Relapse surveillance of acute myeloid leukemia patients in first remission after consolidation chemotherapy: diagnostic value of regular bone marrow aspirations

Abstract

The optimal follow-up care for relapse detection in acute myeloid leukemia (AML) patients in first remission after consolidation therapy with intensive chemotherapy is not established. In this retrospective study, we evaluate the diagnostic value of an intensive relapse surveillance strategy by regular bone marrow aspirations (BMA) in these patients. We identified 86 patients with newly diagnosed non-promyelocytic AML who had reached complete remission (CR) after intensive induction and consolidation chemotherapy between 2007 and 2019. Annual relapse rates were 40%, 17%, and 2% in years 1-3, respectively. Patients in CR were surveilled by BMA scheduled every 3 months for 2 years, followed by BMA every 6 months. This surveillance regimen detected 29 of 55 relapses (53%), 11 of which were molecular relapses (20%). The remaining 26 of 55 relapses (47%) were diagnosed by non-surveillance BMA prompted by specific suspicion of relapse. Most patients showed concurrent morphological abnormalities in peripheral blood (PB) at time of relapse. Seven percent of all morphological relapses occurred without simultaneous PB abnormalities and would have been delayed without surveillance BMA. Intensified monthly PB assessment paired with BMA every 3 months during the first 2 years may be a highly sensitive relapse surveillance strategy.

Keywords: AML; Bone marrow aspiration; CBC; Peripheral blood smears; Relapse surveillance.

Fig. 1

Study flow diagram

Fig. 2

Individual patients, bone marrow aspirations, relapses, and outcome status. Swimmer plot showing individual patients from time of first diagnosis to death or last follow-up (n = 86). Each bar represents a patient. Bars are ordered by disease-free survival (complete remission (CR) duration) and color-coded by type of relapse therapy (allo-HSCT vs non-curative treatment). If relapse occurred, CR duration is marked by vertical line within each patient’s bar. All bone marrow aspirations for each patient between completion of consolidation chemotherapy and relapse or last follow-up are depicted as arrows and color-coded by whether they were conducted as part of the relapse surveillance program or due to specific suspicion of relapse. Each patient’s status (ongoing or deceased) is indicated

Fig. 3

Relapses after consolidation chemotherapy with complete remission. A Empirical frequencies of disease-free survival times after consolidation chemotherapy with complete remission (CR). B Estimated hazard rate of relapse after consolidation chemotherapy with complete remission. Grey area shows 95% confidence interval of the estimated hazard rate