Treatment of erythroleukemia with anthracycline antibiotics and cytosine arabinoside

Prognostic factors and treatment effects on survival in acute myeloid leukemia of M6 subtype: a retrospective study of 54 cases

classification system of acute myeloid leukemia (AML) which designates it as M6 AML. This report describes the data of 54 patients with newly diagnosed M6 AML, consecutively seen in our hospital between May 1976 and May 1999.

PATIENTS AND METHODS

There were 40 males and 14 females. Median age was 59 years. Pancytopenia was the most common feature at diagnosis. Twenty-six percent of cases presented with secondary AML. Karyotype was successfully performed in 35 cases. Eleven patients presented with normal karyotype, nine with simple karyotypic abnormalities, and fifteen with major karyotypic abnormalities. Fifty of the fifty-four patients received one or two courses of induction chemotherapy combining anthracyclines with cytarabine according to different successive protocols. One elderly patient only received low-dose cytarabine, and three patients died before any chemotherapy could be given.

RESULTS

Complete remission (CR) was achieved in 29 cases (54%, 95% confidence interval (CI): 40%-67%). As post-remission therapy, four patients could be allografted, and two underwent autologous transplantation. All other treated patients received continuation chemotherapy. Twenty-one patients have relapsed (72%). Median time to relapse was six months. Among those patients, only eight achieved a second CR (38%). The median disease-free survival (DFS) was eight months (95% CI: 4-10 months) with a five-year survival rate of 17%. Median overall survival (OS) was nine months (95% CI: 5-12 months) with a five-year survival rate of 13%. In univariate analysis, poor prognostic factors for DFS were secondary AML (P = 0.05) and initial platelet count <50 x 109/l (P = 0.02). Poor prognostic factors for OS were age > or = 60 years (P = 0.005), secondary AML (P = 0.05), initial 'blastic' fever (P = 0.0004), and initial haemoglobin level < 90 g/l (P = 0.03). All factors, but haemoglobin level, remained significant in the multivariate analysis. Although it was not statistically significant, there was a trent for a better prognosis of M6 patients presenting with normal karyotype as compared to those displaying chromosomal abnormality.

CONCLUSIONS

This retrospective analysis points to a somewhat heterogenous group of AML in terms of clinical and biological features, and outcome. Distinctive subgroups can be identified according to prognostic factors related to survival. A larger multicenter study with well-defined diagnostic criteria is warranted to further clarify treatment effects.

The erythroid leukemias: a comparative study of erythroleukemia (FAB M6) and Di Guglielmo disease

Pure erythroid malignancies, such as Di Guglielmo disease (DG), in which the predominant immature elements are proerythroblasts, are excluded from the French-American-British (FAB) classification for acute leukemia and do not fit neatly into any of the categories of myelodysplasia. This retrospective review compares the clinical and laboratory features of DG and erythroleukemia (FAB M6) among 37 cases treated at a single institution over a 7-year period. DG was defined as >30% proerythroblasts and the absence of a myeloblastic component. Clinical and laboratory features were similar in both subtypes. High proportions of secondary leukemias and prior myelodysplastic syndromes (MDS) were noted (M6, 13 of 26 cases; DG, five of 11 cases; p = 0.85). Pancytopenia was common at presentation in both groups [median white blood cells (WBC), 2,600/mm3; HgB, 8.65 gm/dl; platelets, 38,000/microl]. Two-thirds of studied cases had chromosomal abnormalities typified by major karyotypic abnormalities (MAKA) involving three or more chromosomes. Abnormalities involving chromosome 5 and/or 7 occurred in 47% (48% M6 and 45% DG). Both erythroid malignancies carried a poor prognosis (M6, 6.0-month median survival; DG, 4-month survival; p = 0.74). Among those patients choosing aggressive rather than palliative therapy, higher remission rate (80 versus 25%) and survival advantage (11.5 versus 2.5 months) were seen in M6 compared to DG. However, only two long-term survivors exist. The similar clinical and laboratory features, cytogenetic patterns, and poor survival data suggest that the FAB classification schema should be modified to include DG.