the therapeutic problem. In the case of CML, routine chemotherapy programs certainly alleviate the symptoms of the disease but have not so far achieved a significant prolongation of survival.