t(11;16)(q23;p13)/KMT2A-CREBBP in hematologic malignancies: presumptive evidence of myelodysplasia or therapy-related neoplasm?

Fusion partners of KMT2A affect disease phenotype and influence the current World Health Organization classification of hematologic neoplasms. The t(11;16)(q23;p13)/KMT2A-CREBBP is considered presumptive evidence of a myelodysplastic syndrome (MDS) and a MDS-related cytogenetic abnormality in the classification of acute myeloid leukemia (AML). Here, we report 18 cases of hematologic neoplasms with t(11;16). There were 8 males and 10 females with a median age of 51.9 years at time of detection of t(11;16). Of 17 patients with enough clinical information and pathological materials for review, 16 had a history of cytotoxic therapies for various malignancies including 12/15 patients who received topoisomerase II inhibitors, and 15 were classified as having therapy-related neoplasms. The median interval from the diagnosis of primary malignancy to the detection of t(11;16) was 23.2 months. Dysplasia, usually mild, was observed in 7/17 patients. Blasts demonstrated monocytic differentiation in 8/8 patients who developed AML at the time or following detection of t(11;16). t(11;16) was observed as the sole chromosomal abnormality in 10/18 patients. KMT2A rearrangement was confirmed in 11/11 patients. The median survival from the detection of t(11;16) was 15.4 months. In summary, t(11;16)(q23;p13) is rare and overwhelmingly associated with prior exposure of cytotoxic therapy. Instead of being considered presumptive evidence of myelodysplasia, we suggest that the detection of t(11;16) should automatically prompt a search for a history of malignancy and cytotoxic therapy so that proper risk stratification and clinical management are made accordingly. The dismal outcome of patients with t(11;16) is in keeping with that of therapy-related neoplasms.