Prognostic significance of trisomy 4 as the sole cytogenetic abnormality in acute myeloid leukemia.

Trisomy 4 is a recurrent but rare cytogenetic abnormality reported in patients with acute myeloblastic leukemia (AML). The prognostic significance of this abnormality in patients with AML is not clear. We report here four cases of trisomy 4 as the sole cytogenetic abnormality in AML patients treated at our institute during the last 15 years and systematically review all reported cases of trisomy 4 as a solitary cytogenetic abnormality in AML with the aim of studying the disease demography and prognostic significance of this abnormality. Collective data on 30 patients (including four in the present report) showed complete remission (CR) rates of 76.6%. Median relapse free survival and overall survival were 7 months (95% CI 5-17) and 9 months (95% CI 3-17), respectively. Given the limitations of reported literature, the prognosis of AML patients with trisomy 4 appears to be poor compared with the intermediate risk cytogenetics. Collaborations between major institutions and cooperative groups are needed to collect better quality data to understand the prognostic significance of such rare karyotypic abnormalities.