Impact of complete cytogenetic response on survival in patients with myelodysplastic syndromes.

6567 Background: Response to therapy prolongs survival in patients with myelodysplastic syndromes (MDS). The aim of this study is to evaluate the impact of complete cytogenetic response (CCyR) on survival in patients with MDS and abnormal cytogenetics. Methods: We reviewed 2311 consecutive patients with MDS and cytogenetic abnormalities who were treated at our institution from 2006 to 2023. Results: CCyR was observed in 330 patients (14%), complete response (CR) in 208 (9%), CR with bilineage recovery (CRbi) in 255 (11%), CR with unilineage recovery (CRuni) in 151 (7%), CR with incomplete hematologic recovery (CRh) in 4 (0.2%), and non-CR in 1363 (59%). With a median follow-up of 59 months, the median overall survival (mOS) was 14 months. Ten months for non-CR, 19 months for CRh/CRbi/CRuni, 21 months for CR, and 26 months for patients with CCyR (p 75 years (HR 3.1, p 1.3 g/dL (HR 1.44, p 50 x10 9 /L (HR 1.31, p <0.001), cardiac comorbidities (HR 1.26, p < 0.001), platelets < 20 x10 9 /L (HR 1.26, p=0.001), pneumonia at diagnosis (1.22, p =0.006), and core-binding factor cytogenetics (HR 0.48, p < 0.001) were independently prognostic for survival in this select group. Conclusions: Achievement of CCyR in patients with MDS and abnormal cytogenetic abnormalities leads to improved survival. Given poor outcomes in older patients with MDS, CCyR can be used as a valid surrogate for long-term outcomes.