CYTOGENETIC AND CLINICAL CORRELATES IN AML PATIENTS WITH ABNORMALITIES OF CHROMOSOME-16

Abnormalities of chromosome 16 in AML include del(16q), inv(16) and t( 16;16). These three groups have been categorized together and have bee n associated with high complete remission (CR) and survival rates foll owing Ara-C-based chemotherapy. We have reviewed the 63 AML or MDS pat ients with an abnormality of chromosome 16 treated at MD Anderson Canc er Center (MDACC) over the past 18 years. Marked differences in surviv al and remission duration (RD) were noted between the inv(16) or t(16; 16) patients and those with del(16q), whose outcome was no better than other M4 AML or MDS patients treated during the same period. Other di fferences characterizing del(16q) included a lack of CNS relapses, low er incidences of eosinophilia and M4 FAB subtype. Half the inv(16) pat ients had additional karyotypic abnormalities. The overall survival an d remission duration for those patients were no different from those f or patients with inv(16) alone, although the probability of remaining in first CR at 2 years was higher in the inv(16) alone group. There wa s no difference in overall survival for the 45 patients who received H DAC vs those who did not. The incidence of CNS relapse was, however, m arkedly reduced for the HDAC patients. Eosinophilia did not correlate with improved survival. We conclude that del(16q) confers a different prognosis from inv(16) and t(16;16) and for the purposes of prognostic ation or treatment recommendations should no longer be categorized wit h them. Additional karyotypic changes however, which accompany inv(16) in 50% of cases do not influence the overall outcome compared to pati ents with inv(16) alone.