The Philadelphia chromosome (Ph1) is the most frequent abnormality in acute adult lymphoblastic leukemia (ALL). Ph1 positive ALL is more frequent in over 50-year-old adults, in B-cell ALL and CD10-positive ALL. Diagnosis is based on the identification of the BCR-ABL gene mRNA in peripheral blood or bone marrow. The 5-year overall survival of patients with Ph1 positive ALL treated with chemotherapy alone is less than 20%. A few cases may be cured by allogeneic stem cell transplantation. The addition of imatinib to the chemotherapeutic treatment has resulted in more complete remissions, more complete molecular responses, more patients able to perform stem cell transplantation, better event-free survival and better overall survival, although the study follow-up period is very short so far. High relapse rates and the emergence of BCR-ABL mutants resistant to imatinib are still significant. In the future, newer tyrosine-kinase inhibitors may be added to the chemotherapy.
Acute lymphoblastic leukemia; Philadelphia; BCR-ABL; imatinib; stem cell transplantation; consensus
