Higher prevalence of poor prognostic markers at a younger age in adult patients with myelodysplastic syndrome - evaluation of a large cohort in India.

Background: The karyotype is a major determinant of prognosis in myelodysplastic syndrome (MDS). Details of the cytogenetic profile of MDS in South Asia are limited because cytogenetic services are not widely available.

Methods: We performed a retrospective analysis of the cytogenetic and clinicopathologic profile of adult primary MDS seen consecutively at a tertiary-care centre in South India between 2003 and 2017. Patients were re-categorised according to the 2022 World Health Organisation (WHO) and the International Consensus classifications (ICC).

Results: There were 936 patients aged 18-86 years (median age 53, 65% males), with MDS with del 5q, low blasts and increased blasts in 7.5%, 58.4% and 34.1% respectively. Clonal abnormalities were seen in 55% of patients, with solitary abnormalities in 29.8% and complex karyotypes (CK, ≥ 3 abnormalities) in 15%. The most frequent abnormalities were monosomy 7/deletion 7q (16.1%), deletion 5q (14.5%), trisomy 8 (11.5%), and deletion 20q (5.1%). Cytogenetic prognosis groups were distributed as follows: very good, 2%; good, 55.6%; intermediate, 16.2%; poor, 15%; very poor, 11.2%. Clinical (IPSS-R) risk stratification (842 patients) showed: very low-risk, 3.9%; low-risk, 30.9%; intermediate-risk, 24.2%; high-risk, 21%; very high-risk, 20%. Age-adjustment (IPSS-RA) raised the very low-risk group to 12.4%; the other groups decreased by 1-3% each.

Conclusion: The most significant finding of this cytogenetic analysis of MDS in India is that abnormal karyotypes with poor prognosis markers including monosomy 7 and CK were more frequent than in most other reports, among patients who were overall younger. Trisomy 8, deletion 20q, the IPSS-R intermediate-risk and both high-risk groups were more common than in the West. Trisomy 8 was less common than in South-East Asia while CK and deletion 20q were comparable. Evaluation of such large cohorts highlights the unique features of MDS in different parts of the world. These findings suggest that there could be differences in predisposing factors, environmental or genetic, and emphasise the need for further exploration to better understand the varied nature of MDS.