Incidence and Clinical Significance of Scoring System in Myelodysplastic Syndromes Including Hematological and Cytogenetic Profiles from a Single Institution

Background: Mydelodysplastic syndromes (MDS) are clonal stem cell disorders characterized by hypercellular marrow with ineffective hematopoiesis determining peripheral cytopenia. Recently, the WHO developed a new classification that identifies the following subtypes: RA, RARS, 5q- syndrome (MDS 5q-), RCMD, RCMD with ringed sideroblasts (RCMDS), RAEB-1, RAEB-2 and MDS unclassifiable (MDS-U). The goals of our study were to establish the incidence of chromosome abnormalities in MDS patients, to correlate chromosomal defects with WHO subtype and peculiar clinical-biological findings.

Patients and Methods: We studied 242 consecutive MDS patients who were admitted in the hematology department of St. Mary’s hospital from 2000 to 2007. The diagnosis was made according to the World Health Organization classification system. The chromosome analysis of the BM cells at diagnosis was performed by the G-staining method with trypsin and karyotyped according to the ISCN 2005.

Results: The median age of patients was 50 (2–84). WHO classification was as follows: RA (n=21, 8.7%), RARS (n=7, 2.9%), RCMD (n=62, 25.6%), RCMDS (n=6, 2.5%), RAEB-1 (n=63, 26.0%), RAEB-2 (n=74, 30.6%), MDSU (n=7, 2.9%), MDS 5q- (n=2, 0.8%). Chromosomal abnormalities were found in 51.2% of patients. The cases with good, intermediate and poor cytogenetic risk features were observed in 55.0%, 29.3%, and 15.7%. Trisomy 8 was most common abnormality in all cases. 1q+, 5q-, 20q- were followed. By International Prognostic Scoring System (IPSS) 13 (5.4%) patients were classified in low group; 141 (58.3%) intermediate-1, 60 (24.8%) intermediate-2, and 28 (11.6%) high were classified. By WHO classification-based prognostic scoring system (WPSS), 14 (5.8%) patients were classified in very low group; 25 (10.3%) low, 57 (23.6%) intermediate, 110 (45.5%) high, and 36 (14.9%) very high were classified. Thirty-six patients (14.9%) progressed into AML. Both IPSS and WPSS was shown to predict survival and leukemia progression, even in a short-term prospective study (P<0.001).

Conclusions: It is important to diagnose MDS accurately on the base of cytopenia, bone marrow morphology and clonal chromosomal abnormalities. IPSS and WPSS provide good prediction of survival and risk of leukemic evolution in MDS patients. The evaluation of clinical, hematological and cytogenetic analysis in more cases for long time follow-up will be helpful to standardize diagnosis of MDS.