Long-term outcome of older patients with newly diagnosed de novo acute promyelocytic leukemia treated with ATRA plus anthracycline-based therapy

Acute myeloid leukemia: challenges for diagnosis and treatment in Latin America

OBJECTIVE

to review the current diagnostic and therapeutic landscape of AML in Latin America as a reflection of other low- and middle-income countries and regions of the world. Encompassing both acute promyelocytic and non-promyelocytic disease types.

METHODS

We reviewed the literature and study registries concerning epidemiological features of patients with AML/APL treated in Latin America, as well as evaluated diagnostic and genetic stratification and patient fitness assessment challenges, the importance of early mortality and supportive care capacity, intensive and non-intensive chemotherapy alternatives, consolidation, and maintenance strategies including novel agents and hematopoietic stem cell transplantation.

RESULTS

Although most of the current technologies and treatment options are available in the region, a significant fraction of patients have only limited access to them. In addition, mortality in the first weeks from diagnosis is higher in the region compared to developed countries.

CONCLUSIONS

Disparities in access to technologies, supportive care capacity, and availability of novel agents and HSCT hinder results in our region, reflecting barriers common to other LMICs. Recent developments in the diagnosis and treatment of this disease must be implemented through education, collaborative clinical research, and advocacy to improve outcomes.

Additional cytogenetic abnormalities in patients with newly diagnosed acute promyelocytic leukemia predict inferior event-free survival

BACKGROUND

The innovative combination of all-trans retinoic acid (ATRA) and arsenic trioxide (ATO) has established a new chapter of curative approach in acute promyelocytic leukemia (APL). The disease characteristics and prognostic influence of additional cytogenetic abnormalities (ACA) in APL with modern therapeutic strategy need to be elucidated.

METHODS

In the present study, we retrospectively investigated disease features and prognostic power of ACA in 171 APL patients treated with ATRA-ATO-containing regimens.

RESULTS

Patients with ACA had markedly decreased hemoglobin levels than that without ACA (p = 0.021). Risk stratification in the ACA group was significantly worse than that in the non-ACA group (p = 0.032). With a median follow-up period of 62.0 months, worse event-free survival (EFS) was demonstrated in patients harboring ACA. Multivariate analysis showed that ACA was an independent adverse factor for EFS (p = 0.033). By further subgroup analysis, in CD34 and CD56 negative APL, patients harboring ACA had inferior EFS (p = 0.017; p = 0.037).

CONCLUSIONS

To sum up, ACA remains the independent prognostic value for EFS, we should build risk-adapted therapeutic strategies in the long-term management of APL when such abnormalities are detected.

Management of Acute Promyelocytic Leukemia at Extremes of Age

Tailored treatment with all-trans retinoic acid (ATRA) and arsenic trioxide (ATO) has revolutionized the outcome of acute promyelocytic leukemia (APL) from a uniformly fatal disease to one of the most curable malignant diseases in humans. Due to its high efficacy, ATO/ATRA is the standard first-line therapy in younger adult, non-high-risk APL patients. However, early death is still a major issue in APL, particularly in older patients. Thus, rapid diagnostics, immediate access to ATRA-based therapy, and supportive care are of utmost importance. Nevertheless, challenging situations occur, particularly in patients excluded from controlled studies with clinical knowledge mainly based on case reports and registries. Besides the treatment of newly diagnosed patients, managing toxicities and complications remains challenging. This review discusses the approach to the treatment of APL in elderly and pediatric patients.

Clinical outcomes after CPX-351 in patients with high-risk acute myeloid leukemia: A comparison with a matched cohort from the Spanish PETHEMA registry

BACKGROUND

CPX-351 is approved for the treatment of therapy related acute myeloid leukemia (t-AML) and AML with myelodysplastic related changes (MRC-AML). The benefits of this treatment over standard chemotherapy has not been addressed in well matched cohorts of real-life patients.

METHODS

Retrospective analysis of AML patients treated with CPX-351 as per routine practice. A propensity score matching (PSM) was used to compare their main outcomes with those observed in a matched cohort among 765 historical patients receiving intensive chemotherapy (IC), all of them reported to the PETHEMA epidemiologic registry.

RESULTS

Median age of 79 patients treated with CPX-351 was 67 years old (interquartile range 62-71), 53 were MRC-AML. The complete remission (CR) rate or CR without recovery (CRi) after 1 or 2 cycles of CPX-351 was 52%, 60-days mortality 18%, measurable residual disease <0.1% in 54% (12 out of 22) of them. Stem cell transplant (SCT) was performed in 27 patients (34%), median OS was 10.3 months, and 3-year relapse incidence was 50%. Using PSM, we obtained two comparable cohorts treated with CPX-351 (n = 52) or IC (n = 99), without significant differences in CR/CRi (60% vs. 54%) and median OS (10.3 months vs. 9.1 months), although more patients were bridged to SCT in the CPX-351 group (35% vs. 12%). The results were confirmed when only 3 + 7 patients were included in the historical cohort. In multivariable analyses, SCT was associated with better OS (HR 0.33 95% CI: 0.18-0.59), p < 0.001.

CONCLUSION

Larger post-authorization studies may provide evidence of the clinical benefits of CPX-351 for AML in the real-life setting.

At What Point Are Long-Term (>5 Years) Survivors of APL Safe? A Study from the SEER Database

BACKGROUND

Acute promyelocytic leukemia (APL) is a highly curable cancer, but it is not clear whether it is also necessary to monitor long-term toxicity in "cured" patients who survive for more than five years, which is critical to ensuring maximum survival in APL patients.

METHODS

A total of 1952 APL 5-year survivors and 5973 non-APL acute myeloid leukemia (AML) 5-year survivors were included from the Surveillance, Epidemiology, and End Results (SEER) database. The standardized mortality ratio (SMR) was calculated to measure the risk of death. Cumulative mortality is calculated as the incidence of specific causes of death under competing risk events.

RESULTS

The SMR of all causes of death in >5-year survivors of APL was higher than that of the general population only at 60-119 months (SMR, 1.41). This was mainly because a significant increase in mortality from AML (SMR, 87.67) and second malignant neoplasms (SMNs) (SMR, 1.56) was found only at 60-119 months. However, there was no higher risk of death from non-cancer-related disease in >5-year survivors of APL than that of the general population (SMR, 0.89). The SMR of all-cause deaths in >5-year survivors of non-APL AML decreased year by year and was no higher than that of the general population until after 216 months. The cumulative incidence of AML-related death, SMN-related death, and non-cancer-related death was significantly lower in APL patients than in non-APL AML patients throughout the follow-up period.

CONCLUSIONS

Compared with the general population, the risk of death of patients with APL was higher within 5 to 10 years but not higher over 10 years. Therefore, we believe that long-term survivors of APL are safe after 10 years.

Long-term follow-up results of cytarabine-containing chemotherapy for acute promyelocytic leukemia

BACKGROUND/AIMS

We evaluated the feasibility and long-term efficacy of the combination of cytarabine, idarubicin, and all-trans retinoic acid (ATRA) for treating patients with newly diagnosed acute promyelocytic leukemia (APL).

METHODS

We included 87 patients with newly diagnosed acute myeloid leukemia and a t(15;17) or promyelocytic leukemia/retinoic acid receptor alpha (PML-RARα) mutation. Patients received 12 mg/m2/day idarubicin intravenously for 3 days and 100 mg/m2/day cytarabine for 7 days, plus 45 mg/m2/day ATRA. Clinical outcomes included complete remission (CR), relapse-free survival (RFS), overall survival (OS), and the secondary malignancy incidence during a 20-year follow-up.

RESULTS

The CR, 10-year RFS, and 10-year OS rates were 89.7%, 94.1%, and 73.8%, respectively, for all patients. The 10-year OS rate was 100% for patients that achieved CR. Subjects were classified according to the white blood cell (WBC) count in peripheral blood at diagnosis (low-risk, WBC < 10,000/mm3; high-risk, WBC ≥ 10,000/mm3). The low-risk group had significantly higher RFS and OS rates than the high-risk group, but the outcomes were not superior to the current standard treatment (arsenic trioxide plus ATRA). Toxicities were similar to those observed with anthracycline plus ATRA, and higher than those observed with arsenic trioxide plus ATRA. The secondary malignancy incidence after APL treatment was 2.7%, among the 75 patients that achieved CR, and 5.0% among the 40 patients that survived more than 5 years after the APL diagnosis.

CONCLUSION

Adding cytarabine to anthracycline plus ATRA was not inferior to anthracycline plus ATRA alone, but it was not comparable to arsenic trioxide plus ATRA. The probability of secondary malignancy was low.

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.

Safety and efficacy of different doses of anthracyclines combined with arsenic trioxide and all-trans retinoic acid in the treatment of de novo acute promyelocytic leukemia

OBJECTIVES

The purpose of this study was to evaluate the efficacy and safety of different doses of anthracyclines combined with arsenic trioxide (ATO) and all-trans retinoic acid (ATRA) for induction in newly diagnosed acute promyelocytic leukemia (APL).

METHODS

One hundred and forty patients were included between January 2011 and December 2017. Seventy patients received low dose anthracycline, ATO and ATRA for induction chemotherapy; and other seventy patients received standard dose anthracycline, ATO and ATRA for induction chemotherapy.

RESULTS

The outcomes of both groups were similar: low dose group versus standard dose group: early mortality 5.7% vs. 10.0% (P = 0.532), disease-free survival (DFS), probabilities of overall-survival (OS) at 2 years 94.6% vs. 95.1% (P = 0.657), 92.8% vs. 88.2% (P = 0.951), respectively. However, the standard-dose group was associated with a longer duration of neutropenia (p < 0.001) and thrombocytopenia (p < 0.001), more volumes of platelets (p = 0.037) and red blood cell transfusions (p < 0.001), and a higher rate of infections (p = 0.042).

CONCLUSION

Low-dose group achieves outcomes similar to those of standard dose group for APL patients, but the low-dose group may be even safer than standard-dose group. So the low-dose anthracycline may be a better choice for newly diagnosed APL patients.

[Analysis of early death factors and prognosis of acute promyelocytic leukemia]

Objective: To summarize the clinical characteristics of an early death in patients with de novo acute promyelocytic leukemia (APL) , analyze the risk factors and direct causes of early death, and perform survival analysis. Methods: The clinical data of 368 patients with de novo APL in three centers (First Affiliated Hospital of Soochow University, Soochow Guangci Hospital, and Soochow Hopes Hospital of Hematology) during January 2011-December 2017 were retrospectively analyzed. The clinical characteristics of patients who suffered hemorrhagic early death and non-hemorrhagic early death were compared. The risk factors for early death, survival, and prognosis of patients with APL were analyzed. Results: Among the 368 de novo APL patients, 31 died early with an early mortality rate of 8.4%. The median time from diagnosis to death was 7 (0-29) d. On comparison of the clinical characteristics of patients with early death and non-early death and subsequent multivariate analysis using a logistic regression model, it was observed that age ≥50 years and WBC ≥10×10(9)/L were independent risk factors for early death (P<0.01) . A total of 27 (87.1%) of the 31 early deaths was directly attributed to hemorrhage as the immediate cause of early death. Hemorrhage was the only cause of death in patients <50 years old and the major cause of death in patients ≥50 years old. A comparison of the clinical characteristics of patients with hemorrhagic early death and patients with non-hemorrhagic early death suggested that the median age and indirect bilirubin concentration of patients with hemorrhagic early death were lower than those with non-hemorrhagic early death (P<0.05) . The median follow-up time for all patients was 41.0 (0.3-101.4) months. The 2-year overall survival (OS) rate was (93.5±1.3) %, and the 5-year OS rate was (91.0±1.5) %. The 2-year disease-free survival (DFS) rate was (98.8±0.6) %, and the 5-year DFS rate was (97.1±0.9) %. The 2-year OS rate of patients ≥50 years old and patients <50 years old was 79.3% vs 94.2%, P=0.000; the 2-year DFS rate was 92.3% vs 98.1%, P=0.023. The respective 2-year OS rates of high-risk and non-high-risk patients were 77.3% and 96.7% (P=0.000) and the respective 2-year DFS rates were 94.0% and 98.4% (P=0.139) . Conclusion: Age and WBC are independent prognostic factors for early death. We observed a difference in early mortality between high-risk and low-risk APL, but no difference in DFS rate.

The History of the Chemo-Free Model in the Treatment of Acute Promyelocytic Leukemia

Acute promyelocytic leukemia (APL) has become a highly curable disease after four decades of endeavors. Thanks to the efforts of investigators throughout the world, the chemo-free concept has become a reality for both low- and high-risk patients. All-trans retinoic acid (ATRA) plus arsenic trioxide (ATO) without chemotherapy has become a first-line treatment for newly diagnosed APL and has been adopted in guidelines or expert recommendations from the NCCN and ELN and in China. Though the regimen has achieved great success, challenges still exist. The rate of early death still has not diminished significantly and is a major obstacle to curing all patients. Leukocytosis is the most important factor for ED, and completely abandoning chemotherapy is dangerous for certain patients in practice. To narrow the gap between guidelines and practice, this review aims to examine the history of the chemo-free model for the treatment of APL in the arsenic-alone era (1974-2002) and the arsenic plus ATRA era (2002-present) and provide practical considerations regarding early death.

Predictors of early death, serious hemorrhage, and differentiation syndrome in Japanese patients with acute promyelocytic leukemia

Significant advancements have been achieved with regard to the outcomes of acute promyelocytic leukemia (APL) patients through the introduction of all-trans retinoic acid; however, early hemorrhagic death and differentiation syndrome remain the major causes of remission induction failure in patients with APL. To investigate early death, serious hemorrhage, and differentiation syndrome during remission induction therapy in terms of incidence, risk factors, influence on outcomes, and prophylactic effects of several new anticoagulants, the results of 344 patients enrolled in the Acute Promyelocytic Leukemia 204 study conducted by the Japan Adult Leukemia Study Group were analyzed. Early death was observed in 16 patients (4.7%), of whom 14 had serious hemorrhage and 2 had differentiation syndrome. Serious hemorrhage and differentiation syndrome of grade 2 or higher were observed in 21 and 54 patients, respectively. Patients who achieved complete remission had a 7-year disease-free survival of 84.8% if they did not experience serious hemorrhage and 40.0% if they experienced serious hemorrhage during remission induction therapy (P = 0.001). Risk factor analyses showed that higher white blood cell count was associated with early death, higher white blood cell count and lower platelet count with serious hemorrhage, and leukocytosis during induction therapy and higher body surface area with differentiation syndrome. In conclusion, these results indicate that patients with such high-risk features may benefit from more intensive supportive care. The hemorrhagic risk was not relieved by the introduction of new anticoagulants. Further studies are required to establish the predictive impact of body surface area on differentiation syndrome. This trial is registered with UMIN-CTR as C000000154 on September 13, 2005.

Treatment of acute promyelocytic leukemia in older patients: recommendations of an International Society of Geriatric Oncology (SIOG) task force

Approximately one third of patients diagnosed with acute promyelocytic leukemia (APL) are above the age of sixty. It is important to ensure older adults receive optimal diagnosis and management since this subtype of acute myeloid leukemia - given appropriate treatment - is highly curable with lower risk of adverse events compared to other types of leukemia. Historically, older age has been a risk factor for early death and poorer overall survival. However, prospects have changed with the introduction of all-trans retinoic acid (ATRA) and arsenic trioxide (ATO). APL is curable in the majority of patients regardless of age, and the threshold of fitness that makes ATRA/ATO therapy possible is likely to be lower than for cytotoxic chemotherapy. APL frequently presents as a medical emergency and rapid diagnosis and intervention - typically involving referral to a specialist centre - is a major determinant of outcome. After diagnosis, management of APL in older adults presents particular challenges. Geriatric assessment, including evaluation of frailty, comorbidities and polypharmacy can assist in providing optimal supportive care for older adults during remission induction and may help individualize therapy in the post-remission phase. Here, we review the available evidence, highlighting areas of consensus, gaps in evidence and opportunities for research to enhance diagnosis, management and survivorship for older patients.

Outcome of older (≥70 years) APL patients frontline treated with or without arsenic trioxide-an International Collaborative Study

Data on outcome in older (≥70 years) patients with acute promyelocytic leukemia after treatment with arsenic trioxide (ATO) compared with standard chemotherapy (CTX) is scarce. We evaluated 433 patients (median age, 73.4 years) treated either with ATO+ all-trans retinoic acid (ATO/ATRA; n = 26), CTX/ATRA + ATO during consolidation (CTX/ATRA/ATO; n = 148), or with CTX/ATRA (n = 259). Median follow-up for overall survival (OS) was 4.8 years. Complete remissions (CR) were achieved in 92% with ATO/ATRA and 82% with CTX/ATRA; induction death rates were 8% and 18%, respectively. For analysis of postremission outcomes we combined the ATO/ATRA and CTX/ATRA/ATO groups (ATO/ATRA ± CTX). Cumulative incidence of relapse (CIR) was significantly lower after ATO/ATRA ± CTX compared with CTX/ATRA (P < 0.001). The same held true when restricting the analysis according to the treatment period after the year 2000. OS of patients in CR1 was not different between ATO/ATRA ± CTX compared with CTX/ATRA (P = 0.20). High (>10 × 10⁹/l) white blood cell (WBC) counts at diagnosis were associated with higher CIR (P < 0.001) compared with lower WBC in the CTX/ATRA group, but not in the ATO/ATRA ± CTX group (P = 0.48). ATO, when added to ATRA or CTX/ATRA is feasible and effective in elderly patients for remission induction and consolidation, particularly in patients with high WBC at diagnosis.

Identification of a new cryptic PML-RARα fusion gene without t(15;17) and biallelic CEBPA mutation in a case of acute promyelocytic leukemia: a case detected only by RT-PCR but not cytogenetics and FISH

Acute promyelocytic leukemia (APL) is characterized by the presence of promyelocytic leukemia-retinoic acid receptor α (PML-RARα) fusion gene, which is formed following the specific chromosomal translocation t(15;17)(q22;q21). However, cases with PML-RARα generated by occult t(15;17) which are negative by both cytogenetics and fluorescence in situ hybridization (FISH), are difficult to diagnose, leading to impaired treatment effectiveness. In the present study, we reported a case of a 66-year-old male patient, and bone marrow morphology, flow cytometry and cytogenetics did not support the diagnosis of APL. Molecular techniques, such as reverse-transcription polymerase chain reaction (RT-PCR), showed the existence of a cryptic PML-RARα fusion gene, and sequence analysis revealed a new variable isoform. Hotspot gene mutation analysis showed a biallelic CEBPA mutation. He received IA chemotherapy and all-trans retinoic acid (ATRA) treatment, and finally achieved complete remission. This case report provided valuable insights into the relevance of the correct identification of atypical PML-RARα fusion gene and biallelic CEBPA mutation. Moreover, combination of IA chemotherapy and ATRA treatment suggested a good clinical effect in this atypical PML-RARα.

Real life outcomes of patients aged ≥75 years old with acute promyelocytic leukemia: experience of the PETHEMA registry

Acute promyelocytic leukemia is infrequent among patients aged ≥75 years old, a population that is rarely eligible for clinical protocols. This study aims to analyze the treatment strategies and clinical outcomes of very old APL patients reported to the international PETHEMA registry. Between 1997 and 2017, among 2501 APL cases registered 120 were ≥75 years old. Treatment approaches were: AIDA regimen, 79 patients; ATRA alone, 23; 16, supportive care (SC) and 2, other strategies. Patients treated with AIDA were younger, had better ECOG and lower leukocytes. Complete remission (CR) was achieved in 65% of AIDA-group vs. 45% in the ATRA-group, being infections followed by bleeding the most frequent causes of induction death. Patients in CR after AIDA showed 3-year DFS of 73%. Our real-life series of very old APL patients provides a reference basis for future treatment strategies aiming to improve clinical outcomes in this challenging population.