Incidence of acute promyelocytic leukemia across Europe: results of RARECAREnet-a population-based study

Impact of aging on acute myeloid leukemia epidemiology and survival outcomes: A real-world, population-based longitudinal cohort study

Acute myeloid leukemia (AML) is a severe and fatal form of leukemia that is prevalent in the older population. In this longitudinal retrospective study, we investigated the epidemiology and survival rates of patients diagnosed with de novo acute myeloid leukemia in South Korea from Jan 1, 2011, to Aug 31, 2020. We used real-world data from the Health Insurance Review and Assessment Service database. We observed an increase in the number of acute myeloid leukemia cases, with age-specific incidence rates escalating in older patients. In contrast a long-term decrease from 1.94 to 1.77 per 100,000 individuals was found in the age-standardized incidence rates. Meanwhile, age-standardized prevalence rates ascended from 8.93 to 9.67 per 100,000 individuals, with a remarkable increase in the age-specific prevalence rate for those aged 80 years and above. Survival rates were notably better in younger or treated patients, and in those who underwent Hematopoietic stem cell transplantation. The time of diagnosis did not affect the survival of patients younger than 65 years. However, the most recent survival rates were significantly lower for patients 65 or older, as shown in the unadjusted Cox survival analysis. After adjustments in the analysis, it was found that the overall survival rates of the most recently diagnosed group improved significantly compared with those diagnosed earlier, with a hazard ratio of 0.90 (95% confidence interval, 0.84-0.97). This improvement may potentially be influenced by the enhanced treatment alternatives available for newly diagnosed older patients aged 65 years or older. In conclusion, aging appears to fuel an increase in the number of acute myeloid leukemia cases and mortality. Further studies are warranted to understand the impact of aging on acute myeloid leukemia treatment outcomes and devise efficacious care strategies for older patients.

Different Isoforms of PML-RARA Chimeric Protein in Patients with Acute Promyelocytic Leukemia: Survival Analysis per Demographic Characteristics, Clinicohematological Parameters, and Cytogenetic Findings

Background & Objective

Acute Promyelocytic Leukemia (APL) is a medical emergency with potentially fatal complications. APL primarily results from a chromosomal translocation (t(15;17)(q22;q21)), leading to the formation of the PML-RARA fusion gene with three possible isoforms. This study aims to investigate the characteristics of Iranian APL patients, the distribution of PML-RARA isoforms, and survival analysis.

Methods

We included 145 consecutive eligible patients in this study. Data were collected through archived documents and phone inquiries, following consent. Subsequently, we analyzed the data using SPSS software version 26.0.

Results

We examined 75 men and 70 women, with a mean age of 34 years (range: 2-78 years). Besides t(15;17) (q22;q21), 45.6% had other chromosomal abnormalities. The prevalence of bcr1 and bcr3 isoforms was 73% and 27%, respectively. bcr3 correlated with higher white blood cell (WBC) counts, additional chromosomal abnormalities, and faster Complete Hematologic Response (CHR). Early death occurred in approximately 36% of all patients. The mean overall survival time was 73.5 months, with 120-month survival rates of 53.8% for all patients and 83.9% for those who achieved CHR. Univariate analysis identified old age, relapse, lower platelet (PLT) counts, higher WBC counts, and leukocytosis as survival risk factors. However, in multivariate analysis, only old age and higher WBC counts were identified as adverse prognostic factors.

Conclusion

In Iranian APL patients, bcr1 predominates, while bcr3 correlates with higher WBC counts, high-risk categorization, additional chromosomal abnormalities, and faster CHR. Survival is negatively impacted by old age, relapse, lower PLT counts, higher WBC counts, and leukocytosis.

Acute Promyelocytic Leukemia and Brugada Syndrome: A Report on the Safety of Arsenic Trioxide/All-Trans-Retinoic Acid Therapy

Acute promyelocytic leukemia (APL) is a rare and aggressive form of acute myeloid leukemia (AML). Instead of cytotoxic chemotherapy, a combination of all-trans-retinoic acid (ATRA) and arsenic trioxide (ATO) represents front-line therapy in low-risk patients. However, the therapeutic approach could be challenging in the case of a concomitant diagnosis of Brugada syndrome (BrS), a genetic disease characterized by an increased risk of arrhythmias and sudden cardiac death. Here, we present the case of a BrS patient who has been diagnosed with low-risk APL and treated with ATRA and ATO without observing arrhythmic events. In particular, we highlight the difficulties encountered by clinicians during the diagnostic work-up and the choice of the best treatment for these patients.

Fatal intracranial haemorrhage in acute promyelocytic leukemia patients with short isoform of PML-RARα: Review of molecular and radiological data

Three major PML-RARα fusion gene transcripts (long [bcr1], variant [bcr2], and short [bcr3]) are currently used in clinical laboratories for the diagnosis and treatment monitoring of APL patients. Despite highly improved outcome, relapse and intracranial haemorrhage that may lead to early death is still an unsolved complication in APL. We reviewed APL patients confirmed by qPCR for the presence of PML-RARα transcripts (n = 27) and studied their outcome in relation to the isoform expression at diagnosis and follow-up in King Fahad Medical City. Eight in twenty-seven patients showed bcr3 and nineteen patients with bcr1 as major isoforms at diagnosis. Half of the bcr3 patients (n = 4/8) showed early mortality, prolonged qPCR positivity, 4-fold higher neutrophil/lymphocyte ratio, higher creatinine levels, and significantly reduced relapse free and overall survival time compared with bcr1 patients. Radiological findings in bcr3 patients revealed CNS involvement in the form of intracranial haemorrhage and periventricular microangiopathy and no CNS involvement in bcr1 patients. In conclusion, PML-RARα isoform expression at diagnosis in selective patients influences disease course over time and may even lead to early mortality due to haemorrhage. Thus, timely reporting of the specific PML-RARα isoform by clinical laboratories and CNS assessment by radiology can prevent complications leading to death in some APL patients.

Epidemiology and early mortality patterns of acute promyelocytic leukemia in the United States

There is a lack of contemporary population-based data on the epidemiology of acute promyelocytic leukemia (APL) in the United States. In this study, we aim to elucidate the demographics and early mortality patterns of APL hospitalizations utilizing the National Inpatient Sample database from 2016-2019. APL's annual age-adjusted incidence rate was 0.28/100,000, and the incidence increased with age, with the peak incidence in the 75-79 age group at 0.62/100,000. Whites constituted the majority of admissions at 67.7%, followed by Hispanics at 15.3%, the youngest racial group with a median age of 40 years. The median length of stay was 31 days for patients age < 60 years and 25 days for age ≥ 60 years (p < 0.001). After adjusting for confounders, the mean length of stay was 7 days higher in teaching hospitals compared to non-teaching hospitals (p 0.001). Overall mortality was 12.1% (22.2% for age ≥ 60 and 6.4% for < 60 years {p < 0.001}), and 56.5% of deaths happened before 7 days, with the median time to death being 6 days. The proportion of early deaths (< 7 days) in non-teaching hospitals was higher than late deaths (≥ 7 days) (19.2% vs. 5%; p 0.03), and admission to a teaching hospital was associated with lower mortality (adjusted odds ratio 0.27; p 0.01). Therefore, optimal treatment strategies need to be explored to mitigate this significant early mortality, especially in non-teaching hospitals.

Acute promyelocytic leukaemia: population-based study of epidemiology and outcome with ATRA and oral-ATO from 1991 to 2021

BACKGROUND

The epidemiology and treatment of acute promyelocytic leukaemia (APL) are changing. We have incorporated oral arsenic trioxide (oral-ATO) into induction/maintenance.

METHODS

Newly-diagnosed APL from 1991 to 2021 divided into three 10-year periods were studied to define its epidemiology and how oral-ATO impacted on its outcome. Primary endpoints included APL incidence, early deaths (ED, first 30 days), and overall survival (OS). Secondary endpoints included post-30-day OS, relapse-free survival (RFS), and incidence of second cancers.

RESULTS

APL occurred in 374 males and 387 females at a median age of 44 (1-97) years. Annual incidences increased progressively, averaging 0.32 per 100,000 people. All-trans retinoic acid (ATRA)-based and oral-ATO-based regimens were used in 469 and 282 patients. There were 144 EDs, occurring almost exclusively in ATRA-based inductions (N = 139), being more with males, age > 50 years, leucocyte > 10 × 10⁹/L, diagnosis during 1991-2009 and fewer with oral-ATO-based regimens. After a median of 75 (interquartile range: 14-161) months, 5-year and 10-year OS were 68.1% and 63.3%, inferior with males, age > 50 years, leucocyte > 10 × 10⁹/L, high-risk Sanz score and superior with oral-ATO-based regimens. Factoring out EDs, 5-year and 10-year post-30-day OS were 84.0% and 78.1%, inferior with males and superior with oral-ATO-based regimens. In 607 CR1 patients, the 5-year RFS was 83.8%, superior with diagnosis in 2010-2021 and oral-ATO-based regimens. Second cancers developed in 21 patients, unrelated to oral-ATO-based regimens.

CONCLUSIONS

There was an increasing incidence of APL, and all survivals were superior with the use of oral-ATO-based regimens. This study formed part of the Acute Promyelocytic Leukaemia Asian Consortium Project (ClinicalTrials.gov identifier: NCT04251754).

Oral arsenic trioxide for treating acute promyelocytic leukaemia: Implications for its worldwide epidemiology and beyond

This account describes how orally administered Arsenic-trioxide (ATO) therapy influences the epidemiology of acute promyelocytic leukaemia (APL), and how the experience that ensued may expand the indications for oral ATO as a treatment for diseases/disorders other than APL. Over the last two decades, experience with APL patients in Hong Kong treated with an oral regimen comprising ATO, all-trans retinoic acid (ATRA), and ascorbic acid (also known as "AAA") has confirmed a dramatic improvement in overall survival. Over that period, there has been an estimated 60-fold increase in the prevalence of APL (proportion of surviving APL patients in the population on December 31 including those deemed to be 'cured'). In contrast to regimens entailing intravenous (IV) ATO, the consequential therapeutic benefits of using oral ATO have been achieved with much less patient inconvenience and quality of life disruption, reduced burdens on health care facilities (hospitalisations and staff involvement), and much enhanced affordability (retail drug & other cost reductions). Numerous experimental and a few clinical studies suggest that ATO may also have a therapeutic role in many other diseases/disorders. Several such diseases (e.g. autoimmune disorders & idiopathic pulmonary fibrosis) are far more prevalent than APL, which means that very large numbers of patients may potentially benefit from ATO treatment, even if its efficacy is limited to selected populations with these diseases. The known safety of oral ATO and its advantages over repeated long-term IV delivery suggests that this route be used in future clinical studies of its possible role in treating such patients. If the clinical utility of oral ATO treatment is validated for patients enduring any such non-APL diseases, very large numbers of patients may stand to benefit.

Atypical Rearrangements in APL-Like Acute Myeloid Leukemias: Molecular Characterization and Prognosis

Acute promyelocytic leukemia (APL) accounts for 10–15% of newly diagnosed acute myeloid leukemias (AML) and is typically caused by the fusion of promyelocytic leukemia with retinoic acid receptor α (RARA) gene. The prognosis is excellent, thanks to the all-trans retinoic acid (ATRA) and arsenic trioxide (ATO) combination therapy. A small percentage of APLs (around 2%) is caused by atypical transcripts, most of which involve RARA or other members of retinoic acid receptors (RARB or RARG). The diagnosis of these forms is difficult, and clinical management is still a challenge for the physician due to variable response rates to ATRA and ATO. Herein we review variant APL cases reported in literature, including genetic landscape, incidence of coagulopathy and differentiation syndrome, frequent causes of morbidity and mortality in these patients, sensitivity to ATRA, ATO, and chemotherapy, and outcome. We also focus on non-RAR rearrangements, complex rearrangements (involving more than two chromosomes), and NPM1-mutated AML, an entity that can, in some cases, morphologically mimic APL.

[Clinical and genetic characteristics of patients with newly diagnosed acute promyelocytic leukemia: a single-center retrospective of 790 cases]

Objective: To retrospectively analyze the data of Chinese patients with newly diagnosed acute promyelocytic leukemia (APL) to preliminarily discuss the clinical and cytogenetic characteristics. Methods: From February 2004 to June 2020, patients with newly diagnosed APL aged ≥ 15 years who were admitted to the Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Science & Peking Union Medical College were chosen. Clinical and laboratory features were retrospectively analyzed. Results: A total of 790 cases were included, with a male to female ratio of 1.22. The median age of the patients was 41 (15-76) years. Patients aged between 20 and 59 predominated, with 632 patients (80%) of 790 patients classified as low and intermediate risk and 158 patients (20%) of 790 patients classified as high risk. The white blood cell, platelet, and hemoglobin levels at diagnosis were 2.3 (0.1-176.1) ×10(9)/L, 29.5 (2.0-1220.8) ×10(9)/L, and 89 (15-169) g/L, respectively, and 4.8% of patients were complicated with psoriasis. The long-form type of PML-RARα was most commonly seen in APL, accounting for 58%. Both APTT extension (10.3%) and creatinine>14 mg/L (1%) are rarely seen in patients at diagnosis. Cytogenetics was performed in 715 patients with newly diagnosed APL. t (15;17) with additional chromosomal abnormalities were found in 155 patients, accounting for 21.7%; among which, +8 was most frequently seen. A complex karyotype was found in 64 (9.0%) patients. Next-generation sequencing was performed in 178 patients, and 113 mutated genes were discovered; 75 genes had an incidence rate>1%. FLT3 was the most frequently seen, which accounted for 44.9%, and 20.8% of the 178 patients present with FLT3-ITD. Conclusions: Patients aged 20-59 years are the most common group with newly diagnosed APL. No obvious difference was found in the ratio of males to females. In terms of risk stratification, patients divided into low and intermediate risk predominate. t (15;17) with additional chromosomal abnormalities accounted for 21% of 715 patients, in which +8 was most commonly seen. The long-form subtype was most frequently seen in PML-RARα-positive patients, and FLT3 was most commonly seen in the mutation spectrum of APL.

Incidence of myeloid neoplasms in Spain (2002-2013): a population-based study of the Spanish network of cancer registries

Comprehensive population-based data on myeloid neoplasms (MNs) are limited, mainly because some subtypes were not recognized as hematological cancers prior to the WHO publication in 2001, and others are too rare to allow robust estimates within regional studies. Herein, we provide incidence data of the whole spectrum of MNs in Spain during 2002–2013 using harmonized data from 13 population-based cancer registries. Cases (n = 17,522) were grouped following the HAEMACARE groupings and 2013-European standardized incidence rates (ASR_E), incidence trends, and estimates for 2021 were calculated. ASR_E per 100,000 inhabitants was 5.14 (95% CI: 5.00–5.27) for myeloproliferative neoplasms (MPN), 4.71 (95% CI: 4.59–4.84) for myelodysplastic syndromes (MDS), 3.91 (95% CI: 3.79–4.02) for acute myeloid leukemia, 0.83 (95% CI: 0.78–0.88) for MDS/MPN, 0.35 (95% CI: 0.32–0.39) for acute leukemia of ambiguous lineage, and 0.58 (95% CI: 0.53–0.62) for not-otherwise specified (NOS) cases. This study highlights some useful points for public health authorities, such as the remarkable variability in incidence rates among Spanish provinces, the increasing incidence of MPN, MDS, and MDS/MPN during the period of study, in contrast to a drop in NOS cases, and the number of cases expected in 2021 based on these data (8446 new MNs).

Real-life outcomes of unselected acute promyelocytic leukemia patients: a single-center 14-year experience

BACKGROUND

After the inclusion of all-trans retinoic acid (ATRA) into the treatment of Acute Promyelocytic leukemia (APL), a notable improvement concerning the survival rates of patients with APL has been observed. However, the population-based studies demonstrated that there was no marked improvement in the survival of patients after the 2000s. We aim to describe the clinical response and prognosis of adult patients diagnosed with APL and examine the change in these outcomes by the time period of diagnosis.

METHODS

We retrospectively reviewed thirty-six unselected APL patients who were diagnosed between September 2003 and February 2016.

RESULTS

The probability of survival at two years was 58%, while disease-free survival (DFS) was 87%. The overall early death (ED) rate was 33% and remain stable over time [42% in 2003-2009 vs. 24% in 2010-2016 (p=.20)]. In addition, the 2-year overall survival (OS) rates were 47% in 2003-2009 and 70% in 2010-2016 (p=.29), and no differences were noted. Univariate analyses showed possible predictors of poor OS were defined as leukocytosis (≥10x109/L), high Sanz score, hemorrhage, infection, disseminated intravascular coagulopathy (DIC) at presentation and microgranular morphologic subtype.

CONCLUSIONS

This study shows that long-term survival remains low in APL patients, particularly related to a high ED rate. Initiatives to reduce ED are exceedingly substantial for improving the survival in APL.

Classic and Variants APLs, as Viewed from a Therapy Response

Most acute promyelocytic leukemia (APL) are caused by PML-RARA, a translocation-driven fusion oncoprotein discovered three decades ago. Over the years, several other types of rare X-RARA fusions have been described, while recently, oncogenic fusion proteins involving other retinoic acid receptors (RARB or RARG) have been associated to very rare cases of acute promyelocytic leukemia. PML-RARA driven pathogenesis and the molecular basis for therapy response have been the focus of many studies, which have now converged into an integrated physio-pathological model. The latter is well supported by clinical and molecular studies on patients, making APL one of the rare hematological disorder cured by targeted therapies. Here we review recent data on APL-like diseases not driven by the PML-RARA fusion and discuss these in view of current understanding of "classic" APL pathogenesis and therapy response.