Predictive value of pretreatment risk group and baseline LDH levels in MDS patients receiving azacitidine treatment

This study analyzed the outcomes of myelodysplastic syndrome patients treated with azacitidine. Between August 2006 and June 2008, a total of 126 patients were treated with azacitidine at a dose of 75 mg/m²/day subcutaneously for 7 days, which was repeated every 28 days. The median age of the patients was 64 (range, 20–82) years. Forty-three patients (33.4%) were classified as intermediate-2 and high risk according to International Prognostic Scoring System (IPSS), while 61 patients (47.3%) were classified as high and very high risk according to WHO Prognostic Scoring System (WPSS). Sixty patients (47.6%) exhibited a response at the median of 3 (range, 1–5) cycles. A complete response was observed in 21 patients (16.7%), a partial response in six patients (4.8%), and total hematologic improvement in 61 patients (48.4%). For the IPSS risk group, the median survival for the patients with intermediate-1 was 20.0 months, for intermediate-2 was 14.9 months, and for high risk was 6.3 months (p = 0.008). For the WPSS risk group, the median survival duration was 21.3 months for the very low and low risk patients, 16.5 months for intermediate risk patients, and 14.9 months for the high and very high risk patients (p = 0.003). The patients with higher than normal lactate dehydrogenase (LDH) levels at the time of diagnosis showed a poor survival (p = 0.003). The median survival duration for the patients with high LDH levels was 13.9 months, while that for the patients with normal LDH levels was 20.6 months. The multivariate analyses revealed that high LDH levels [hazard ratio (HR) 4.384, p < 0.001] and high and very high WPSS risk group (HR 3.855, p = 0.014) were significantly associated with a worse survival, whereas a response to azacitidine was identified as a good prognostic factor for survival (HR 0.224, p = 0.019). In conclusion, while the pretreatment risk group and initial LDH levels were both confirmed as important prognostic factors to predict the outcomes for patients treated with azacitidine, more effective therapies are still needed to prevent disease progression.