Lone S. Friis

NPM1 mutation is a stable marker for minimal residual disease monitoring in acute myeloid leukaemia patients with increased sensitivity compared to WT1 expression.

Mutation in the NPM1 gene occurs in 60% of acute myeloid leukaemia (AML) patients with normal karyotype. NPM1 mutation is potentially a superior minimal residual disease (MRD) marker compared to WT1 gene overexpression by being specific to the malignant clone, although experimental evidence published so far includes very limited numbers of relapsed cases. Also, the stability of the NPM1 mutation has been questioned by reports of the mutation being lost at relapse. In the present study we compared NPM1 mutation and WT1 overexpression as MRD markers in 20 cases of relapsed AML. The 20 patients experienced a total of 28 morphological relapses. Karyotypic evolution was detected in 56% of relapses. All relapses were accompanied by high levels of NPM1 mutation, along with high WT1 mRNA levels, thus demonstrating complete stability of both markers during relapse. Detectable NPM1 mutation following a period of morphological remission was accompanied by a morphological relapse in all cases. In contrast, WT1 expression was detected in 33% of the NPM1 mutation negative samples. This background WT1 expression produced by non‐leukaemia cells was highly variable, both between and within patients, and limited the de facto sensitivity of the WT1 expression analysis. The present study therefore provides important experimental evidence demonstrating that NPM1 mutation is superior to WT1 overexpression as marker of MRD in NPM1‐mutated AML, even in the presence of extensive karyotypic evolution.

Cytogenetic findings in adult secondary acute myeloid leukemia (AML): frequency of favorable and adverse chromosomal aberrations do not differ from adult de novo AML

During a 15-year period, 161 adult patients were diagnosed with secondary acute myeloid leukemia (s-AML) in the region of Southern Denmark. In 73 patients, the AML diagnosis was preceded by myelodysplastic syndrome (MDS-AML), in 31 patients by an antecedent hematologic disease, and in 57 patients by treatment with chemotherapy and/or irradiation (t-AML). Cytogenetic analysis was carried out in 93%, of which 61% had clonal chromosome aberrations. MDS-AML correlated to a normal karyotype (P < 0.001). t-AML correlated to abnormal clones with numerical and structural aberrations (P = 0.03), five or more unrelated aberrations (P = 0.03), marker chromosomes (P = 0.006), abnormal mitoses only (P = 0.01), female sex (P < 0.001), and -7 (P = 0.006). Centromeric breakage correlated to a complex karyotype (P = 0.01). The frequencies of aberrations in s-AML patients were compared with an age-matched group of de novo AML patients diagnosed in the same area and period. In this comparison, s-AML only correlated to -7 (P = 0.02). In 42 patients, we found that MDS patients with an abnormal karyotype were more likely to show cytogenetic evolution during progression to AML than MDS patients with a normal karyotype (P = 0.01). We conclude that population-based cytogenetic studies of adult s-AML and age- and sex-matched de novo AML show comparable distributions of chromosome abnormalities.

Extramedullary disease in patients with acute myeloid leukemia assessed by (18)F-FDG PET

Prevalence of extramedullary disease (EMD) in acute myeloid leukemia (AML) at the time of diagnosis is unknown. Previous estimates range from 2.5% to 30.5% and are usually based on clinical examination. This may cause an under diagnosis of EMD as not all extramedullary manifestations are easily detectable. Few recent studies have used positron emission tomography (PET) scans for diagnosing EMD in patients AML.

Data quality in the Danish National Acute Leukemia Registry: a hematological data resource.

Background The Danish National Acute Leukemia Registry (DNLR) has documented coverage of above 98.5%. Less is known about the quality of the recorded data. Objective To describe the present coverage of the DNLR, its completeness, and accuracy of individual variables for acute myeloid leukemia (AML). Furthermore, as a second measure of true coverage of the DNLR, to estimate AML incidence in Denmark from DNLR data and compare it to incidence reported from other AML registries. Patients and methods By the end of December 2011, the DNLR (established January 2000) included detailed data on a large, well-defined, and nonselected Danish population of 2,665 AML patients. We estimated positive predictive values (PPVs) and completeness for 30 variables, which included patient and disease characteristics, treatment, and treatment outcomes. We identified 260 AML patients (10% of all AML patients recorded in the DNLR). We used information from medical records as the gold standard. Results Using the Danish National Registry of Patients as a reference, the coverage of the DNLR was 99.6%. The PPVs of the individual variables ranged from 89.4% to 100%. The completeness of individual variables varied between 60.7% and 100%. Stratification by time of registration in the DNLR (before 2006 versus 2006 and later) revealed higher PPVs and lower frequencies of missing data from 2006. Sex-adjusted incidence rates were 6.2/100,000 person-years (95% confidence interval 5.8–6.6) in males and 4.9/100,000 person-years (95% confidence interval 4.5–5.4) in females. Yearly incidence rates of AML were higher than the incidence rates reported from Sweden (4.5 and 4.2/100,000) and the US (4.5 and 3.1/100,000 in Caucasians). Conclusion With few exceptions, there were high values for PPVs and completeness of recorded data. Data accuracy and completeness have improved since the registry was established. The estimated incidence may indicate that the DNLR truly is more complete than other registries. In conclusion, the DNLR is a valuable resource for clinical research of AML.

Systemic mastocytosis is uncommon in KIT D816V mutation positive core-binding factor acute myeloid leukemia.

Abstract The KIT D816V mutation is detected in the vast majority of adult cases of systemic mastocytosis (SM). The mutation is also frequently detected in core-binding factor acute myeloid leukemia (CBF AML) defined by the presence of t(8;21)(q22;q22); RUNX1-RUNX1T1 or inv(16)(p13.1;q22)/t(16;16)(p13.1;q22); CBFB-MYH11 chromosomal rearrangements, but whether the mutation is indicative of associated SM is unclear. In the present study, patients with CBF AML were therefore analyzed for the KIT D816V mutation and mutation positive cases subsequently analyzed for the presence of SM. The KIT D816V mutation was detected in eight of 20 cases of CBF AML, with the frequency in t(8;21)(q22;q22) and inv(16)(p13.1;q22) positive cases being 31% and 57%, respectively. The fraction of KIT D816V mutation positive cells was highly variable among the eight mutation positive patients, with levels ranging from 0.04 to 98% in a pretreatment blood sample. Five of the eight cases carried the mutation in a cell fraction below one-tenth of the blast cell fraction, thus suggesting that KIT mutation is often a late event in leukemogenesis. None of the eight KIT D816V mutation positive cases fulfilled the World Health Organization diagnostic criteria of SM. The presence of the KIT D816V mutation in the CBF AML subgroup can therefore not be considered indicative of associated SM.

Influence of selected clinical events on the need for red blood cell transfusion in patients with severe cytopenia following myeloablative chemotherapy

Abstract: The transfusional need in patients treated with myeloablative chemotherapy appears to be greater than that resulting from bone marrow suppression alone. The erythrocyte transfusional need may be expressed as Δhb = the daily loss of haemoglobin (mmol/1/day), and multivariate analyses of factors influencing Δhb have been carried out. We have studied 124 patients, mainly with acute myeloid leukaemia, treated with 537 courses of chemotherapy, inducing cytopenia (a white cell count < 1.0 times 109/1) in 476 cases. The transfusional need was 2.5–3 times greater than expected, suggesting the presence of haemolysis and/or occult bleedings. Using multiple regression analysis and repeated measurement analysis the main factor influencing the transfusional need was type/dose of chemotherapy. The higher the dose of cytarabine the greater the transfusional need. Other factors significantly influencing the transfusional need were tumour burden, fever, treatment‐related events such as positive blood cultures, systemic fungal infection, mucosal bleeding, melaena/haematemesis and diarrhoea. Finally, it was found that the transfusional need decreased gradually during the cytopenic period.

Early Natural Killer Cell Reconstitution Predicts Overall Survival in T Cell–Replete Allogeneic Hematopoietic Stem Cell Transplantation

Early immune reconstitution plays a critical role in clinical outcome after allogeneic hematopoietic stem cell transplantation (HSCT). Natural killer (NK) cells are the first lymphocytes to recover after transplantation and are considered powerful effector cells in HSCT. We aimed to evaluate the clinical impact of early NK cell recovery in T cell-replete transplant recipients. Immune reconstitution was studied in 298 adult patients undergoing HSCT for acute myeloid leukemia, acute lymphoblastic leukemia, and myelodysplastic syndrome from 2005 to 2013. In multivariate analysis NK cell numbers on day 30 (NK30)u2009>u2009150 cells/µL were independently associated with superior overall survival (hazard ratio, .79; 95% confidence interval, .66 to .95; Pu2009=u2009.01). Cumulative incidence analyses showed that patients with NK30 > 150 cells/µL had significantly less transplant-related mortality (TRM), P = .01. Patients with NK30 > 150 cells/µL experienced significantly lower numbers of life-threatening bacterial infections as well as viral infections, including cytomegalovirus. No association was observed in relation to relapse. These results suggest an independent protective effect of high early NK cell reconstitution on TRM that translates into improved overall survival after T cell-replete HSCT.

Evolution of relative survival for acute promyelocytic leukemia patients alive at landmark time-points: a population-based study

Acute promyelocytic leukemia (APL) is a rare subtype of acute myeloid leukemia (AML) accounting for ~5% of all new cases [1]. Through a variety of mechanisms, accumulation of APL cells leads to coagulopathy which in turn gives rise to severe bleeding diathesis, a distinct presenting feature of APL, and the reason for the high incidence of early hemorrhagic deaths [2, 3]. Therefore, prompt initiation of all-trans retinoic acid (ATRA)-treatment and supportive care upon first suspicion of APL is critical to restore normal coagulation and reduce risk of early deaths [3]. Contrasting to the life-threatening initial phase of APL, patients surviving this critical period have excellent outcomes characterized by low relapse risk and survival rates surpassing those of other AML subtypes [4]. The objective of this study was to investigate when the survival of APL patients normalizes to that of a gender, age, and calendar-yearmatched general population. The study was approved by the Danish Data Protection Agency (2014-41-3204) and was based on the Danish National Acute Leukemia Registry (DNLR) [5]. We included newly diagnosed patients with de novo APL (dnAPL), secondary APL (sAPL), or therapy-related APL (tAPL) between 2000 and 2014. The diagnosis of APL required fulfillment of one or more of following diagnostic criteria: (i) presence of the chromosomal translocation of t(15;17) (q22;q12) by classical G-banding, (ii) fluorescence in-situ hybridization (FISH) analysis positive for PML-RARA fusion gene product, and/or (iii) a polymerase chain reaction (PCR) confirming presence of the PML-RARA fusion gene product. One case of variant APL with the variant translocation t(5;17)(q35;q21) was included [6]. sAPL was defined as APL diagnosed in the setting of an existing myeloid disease [7]. tAPL was defined as APL occurring after chemotherapy and/or radiotherapy for other hematological cancers, solid tumors, or non-malignant diseases [7]. For simplicity and due to the limited number of cases, the sAPL and tAPL cases were grouped together as non-dnAPL. During the study period, ATRA-containing treatment regimens were standard of care in Denmark and treatment was only provided by specialized hematology units at public hospitals. Medical records and pathology files for all patients registered with APL were reviewed to confirm fulfillment of diagnostic criteria for APL and to collect treatment information in case of missing information in DNLR. Patients were followed from diagnosis of APL until death or end of follow-up (18/02/2016). Overall survival (OS) was defined as time from diagnosis until death or censoring for patients alive at end of follow-up. The relative survival of APL patients was described using standardized mortality rates (SMR) and an excess These authors contributed equally: Tarec Christoffer El-Galaly, Jan Maxwell Nørgaard.