[Does the Philadelphia chromosome disappear after treatment with interferon?]

Chronic myelocytic leukaemia is a myeloproliferative syndrome with two highly specific characteristics: it has a cytogenetic clonal marker known as Philadelphia chromosome and a molecular marker in the form of bcr-abl rearrangement, and it progresses in two phases: a chronic phase followed by an acute terminal phase of blastic transformation. The fatal outcome of this blood disease can only be checked if we possess one or several treatments providing a complete and stable clinical, haematological and cytogenetic remission. Such a course is seldom observed. The conventional treatment of the chronic phase consists of single drug chemotherapeutic regimens which have succeeded in increasing the patients' median survival but do not prevent blastic transformation which is beyond therapeutic resources. In some cases multiple drug chemotherapy, and notably bone marrow transplantation, may result in disappearance of the Philadelphia chromosome and arrest of the natural course of the disease. Interferon is a new treatment which eradicates the Philadelphia chromosome and offers hopes of complete and prolonged, if not permanent, remissions. The present experience, although limited, suggests that alpha-interferons are effective. Judging from the available data, it is very likely that the future treatment of myelocytic leukaemia will consist of chemotherapy combined with interferon(s) with or without bone marrow transplantation.