Pre-analytical parameters associated with unsuccessful karyotyping in myeloid neoplasm: a study of 421 samples

High Counts in Hematologic Malignancies Predict Low Metaphase Yield for Cytogenetic Analysis

OBJECTIVES

This study examined the impact of various preanalytical variables on metaphase yield in hematologic malignancies.

METHODS

Marrow samples from patients with hematologic malignancies that were subjected to cytogenetic analysis were categorized into two groups: one with samples that yielded an adequate number of metaphases, defined as at least 20, and a second with a low number of metaphases (LNM), having fewer than 20 metaphases. Age, sex, bone marrow nucleated cell (MNC) count, and peripheral blood counts (hemoglobin, total WBC count, and platelet count) were analyzed for an association with LNM.

RESULTS

Of 455 samples, 17% (79/455) belonged to the LNM group, including 6% (27/455) that yielded no metaphases. MNCs and WBCs were higher in the LNM group (P < .001 for both). MNCs were higher in LNM groups in both acute myeloid leukemia (P = .008) and acute lymphoblastic leukemia (P = .001). Receiver operating characteristic curves showed moderate prediction of MNC and WBC counts for LNM with areas under the curves of 0.7. Other analyzed parameters showed no significant associations with LNM.

CONCLUSIONS

Low metaphase yields occur frequently in hematologic malignancies with high counts. This could reflect biological characteristics of these malignancies that merit further investigation.

Multiplex ligation-dependent probe amplification identifies copy number changes in normal and undetectable karyotype MDS patients

Chromosomal abnormalities play an important role in classification and prognostication of myelodysplastic syndrome (MDS) patients. However, more than 50% of low-risk MDS patients harbor a normal karyotype. Recently, multiplex ligation-dependent probe amplification (MLPA) has emerged as an effective and robust method for the detection of cytogenetic aberrations in MDS patients. To characterize the subset of MDS with normal karyotype or failed chromosome banding analysis, we analyzed 144 patient samples with normal karyotype or undetectable through regular chromosome banding analysis, which were subjected to parallel comparison via fluorescence in situ hybridization (FISH) and MLPA. MLPA identifies copy number changes in 16.7% of 144 MDS patients, and we observed a significant difference in overall survival (OS) (median OS: undefined vs 27 months, p=0.0071) in patients with normal karyotype proved by MLPA versus aberrant karyotype cohort as determined by MLPA. Interestingly, patients with undetectable karyotype via regular chromosome banding indicated inferior outcome. Collectively, MDS patients with normal or undetectable karyotype via chromosome banding analysis can be further clarified by MLPA, providing more prognostic information that benefit for individualized therapy.

Outcomes of adult patients with acute myeloid leukemia and unsuccessful cytogenetic analysis undergoing allogeneic hematopoietic stem cell transplantation

OBJECTIVE/BACKGROUND

Unsuccessful cytogenetic (US) analysis at baseline has been reported to be a poor prognostic feature in patients with acute myeloid leukemia (AML). We conducted this study to examine the prognostic impact of UC/inconclusive cytogenetic analysis on outcomes in patients with AML undergoing allogeneic hematopoietic stem cell transplantation (Allo HSCT).

METHODS

We retrospectively analyzed all adults undergoing Allo HSCT for AML from January 2011 to August 2019. Patients with any documented cytogenetic abnormalities were excluded. Baseline characteristics and transplant outcomes were compared between patients with normal cytogenetics and those with UC.

RESULTS

Overall, 243 AML patients (median age, 55 years; 55.1% female) were included. UC were reported in 79 patients, whereas 164 patients had a normal karyotype. The two groups were similar to each other in terms of baseline demographics, treatment received, and transplant related variables. There was no difference between patients with UC and normal cytogenetics in terms of relapse-free survival (66 months vs. 42 months, p = .53) or overall survival (OS; 77 months vs. 76 months, p = .72). Survival parameters remained similar even in subgroup analysis based on NPM1 and FLT3 mutation status. Significant predictors of OS after Allo HSCT in AML patients with UC were increased age at time of Allo HSCT (hazard ratio [HR] = -1.049; 95% confidence interval [CI], 1.005-1.095), favorable (NPM1^Mut/FLT3^wt) mutation profile (HR = 0.11; 95% CI, 0.01-0.84), neutrophil engraftment < 17 days, and absence of chronic graft-versus-host disease (HR = 3.27; 95% CI, 1.20-8.60).

CONCLUSION

Outcomes after Allo HSCT are comparable between AML patients with UC analysis and patients with normal cytogenetics even after stratification based on molecular risk factors. Allogeneic Allo HSCT may mitigate the poor prognosis of UC analysis in patients with AML.