Incidence and prognostic significance of karyotypic subgroups in older patients with acute myeloid leukemia: the Swedish population-based experience

Abstract

The Swedish population-based acute myeloid leukemia registry contains data from 3251 patients (excluding acute promyelocytic leukemia) diagnosed between 1997 and 2006. Informative cytogenetic data from 1893 patients were retrospectively added, including 1054 patients aged between 60 and 79 years. Clonal abnormalities were found in 57% of the informative karyotypes. Karyotypic patterns differed by age: t(8;21), inv(16) and t(11q23) were more common in younger patients, whereas loss of 5q, 7q and 17p, monosomal karyotype (MK) and complex karyotypes were more common in older patients. Loss of 5q, 7q and 17p often occurred together within MK. Patients with 5 chromosome abnormalities had worse overall survival than those with fewer abnormalities or normal karyotype in all age groups. Loss of 5q, 7q and/or 17p had, in contrast to MK, a further negative impact on survival. Multivariable Cox regression analyses on risk factors in patients <80 years with cytogenetic abnormalities and intensive treatment revealed that age and performance status had the most significant impact on survival (both P<0.001), followed by sex (P=0.0135) and a karyotype including -7/del(7q) (P=0.048).

Figure 1

Overall survival for intensively treated patients according to age and cytogenetic-risk group. HR, high risk; LR, low risk (that is, core binding factor leukemia); IR, intermediate risk. (a) Patients below 60 years of age. HR vs IR (P<0.001) and LR vs IR (P=0.05). (b) Patients between 60 and 79 years of age. HR vs IR (P<0.001) and LR vs IR (P=0.1).

Figure 2

Overall survival for intensively treated patients according to the number of chromosomal abnormalities (CBF leukemias included). Normal karyotype, 1–2 abnormalities, 3–4 abnormalities and ⩾5 abnormalities. (a) Patients below 60 years of age. Normal vs 1–2 (P=0.009), normal vs 3–4 (P=0.01) and normal vs ⩾5 (P<0.001). (b) Patients between 60 and 69 years of age. Normal vs 1–2 (P=0.8), normal vs 3–4 (P=0.02) and normal vs ⩾5 (P<0.001). (c) Patients between 70 and 79 years of age. Normal vs 1–2 (P=0.2), normal vs 3–4 (P=0.09) and normal vs ⩾5 (P<0.001).

Figure 3

Overall survival for intensively treated patients according to the number of chromosomal abnormalities and monosomal karyotype (CBF leukemias excluded). MK+, monosomal karyotype, MK−, not monosomal karyotype, 3–4 abnormalities and ⩾5 abnormalities. (a) Patients below 60 years of age. 3–4 and MK+ vs ⩾5 and MK+ (P=0.01), ⩾5 and MK+vs ⩾5 and MK− (P=0.3), and 3–4 and MK+ vs 3–4 and MK− (P=0.9). (b) Patients between 60 and 79 years of age. 3–4 and MK− vs ⩾5 and MK+ (P<0.001), 3–4 and MK− vs ⩾5 and MK− (P=0.3), ⩾5 and MK+ vs ⩾5 and MK− (P=0.1), and 3–4 and MK+ vs 3–4 MK− (P=0.5).

Figure 4

Overall survival for intensively treated patients below the age of 80 years according to loss of 5q, 7q or 17p and monosomal karyotype (CBF leukemias excluded). (a) One, two or three of 5q, 7q and 17p abnormalities. One vs two (P=0.02), one vs three (P<0.001) and two vs three (P<0.001). (b) MK−, cytogenetically abnormal but not monosomal karyotype; MK+ incl 5q/7q/17p, monosomal karyotype with one or more abnormalities resulting in loss of 5q, 7q and/or 17p; and MK+ excl 5q/7q/17p, monosomal karyotype but no losses of 5q, 7q or 17p. MK− vs MK+ excl 5q/7q/17p (P=0.9), MK− vs MK+ incl 5q/7q/17p (P<0.001) and MK+ incl vs MK+ excl 5q/7q/17p (P<0.001).