Clinico-Pathological Spectrum and Novel Karyotypic Findings in Myelodysplastic Syndrome: Experience of Tertiary Care Center in India
Received: April 22, 2017
Accepted: July 19, 2017
Mediterr J Hematol Infect Dis 2017, 9(1): e2017048 DOI 10.4084/MJHID.2017.048
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Myelodysplastic syndrome (MDS) is a heterogeneous disorder
characterized clinically by the presence of cytopenia/s. Limited data
are available about the morphological spectrum and cytogenetic profile
of Indian MDS patients. The aim of the study was to ascertain the
clinico-pathological, morphological and cytogenetic spectrum of Indian
There are a limited number of studies describing the cytogenetic profile of MDS from India,[9-13] and hence this highlights the importance of the present study. It has been previously observed that the disease biology among Indian subcontinent is distinct when compared to the Western population. In this study, we describe the clinico-pathological profile and cytogenetic abnormalities in patients with MDS and categorize them according to the IPSS-R scoring system to assess the disease burden in our cohort of patients.
Materials and Methods
Morphological examination. May-Grunwald Giemsa (MGG) stained bone marrow aspirate smears were reviewed by two independent pathologists (RG and KR) and diagnosis of MDS was made according to WHO 2016 classification. Perl's staining for iron stores was also carried out in all the cases to assess for the presence of ring sideroblasts.
Cytogenetic analysis. Heparinized bone marrow samples were collected for conventional karyotyping. The G-banding technique was used, and a minimum of 20 metaphases was analyzed. Karyotypes were described with reference to the International System of Human Cytogenetic Nomenclature (ISCN) 2009 & 2013. The cytogenetic abnormalities were then scored according to IPSS-R cytogenetic categories. Complex karyotype was defined as the presence of three or more structural defects or monosomies. Monosomal karyotype was defined as the presence of at least two autosomal monosomies or a single monosomy associated with at least one additional structural abnormality.
Statistical analysis. Statistical analysis was performed using SPSS version 16.0. The difference among groups and correlation studies were analyzed by analysis of variance and Pearson correlation. The level of significance was assigned at p-value <0.05.
Morphology. The patients were classified according to WHO 2016 into single lineage dysplasia (MDS-SLD, n = 13), multilineage dysplasia (MDS-MLD, n = 63), single lineage dysplasia with ring sideroblasts (MDS-SLD-RS, n = 2), multilineage dysplasia with ring sideroblasts (MDS-MLD-RS, n = 2), excess of blast 1 (MDS -EB 1, n = 32), excess of blast 2 (n = 33), two cases of refractory cytopenia of childhood (RCC) and 3 cases of 5q – MDS. Morphologically, 16 patients showed hypoplastic marrow, and the majority of them had excess blasts (57%); with a median blast count of 5%. Clonal abnormalities were detected in 62.5% cases of MDS-SLD, 48.7% cases of MDS-MLD, 44.4% cases of MDS-EB-1, 50% cases of MDS-EB-2 and 78% cases of hypoplastic MDS.
Cytogenetic and risk stratification. Cytogenetic analysis by conventional karyotyping was available in 86/150 (57.3%) cases (Supplementary Table S1). An abnormal karyotype was detected in 43 cases (50%). According to the IPSS-R cytogenetic risk stratification, a significant number of patients exhibited high-risk cytogenetic abnormalities (56.9%). Age adjusted analysis showed an abnormal cytogenetic profile in 70.5% patients aged less than 40 years, in 42.5% patients in the 40-60 years sub-group and 44.8% patients above 60 years old.
The presence of a complex karyotype was found to be the most common cytogenetic abnormality and detected in 32.5% patients. Isolated chromosomal abnormalities were detected in 39.5% (17/43) patients and double abnormalities were present in 16.2% cases. A monosomal karyotype was identified in 15/43 patients (34.9%) patients, of which 73% cases (11/15) had a complex karyotype. Chromosome 7 was the most frequently [32.5% (14/43)] involved chromosome, in the form of monosomy and interstitial deletions and occasional translocation. Isolated monosomy seven was seen in only 6.9% (3/43) cases. Deletion 20q (del 20q) and deletion 5q (del 5q), in isolation or combination with other chromosomal aberrations, were present in 9.3% and 6.9% patients respectively. The incidence of trisomy 8 was found to be very low (2.3%, 1/43). Interestingly, the presence of t(9;22)(q34;q11.2) was noted in three cases (6.9%), one each of MDS-SLD, MDS-MLD and MDS-EB 2. None of them had any clinical or morphological features suggestive chronic myeloid leukemia (CML). Four patients revealed the presence of chromosomal translocation, unusually reported in MDS, which were 46,XY,t(1;5)(p22;q33), in MDS-SLD, t(1;12)(p34;p11.2) and t(5;7;9;)(q13;q32;p22) in a case of MDS-EB 1, and t(1;2)(p36.1;q21) in MDS-EB 2.
The majority of the patients were assigned to the high risk IPSS-R prognostic group (31.4%); followed by intermediate and very high-risk groups, 29% and 24.4% respectively. Only 2.3% patients belonged to the very low-risk category. Age adjusted IPSS-R revealed that 70% patients aged less than <40 years were in the very high and high-risk categories as compared to 51% in the high-risk groups (Supplementary Table S2).
There was no statistically significant correlation between the complex cytogenetic abnormalities and the WHO sub groups and age. The complex karyotype was also detected with equal frequency in both low risk and high-risk morphological categories of MDS and across all age groups.
Clinically, the majority of the patients in our population presented with 2 or 3 lineage cytopenias rather than isolated ones. Morphologically, the incidence of low-risk categories, RA and RARS was only 10%, while high-grade MDS (EB-1 and EB-2) was observed to be 43.4%. The frequency of high-risk MDS is comparable to the data from other Asian countries; however, it is significantly higher (30-40% vs 10-30%) as compared to the western literature.[8,19,20] In an attempt to delineate the difference in MDS in the eastern and western countries, a comparative analysis was performed by Matsuda et al in 2005. They compared the Japanese and German FAB – RA (refractory anemia) categories, and found that Japanese patients were significantly younger (57 vs 71 years) and had more severe cytopenias than the German patients. An abnormal karyotype was detected in 29% Japanese patients and 53% patients of the German cohort in this subgroup. In our study, the median age of patients in FAB-RA was 52 years, which is comparable to the Japanese cohort, however, the incidence of cytogenetic alterations was very high (62.5%). The high incidence of cytogenetic abnormalities in RA has also been reported previously from India, where they observed clonal abnormalities in 63.6% patients. Another morphological variation worth discussion is the hypoplastic MDS group. The frequency of hypoplastic MDS documented in literature is 8-20%.[22,23] In a recent study of 100 hypoplastic MDS patients, it was observed that these patients have statistically significant lower peripheral blood counts, bone marrow blast percentages and a lower incidence of poor-risk cytogenetic abnormalities, as compared to the non hypoplastic groups. On the contrary, in our cohort of 9.3% (14/150) patients with hypoplastic MDS, the median blast count was 5% and 78% (7/9) of these patients were found to harbor abnormal karyotype (Supplementary table S2).
Clonal abnormalities were found in 50% cases in our study, which is in concordance with the documented western and Indian literature.[9-13,19,20] Importantly, a significantly higher incidence of complex abnormalities and monosomal karyotype was noted in our population (Figure 1) as compared to other published Indian, Chinese and western data (32.5% vs 6.5-11%, and 34.5% vs 8.1-15%),[19,20,25] while the frequency of 5q deletion and trisomy 8 were much lower (6.9 vs 26-30% and 2.3 vs 15-31%, respectively). In recent studies, monosomal karyotype has also been proposed to be a predictor of bad prognosis. Patients with a monosomal karyotype, invariably belong to poor or very poor cytogenetic risk groups and it has been observed the rate of overall mortality and relapse was significantly higher among patients with monosomal karyotype than in those without it.[14,25] We also detected a few novel cytogenetic abnormalities, mostly in association with complex karyotype. It has been previously observed too, that these rare translocations are usually found in association with other chromosomal alterations and thus their role in disease pathogenesis is unclear. Other rarely reported abnormality includes the presence of Philadelphia chromosome in MDS. Keung MB et al, retrospectively screened 148 Philadelphia positive patients and observed 2% cases of MDS to harbor this mutation. Three patients in our study group showed presence of Philadelphia chromosome or t(9;22)(q34;q11.2) in addition to other cytogenetic alterations. It is intriguing that Armas et al. in their recent review of Philadelphia positive de novo MDS cases have shown that, t(9;22) was the sole abnormality in 50% cases. Additionally, trisomy 8 has been reported in approximately 40% cases along with other complex cytogenetic abnormalities. In our series, all three patients had presented with complaints of cytopenias and past history of packed RBC/platelet transfusion. None of these patients had organomegaly or lymphadenopathy. Morphologically, two of these patients had a normocellular to mildly hypocellular marrow, with evidence of dyspoiesis. The absence of organomegaly, leukocytosis or hypercellular bone marrow and presence of cytopenias with significant dyspoiesis and a complex karyotype favored the diagnosis of MDS over chronic myeloid leukemia in these patients.
As per the IPSS-R prognostic risk stratification, 55.8% of our patients belonged to the high and very high risk categories and only 2.3% and 12.8% of our patients belonged to the very low-risk category and low risk categories respectively. Seventy percent of the individuals aged below 40 years, belonged to the high and very high risk prognostic risk categories. This is in contrast to the available Indian data from southern India and the western data, where IPSS-R risk stratification has been performed (Figure 2).[4,13,16,19,20] Narayanan S, in their study cohort of 60 patients from southern India, observed majority (73%) of their patients to be aged above 70 years and only 19.2% patients in high risk IPSS-R category. In a multi centric study by Greenberg P et al, data for 7012 primary untreated MDS patients, from multiple international institutions including Spanish, French, Piemonte (Italy) and Brazilian MDS Registries and the International MDS Risk Analysis Workshop (IMRAW), was compiled and evaluated. IPSS-R stratification revealed 57% patients in very low/low risk and 23% patients in the high/very high risk categories. Similarly, in a report from the European LeukemiaNet MDS registry, 71.5% and 3.5% patients were assigned in the very low/low risk and high/very high risk categories respectively. These studies clearly highlight the differences in the disease burden in Indian and Western population.
|Figure 2. Comparative bar diagram highlighting the difference between the IPSS-R risk groups in different studies.[8,13,20,30]|
The inclusion of FISH in the diagnostic armamentarium would aid in identifying additional patients with cryptic abnormalities of chromosome 5 and 7 which might be missed in conventional cytogenetics. This has been confirmed by Lai et al in a large multi centric study of 2032 chinese patients, where they observed clonal abnormalities by FISH in 23.6% cases with apparently normal cytogenetics. Further, abnormalities detected by FISH were more frequently observed among patients with <5% bone marrow blasts.
In conclusion, the average age of MDS in our country is about a decade less than that reported in western literature. The cytogenetic profile is largely distinct, though there is significant overall heterogeneity in the Indian data, from different parts of the country. Overall, we observed a very high incidence of complex karyotypes and the incidence of isolated del 5q, appears to be much lower as compared to the western data. The majority of our patients belong to high IPSS-R risk categories; indicating the need for early intervention and counseling for stem cell transplantation. A larger population and gene expression profiling based studies with follow up data are required to understand the reasons for the regional variations, genetic mechanism of MDS in our part of the world and their therapeutic implications.
- Swerdlow S CE, Harris N et al (2008) WHO classification of tumors of hematopoietic and lymphoid tissues. Lyon.
- Hasse D. Cytogenetic features in myelodysplastic syndromes. Annals of Hematology 87:515-26. https://doi.org/10.1007/s00277-008-0483-y .
- Jonas BA, Greenberg PL MDS prognostic scoring systems - past, present, and future. Best Pract Res Clin Haematol. 2015 March; 28(1): 3-13 https://doi.org/10.1016/j.beha.2014.11.001 PMid:25659725 PMCid:PMC4324398.
- Greenberg PL, Tuechler H, Schanz J, Sanz G, Garcia-Manero G, Solé F, et al. Revised international prognostic scoring system for myelodysplastic syndromes. Blood. 2012 Sep 20;120(12):2454-65. https://doi.org/10.1182/blood-2012-03-420489 PMid:22740453 PMCid:PMC4425443.
- Schanz J, Tuchler H, Sole F, et al. New comprehensive cytogenetic scoring system for primary myelodysplastic syndromes (MDS) and oligoblastic acute myeloid leukemia after MDS derived from an international database merge. Journal of clinical oncology: official journal of the American Society of Clinical Oncology. 2012; 30(8):820-9. https://doi.org/10.1200/JCO.2011.35.6394 PMid:22331955 PMCid:PMC4874200.
- Borjas-Gutiérrez C, Domínguez-Cruz MD, González-GarcíaJR. Cytogenetics of myelodysplastic syndromes and its impact as prognostic factor. Rev Med Inst Mex Seguro Soc. 2017 Jul-Aug;55(4):481-489. PMid:28591503.
- Kennedy JA, Ebert BL. Clinical Implications of Genetic Mutations in Myelodysplastic Syndrome. J ClinOncol. 2017 Mar 20;35(9):968-974. https://doi.org/10.1200/JCO.2016.71.0806 PMid:28297619.
- Haferlach T, Nagata Y, Grossmann V, Okuno Y, Bacher U, Nagae G et al. Landscape of genetic lesions in 944 patients with myelodysplastic syndromes. Leukemia. 2014 Feb;28(2):241-7. https://doi.org/10.1038/leu.2013.336 PMid:24220272 PMCid:PMC3918868.
- Varma N, Varma S. Proliferative indices, cytogenetics, immunophenotye and other prognostic parameters in myelodysplastic syndromes. Indian J Pathol Microbiol. 2008 Jan-Mar;51(1):97-101 https://doi.org/10.4103/0377-4929.40416 PMid:18417875.
- Vundinti BR, Kerketta L, Jijina F, Ghosh K. Cytogenetic study of myelodysplastic syndrome from India. Indian J Med Res. 2009 Aug;130(2):155-9. PMid:19797812.
- Shah NM, Prajapati SG, Adesara RP, Patel AP. An analysis of 30 cases of myelodysplastic syndrome. Indian J Pathol Microbiol. 2009 Apr-Jun;52(2):206-9. https://doi.org/10.4103/0377-4929.48919 PMid:19332914.
- Chaubey R, Sazawal S, Dada R, Mahapatra M, Saxena R. Cytogenetic profile of Indian patients with de novo myelodysplastic syndromes. Indian J Med Res. 2011 Oct;134:452-7. PMid:22089606 PMCid:PMC3237242 .
- Narayanan S. Clinical, hematological, and cytogenetic profile of adult myelodysplastic syndrome in a tertiary care center. J Blood Med. 2017 Feb 23;8:21-27. https://doi.org/10.2147/JBM.S129111 PMid:28260960 PMCid:PMC5328424.
- Zhang T, Xu Y, Pan J, Qiu H, Wu D, Chen S et al. Monosomal karyotype of chromosome 5/7 was an independent poor prognostic factor for Chinese myelodysplastic syndrome patients. Cancer Genet. 2016 Sep;209(9):423-429. https://doi.org/10.1016/j.cancergen.2016.06.007 PMid:27423487.
- Demirkan F, Alacacioglu I, Piskin O, Ozsan HG, Akinci B, Ozcan AM et al. The clinical, haematological and morphological profile of patients with myelodysplastic syndromes: a single institution experience from Turkey. Leuk Lymphoma. 2007 Jul;48(7):1372-8. https://doi.org/10.1080/10428190701377063 PMid:17613766.
- Qu S, Xu Z, Zhang Y, Qin T, Zhang T, Cui R et al. Impacts of cytogenetic categories in the Revised International Prognostic Scoring System on the prognosis of primary myelodysplastic syndromes: results of a single-center study. Leukemia & Lymphoma, May 2012; 53(5): 940–946 https://doi.org/10.3109/10428194.2011.634049 PMid:22023524.
- Oguma S, Yoshida Y, Uchino H, Maekawa T, Nomura T, Mizoguchi H. Clinical characteristics of Japanese patients with primary myelodysplastic syndromes: a co-operative study based on 838 cases. Anemia Study Group of the Ministry of Health and Welfare. Leuk Res. 1995 Mar;19(3):219-25. https://doi.org/10.1016/0145-2126(94)00135-W .
- Kuendgen A, Matsuda A, Germing U. Differences in epidemiology of MDS between Western and Eastern countries: Ethnic differences or environmental influence? Leuk Res. 2007 Jan;31(1):103-4. https://doi.org/10.1016/j.leukres.2006.03.007 PMid:16630658.
- Haase D, Germing U, Schanz J, Pfeilstöcker M, Nösslinger T, Hildebrandt B et al. New insights into the prognostic impact of the karyotype in MDS and correlation with subtypes: evidence from a core dataset of 2124 patients. Blood. 2007 Dec 15;110(13):4385-95 https://doi.org/10.1182/blood-2007-03-082404 PMid:17726160.
- Gangat N, Patnaik MM, Begna K, Kourelis T, Al-Kali A, Elliott MA. Primary Myelodysplastic Syndromes: The Mayo Clinic Experience with 1000 Patients. Mayo Clin Proc. 2015 Dec;90(12):1623-38 https://doi.org/10.1016/j.mayocp.2015.08.022 PMid:26546107.
- Matsuda A, Germing U, Jinnai I, Misumi M, Kuendgen A, Knipp S et al. Difference in clinical features between Japanese and German patients with refractory anemia in myelodysplastic syndromes. Blood. 2005 Oct 15;106(8):2633-40 https://doi.org/10.1182/blood-2005-01-0040 PMid:15972453.
- De Souza DC, Fernandez Cde S, Camargo A, Apa AG, Da Costa ES, Bouzas LF et al. Cytogenetic as an important tool for diagnosis and prognosis for patients with hypocellular primary myelodysplastic syndrome. Biomed Res Int. 2014;2014:542395.
- Huang TC, Ko BS, Tang JL, Hsu C, Chen CY, Tsay W et al Comparison of hypoplastic myelodysplastic syndrome (MDS) with normo-/hypercellular MDS by International Prognostic Scoring System, cytogenetic and genetic studies. Leukemia. 2008 Mar;22(3):544-50. https://doi.org/10.1038/sj.leu.2405076 PMid:18094713.
- Yao CY, Hou HA, Lin TY, Lin CC, Chou WC, Tseng MH et al. Distinct mutation profile and prognostic relevance in patients with hypoplastic myelodysplastic syndromes (h-MDS). Oncotarget. 2016 Sep 27;7(39):63177-63188. https://doi.org/10.18632/oncotarget.11050 PMid:27527853 PMCid:PMC5325355.
- Deeg HJ, Scott BL, Fang M, Shulman HM, Gyurkocza B et al. Five-group cytogenetic risk classification, monosomal karyotype, and outcome after hematopoietic cell transplantation for MDS or acute leukemia evolving from MDS. Blood. 2012 Aug 16;120(7):1398-408. https://doi.org/10.1182/blood-2012-04-423046 PMid:22767498 PMCid:PMC3478516.
- Keung YK, Beaty M, Powell BL, Molnar I, Buss D, Pettenati M. Philadelphia chromosome positive myelodysplastic syndrome and acute myeloid leukemia- retrospective study and review of literature. Leuk Res. 2004 Jun;28(6):579-86. https://doi.org/10.1016/j.leukres.2003.10.027 PMid:15120934.
- Armas A, Chen C, Mims M, Rivero G. Uncovering Clinical Features of De Novo Philadelphia Positive Myelodysplasia. Case Rep Hematol. 2017;2017:5404131 https://doi.org/10.1155/2017/5404131 .
- De Swart L, Smith A, Johnston TW, Haase D, Droste J, Fenaux P et al. Validation of the revised international prognostic scoring system (IPSS-R) in patients with lower-risk myelodysplastic syndromes: a report from the prospective European LeukaemiaNet MDS (EUMDS) registry. Br J Haematol. 2015 Aug;170(3):372-83. https://doi.org/10.1111/bjh.13450 PMid:25907546.
- Lai YY, Huang XJ, Li J, Zou P, Xu ZF, Sun H et al. Standardized fluorescence in situ hybridization testing based on an appropriate panel of probes more effectively identifies common cytogenetic abnormalities in myelodysplastic syndromes than conventional cytogenetic analysis: A multicenter prospective study of 2302 patients in China. Leuk Res. 2015 May;39(5):530-5 https://doi.org/10.1016/j.leukres.2015.02.005 PMid:25823643.
- Yang YT, Hou HA, Liu CY, Lin CC, Chou WC, Lee FY et al. IPSS-R in 555 Taiwanese patients with primary MDS: Integration of monosomal karyotype can better risk-stratify the patients. Am J Hematol. 2014 Sep;89(9):E142-9. https://doi.org/10.1002/ajh.23765 PMid:24845799.
|Supplementary Table 1. Cytogenetic profile of MDS patients in different sub groups.|
|Supplementary Table 2. Age related IPSS-R|