Clinical Outcome of CML Patients with Philadelphia Chromosome Complex Variants.

The presence of translocation between chromosomes 9 and 22 that characterizes the chronic myeloid leukemia (CML) is occasionally accompanied by more complex variations involving additional exchange of genetic material with other chromosomes. This variants of Philadelphia chromosome have no worse prognosis than those others with the common translocation.

Since 1997 we have diagnosed in our hospital 5 CML patients who didn't show any of these variants. Three women 17, 23 and 76 years old and two men of 36 and 65. All of them diagnosed in chronic phase. Risk stage at diagnosis by Sokal were 1 high, 1 intermediate and 3 low. By Hasford 2 were intermediate end 3 low.

Philadelphia chromosome variants involve a third chromosome in 4 cases (translocations 2;9;22, 9;22;12, 9;22;9 and 6;9;22) and in one case involving four chromosomes (translocation 1;2;9;22).

Three patients diagnosed before the imatinib approval started treatment with IFN and Ara-C and subsequently changed to Imatinib treatment. Two others started treatment with imatinib directly.

All patients had a good outcome with treatment being the current state of 2 patients in complete molecular response (105 and 60 months of follow-up) and 2 patients in Major Molecular Response (146 and 143 months). The 5th patient, a 17 years old woman, has been treated for three months with Imatinib and showed complete haematological response at first month and major cytogenetic response at third month. It is striking in this last patient the fact that two years earlier had been referred for study of myeloid moderate leukocytosis (20,000 leukocytes with circulating myeloid progenitors without anemia, thrombocytosis, or splenomegaly). The patient didn't come to clinic when Bone Marrow Test was cited and two years later resumes the visit continuing with the same leukocytosis in peripheral blood and without splenomegaly unchanged despite not having received any treatment.

Our experience confirm that this type of patients with complex translocation variants have no worse prognosis than normal translocation under imatinib treatment and suggests that may have a more benign clinical behavior.

No relevant conflicts of interest to declare.