Cytogenetic Response Based On Revised IPSS Cytogenetic Risk Stratification and Minimal Residual Disease Monitoringby FISH In MDS Patients Treated By Low-Dose Decitabine

To observe and analyze the response characteristics based on revised IPSS (IPSS-R) cytogenetic risk stratification in patients with myelodysplastic syndromes (MDS) who received low-dose decitabine treatment.

Eighty-seven MDS patients received decitabine treatment (15-20mg/M²/d×5/per course) with a median of 4 courses (range, 1-10). The clinical and cytogenetic response after treatment were observed to evaluate whether the IPSS-R cytogenetic risk stratification could predict treatment response. For those patients with abnormal karyotypes who achieved clinical complete response (CR), percentage of clonal cells in bone marrow (BM) was calculated by G-banding together with fluorescence in situ hybridization (FISH) to determine the minimal residual disease (MRD). In addition, the effect of cytogenetic response on overall survival (OS) was also analyzed.

Sixty of 87 patients (69.0%) achieved treatment response including 25 cases (28.7%) with CR. For the 44 patients with abnormal chromosome, 27 cases (61.3%) achieved cytogenetic response including 18 with complete cytogenetic response (cCR). The patients carrying poor or very poor karyotypes presented better clinical and cytogenetic response than those with intermediate or good karyotypes. Among the patients with poor or very poor karyotypes, the ones carrying chromosome 7 aberrance showed better response than the others. Among 18 patients with abnormal karyotypes who achieved clinical CR, 4 cases presented cytogenetic PR or NR through G-banding analysis. FISH analysis revealed an over 5 % of clonal cells in BM in two patients who presented G-banding defined cytogenetic CR. In addition, longer median OS (24 months) were observed for patients who achieved cytogenetic response than those who did not (12 months) (P=0.007)

IPSS-R cytogenetic risk stratification could be used to predict the clinical and cytogenetic response to decitabine treatment in MDS patients. The predicting effect may be related to the chromosome 7 involvement rather than the number of abnormal karyotypes. FISH together with G-banding analysis should be available in determining MRD in MDS patients after treatment.

No relevant conflicts of interest to declare.