Abstract
6565 Background: Most AML pts will experience relapse caused by persistent leukemic cells during complete remission (CR). The aim of our study was to predict outcome in AML pts in CR by assessing their MRD using standard 4-colour FC panels available at our institute. Methods: We queried our AML database between 1/2004 to 10/2010 for newly diagnosed untreated AML pts >18 years of age who achieved CR after one induction regimen. Treatment included 7+3 or similar intensive approaches. The gating strategy used a series of Boolean regions that best defined the diagnostic abnormal population based on its expression patterns using three 4-colour FC panels (F7-CD38,CD10,CD19,CD34; F9-C11b,CD33,CD13,CD34; F38-CD15,CD56,CD7,CD34). The same regions were applied to post-induction samples, and the number of residual events was determined. Results: 140 AML patients with a median age of 64 (range 24-93) years, including 74 females (52.8%) were analyzed; 67 (47.8%) patients relapsed. Eighty-eight (62.8%) pts were CD34-positive (CD34+) at diagnosis. Normal karyotype was detected in 27 (30.7%): FLT-3 ITD was detected in 4/23 (17.4%) and NPM-1 mutation was detected in 1/15 (0.07%) samples. Median follow-up for CD34+ pts was 17.9 months. Forty-two (30%) pts underwent stem cell transplantation (SCT) in first CR: 31 (22.1 %) were allogeneic and 11 (7.9%) autologous. In multivariate analysis, a detectable MRD in any of the 3 panels at or beyond week 16 among CD34+ AML pts in CR was significantly associated with inferior relapse free survival (F7: P=0.035 , F9: P=0.027, F38: P=0.042). In addition, MRD ≥ week 16 using panel F9 was also significantly associated with inferior overall survival (P=0.0224). In pair-wise comparison, those who were MRD-negative ≥ week 16 did not benefit from SCT compared to the non-SCT group. Similar analyses among CD34– AML pts did not achieve statistical significance. Conclusions: MRD+ by FC in CD34+ AML is an independent prognostic factor and can identify pts who may benefit from SCT/more intensive therapy to maintain remission. However, the value of studying MRD in CD34– AML requires further consideration. More effort is needed to identify stem cells in CD34– AML.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
