Cancer Treatment Today

A minority of acute leukemias have features characteristic of both the myeloid and lymphoid lineages and for this reason are designated mixed-lineage, hybrid or biphenotypic acute leukemias (BAL). There have been difficulties in establishing whether BAL represents a distinct clinico-biological entity due to a lack of objective criteria for distinguishing BAL from acute myeloid leukemias (AML) or acute lymphoblastic leukemias (ALL) with aberrant expression of a marker from another lineage. As such, it is often treated as AML but with some component of treatment being taken from acute lymphocytic leukemia regimens.There is no agreement on how the disease should be treated. The majority of patients receive treatment according to the morphology of the blasts, with either AML or ALL induction. Cytogenetic abnormalities are observed in a high percentage of bilineal and biphenotypic leukemias. Approximately 33% of cases have the Philadelphia chromosome, and some cases are associated with t(4;11)(q21;q23) or other 11q23 abnormalities. Gleevec can be added in such cases. The basis for such a recommendation is, however, limited, consisting of case reports and one small study that showed minimal response rates(Ahmed et al).

REFERENCES:
Brunning RD, Matutes E, Harris NL, et al.: Acute myeloid leukaemia: introduction. In: Jaffe ES, Harris NL, Stein H, et al., eds.: Pathology and Genetics of Tumours of Haematopoietic and Lymphoid Tissues. Lyon, France: IARC Press, 2001. World Health Organization Classification of Tumours, 3, pp 77-80.

Aribi, Ahmed et al, Acute leukaemia: a case series.British Journal of Haematology. 138(2):213-216, July 2007.

Molecular Genetic Pathways as Therapeutic Targets in Acute Myeloid Leukemia
ASH Education Book 2008 2008:400-411

Kondo T, Tasaka T, Sano F, Matsuda K, Kubo Y, Matsuhashi Y, Nakanishi H, Sadahira Y, Wada H, Sugihara T, Tohyama K.
Philadelphia chromosome-positive acute myeloid leukemia (Ph + AML) treated with imatinib mesylate (IM): a report with IM plasma concentration and bcr-abl transcripts.Leuk Res. 2009 Sep;33(9):e137-8.

Pier Paolo Piccaluga et al, Imatinib mesylate in the treatment of newly diagnosed or refractory/resistant c-KIT positive acute myeloid leukemia. Results of an italian multicentric phase II study. haematol 2007 92:1721-1722

Pompetti F, Spadano A, Sau A, Mennucci A, Russo R, Catinella V, Franchi PG, Calabrese G, Palka G, Fioritoni G, Iacone A.
 Long-term remission in BCR/ABL-positive AML-M6 patient treated with Imatinib Mesylate.Leuk Res. 2007 Apr;31(4):563-7.