Early intracranial haemorrhages in acute promyelocytic leukaemia: analysis of neuroradiological and clinico-biological parameters

Chemotherapy-free approaches to newly-diagnosed acute promyelocytic leukaemia: is oral-arsenic trioxide/all-trans retinoic acid/ascorbic acid the answer?

INTRODUCTION

Acute promyelocytic leukemia (APL) is a distinct form of acute myeloid leukemia characterized by the presence of t(15;17)(q24;21) and the PML:RARA gene fusion. Frontline use of intravenous arsenic trioxide (i.v.-ATO) and all-trans retinoic acid (ATRA) has vastly improved cure rates in APL. Researchers in Hong Kong invented the oral formulation of ATO (oral-ATO) and have confirmed a bioavailability comparable to i.v.-ATO. A plethora of studies have confirmed the safety and efficacy of oral-ATO-based regimens in the frontline and relapsed setting.

AREAS COVERED

Aspects on the development of oral-ATO-based regimens for APL in the frontline and relapsed setting are discussed. The short-term and long-term safety and efficacy of oral-ATO-based regimens are discussed. The frontline use of oral-ATO in combination with ATRA and ascorbic acid (AAA) induction in a 'chemotherapy-free' is highlighted.

EXPERT OPINION

Current and ongoing data on the use of oral-ATO-based regimens in APL support the use of oral-ATO as an alternative to i.v.-ATO allowing a more convenient and economical approach to the management of APL.

Characteristics and complications of acute promyelocytic leukemia in children: an analysis of a national database

Acute promyelocytic leukemia (APL) is an uncommon subtype of acute myelogenous leukemia (AML) that was previously one of the most fatal forms of acute leukemia. With advances in diagnosis and treatment, APL has become one of the most curable myeloid leukemias. The major reason for treatment failure in APL is early death after initiation of treatment. We performed a retrospective cross-sectional analysis of the Healthcare Cost and Utilization Project 2016 and 2019 Kids' Inpatient Database, with the diagnosis of APL or AML not in remission as defined by ICD-10-CM codes. We compared complications and outcomes associated with APL and AML (exclusive of APL) in hospitalized children in the U.S. and described yearly national incidence. The national incidence of APL was 2.2 cases per million children per year. Children with APL were more likely to have cardiopulmonary complications (OR 1.79; CI 1.20-2.67; p = 0.004), coagulation abnormalities or DIC (OR 7.75; CI 5.81-10.34; p < 0.001), pulmonary hemorrhage (OR 2.18; CI 1.49-3.17; p < 0.001), and intracranial hemorrhage (OR 10.82; CI 5.90-19.85; p < 0.001) and less likely to have infectious complications (OR 0.48; CI 0.34-0.67; p < 0.001) compared to children with AML. In-hospital mortality rates were similar in children with APL and AML (4.2% vs 2.6%; OR 1.62; CI 0.86-3.06; p = 0.13), while the median length of stay for children who died from APL was shorter compared to AML (2 (IQR: 1-7) versus 25 (IQR: 5-66) days; p < 0.05). Hemorrhagic complications occur more often, and infectious complications occur less often in hospitalized children with APL compared to AML.

Machine learning-based model for predicting outcomes in cerebral hemorrhage patients with leukemia

BACKGROUND AND PURPOSE

Intracranial hemorrhage (ICH) in leukemia patients progresses rapidly with high mortality. Limited data are available on imaging studies in this population. The study aims to develop prediction models for 7-day and short-term mortality risk based on the non-contrast computed tomography (NCCT) image features.

METHODS

The NCCT image features of ICH in 135 leukemia patients between 2007-2023 were retrospectively extracted using manual assessment and radiomics methods. After multiple imputation of missing laboratory data, univariate logistic regression and least absolute shrinkage and selection operator (LASSO) were used for feature selection. Random forest models were built with comprehensive evaluation and ranking of feature importance.

RESULT

135 and 129 patients were included in the studies for 7-day and short-term prognostic models, respectively. The median age of all enrolled patients was 35 years, and there were 86 male patients (63.7 %). Clinical models (validation: AUC [area under the curve] = 0.78, AUPRC [area under the precision-recall curve] = 0.73; AUC = 0.84, AUPRC = 0.86), radiomics models (validation: AUC = 0.82, AUPRC = 0.78; AUC = 0.75, AUPRC = 0.77), and the combined models (validation: AUC = 0.84, AUPRC = 0.83; AUC = 0.87, AUPRC = 0.89) predicted 7-day and short-term mortality with good predictive efficacy. Clinical decision curve analysis showed that the combined models predicted 7-day and 30-day risk of death would be more beneficial than other models. Shape features contributed significantly more than semantic features in both radiomics models and combined models (93.3 %, 52.1 %, as well as 85.2 %,37.4 %, respectively) for 7-day and 30-day mortality.

CONCLUSIONS

Combined models constructed based on NCCT perform well in predicting the risk of 7-day and short-term mortality in ICH patients with leukemia. Shape features extracted by radiomics are important markers for modeling the prognosis.

Association between Serum Lactate Dehydrogenase Level and 30-day Mortality in Patients with Intracranial Hemorrhage with Acute Leukemia in the Induction Phase: A Cohort Study

Objectives  This study aimed to identify the association between lactate dehydrogenase (LDH) levels and 30-day mortality in patients with intracranial hemorrhage (ICH) with acute leukemia during the induction phase. Methods  This cohort study included patients with acute leukemia with ICH during induction. We evaluated serum LDH levels upon admission. Multivariable Cox regression analyzed the LDH 30-day mortality association. Interaction and stratified analyses based on factors like age, sex, albumin, white blood cell count, hemoglobin level, and platelet count were conducted. Results  We selected 91 patients diagnosed with acute leukemia and ICH. The overall 30-day mortality rate was 61.5%, with 56 of the 91 patients succumbing. Among those with LDH levels ≥ 570 U/L, the mortality rate was 74.4% (32 out of 43), which was higher than the 50% mortality rate of the LDH < 570 U/L group (24 out of 48) ( p  = 0.017). In our multivariate regression models, the hazard ratios and their corresponding 95% confidence intervals for Log2 and twice the upper limit of normal LDH were 1.27 (1.01, 1.58) and 2.2 (1.05, 4.58), respectively. Interaction analysis revealed no significant interactive effect on the relationship between LDH levels and 30-day mortality. Conclusions  Serum LDH level was associated with 30-day mortality, especially in patients with LDH ≥ 570 U/L.

The ISTH DIC-score predicts early mortality in patients with non-promyelocitic acute myeloid leukemia

Coagulation disorders frequently complicate the clinical course of acute myeloid leukemia (AML) patients. This study examined the frequency and prognostic significance, with regards of early mortality, of the presence of overt disseminated intravascular coagulation (DIC) at AML diagnosis and its correlation with clinical and biological characteristics. A retrospective analysis of 351 newly diagnosed non-promyelocytic AML patients was conducted, utilizing the 2018 ISTH DIC-Score criteria to evaluate the presence of overt DIC at AML onset. The study cohort had a median age of 65 years with a predominance of male gender (59 %). Overt DIC was present in 21 % of cases and was associated with advanced age, comorbidities, poor performance status, hyperleukocytosis, LDH levels, NPM1 mutations, expression of CD33 and CD4, and lack of expression of CD34. With a median follow-up of 72 months (3-147 months), the 6-year overall survival (OS) was 17.4 %, with patients having overt DIC showing significantly poorer outcomes (7.2 % compared to 20.3 % of those without DIC, p < 0.001). Patients with overt DIC showed markedly high early mortality rates at 30 (42.5 % vs 8 %), 60 (49.3 % vs 16.9 %), and 120 days (64.4 % vs 25.6 %) from disease onset. In multivariate analysis overt DIC retained its independent prognostic value for early mortality. In conclusion, the prevalence and clinical relevance of DIC in non-promyelocytic AML is not negligible, underlining its potential as an unfavorable prognostic marker. In newly diagnosed patients with AML, early recognition and measure to counteract coagulation disturbances might help mitigate the elevated mortality risk associated with DIC.

Risk stratification for early mortality in newly diagnosed acute promyelocytic leukemia: a multicenter, non-selected, retrospective cohort study

Introduction

Despite the current effective treatments for acute promyelocytic leukemia (APL), early mortality (EM), defined as death within 30 days of presentation, is a major hurdle to long-term survival.

Methods

We performed a multicenter retrospective study to evaluate the incidence and clinical characteristics of EM in patients with newly diagnosed APL and to develop a risk stratification model to predict EM.

Results

We identified 313 eligible patients diagnosed between 2000 and 2021 from five academic hospitals. The median age was 50 years (range 19-94), and 250 (79.9%) patients were <65 years. Most patients (n=274, 87.5%) received their first dose of all-trans retinoic acid (ATRA) within 24 hours of presentation. EM occurred in 41 patients, with a cumulative incidence of 13.1%. The most common cause of EM was intracranial hemorrhage (n=22, 53.6%), and most EMs (31/41, 75.6%) occurred within the first seven days of APL presentation. In a multivariable analysis, we identified three independent factors predicting EM: age ≥65 years (HR, 2.56), white blood cell count ≥8.0 x 109/L (HR, 3.30), and ATRA administration >24 hours of presentation (HR, 2.95). Based on these factors, patients were stratified into three categories with a significantly increasing risk of EM: 4.1% for low risk (54.3%; no risk factors; HR 1), 18.5% for intermediate risk (34.5%; 1 factor; HR 4.81), and 40.5% for high risk (11.2%; 2-3 factors; HR 13.16).

Discussion

The risk of EM is still not negligible in this era of ATRA-based therapies. Our risk model serves as a clinically useful tool to identify high-risk patients for EM who may be candidates for novel treatments and aggressive supportive strategies.

Thrombosis in Myeloid Malignancies: From CHIP to AML

The development of myeloid malignancies is a multi-step process starting from pre-malignant stages. Large-scale studies on clonal hematopoiesis of indeterminate potential (CHIP) identified this condition as a risk factor for developing hematologic malignancies, in particular myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML). In parallel, CHIP was found to confer an enhanced thrombotic risk, in particular for cardiovascular diseases. In a similar fashion, in recent years, alongside their life-threatening features, increasing attention has been drawn toward thrombotic complications in myeloid malignancies. Thus, the purpose of this review is to gather a growing body of evidence on incidence, pathogenesis and clinical impact of thrombosis in myeloid malignancies at every step of malignant progression, from CHIP to AML.

The characteristics and long-term outcomes of acute promyelocytic leukemia patients with early intracranial hemorrhage

Intracranial hemorrhage (ICH) is a major cause of early death (ED) and leads to poor prognosis in acute promyelocytic leukemia (APL). We retrospectively described 27 unselected APL patients who experienced early ICH. The ED rate was 37%. The 3-year overall survival (OS) rate was 45.4%, while the 3-year OS rate of patients who survived through induction therapy was 87.5%. No patient experienced central nervous system leukemia (CNSL). Concurrent differentiation syndrome, white blood cell count, prothrombin time and D-dimer were related to death. Although the ED rate among APL patients with early ICH was high, patients with early ICH had a favorable outcome after surviving through induction therapy. CNSL was rare despite a history of ICH during induction therapy. Compared with APL patients without ICH, it seems unnecessary to administer additional measures to prevent CNSL for this subpopulation in the era of all-trans retinoic acid and arsenic trioxide, but this needs further validation in prospective trials.

Predictive values of plasma TNFα and IL-8 for intracranial hemorrhage in patients with acute promyelocytic leukemia

In patients with acute promyelocytic leukemia (APL), intracranial hemorrhage (ICH), if not identified promptly, could be fatal. It is the leading cause of failure of induction and early death. Thus, biomarkers that could promptly predict severe complications are critical. Here, cytokine differences between patients with APL with and without ICH were investigated to develop predictive models for this complication. The initial cytokine profiling using plasma samples from 39 patients and 18 healthy donors found a series of cytokines that were remarkedly different between patients with APL and healthy controls. The APL patients were subsequently divided into high and low white blood cell count groups. Results showed that tumor necrosis factor a and interleukin 8 (IL-8) were vital in distinguishing patients with APL who did or did not develop ICH. In addition, verification in 81 patients with APL demonstrated that the two cytokines were positively correlated with the cumulative incidence of ICH. Finally, in-vitro and in-vivo experimental evidence were provided to show that IL-8 influenced the migration of APL-derived NB4 cells and impaired the blood-brain barrier in PML/RARα positive blast-transplanted FVB/NJ mice. These assessments may facilitate the early warning of ICH and reduce future mortality levels in APL.

Predictors of Early Thrombotic Events in Adult Patients with Acute Myeloid Leukemia: A Real-World Experience

Information regarding the incidence and the prognostic impact of thrombotic events (TE) in non-promyelocytic acute myeloid leukemia (AML) is sparse. Although several risk factors associated with an increased risk of TE development have been recognized, we still lack universally approved guidelines for identification and management of these complications. We retrospectively analyzed 300 consecutive patients with newly diagnosed AML. Reporting the incidence of venous TE (VTE) and arterial TE (ATE) was the primary endpoint. Secondarily, we evaluated baseline patient- and disease-related characteristics with a possible influence of VTE-occurrence probability. Finally, we evaluated the impact of TE on survival. Overall, the VTE incidence was 12.3% and ATE incidence was 2.3%. We identified three independent predictors associated with early-VTE: comorbidities (p = 0.006), platelets count >50 × 109/L (p = 0.006), and a previous history of VTE (p = 0.003). Assigning 1 point to each variable, we observed an overall cumulative incidence of VTE of 18.4% in the high-risk group (≥2 points) versus 6.4% in the low-risk group (0−1 point), log-rank = 0.002. Overall, ATE, but not VTE, was associated with poor prognosis (p < 0.001). In conclusion, TE incidence in AML patients is not negligible. We proposed an early-VTE risk score that could be useful for a proper management of VTE prophylaxis.

Incidence of stroke in the first year after diagnosis of cancer-A systematic review and meta-analysis

Background

Patients newly diagnosed with cancer represent a population at highest risk for stroke. The objective of this systematic review and meta-analysis was to estimate the incidence of stroke in the first year following a new diagnosis of cancer.

Methods

We searched MEDLINE and EMBASE from January 1980 to June 2021 for observational studies that enrolled adults with a new diagnosis of all cancers excluding non-melanoma skin cancer, and that reported the incidence of stroke at 1 year. PRISMA guidelines for meta-analyses were followed. Two reviewers independently extracted data and appraised risk of bias. We used the Dersimonian and Laird random effects method to pool cumulative incidences after logit transformation, and reported pooled proportions as percentages. Statistical heterogeneity was assessed using the I 2 statistic.

Results

A total of 12,083 studies were screened; 41 studies were included for analysis. Data from 2,552,121 subjects with cancer were analyzed. The cumulative incidence of total stroke at 1 year was 1.4% (95% CI 0.9-2.2%), while the pooled incidence of ischemic stroke was 1.3% (95% CI 1.0-1.8%) and 0.3% (95% CI 0.1-0.9%) for spontaneous intracerebral hemorrhage (ICH), with consistently high statistical heterogeneity (>99% I 2).

Conclusion

The estimated incidence of stroke during the first year after a new diagnosis of cancer is 1.4%, with a higher risk for ischemic stroke than ICH. Cancer patients should be educated on the risk of stroke at the time of diagnosis. Future studies should evaluate optimal primary prevention strategies in this high-risk group of patients.

Systematic review registration

https://osf.io/ucwy9/.

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.

Analysis of risk factors for early death in patients with acute promyelocytic leukaemia treated with arsenic trioxide

To date, no specific studies have evaluated early death (ED) in patients with acute promyelocytic leukaemia (APL) homogeneously treated with arsenic trioxide induction therapy and investigated according to the white blood cell (WBC) count at onset. Such patients were retrospectively analysed in this study, including 314 patients with a WBC count ≤ 10 × 10⁹/L (standard-risk (SR) group) and 144 with a WBC count > 10 × 10⁹/L (high-risk (HR) group). The baseline clinical characteristics and risk factors for ED were compared between the two groups. The incidence of fibrinogen < 1.0 g/L and elevated serum uric acid, aspartate aminotransferase and creatinine levels were higher in the HR group than in the SR group (P = 0.001; P < 0.001; P < 0.001; P = 0.044, respectively). The ED rate was significantly higher in the HR group than in the SR group (29.17% vs. 10.83%, P < 0.001). The main cause of ED was bleeding, followed by infection and differentiation syndrome (DS) in the HR group, while it was bleeding, followed by DS and infection in the SR group. Male sex, age > 50 years old, and fibrinogen < 1.0 g/L were independent risk factors for ED in the SR group. Increased serum creatinine levels, decreased albumin levels, and fibrinogen < 1.0 g/L were independent risk factors for ED in the HR group. Overall, the incidence of ED was higher in the HR group, and the baseline clinical characteristics, causes, times, and predictors of ED in the HR group differed from those in the SR group.

Predictive factors for differentiating thrombohemorrhagic disorders in high-risk acute promyelocytic leukemia

INTRODUCTION

Acute promyelocytic leukemia (APL) is often accompanied by potentially fatal coagulopathy, especially in high-risk APL. Bleeding, particularly severe bleeding is the leading cause of early death (ED). Meanwhile, thrombosis, the other major coagulopathic complication, is being increasingly recognized. However, predictors of thrombohemorrhagic disorders are still not well investigated.

MATERIALS AND METHODS

In this study, we retrospectively studied 83 patients with high-risk APL and categorized them into severe bleeding, thrombosis and no evident events groups.

RESULTS

Severe bleeding was observed in 15 patients, nearly half of whom died of hemorrhage, while thrombosis was observed in 12 patients. Risk factor analysis showed that high WBC (>58.76 × 10⁹/L) (p = 0.001) and prolonged PT (>17.7 s) (p = 0.015) could be independent predictors for severe bleeding, while high WBC/D-dimer>5.12 (p = 0.002) and low D-dimer/FIB<5.14 (p = 0.03) could be independent predictors for thrombosis in high-risk APL patients. Moreover, there are significant differences in WBC/D-dimer and D-dimer/FIB between DIC and Non-DIC groups (p < 0.001). Notably, we found that the WBC/D-dimer was dramatically higher in the thrombotic group than in the other two groups at the time of admission or during the first week of induction therapy.

CONCLUSIONS

High WBC and prolonged PT could predict severe bleeding in high-risk APL patients, while high WBC/D-dimer and low D-dimer/FIB could be independent predictors for thrombosis. For high-risk APL, WBC/D-dimer and D-dimer/FIB are also beneficial in the diagnosis of DIC. WBC/D-dimer might help early identification of thrombosis at the time of admission or during the first week of induction therapy.

Acute promyelocytic leukemia (APL) in very old patients: real-life behind protocols

BACKGROUND

Acute promyelocytic leukemia (APL) is uncommon among subjects aged ≥ 70 years and the better therapeutic strategy represents an unmet clinical need.

MATERIALS AND METHODS

This prompted us to explore our real-life data on a retrospective cohort of 45 older APL patients (≥ 70 years) consecutively diagnosed at eight different hematologic institutions in Latium, Italy, from July 1991 to May 2019.

RESULTS

Two patients (4.4%) died from early hemorrhagic complications before treatment could begin. Twenty-two patients (51.1%) (Group A) were enrolled or treated according to standard clinical protocols, while 21 (48.8%) (Group B) received an ATRA-based personalized approach due to poor performance status. Morphologic complete remission (CR) after induction therapy was achieved in 33 patients (76.7%) with 100% of patients in Group A and 52.3% in Group B (p < 0.001). Molecular CR was documented in 30 patients (69.7%) [20/22 (90.9%) in Group A and 10/21 (47.6%) in Group B (p = 0.002)]. Ten patients (23.2%) died during induction therapy, all in Group B. Five-year overall survival (OS) of the entire cohort was 46.1% (95% CI 28.2-64.0), with 72.6% (95% CI 42.9-100) in Group A vs. 27.2% (95% CI 7.5-46.9) in the Group B (p = 0.001).

CONCLUSIONS

The present analysis highlights that almost half of the patients received sub-optimal induction treatments and registered dismal outcomes demonstrating the importance of adopting standard therapies instead of modified or reduced personalized approaches also in the setting of frail older patients.

Drug treatment options for acute promyelocytic leukemia

INTRODUCTION

Until the late 1980s, acute promyelocytic leukemia (APL) was the most rapidly fatal leukemia; however, nowadays, it is a curable disease with survival rates exceeding 90-95%. The improvement of APL outcome is mainly due to two agents, which target the typical translocation t(15;17) and its fusion transcript PML-RARα responsible for initiating and maintaining the disease: all-trans retinoic acid (ATRA) and arsenic trioxide (ATO). The story of APL represents a pioneering model for the development of precision medicine and curative chemotherapy-free approaches for acute leukemia.

AREA COVERED

The authors examine the major advances in the treatment of patients with APL focusing on three different eras: 1) the pre-ATRA era; 2) the ATRA era; 3) the ATO era.

EXPERT OPINION

The combination of ATRA and ATO is effective and curative for the majority of APL patients. It has been approved for low/intermediate risk cases while an experimental trial with a minimal addition of chemotherapy for high-risk ones is ongoing. Disease relapse is infrequent and can be cured with ATRA-ATO rechallenging, with or without subsequent transplantation depending on the interval between complete remission and relapse. New therapeutic landscapes contemplate the use of an oral chemo-free ATRA-ATO combination, implementing treatment as outpatient care, thus increasing quality of life and decreasing medical costs.

Characteristics and predictors of early hospital deaths in newly diagnosed APL: a 13-year population-wide study

Despite therapeutic advances, early death (ED) remains a major factor curtailing survival of acute promyelocytic leukemia (APL). Studies examining factors that cause early death (ED; within 30 days of admission) and the correlation of survival with the timing of administration of all-trans retinoic acid (ATRA) and hemostatic parameters are scarce. We performed a cohort analysis of nonselect patients with newly diagnosed APL who presented to the health care system in Hong Kong, where oral arsenic trioxide was used. From 1 January 2007 to 30 April 2020, 358 patients (median age, 47 [1-97] years) with newly diagnosed APL were identified. ED occurred in 56 patients (16%): 11 (3%) died in the first 2 days after admission (intracranial hemorrhage [ICH], n = 6; APL-differentiation syndrome [APL-DS], n = 4; infection, n = 1); 22 (6%) died within 3 to 7 days (ICH, n = 12; APL-DS, n = 8; infections, n = 2), and 23 (6%) died within 8 to 30 days (ICH, n = 7; APL-DS, n = 11; infection, n = 5). Factors significantly associated with ED by multivariate analysis included male sex (P = .01); presenting leukocyte count ≥10 × 109/L (P = .03); fibrinogen <1.5 g/L (P = .02); and ATRA administration >24 hours after hospital admission (P < .001). After a median follow-up of 47 (0-166) months, the 5- and 10-year overall survival (OS) was 68.6% and 61.2%, respectively. Excluding EDs, the 5- and 10-year post-30-day OS improved to 81.3% and 72.5%. Early administration of ATRA (<24 hours) and vigorous correction of hemostatic abnormalities, including hypofibrinogenemia, are key to reducing ED.

Acute Promyelocytic Leukemia in Children: A Model of Precision Medicine and Chemotherapy-Free Therapy

Acute promyelocytic leukemia (APL) represents a paradigm of precision medicine. Indeed, in the last decades, the introduction of all-trans retinoic acid (ATRA) and arsenic trioxide (ATO) completely revolutionized the therapeutic approach to this previously highly fatal disorder. This entirely chemotherapy-free treatment, which provided excellent survival rates, has been initially validated in adults and, recently, translated in the pediatric setting. This review summarizes currently available data on the use of ATRA and ATO combination in pediatric APL, providing a particular focus on peculiar issues and challenges, such as the occurrence of pseudotumor cerebri and death during induction (early death), as well as the advantage offered by the ATO/ATRA combination in sparing long-term sequelae.