Multiplex technologies for the assessment of minimal residual disease and low-level mutation detection in leukaemia: mass spectrometry versus next-generation sequencing.

With the focus of leukaemia management shifting to the implications of low-level disease burden, increasing attention is being paid on the development of highly sensitive methodologies required for detection. There are various techniques capable of identification of measurable residual disease (MRD) either evidencing as relevant mutation detection [e.g. nucleophosmin 1 (NPM1) mutation] or trace levels of leukaemic clonal populations. The vast majority of these methods only permit detection of a single clone or mutation. However, mass spectrometry and next-generation sequencing enable the interrogation of multiple genes simultaneously, facilitating a more complete genomic profile. In the present review, we explore the methodologies of both techniques in conjunction with the important advantages and limitations associated with each assay. We also highlight the evidence and the various instances where either technique has been used and propose future strategies for MRD detection.

Do patients with haematological malignancies suffer financial burden? A cross-sectional study of patients seeking care through a publicly funded healthcare system.

BACKGROUND: It is increasingly appreciated that some patients with cancer will experience financial burden due to their disease but little is known specifically about patients with haematological malignancies. Therefore, this study aimed to measure financial toxicity experienced by patients with haematological malignancies in the context of a publicly funded health care system. METHOD: All current patients diagnosed with leukaemia, lymphoma or multiple myeloma, from two major metropolitan health services in Melbourne, Australia were invited to complete a survey capturing; patient demographics, employment status, income sources, financial coping and insurances, OOP expenses and self-reported financial toxicity using a validated measure. RESULTS: Of the 240 people approached, 113 (47 %) participated and most had leukaemia (62 %). Forty-seven (42 %) participants experienced some degree of financial toxicity using the Comprehensive Score for financial toxicity (COST) instrument. On multivariate linear regression, older age (>65 years, p = 0.007), higher monthly income (>$8000, p = 0.008), not having and being forced into unemployment or early retirement (p < 0.001) remained significantly associated with less financial toxicity. CONCLUSION: Financial toxicity is present in Australian haematology patients and those at higher risk may be patients of working age, those without private health insurance and patients that have been forced to retire early or have become unemployed due to their diagnosis.

Costs for Childhood and Adolescent Cancer, 90 Days Prediagnosis and 1 Year Postdiagnosis: A Population-Based Study in Ontario, Canada.

BACKGROUND: Childhood and adolescent cancers are uncommon, but they have important economic and health impacts on patients, families, and health care systems. Few studies have measured the economic burden of care for childhood and adolescent cancers. OBJECTIVES: To estimate costs of cancer care in population-based cohorts of children and adolescents from the public payer perspective. METHODS: We identified patients with cancer, aged 91 days to 19 years, diagnosed from 1995 to 2009 using cancer registry data, and matched each to three noncancer controls. Using linked administrative health care records, we estimated total and net resource-specific costs (in 2012 Canadian dollars) during 90 days prediagnosis and 1 year postdiagnosis. RESULTS: Children (≤14 years old) numbered 4,396: 36% had leukemia, 21% central nervous system tumors, 10% lymphoma, and 33% other cancers. Adolescents (15-19 years old) numbered 2,329: 28.9% had lymphoma. Bone and soft tissue sarcoma, germ cell tumor, and thyroid carcinoma each comprised 12% to 13%. Mean net prediagnosis costs were $5,810 and $1,127 and mean net postdiagnosis costs were $136,413 and $62,326 for children and adolescents, respectively; the highest were for leukemia ($157,764 for children and $172,034 for adolescents). In both cohorts, costs were much higher for patients who died within 1 year of diagnosis. Inpatient hospitalization represented 69% to 74% of postdiagnosis costs. CONCLUSIONS: Treating children with cancer is costly, more costly than treating adolescents or adults. Substantial survival gains in children mean that treatment may still be very cost-effective. Comprehensive age-specific population-based cost estimates are essential to reliably assess the cost-effectiveness of cancer care for children and adolescents, and measure health system performance.

Simultaneous detection of 45 fusion genes in leukemia by dual-color fluorescence real-time PCR.

INTRODUCTION: Detection of recurrent genetic abnormalities is of great significance for a refined diagnosis and assessment of prognosis in leukemia. Conventional nested reverse transcription PCR is labor intensive and time-consuming. METHODS: We have developed a novel dual-color TaqMan probe-based real-time PCR method for the simultaneous screening of 45 fusion transcripts in 12 parallel reactions. The method was tested and validated with cell lines carrying known fusion transcripts and patient samples. RESULTS: A multiplex real-time PCR method was successfully developed for rapid detection of 45 fusion genes and validated for 15 of the more commonly detected fusion genes. Intra-assay reproducibility assessed for the most frequent rearrangements ranged from 0.41% to 0.74% for the coefficient of variation (CV) of cycle threshold (Ct) and the interassay reproducibility ranged from 1.62% to 2.83% in five separate experiments. The lowest detection limit for the translocations tested ranged between 1 : 16 000 and 1 : 32 000. Validation of the method with 213 patient samples showed 100% specificity and excellent consistence with conventional nested RT-PCR. CONCLUSION: Overall, we believe that this method is easily applicable, cost-effective, and clinically useful for a rapid screening of fusion genes in the initial diagnostic phase of leukemia. Its use can also be extended to the monitoring of minimal residual disease.

Scientific Achievements May Not Reach Everyone: Understanding Disparities in Acute Leukemia.

Over the past decade, scientific advancements have resulted in improved survival from acute leukemia. Continued advancements are expected given the attention to precision medicine and the resulting growth in development and adoption of risk-stratified, personalized therapies. While precision medicine has great potential to improve acute leukemia outcomes, there remain significant barriers to ensuring equitable access to these technologies and receipt of these prescribed targeted, personalized therapies. Over the past 3 years, studies report persistent outcome disparities among patients from specific racial and ethnic backgrounds, insurance and socioeconomic status, and other socio-demographic factors after a diagnosis of acute leukemia. A few recent studies examine etiologies for acute leukemia disparities and highlight the importance of ensuring access and equitable delivery of scientific advancements. In the context of continued scientific progress, future strategies require thoughtfully considered improvements in the delivery of care that can overcome the current challenges our patients face.

Symptoms of adult chronic and acute leukaemia before diagnosis: large primary care case-control studies using electronic records.

BACKGROUND: Leukaemia is the eleventh commonest UK cancer. The four main subtypes have different clinical profiles, particularly between chronic and acute types. AIM: To identify the symptom profiles of chronic and acute leukaemia in adults in primary care. DESIGN AND SETTING: Matched case-control studies using Clinical Practice Research Datalink records. METHOD: Putative symptoms of leukaemia were identified in the year before diagnosis. Conditional logistic regression was used for analysis, and positive predictive values (PPVs) were calculated to estimate risk. RESULTS: Of cases diagnosed between 2000 and 2009, 4655 were aged ≥40 years (2877 chronic leukaemia (CL), 937 acute leukaemia (AL), 841 unreported subtype). Ten symptoms were independently associated with CL, the three strongest being: lymphadenopathy (odds ratio [OR] 22, 95% confidence interval [CI] = 13 to 36), weight loss (OR 3.0, 95% CI = 2.1 to 4.2), and bruising (OR 2.3, 95% CI = 1.6 to 3.2). Thirteen symptoms were independently associated with AL, the three strongest being: nosebleeds and/or bleeding gums (OR 5.7, 95% CI = 3.1 to 10), fever (OR 5.3, 95% CI = 2.7 to 10), and fatigue (OR 4.4, 95% CI = 3.3 to 6.0). No individual symptom or combination of symptoms had a PPV >1%. CONCLUSION: The symptom profiles of CL and AL have both overlapping and distinct features. This presents a dichotomy for GPs: diagnosis, by performing a full blood count, is easy; however, the symptoms of leukaemia are non-specific and of relatively low risk. This explains why many leukaemia diagnoses are unexpected findings.

Transfusion strategy in hematological intensive care unit: study protocol for a randomized controlled trial.

BACKGROUND: Packed red blood cell (PRBC) transfusion is required in hematology patients treated with chemotherapy for acute leukemia, autologous (auto) or allogeneic (allo) hematopoietic stem cell transplantation (HSCT). In certain situations like septic shock, hip surgery, coronary disease or gastrointestinal hemorrhage, a restrictive transfusion strategy is associated with a reduction of infection and death. A transfusion strategy using a single PRBC unit has been retrospectively investigated and showed a safe reduction of PRBC consumption and costs. We therefore designed a study to prospectively demonstrate that the transfusion of a single PRBC unit is safe and not inferior to standard care. METHODS: The 1versus2 trial is a randomized trial which will determine if a single-unit transfusion policy is not inferior to a double-unit transfusion policy. The primary endpoint is the incidence of severe complication (grade ≥ 3) defined as stroke, transient ischemic attack, acute coronary syndrome, heart failure, elevated troponin level, intensive care unit transfer, death, new pulmonary infiltrates, and transfusion-related infections during hospital stays. The secondary endpoint is the number of PRBC units transfused per patient per hospital stay. Two hundred and thirty patients will be randomized to receive a single unit or double unit every time the hemoglobin level is less than 8 g/dL. All patients admitted for induction remission chemotherapy, auto-HSCT or allo-HSCT in hematology intensive care units will be eligible for inclusion. Sample size calculation has determined that a patient population of 230 will be required to prove that the 1-unit PRBC strategy is non-inferior to the 2-unit PRBC strategy. Hemoglobin threshold for transfusion is below 8 g/dL. Estimated percentage of complication-free hospital stays is 93 %. In a non-inferiority hypothesis, the number of patients to include is 230 with a power of 90 % and an alpha risk of 5 %. TRIAL REGISTRATION: 14-128; Clinicaltrials.gov NCT02461264 (registered on 3 June 2015).

Genome-wide assessment of recurrent genomic imbalances in canine leukemia identifies evolutionarily conserved regions for subtype differentiation.

Leukemia in dogs is a heterogeneous disease with survival ranging from days to years, depending on the subtype. Strides have been made in both human and canine leukemia to improve classification and understanding of pathogenesis through immunophenotyping, yet classification and choosing appropriate therapy remains challenging. In this study, we assessed 123 cases of canine leukemia (28 ALLs, 24 AMLs, 25 B-CLLs, and 46 T-CLLs) using high-resolution oligonucleotide array comparative genomic hybridization (oaCGH) to detect DNA copy number alterations (CNAs). For the first time, such data were used to identify recurrent CNAs and inclusive genes that may be potential drivers of subtype-specific pathogenesis. We performed predictive modeling to identify CNAs that could reliably differentiate acute subtypes (ALL vs. AML) and chronic subtypes (B-CLL vs. T-CLL) and used this model to differentiate cases with up to 83.3 and 95.8 % precision, respectively, based on CNAs at only one to three genomic regions. In addition, CGH datasets for canine and human leukemia were compared to reveal evolutionarily conserved copy number changes between species, including the shared gain of HSA 21q in ALL and ∼25 Mb of shared gain of HSA 12 and loss of HSA 13q14 in CLL. These findings support the use of canine leukemia as a relevant in vivo model for human leukemia and justify the need to further explore the conserved genomic regions of interest for their clinical impact.

Real-time assessment of relapse risk based on the WT1 marker in acute leukemia and myelodysplastic syndrome patients after hematopoietic cell transplantation.

Relapse is the major cause of treatment failure after allogeneic hematopoietic cell transplantation (alloHCT) for acute leukemia and myelodysplastic syndrome (MDS). Wilms' tumor Ag (WT1) is overexpressed in the majority of acute leukemia and MDS patients and has been proposed as a universal diagnostic marker for detection of impending relapse. Comprehensive studies have shown that WT1 transcript levels have predictive value in acute leukemia patients in CR after chemotherapy. However, the focus of this study is the period after alloHCT for predicting relapse onset. We analyzed the accumulation of WT1 mRNA transcripts in PB of 82 leukemia and MDS patients and defined specific molecular ratios for relapse prediction. The extensively validated WT1/c-ABL ratio was used to normalize increases in WT1 transcript levels. The observed lead time of crossing or exceeding set WT1 levels is presented along with linear interpolation to estimate the calculated day the WT1 thresholds were crossed. The WT1/c-ABL transcript ratio of 50 or above yielded 100% specificity and 75% sensitivity reliably predicting future relapse with an observed average of 29.4 days (s.d.=19.8) and a calculated average of 63 days (s.d.=29.3) lead time before morphologic confirmation. A lower ratio of 20 or above gave lower specificity, but higher sensitivity (84.8% and 87.5%, respectively) identified more patients who relapsed, at earlier times, providing an earlier warning with actual average lead time of 49.1 days (s.d.=30.8) and calculated average of 78 days (s.d.=28.8). WT1 transcript levels serve as a diagnostic relapse test with greater sensitivity than the morphologic approach used in the clinic as a readout.

Quality assessment program for EuroFlow protocols: summary results of four-year (2010-2013) quality assurance rounds.

Flow cytometric immunophenotyping has become essential for accurate diagnosis, classification, and disease monitoring in hemato-oncology. The EuroFlow Consortium has established a fully standardized "all-in-one" pipeline consisting of standardized instrument settings, reagent panels, and sample preparation protocols and software for data analysis and disease classification. For its reproducible implementation, parallel development of a quality assurance (QA) program was required. Here, we report on the results of four consecutive annual rounds of the novel external QA EuroFlow program. The novel QA scheme aimed at monitoring the whole flow cytometric analysis process (cytometer setting, sample preparation, acquisition and analysis) by reading the median fluorescence intensities (MedFI) of defined lymphocytes' subsets. Each QA participant applied the predefined reagents' panel on blood cells of local healthy donors. A uniform gating strategy was applied to define lymphocyte subsets and to read MedFI values per marker. The MedFI values were compared with reference data and deviations from reference values were quantified using performance score metrics. In four annual QA rounds, we analyzed 123 blood samples from local healthy donors on 14 different instruments in 11 laboratories from nine European countries. The immunophenotype of defined cellular subsets appeared sufficiently standardized to permit unified (software) data analysis. The coefficient of variation of MedFI for 7 of 11 markers performed repeatedly below 30%, average MedFI in each QA round ranged from 86 to 125% from overall median. Calculation of performance scores was instrumental to pinpoint standardization failures and their causes. Overall, the new EuroFlow QA system for the first time allowed to quantify the technical variation that is introduced in the measurement of fluorescence intensities in a multicentric setting over an extended period of time. EuroFlow QA is a proficiency test specific for laboratories that use standardized EuroFlow protocols. It may be used to complement, but not replace, established proficiency tests. © 2014 International Society for Advancement of Cytometry.

Socioeconomic disparities in survival from childhood leukemia in the United States and globally: a meta-analysis.

BACKGROUND: Despite advancements in the treatment of childhood leukemia, socioeconomic status (SES) may potentially affect disease prognosis. This study aims to evaluate whether SES is associated with survival from childhood leukemia. METHODS: The US National Cancer Institute Surveillance, Epidemiology and End Results Program (SEER) 1973-2010 data were analyzed; thereafter, results were meta-analyzed along with those from survival (cohort) studies examining the association between SES indices and survival from childhood leukemia (end-of-search date: 31 March 2014). Random-effects models were used to calculate pooled effect estimates (relative risks, RRs); meta-regression was also used. RESULTS: We included 29 studies yielding 28 804 acute lymphoblastic leukemia (ALL), 3208 acute myeloblastic leukemia (AML) and 27 650 'any' leukemia (denoting joint reporting of all subtypes) cases. According to individual-level composite SES indices, children from low SES suffered from nearly twofold higher death rates from ALL (pooled RR: 1.83, 95% confidence interval 1.00-3.34, based on four study arms); likewise, death RRs derived from an array of lower area-level SES indices ranged between 1.17 and 1.33 (based on 11 study arms). Importantly, the survival gap between higher and lower SES seemed wider in the United States, with considerably (by 20%-82%) increased RRs for death from ALL in lower SES. Regarding AML, poorer survival was evident only when area-level SES indices were used. Lastly, remoteness indices were not associated with survival from childhood leukemia. CONCLUSION: Children with lower SES suffering childhood leukemia do not seem to equally enjoy the impressive recent survival gains. Special health policy strategies and increased awareness of health providers might minimize the effects of socioeconomic disparities.

Insights on practice variations in the management of lymphoma and leukemia.

Clinical practice guidelines are systematically developed statements designed to assist practitioners in making decisions about appropriate healthcare for specific clinical circumstances. Their successful implementation should improve quality of care by decreasing inappropriate variation and expediting the application of effective advances to everyday practice. Despite wide promulgation, guidelines have had limited effect on changing physician behaviors. This two-part review article highlights variations in the current recommended management of lymphoma (Part I) and leukemia (Part II), with some focus on targeted therapies. Focus on variations that may be amenable to educational programs designed for physicians were also considered in the review. For the purpose of this report, "variation" is defined as any deviation in the treatment or management of a particular hematologic malignancy where practice guidelines exist. Specific studies that demonstrate factors that may cause variations in clinical outcomes of hematologic malignancies and may contribute to variations in practice are featured.

Cost-effectiveness and clinical outcomes of double versus single cord blood transplantation in adults with acute leukemia in France.

Double cord blood transplantation extends the use of cord blood to adults for whom a single unit is not available, but the procedure is limited by its cost. To evaluate outcomes and cost-effectiveness of double compared to single cord blood transplantation, we analyzed 134 transplants in adults with acute leukemia in first remission. Transplants were performed in France with reduced intensity or myeloablative conditioning regimens. Costs were estimated from donor search to 1 year after transplantation. A Markov decision analysis model was used to calculate quality-adjusted life-years and cost-effectiveness ratio within 4 years. The overall survival at 2 years after single and double cord blood transplants was 42% versus 62%, respectively (P=0.03), while the leukemia-free-survival was 33% versus 53%, respectively (P=0.03). The relapse rate was 21% after double transplants and 42% after a single transplant (P=0.006). No difference was observed for non-relapse mortality or chronic graft-versus-host-disease. The estimated costs up to 1 year after reduced intensity conditioning for single and double cord blood transplantation were € 165,253 and €191,827, respectively. The corresponding costs after myeloablative conditioning were € 192,566 and € 213,050, respectively. Compared to single transplants, double cord blood transplantation was associated with supplementary costs of € 21,302 and € 32,420 up to 4 years, but with increases in quality-adjusted life-years of 0.616 and 0.484, respectively, and incremental cost-effectiveness ratios of € 34,581 and €66,983 in the myeloablative and reduced intensity conditioning settings, respectively. Our results showed that for adults with acute leukemia in first complete remission in France, double cord transplantation is more cost-effective than single cord blood transplantation, with better outcomes, including quality-adjusted life-years.

The impact of spatial scales and spatial smoothing on the outcome of bayesian spatial model.

Discretization of a geographical region is quite common in spatial analysis. There have been few studies into the impact of different geographical scales on the outcome of spatial models for different spatial patterns. This study aims to investigate the impact of spatial scales and spatial smoothing on the outcomes of modelling spatial point-based data. Given a spatial point-based dataset (such as occurrence of a disease), we study the geographical variation of residual disease risk using regular grid cells. The individual disease risk is modelled using a logistic model with the inclusion of spatially unstructured and/or spatially structured random effects. Three spatial smoothness priors for the spatially structured component are employed in modelling, namely an intrinsic Gaussian Markov random field, a second-order random walk on a lattice, and a Gaussian field with Matérn correlation function. We investigate how changes in grid cell size affect model outcomes under different spatial structures and different smoothness priors for the spatial component. A realistic example (the Humberside data) is analyzed and a simulation study is described. Bayesian computation is carried out using an integrated nested Laplace approximation. The results suggest that the performance and predictive capacity of the spatial models improve as the grid cell size decreases for certain spatial structures. It also appears that different spatial smoothness priors should be applied for different patterns of point data.