OBJECTIVETo investigate the features and prognostic significance of chromosomal karyotype in patients with primary myelodysplastic syndromes (MDS).

METHODSResults of chromosomal karyotypes of 351 adult patients with primary MDS were retrospectively analyzed.

RESULTSTwo hundred and thirty-seven cases (67.5%) had karyotypic abnormalities. Of them, 99 (41.7%) were numerical, 70 (29.5%) were structural, and 68 (28.8%) were complex abnormalities. In addition, among the 237 patients with chromosomal abnormalities, 130 (54.8%) showed single abnormality, 54 (22.8%) double abnormalities and 53 (22.4%) complex abnormalities (> or = 3 two independent aberrations). Four cases (1.7%) were multiploid. Aneuploidy or of chromosomal arm anomaly were detected all of the 46 chromosomes and the aberrations in frequent order were +8, -20/20q-, -7/7q-, -5/5q-, -18, -11/11q-/, +21, -Y, -21, -10, -16, -22, +9, del(12)(p12). The incidence of -5/5q- (5.1%) was lower in our series than in western countries (8.7% -23.4%) and 5q- syndrome was even less (0.3%). The incidences of +8 (19.1%) and -20/20q- (9.4%) were higher in our series than in western countries (1.2% -7.0%, 2.0% -3.5%, respectively). Chromosome translocations were detected in 31 cases (13.1%), including 12 novel translocations that have not been reported in MDS patients before. In addition, i(17)(q10) was detected in 9 cases (3.8%) of which 6 were simplex abnormality. Chromosomal duplication presented in 7 cases (3.0%) with 4 cases involved chromosome 1. According to IPSS chromosomal prognostic classification, the incidence of poor-risk karyotypes was increased in the advanced WHO subtypes (P < 0.001). The follow-up data were available in 177 patients with a median follow-up duration of 14.5 (1-131) months. The median OS was 36 [95% confident interval (CI) 25-46] months. According to IPSS chromosomal prognostic classification, the median OS of patients with good, intermediate and poor-risk cytogenetic subgroup were 51 (95% CI 25-77), 35 (95% CI 5-65) and 13 (95% CI 9-17) months, respectively (P = 0.004) and for NN-AN-AA karyotype classification, the median OS of NN, AN and AA were 51 (95% CI 24-78), 36 (95% CI 0.3-71) and 23 (95% CI 10-35) months, respectively (P = 0.039).

CONCLUSIONThe features of chromosomal abnormalities in Chinese patients with primary MDS shows some difference from that in western countries. Karyotype analysis is of great importance to predict prognosis and to tailor individualized therapy for MDS.