Cytogenetic And Prognostic Characteristics Of Single Karyotype Acute Myeloid Leukemia

Objective To explore the cytogenetic characteristics and prognostic significance of monosomal karyotype(MK) in adult patients with acute myeloid leukemia(AML).Methods From September 2002 to November 2014 in Blood Diseases Hospital, Chinese Academy of Medical Sciences,97 cases with AML were included in this analysis, including 96 cases within the unfavorable cytogenetic risk category and an MK case within the intermediate risk category. The clinical data of MK-positive cases and unfavorable risk MK-negative cases were analyzed. Comparisons between continuous variables were performed using independent-samples T-test. Comparisons between categorical variables were performed using Chi-square test. The Kaplan-Meier method was used to estimate survival curves. Log-Rank tests were used to assess differences between survival curves.Results Among 97 patients included in this study, there were 31 MK cases, accounting for 2.5% of all the AML patients diagnosed during that time, with a median age of 40 years, and no age distribution differences were noted between MK-positive and MK-negative cases excluding APL(P=0.499). Thirty of MK cases were complex aberrant karyotypes defined as showing three or more chromosome abnormalities and classified into adverse group based on SWOG/ECOG criteria. The other one of these 31 MK was intermediate risk according to SWOG/ECOG criteria.66 patients in this study were MK-negative cases. Among MK cases, autosomal chromosome monosomies were detected in all 22 autosomes. The most frequent monosomal chromosome were-17、-5、-7、-21、-8、-22. Among MK-positive cases, the most frequent unfavorable risk chromosome abnormalities were-5,-7, abn(11q),5q-and abn(17p).In 96 cytogenetic unfavorable AML cases, the median overall survival(OS) was 6.1 months for MK, the median OS did not reach for non-MK AML (P=0.001). And the median relapse-free survival(RPS) was 3.1 and 18.6 months for MK and non-MK AML (P< 0.001), respectively. In 49 complex karyotype AML cases, the median OS was 6.1 and 10.8 months for MK(n=30) and non-MK AML(n=19) (P=0.088), respectively. And the median RFS was 3.1 and 8.6 months for MK and non-MK AML (P=0.009), respectively. There was significant difference in RFS between MK and non-MK categories. MK defined by one single autosomal monosomy with at least one structural chromosomal abnormality was detected in 5 patients, and MK defined by≥2 autosomal monosomies was detected in 26 patients. The median OS was 2.5 and 6.1 months, respectively. And the median RFS was 4.5 and 2.5 months, respectively. There were no significant differences in OS (P=0.812) and RFS (P=0.205) between two groups.Conclusion Most of MK AML was complex karyotype in cytogenetic unfavorable group. Within unfavorable or complex karyotype catagories, MK-positive cases had a more adverse prognosis than MK-negative cases.