Is Extramedullary Disease at Diagnosis Prognostic in Adult Acute Myeloid Leukemia?


Key Points

  • Extramedullary disease was present in 24% of patients at diagnosis of AML.
  • Extramedullary disease was associated with poorer overall survival on univariate analysis but not on multivariate analysis.

The presence of extramedullary disease at acute myeloid leukemia (AML) diagnosis was not an independent prognostic factor for worse survival, based on an analysis of data from the Eastern Cooperative Oncology Group–American College of Radiology Imaging Network (ECOG-ACRIN) reported by Ganzel et al in the Journal of Clinical Oncology.

Study Details

The study involved data from 3,240 patients aged ≥ 15 years enrolled in 11 consecutive ECOG-ACRIN Cancer Research Group front-line clinical trials (1980–2008). Diagnosis of extramedullary disease was based on physical examination, laboratory findings, and imaging results. Extramedullary disease was present at diagnosis in 23.7% of patients, with involved sites including lymph nodes (11.5%), spleen (7.3%), liver (5.3%), skin (4.5%), gingiva (4.4%), and central nervous system (CNS; 1.1%). Extramedullary disease was present at 1 site in 65.3%, 2 sites in 20.9%, 3 sites in 9.5%, and 4 sites in 3.4%.

Overall Survival

Among all patients, median overall survival was 1.035 years. In univariate analysis, the presence of any extramedullary disease (P = .005) and involvement of skin (P = .002), spleen (P < .001), and liver (P < .001)—but not CNS (P = .34), lymph nodes (P = .94), or gingiva (P = .24)—was associated with poorer overall survival. A greater number of extramedullary disease sites was associated with poorer survival, both as a categorical (P = .002) and continuous variable (P < .001). However, on multivariate analysis adjusting for known prognostic factors, including cytogenetic risk and white blood cell count, the presence of extramedullary disease (hazard ratio [HR] = 0.96, P = .67) and the number of sites (HR = 1.32, P = .14) were no longer associated with survival; no significant association was observed for extramedullary disease involving specific sites, including skin, spleen, and liver.

The investigators concluded: “This large study demonstrates that [extramedullary disease] at any site is common but is not an independent prognostic factor. Treatment decisions for patients with [extramedullary disease] should be made on the basis of recognized AML prognostic factors, irrespective of the presence of [extramedullary disease].

The study was supported by the National Cancer Institute.

Chezi Ganzel, MD, of the Shaare Zedek Medical Center, Jerusalem, Israel, is the corresponding author of the Journal of Clinical Oncology article.

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