Analysis of the 2017 ELN risk stratification in Japanese adult AML patients

Yasuhiko Harada from Nagoya University Graduate School of Medicine, Nagoya, Japan, and colleagues assessed the effectiveness of the 2017 European LeukemiaNet (ELN) risk stratification system in comparison with the 2010 ELN  and the refined Medical Research Council (MRC)  system in  Japanese newly diagnosed Acute Myeloid Leukemia (AML) patients who were treated in the Japan Adult Leukemia Study Group (JALSG) AML-201 multi-center phase III randomized study (C000000157). The study was published in Leukemia Research.

In this AML-201 study, 1,057 newly diagnosed AML patients were enrolled. Of these, 197 patients were available for comprehensive genetic analysis and thus their clinical and genetic data were used in this study. The median follow-up was 32.5 months.

Key highlights:

• According to the 2017 ELN risk stratification, favorable, intermediate and adverse categories included 108 (54.8%), 43 (21.8%), and 46 (23.4%) patients respectively
• According to the 2010 ELN risk stratification, favorable, Intermediate-risk I, intermediate-risk II and adverse categories included 92 (47%), 35 (18%), 42 (21%), and 28 (14%) patients respectively
• According to the refined MRC, favorable, intermediate and adverse categories included 108 (28%), 43 (60%), and 46 (12%) patients respectively
• ELN-2017 system, the numbers of patients in the favorable and adverse risk group increased due to changes in the risk categories based on genetic status

Prognostic analysis:

• ELN 2017
  • Complete Response (CR) rate: 81.7% (161/197)
  • CR rate was significantly higher in the favorable-risk group (94.4%) than in the intermediate- (65.1%) and adverse- (67.4%) risk groups
  • 5-year Overall Survival (OS) in the favorable-, intermediate- and adverse- risk groups were 59.1%, 32.6%, and 22.6% respectively, P < 0.001
• ELN-2010
  • CR rates in the favorable, intermediate-I, intermediate-II and adverse groups were 93.5%,1%, 69.0%, and 67.9%, respectively
  • 5-year OS in the favorable, intermediate-I, intermediate-II and adverse- risk groups were 64.8%, 17.8%, 38.1%, and 24.1% respectively, P < 0.0001
• Refined MRC
  • CR rates in the favorable, intermediate and adverse groups were 90.9%, 8%, and 69.6% respectively
  • 5-year OS in the favorable, intermediate and adverse groups were 71.1%, 38.7%, and 17.4% respectively, P = 0.0001

It was observed that the allelic ratio of FLT3-ITD did not affect the prognosis in patients with FLT3-ITD, CN-AML, wild-type NPM1, and mutated NPM1.

In summary, “the 3-risk category system of the ELN 2017 successfully discriminated the OS and CR rates” in patients in comparison with the 4-risk category of the ELN-2010. The authors concluded by stating that the ELN-2017 system “clearly distinguished long-term prognosis in Japanese adult patients with de novo AML."