The outcomes for patients with lower-risk myelodysplastic syndromes (LR-MDS) by the International Prognostic Scoring System (IPSS) vary widely. For more precise prognostication, this study evaluates the prognostic value of revised IPSS with the response to hypomethylating therapy (HMT). Using the Korean MDS Working Party database, treatment outcomes for 236 patients with HMT were retrospectively evaluated. The patients were then reclassified into very low/low (VL/L), intermediate (INT), and high (H) risk groups according to IPSS-R. According to the HMT response, the 3-year overall survival (OS) did not differ between the response group (37.9 ± 9.1 %) and the stable group (52.9 ± 6.6 %, p = 0. 782). When reclassifying according to IPSS-R, 42 patients (20.8 %) were reclassified into the H risk group. Most of them did not have benefit from continued HMT and progressed to secondary failure. The median OS was 59.0 months (range, 40.0-77.9 months) for the VL/L risk group, 31 months (range, 22.7-439.3 months) for the INT risk group, and 20.0 months (range, 15.9-24.1 months) for the H risk group (p < 0.001). In the multivariate analysis, the following factors were associated with survival: age ≥ 65 (HR = 1.515, p = 0.023), ECOG ≥ 2 (HR = 2.968, p < 0.001), H risk group according to IPSS-R (HR = 3.054, p < 0.001), P/VP cytogenetic risk according to IPSS-R (HR = 4.912, p = 0.003), and transformation to AML (HR = 2.158, p = 0.002). If IPSS-R reclassifies LR-MDS patients as H risk, these patients should be considered for early allo-HCT, regardless of the current benefits from HMT.
Keywords: Hypomethylating agent; IPSS; IPSS-R; Lower-risk; Myelodysplastic syndromes.