A pair of new indices may help individualize prognostication and treatment for adults with cytogenetically normal acute myeloid leukemia, the largest and most heterogeneous cytogenetic subgroup, Dr. Friederike Pastore and associates reported in Journal of Clinical Oncology.
The indices are likely the first that can be applied to adult patients with acute myeloid leukemia (AML) of all ages, wrote Dr. Pastore of University Hospital Munich, Germany, and his associates.
The investigators developed and validated the indices using data from 669 patients with cytogenetically normal disease who were treated within the German AML Cooperative Group 99 study.
Median age of the patients was 60 years, with a range from 17 to 85 years. Median overall survival was 1.9 years and median relapse-free survival was 1.5 years. About two-thirds of the patients had a treatment response, Dr. Pastore and associates reported.
The indices were based on the 572 patients with complete data and included age, performance status, white blood cell count, and mutation status of NPM1, CEBPA, and FLT3-internal tandem duplication, the investigators reported (J. Clin. Oncol. 2014 April 7 [doi:10.1200/JCO.2013.52.3480).
The prognostic index for cytogenetically normal AML for overall survival classified 29%, 56%, and 15% of all patients as having low-, intermediate-, and high-risk disease, respectively. Their corresponding 5-year rates of overall survival were 74%, 28%, and 3% (P less than .001).
The prognostic index for cytogenetically normal AML for relapse-free survival classified 32%, 39%, and 29% of patients a treatment response as having low-, intermediate-, and high-risk disease. Their corresponding 5-year rates of relapse-free survival were 55%, 27%, and 5% (P less than .001).
Both indices performed well at stratifying patients within European LeukemiaNet genetic groups, and both were externally validated in a cohort of 529 patients treated in Cancer and Leukemia Group B/Alliance trials.
"We have developed and validated, to our knowledge, the first prognostic indices specifically designed for adult patients of all ages with [cytogenetically normal AML] that combine well-established molecular and clinical variables and that are easily applicable in routine clinical care," the investigators wrote, noting that web-based calculators for the indices are now accessible online.
"The new prognostic indices should be able to be easily adopted in routine practice for prognostication and guidance of risk-adapted postremission therapy in analogy to the Euro score ... in chronic myelogenous leukemia or the mantle cell lymphoma international prognostic index," they concluded.
The investigators disclosed no potential conflicts of interest.