Multiphenotypic acute leukemias: clinicopathologic correlations and response to therapy

Area of Science:

• Hematology
• Oncology
• Immunophenotyping

Background:

• Multiphenotypic acute leukemias (MAL) are rare hematologic malignancies characterized by the coexpression of antigens from distinct cell lineages on blast cells.
• Accurate immunophenotypic classification is crucial for understanding MAL biology and patient outcomes.

Purpose of the Study:

• To investigate the frequency and prognostic significance of different immunophenotypic subtypes of MAL.
• To analyze clinical features and survival outcomes in patients with MAL based on their immunophenotype.

Main Methods:

• Retrospective analysis of 1565 leukemic patients.
• Immunophenotyping of diagnostic blast cells to identify MAL.
• Categorization of MAL into B-myeloid (BM), B-T-cell (BT), and T-cell myeloid (TM) subtypes.
• Comparison of clinical features and event-free survival (EFS) among subtypes.

Main Results:

• 26 cases of MAL were identified (1.7% of cohort).
• BM-MAL (62%) showed a median EFS of 24 months, TM-MAL (27%) had 4 months, and BT-MAL (11%) had 7 months.
• TM-MAL exhibited a significantly poorer prognosis than BM-MAL (p < 0.001), associated with CD7 expression or CD10 absence.

Conclusions:

• Immunophenotypic classification of MAL is critical for prognosis.
• T-cell myeloid MAL represents a distinct subtype with a poor prognosis, warranting further investigation and targeted therapies.
• B-myeloid MAL demonstrates a more favorable outcome compared to other MAL subtypes.