Research Suggests ‘Clone Size by Conventional Cytogenetics’ Can Predict Outcomes in MDS

Many patients with myelodysplastic syndromes (MDS) have chromosomal abnormalities per conventional karyotyping. This cytogenetic information is important for MDS diagnosis and risk stratification, according to a study presented at the 64th American Society of Hematology Annual Meeting & Exposition. The research found that the number of cells with chromosomal abnormalities using “clone size by conventional cytogenetics” was significantly associated with clinical features and outcomes in MDS.

The researchers defined “clone size by conventional cytogenetics” as percentage of metaphases, then explored whether there were any associations between percentage of cells/metaphases harboring chromosome abnormalities and clinical features and outcomes. They extracted data from the lead author’s institutional database and focused on cytogenetics of interest. To be included, a case had to have had at least 10 metaphase analyses of chromosome abnormalities by conventional cytogenetics at the time of diagnosis or prior to any therapy.

The sample size ultimately included 1,096 patients, and notable results included:

• Among 151 patients with isolated del5q, those who had more than 75% metaphases had more severe anemia and showed a trend for better response to lenalidomide
• Among 134 patients with del20q, those who had more than 75% metaphases experienced more thrombocytopenia
• Among 113 patients with del7q/–7, median overall survival (OS) was worse among those with –7 than those with del7q (18.5 months vs 29.0 months). OS was also strongly correlated with percentage of metaphases (98 months when less than 25% vs 18 months when more than 25%)
• Among 38 patients with isolated ch3, median OS was 122 months among those with less than 25% metaphases versus 24 months for those with more than 25%
• Among 163 patients with +8, patients with less than 25% metaphases had better median OS than those with more than 25% (59 months vs 36 months)
• Among 497 patients with complex karyotype, median OS was better for patients with less than 25% metaphases (20 months) compared to those with more than 25% (12 months)

The authors, led by Rami S. Komrokji, MD, of the Department of Malignant Hematology at H. Lee Moffitt Cancer Center and Research Institute in Tampa, Florida, suggested that the strong correlations they found indicate that the revised International Prognostic Scoring System and the newer molecular version should use a 25% cutoff to assess cytogenetic risk rather than dichotomous assignment to risk group.

Reference

Komrokji RS, Al Ali N, Volpe VO, et al. Clone size by conventional cytogenetics in myelodysplastic syndromes correlates with clinical features and outcomes. Abstract #4406. Presented at the 64th American Society of Hematology Annual Meeting, December 10-13, 2022; New Orleans, Louisiana.