Chronic myelogenous leukemia in chronic phase for 16 years: Ongoing hematological remission and late minor cytogenetic response under minimal interferon maintenance therapy

Philadelphia chromosome-positive chronic myelogenous leukemia was diagnosed in a now 37-year old woman 16 years ago. Induction therapy with hydroxyure a and busulphan led to hematological remission lasting for about 4 months w ithout treatment. Then, intermittent busulphan over a 7 years' period? and subsequently, alpha-interferon was given, of which ever decreasing doses (c urrently 3.5 megaunits interferon-alpha-2c once every 14 days) have been re quired to keep leukocyte counts in the target range. Although no major cyto genetic response was achieved by maintenance therapy, the patient has now b een in an ongoing chronic phase of disease for 16 years. This is a rare cas e of indolent chronic myelogenous leukemia, in which, for undefined reasons , the leukemic cells have not aquired the capacity to transform leading to disease acceleration, which usually is imminent after a few years.