Cytogenetic and clinical assessment of six patients with erythroleukemia.

We report the detailed karyotypic analysis and clinical features of six patients with erythroleukemia (EL). Five of six patients studied displayed substantial numeric and structural chromosome abnormalities. The most common alterations in these patients were monosomy for chromosome 7 and 16. All five patients displaying chromosomal abnormalities presented with 100 percent abnormal metaphases in their bone marrow at the time of initial diagnosis. The remaining patient was studied only during remission and had a normal diploid karyotype in all marrow cells analyzed. No patient in this study had either a Ph1 -chromosome (characteristic of CML), or translocations of chromosome #8-#21 (characteristic of AML-M2). Clinically, all but one patient had a brief history; the exception having had polycythemia rubra vera for 18 years prior to the onset of EL. All patients were treated with current Southwest Oncology Group (SWOG) protocols using cytosine arabinoside and anthracycline combinations. Three of five patients entered complete remission. However, remission durations were short (approximately six months) and median survival just over one year. Cytogenetic analysis of three patients in hematologic remission revealed persistence of chromosomal alterations. It is suggested that such remissions be reclassified as partial rather than complete based upon the cytogenetic information.