A clinicopathological experience in acute myeloid leukemia: Effects of clinical data and status of FLT3, CEBPA and NPM1 on prognosis

ABSTRACT

Background: The purpose of the study was to analyze the expression of nucleophosmin (NPM1), CCAT/enhancer-binding protein alpha (CEBPA), and FMS-like tyrosine kinase 3 (FLT3) with immunohistochemistry and evaluate the relationship with clinicopathologic data with special emphasis on prognosis in bone marrow biopsy specimens diagnosed with acute myeloid leukemia (AML). Materials and Methods: Bone marrow biopsies of 104 patients who were diagnosed with AML were re-evaluated for diagnosis and subclassification. Immunohistochemically, anti-NPM1, anti-CEBPA, and anti-FLT3 antibodies were applied to slides prepared from formalin-fixed paraffin-embedded tissues. Sixty-three of these patients had their follow-up in our institutional hematology clinic and these patients' clinical, biochemical, and radiological data were obtained and analyzed from patient files. These data were analyzed with survival times statistically. Results: Except for age, no significant effect of clinical data on prognosis was detected. Immunohistochemical results were also statistically compared with clinical data. No correlation was found between overall survival and disease-free survival with the expression of anti-CEBPA or anti-NPM1 antibodies. However, immunohistochemical reactivity for anti-FLT3 antibody was found to be a poor prognostic factor and statistically significant. Also, when the expression of FLT3 was analyzed with that of NPM1 or CEBPA, a correlation (dependent on the expression of FLT3) was found with disease-free survival. Conclusions: FLT3 is an independent prognostic factor for AML. CEBPA and NPM1 should be considered as good prognostic factors only in the absence of FLT3 abnormalities.