Features of Chromosomal Karyotype in 351 Chinese Adult Patients with Primary Myelodysplastic Syndromes: A Retrospective Analysis from a Single Institution

Myelodysplastic syndromes(MDS) are a heterogeneous group of myeloid neoplasms characterized by bone marrow failure with peripheral cytopenia and morphologic dysplasia in one or more of hematopoietic cell lineages. Chromosomal abnormalities, detected in 40–70% patients with primary MDS, are presented heterogeneous due to the disparities in race and environment. In the current study, 351 adult patients in our institution were retrospectively analyzed to clarify features of karyotype in Chinese primary MDS. There were 237 cases (67.5%) demonstrated karyotypic abnormalities including numeral changes alone(99 cases, 41.7%), structural changes alone(70 cases,29.5%) and both changes(68 cases,28.8%). Single, double and complex (more than two independent aberrations) anormaly were 130 cases(54.8%),54 cases(22.8%), 53 cases(22.4%), respectively. There were 3 cases(1.3%) with tetraploid, 1 case(0.4%)with multiploid,1 case(0.4%) with hyperdiploid and 3 cases(1.3%) with hypodiploid. Changes of aneuploid or anomaly of chromosomal arm could be detected in all of the 24 chromosomes and the aberrations frequently seen were +8, −20/20q-/del(20)(q11–13), −7/7q-/del(7)(q21–32), −5/5q-/del(5)(q13–33), −18, −11/11q-/del(11) (q23–25), +21, −Y, −21, −10, −16, −22, +9, del(12) (p12) in order. The incidence of −5/5q-/del(5)(q13–33)(5.1%)was lower than western countries(8.7–23.4%)and 5q-syndrome was even less (0.3%). The incidences of +8(19.1%) and −20/20q-/del(20)(q11–13) (9.4%) were higher than western countries(1.2–7.0%, 2.0– 3.5%, respectively). Chromosome translocations could be detected in 31 cases(13.1%) and among them 12 translocations have not been reported in MDS. In addition, i(17)(q10) could be detected in 9 cases(3.8%)in which 6 cases were single anormaly. Chromosomal duplication presented in 7 cases(3.0%) in which 4 cases involved chromosome 1. According to IPSS chromosomal prognositic classification, the incidence of poor-risk karyotypes was increasing as following orders: RA, RARS and 5q-syndrome;RCMD and RCMDRS;RAEB-I;RAEB-II and the difference was statistically significant(χ² = 59.169, P < 0. 001). Among the 178 patients with follow-up data, the median follow-up time was 14.5(1–131)months and the median OS was 36 (95% confident interval(CI) 25–46) months with 2 and 5 year of OS 58.7% and 38.0%, respectively. According to IPSS chromosomal prognositic classification, the median OS of patients with good, intermediate and poor-risk cytogenetic subgroups were 51(95%CI 25–77),35(95%CI 5–65),13(95%CI 9–17)months respectively and the difference of OS was statistically significant by log rank test(P=0. 004). According to NN-AN-AA classification, the median OS of patients with NN, AN, AA were 51(95%CI 24–78),36(95%CI 0.3–71), 23(95%CI 10–35)month respectively and the difference of OS was statistically significant by log rank test(P =0. 039). In summary, features of chromosomal abnormalities in Chinese patients with primary MDS were not the same with that in western countries. Cytogenetical abnormalities validate vigorously malignant texture of MDS and are considered to be of great importance in revealing pathogenesis, determinating diagnosis and evaluating prognosis in MDS.