Clinicobiological features and outcome of acute promyelocytic leukemia occurring as a second tumor: the GIMEMA experience

Therapy-related Myeloid Neoplasms: Considerations for Patients' Clinical Evaluation

Therapy-related myeloid neoplasms (t-MNs) encompass a specific sub-group of myeloid malignancies arising after exposure to radio/cytotoxic agents for the treatment of unrelated diseases. Such malignancies present unique features, including advanced age, high comorbidities burden, and unfavorable genetic profiles. All these features justify the need for a specific diagnostic work-up and dedicated treatment algorithms. However, as new classification systems recognize the unique clinical characteristics exhibited by t-MN patients, how to assess fitness status in this clinical setting is largely unexplored. Optimizing fitness assessment would be crucial in the management of t-MN patients, considering that factors usually contributing to a worse or better outcome (like age, comorbidities, and treatment history) are patient-specific. In the absence of specific tools for fitness assessment in this peculiar category of AML, the aim of this review is to describe all those factors related to patient, treatment, and disease that allow planning treatments with an optimal risk/benefit ratio.

Therapy-Related Acute Promyelocytic Leukemia: A Case Report and a Review of Literature

Acute promyelocytic leukemia (APL) is a subgroup of acute myeloid leukemia (AML), and while not a common form of cancer, it does make up a modest portion of acute leukemia. The genetic hallmark of APL is the t(15;17)(q24.1;q21.2) promyelocytic leukemia/retinoic acid receptor alpha (PML/RARA) protein. We present the case of a patient who had undergone prior therapy for stage IIIC squamous cell carcinoma of the anorectal region with 5-fluorouracil, mitomycin C, and radiation and developed therapy-related acute promyelocytic leukemia about 18 months later. We also review the clinical features and management of APL while also highlighting that therapy-related APL, although uncommon, can develop from chemoradiation. The specific diagnosis of therapy-related APL is its own distinct diagnosis, but its treatment remains the same as primary APL.

Differential Survival Outcomes Between De Novo and Secondary Acute Promyelocytic Leukemia: An Updated Population-based study

BACKGROUND

Whether the characteristics and outcome of secondary acute promyelocytic leukemia (s-APL) are similar to de no APL (dn-APL) remains unknown.

PATIENTS AND METHODS

Using the SEER database, we identified 3877 patients with APL diagnosed from 2000 to 2014, including 465 s-APL and 3412 dn-APL.

RESULTS

Compared with dn-APL, s-APL werecharacterized by older median age, and a higher early mortality rate. Multivariate Cox model showed s-APL, older age, earlier year of diagnosis, and male gender were independently associated with worse survival. Notably, s-APL had a significantly inferior survival regardless of gender, race, marital status, and year of diagnosis. However, the difference between the 2 cohorts was only evident in younger patients (≤ 65 years) but was lost in older patients (> 65 years). Additionally, the majority of index cancer type was breast and prostate in female and male s-APL, respectively. Latency < 3 years was associated with superior survival in s-APL with breast index cancer.

CONCLUSIONS

Inferior survival of s-APL points to the need for treatment improvement.

Acute promyelocytic leukemia current treatment algorithms

In 1957, Hillestad et al. defined acute promyelocytic leukemia (APL) for the first time in the literature as a distinct type of acute myeloid leukemia (AML) with a “rapid downhill course” characterized with a severe bleeding tendency. APL, accounting for 10–15% of the newly diagnosed AML cases, results from a balanced translocation, t(15;17) (q22;q12-21), which leads to the fusion of the promyelocytic leukemia (PML) gene with the retinoic acid receptor alpha (RARA) gene. The PML–RARA fusion oncoprotein induces leukemia by blocking normal myeloid differentiation. Before using anthracyclines in APL therapy in 1973, no effective treatment was available. In the mid-1980s, all-trans retinoic acid (ATRA) monotherapy was used with high response rates, but response durations were short. Later, the development of ATRA, chemotherapy, and arsenic trioxide combinations turned APL into a highly curable malignancy. In this review, we summarize the evolution of APL therapy, focusing on key milestones that led to the standard-of-care APL therapy available today and discuss treatment algorithms and management tips to minimize induction mortality.

Therapy-related acute promyelocytic leukemia with FMS-like tyrosine kinase 3-internal tandem duplication mutation in solitary bone plasmacytoma: A case report

BACKGROUND

Therapy-related acute promyelocytic leukemia (t-APL) is a rare complication observed in solitary bone plasmacytoma (SBP), and SBP after radiotherapy evolving to APL harboring the FMS-like tyrosine kinase 3-internal tandem duplication (FLT3-ITD) mutation has never been reported. Here, we present the first case reported until now.

CASE SUMMARY

We describe a 64-year-old woman who presented with lumbar pain and was initially diagnosed with SBP. However, after one year of radiotherapy treatment, this patient experienced a long-standing bone-marrow-suppressive period and finally developed APL harboring the FLT3-ITD mutation, as confirmed by analyses of clinical features, bone marrow morphology, flow cytometry, cytogenetic examination, and molecular biology. On admission, the patient had disseminated intravascular coagulation and intracranial hemorrhage, and the peripheral blood and bone marrow smear displayed abundant abnormal promyelocytes. Unfortunately, she died when the definite diagnosis was made.

CONCLUSION

The patient with t-APL harboring FLT3-ITD mutation evolving from SBP after radiotherapy had not been reported and had poor clinical outcomes. FLT3-ITD mutation in t-APL may be a potential pathogenesis of leukemogenesis. We should consider the potential risk of secondary neoplasms in SBP patients after radiotherapy.

Acute Myeloid Leukemia, Version 3.2019, NCCN Clinical Practice Guidelines in Oncology

Acute myeloid leukemia (AML) is the most common form of acute leukemia among adults and accounts for the largest number of annual deaths due to leukemias in the United States. Recent advances have resulted in an expansion of treatment options for AML, especially concerning targeted therapies and low-intensity regimens. This portion of the NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for AML focuses on the management of AML and provides recommendations on the workup, diagnostic evaluation and treatment options for younger (age <60 years) and older (age ≥60 years) adult patients.

Therapy-related myelodysplastic syndromes deserve specific diagnostic sub-classification and risk-stratification-an approach to classification of patients with t-MDS

In the current World Health Organization (WHO)-classification, therapy-related myelodysplastic syndromes (t-MDS) are categorized together with therapy-related acute myeloid leukemia (AML) and t-myelodysplastic/myeloproliferative neoplasms into one subgroup independent of morphologic or prognostic features. Analyzing data of 2087 t-MDS patients from different international MDS groups to evaluate classification and prognostication tools we found that applying the WHO classification for p-MDS successfully predicts time to transformation and survival (both p < 0.001). The results regarding carefully reviewed cytogenetic data, classifications, and prognostic scores confirmed that t-MDS are similarly heterogeneous as p-MDS and therefore deserve the same careful differentiation regarding risk. As reference, these results were compared with 4593 primary MDS (p-MDS) patients represented in the International Working Group for Prognosis in MDS database (IWG-PM). Although a less favorable clinical outcome occurred in each t-MDS subset compared with p-MDS subgroups, FAB and WHO-classification, IPSS-R, and WPSS-R separated t-MDS patients into differing risk groups effectively, indicating that all established risk factors for p-MDS maintained relevance in t-MDS, with cytogenetic features having enhanced predictive power. These data strongly argue to classify t-MDS as a separate entity distinct from other WHO-classified t-myeloid neoplasms, which would enhance treatment decisions and facilitate the inclusion of t-MDS patients into clinical studies.

Genomic analysis of biomarkers related to the prognosis of acute myeloid leukemia

Acute myeloid leukemia (AML) is the most common childhood cancer and is a major cause of morbidity among adults with hematologic malignancies. Several novel genetic alterations, which target critical cellular pathways, including alterations in lymphoid development-regulating genes, tumor suppressors and oncogenes that contribute to leukemogenesis, have been identified. The present study aimed to identify molecular markers associated with the occurrence and poor prognosis of AML. Information on these molecular markers may facilitate prediction of clinical outcomes. Clinical data and RNA expression profiles of AML specimens from The Cancer Genome Atlas database were assessed. Mutation data were analyzed and mapped using the maftools package in R software. Kyoto Encyclopedia of Genes and Genomes, Reactome and Gene Ontology analyses were performed using the clusterProfiler package in R software. Furthermore, Kaplan-Meier survival analysis was performed using the survminer package in R software. The expression data of RNAs were subjected to univariate Cox regression analysis, which demonstrated that the mutation loads varied considerably among patients with AML. Subsequently, the expression data of mRNAs, microRNAs (miRNAs/miR) and long non-coding RNAs (lncRNAs) were subjected to univariate Cox regression analysis to determine the the 100 genes most associated with the survival of patients with AML, which revealed 48 mRNAs and 52 miRNAs. The top 1,900 mRNAs (P<0.05) were selected through enrichment analysis to determine their functional role in AML prognosis. The results demonstrated that these molecules were involved in the transforming growth factor-β, SMAD and fibroblast growth factor receptor-1 fusion mutant signaling pathways. Survival analysis indicated that patients with AML, with high MYH15, TREML2, ATP13A2, MMP7, hsa-let-7a-2-3p, hsa-miR-362-3p, hsa-miR-500a-5p, hsa-miR-500b-5p, hsa-miR-362-5p, LINC00987, LACAT143, THCAT393, THCAT531 and KHCAT230 expression levels had a shorter survival time compared with those without these factors. Conversely, a high KANSL1L expression level in patients was associated with a longer survival time. The present study determined genetic mutations, mRNAs, miRNAs, lncRNAs and signaling pathways involved in AML, in order to elucidate the underlying molecular mechanisms of the development and recurrence of this disease.

Clinicopathological aspects of therapy-related acute myeloid leukemia and myelodysplastic syndrome

Therapy-related myeloid neoplasm (t-MN) is a rare but devastating consequence of chemotherapy and/or radiotherapy used for the treatment of solid cancers and various hematologic malignancies. Our current understanding of the etiology is that hematopoietic clones that are contemporaneous with the primary cancer and resistant to the cytotoxic exposure have the potential to undergo selective expansion and transformation to t-MN. Consequently, a large proportion of cases are associated with adverse risk factors, resulting in limited effective treatment options. Despite the emergence of some therapies with promising activity in t-MN, most effects are short-lived and allogeneic stem cell transplantation remains the only curative option for eligible patients. This review summarizes the current literature on t-AML and t-MDS, with the aim of providing practical recommendations on the clinical evaluation and management of these conditions.

Identification of the novel deletion-type PML-RARA mutation associated with the retinoic acid resistance in acute promyelocytic leukemia

All-trans retinoic acid (ATRA) and arsenic trioxide (ATO) are essential for acute promyelocytic leukemia (APL) treatment. It has been reported that mutations in PML-RARA confer resistance to ATRA and ATO, and are associated with poor prognosis. Although most PML-RARA mutations were point mutations, we identified a novel seven amino acid deletion mutation (p.K227_T233del) in the RARA region of PML-RARA in a refractory APL patient. Here, we analyzed the evolution of the mutated clone and demonstrated the resistance of the mutated clone to retinoic acid (RA). Mutation analysis of PML-RARA was performed using samples from a chemotherapy- and ATRA-resistant APL patient, and the frequencies of mutated PML-RARA transcript were analyzed by targeted deep sequencing. To clarify the biological significance of the identified PML-RARA mutations, we analyzed the ATRA-induced differentiation and PML nuclear body formation in mutant PML-RARA-transduced HL-60 cells. At molecular relapse, the p.K227_T233del deletion and the p.R217S point-mutation in the RARA region of PML-RARA were identified, and their frequencies increased after re-induction therapy with another type of retinoiec acid (RA), tamibarotene. In deletion PML-RARA-transduced cells, the CD11b expression levels and NBT reducing ability were significantly decreased compared with control cells and the formation of PML nuclear bodies was rarely observed after RA treatment. These results indicate that this deletion mutation was closely associated with the disease progression during RA treatment.

Characteristics and outcome of patients with therapy-related acute promyelocytic leukemia front-line treated with or without arsenic trioxide

Therapy-related acute promyelocytic leukemia (t-APL) is relatively rare, with limited data on outcome after treatment with arsenic trioxide (ATO) compared to standard intensive chemotherapy (CTX). We evaluated 103 adult t-APL patients undergoing treatment with all-trans retinoic acid (ATRA) alone (n=7) or in combination with ATO (n=24), CTX (n=53), or both (n=19). Complete remissions were achieved after induction therapy in 57% with ATRA, 100% with ATO/ATRA, 78% with CTX/ATRA, and 95% with CTX/ATO/ATRA. Early death rates were 43% for ATRA, 0% for ATO/ATRA, 12% for CTX/ATRA and 5% for CTX/ATO/ATRA. Three patients relapsed, two developed therapy-related acute myeloid leukemia and 13 died in remission including seven patients with recurrence of the prior malignancy. Median follow-up for survival was 3.7 years. None of the patients treated with ATRA alone survived beyond one year. Event-free survival was significantly higher after ATO-based therapy (95%, 95% CI, 82-99%) as compared to CTX/ATRA (78%, 95% CI, 64-87%; P=0.042), if deaths due to recurrence of the prior malignancy were censored. The estimated 2-year overall survival in intensively treated patients was 88% (95% CI, 80-93%) without difference according to treatment (P=0.47). ATO when added to ATRA or CTX/ATRA is feasible and leads to better outcomes as compared to CTX/ATRA in t-APL.

Outcome of Patients With Therapy-Related Acute Myeloid Leukemia With or Without a History of Myelodysplasia

PURPOSE

To learn whether an antecedent hematologic disorder (AHD) is associated with additional risk in patients with therapy-related acute myeloid leukemia (t-AML).

PATIENTS AND METHODS

We reviewed data of 301 patients with newly diagnosed t-AML who sought care from January 2000 to January 2014 (183 t-AML without AHD, 118 t-AML with AHD). Overall, median follow-up was 44 months.

RESULTS

The primary malignancy was non-Hodgkin lymphoma in 92 (31%), breast cancer in 80 (27%), and prostate cancer in 49 (16%). Median relapse-free survival (RFS) in t-AML without or with AHD was 10 months and 29 months, respectively (P = .032); median overall survival (OS) was 8 months and 8 months, respectively (P = .53). Multivariate analysis for OS identified older age, poor performance status, thrombocytopenia, nonfavorable cytogenetics, and lack of response as adverse factors.

CONCLUSION

The favorable-risk cohort had better RFS and OS compared to the outcomes of patients in the intermediate- and adverse-risk cohorts; the RFS and OS did not differ between intermediate- and adverse-risk cohorts. The presence of AHD did not affect OS.

CD34(+) therapy-related acute promyelocytic leukemia in a patient previously treated for breast cancer

Therapy-related acute myeloid leukemia (AML) is a long term complication of chemotherapy for a variety of cancers. In most cases, the marrow demonstrates high risk cytogenetics and the prognosis is poor. In a minority of patients "good risk" cytogenetics, including t(15;17)(q22;q12), are seen and the patient's prognosis is similar to those who have de novo disease. Currently we present a patient who developed therapy-related acute promyelocytic leukemia (APL) after chemoradiotherapy for breast cancer. This case was especially atypical because the leukemic cells were CD34(+), which is an unusual immunophenotype for APL. Recognition that this patient had APL, rather than the more common therapy-related MDS or AML, was imperative to initiate chemotherapy in a timely manner.

Secondary Adult Acute Myeloid Leukemia: a Review of Our Evolving Understanding of a Complex Disease Process

OPINION STATEMENT

Secondary AML (s-AML) encompasses AML evolving from myelodysplasia (AML-MDS) and treatment-related AML (t-AML) after exposure to chemotherapy, radiation, or environmental toxins. S-AML has traditionally been considered a devastating disease, affecting a vulnerable population of heavily pretreated, older adults. A limited understanding of disease pathogenesis/heterogeneity and lack of effective treatments have hampered overall improvements in patient outcomes. With the recent understanding that the secondary nature of sAML does not by itself incur a poor prognosis and incorporation of cytogenetics and molecular genetics into patient care and the advancement of treatment, including improved supportive care, novel chemotherapeutics agents, and nonmyeloablative conditioning regimens as part of allogeneic hematopoietic cell transplantation (HCT), modest gains in survival and quality of life are beginning to be seen among patients with s-AML.

Therapy-related acute myeloid leukemia in patients with lymphoma: A report of four cases and review of the literature

Due to advances in the treatment of lymphoma, the remission and overall survival rates for this disease have improved in recent years. However, the incidence of therapy-related myelodysplastic syndrome/acute myeloid leukemia (t-MDS/AML) has increased. In order to further the understanding of the mechanisms of t-MDS/AML and reduce its incidence, the present study reports 4 cases of t-AML following treatment for lymphoma. The 4 patients presented aggressive forms of lymphoma in stage III/IV, and 3 were diagnosed with non-Hodgkin's lymphoma. All patients had previously undergone chemotherapy containing alkylating agents and/or topoisomerase II inhibitors. The latency period between the time of primary diagnosis and occurrence of t-AML ranged from 15 to 42 months. At the time of diagnosis of t-AML, 3 of the 4 patients presented pancytopenia, whilst the remaining patient exhibited leukocytosis. The majority of the patients succumbed to their disease within 1 year of t-AML diagnosis, with the exception of the patient in case 3, who survived following allogeneic hematopoietic stem cell transplantation (allo-HSCT). The present cases indicate that an advanced stage of disease at the time of primary diagnosis, prior exposure to radiotherapy, and administration of ≥4 regimens and ≥8 cycles of chemotherapy may be risk factors for the development of t-AML. Based on the present findings and a review of the literature, we propose that allo-HSCT should be recommended for patients at high risk of developing t-AML. In addition, chimeric antigen receptor T-cell immunotherapy may constitute a novel type of immunotherapy for the treatment of cancer, particularly for cases of relapsed and refractory lymphoma or leukemia.

Survival of de novo and secondary acute promyelocytic leukemia: a propensity-matched analysis of the SEER database

Prior studies demonstrated that secondary acute promyelocytic leukemia (sAPL) and de novo APL may but not consistently have similar overall survival (OS). We used the Surveillance, Epidemiology, and End Results (SEER) 13 database to compare their OS. Patients with sAPL (n = 90), compared to de novo APL (n = 1600), were more likely to be older, White and diagnosed after year 2005. Mortality rate at 1 month (28.9% vs. 23.0%, p = 0.20) and 5-year OS (42% vs. 50%, p = 0.24) was similar between sAPL and de novo APL. In a multivariate analysis, sAPL was associated with similar OS as de novo APL (hazard ratio, HR 1.11; 95% confidence interval, CI 0.78-1.58; p = 0.546). This population-based study demonstrated no difference in OS or early mortality rate between sAPL and de novo APL. sAPL can be managed very similarly to de novo APL and does not need to be excluded from clinical trials of APL.

Outcomes of ovarian germ cell tumors: ten years of experience at the Brazilian National Cancer Institute

OBJECTIVE

Ovarian germ cell malignancies are a rare group of chemosensitive malignances that predominantly occur in young women. Bleomycin, etoposide, cisplatin (BEP) regimen was consolidated, by previous studies, as the standard treatment. This Brazilian single institutional study was performed to evaluate our experience in treating patients with ovarian germ cell tumors (OGCTs).

METHODS/MATERIALS

A retrospective analysis of all patients as having OGCTs, from April 2003 to July 2013, was carried out at the Brazilian National Cancer Institute.

RESULTS

Data on 30 patients were obtained, and 19 patients were treated with BEP. Median overall survival and progression-free survival were not reached. Just 4 (13.3%) patients had progressed and 5 (16.7%) had died up to the date of analysis. The proportion of patients who had dysgerminoma was 53.3%. From the 18 patients considered to have had an incomplete resection, 84.6% achieved objective response (partial or complete response) with chemotherapy. Patients with stage IV and incomplete resection had markedly ominous prognosis. Alopecia was the most frequent adverse event; grade 2 was presented in 17 (89.4%) patients. Nausea and vomiting were related by more than one-half of the patients. Grade 3 and 4 neutropenia was presented in 5 (26.3%) patients. One patient died of pneumonitis related to bleomycin.

CONCLUSIONS

Our study confirms the effectiveness of BEP regimen and the great prognosis for patients with OGCTs. Advanced-stage and persistent disease configured as an important risk factor for survival. The chemotherapy regimen was associated with significant but manageable toxicity.

Topoisomerase-mediated chromosomal break repair: an emerging player in many games

The mammalian genome is constantly challenged by exogenous and endogenous threats. Although much is known about the mechanisms that maintain DNA and RNA integrity, we know surprisingly little about the mechanisms that underpin the pathology and tissue specificity of many disorders caused by defective responses to DNA or RNA damage. Of the different types of endogenous damage, protein-linked DNA breaks (PDBs) are emerging as an important player in cancer development and therapy. PDBs can arise during the abortive activity of DNA topoisomerases, a class of enzymes that modulate DNA topology during several chromosomal transactions, such as gene transcription and DNA replication, recombination and repair. In this Review, we discuss the mechanisms underpinning topoisomerase-induced PDB formation and repair with a focus on their role during gene transcription and the development of tissue-specific cancers.

The evolving challenge of therapy-related myeloid neoplasms

Therapy-related myelodysplastic syndrome (t-MDS) and therapy-related acute myeloid leukemia (t-AML) are late complications of cytotoxic therapies used to treat malignant, and increasingly, non-malignant conditions. Although distinct clinical, morphologic, and genetic features can be recognized, these disorders should be seen as part of a single disease spectrum recognized by the WHO in a singular classification, therapy-related myeloid neoplasms (t-MNs). Etiologic factors for t-MNs remain elusive, but ongoing research has characterized risk factors which vary between patient subgroups and exposures. Agents that damage DNA directly, interfere with DNA repair, and suppress the immune system's ability to detect malignant cells increase the risk of t-MNs. As in primary MDS and de novo AML, prognosis and treatment strategies rely on patient characteristics as well as cytogenetics. However, the overall outcome for patients with t-MNs remains poor. Here we review our current understanding of t-MNs as they are most often encountered by the practicing clinician.

Evaluation of prognostic factors in patients with therapy-related acute myeloid leukemia

Background

Therapy-related AML (t-AML) occurs as a late complication of chemotherapy administered to treat a prior disorder. Prognostic factors affecting the clinical outcome in t-AML have not yet been clearly defined; therefore, we evaluated these factors in this study.

Methods

Forty-eight patients diagnosed with t-AML within the past 10 years were enrolled, and their chemotherapy regimens categorized into 4 groups: alkylating agents (AK) only, topoisomerase II inhibitors (TI) and AK, TI only, and others. The prognostic factors affecting clinical outcome were evaluated.

Results

Five (10.4%), 21 (43.8%), 9 (18.8%), and 13 (27.0%) patients were treated with AK only, AK and TI, TI only, and others, respectively. Patients with an AML M3 phenotype showed significantly longer overall survival (OS; 55.1 vs. 14.3 months, P=0.040) and disease-free survival (DFS; 61.2 vs. 17.5 months, P=0.049) than other phenotypes. In contrast, patients with a complex karyotype showed significantly shorter OS (7.9 vs. 31.3 months, P=0.008) and DFS (9.5 vs. 38.6 months, P=0.046); additionally, patients with chromosome 5 or 7 abnormalities showed significantly shorter OS (9.1 vs. 30.7 months, P=0.011) than other phenotypes. Only the presence of a complex karyotype or AML M3 phenotype retained prognostic impact in a multivariate analysis.

Conclusion

Only the AML M3 phenotype was identified as having a good prognosis, and this might suggest that it exhibits unique clinical features in t-AML patients. Moreover, our findings indicated that karyotype was the strongest prognostic indicator and predicted a poor prognosis for t-AML patients with a complex karyotype.

Inclusion of hemoglobin level in prognostic score provides better prognostic stratification in patients with acute promyelocytic leukemia (APL)

The clinical outcomes of acute promyelocytic leukemia (APL) have improved greatly, but treatment failure still occurs. Identification of patients with poor prognosis is fundamental, and we propose a new clinical prognostic system (CBC-score) consisting of WBC, platelet count, and hemoglobin level. Between 1995 and 2009, 156 patients with APL from seven institutes in Korea were retrospectively reviewed. In the new CBC-score system, each of the following (WBC ≥ 10 × 109/L, platelet <40 × 109/L, hemoglobin <8.0 g/dL) was considered as a risk factor; the sum of each was designated as the CBC-score. With a median follow-up of 8.4 years, the complete remission (CR) rate was 81.4 % (127/156), while 24 (15.4 %) were considered as treatment failures due to early death (ED). The 5-year overall survival (OS), leukemia-free survival, and cumulative incidence of relapse were 73.8, 82.8, and 13.5 %, respectively. Compared to the individual CBC parameters, combined prognostic systems such as PETHEMA or CBC-score provided better prognostic stratification. Compared to PETHEMA stratification, the proposed prognostic CBC-score system showed better stratification of APL patients in terms of CR rates (p = 0.004), OS (p = 0.004), and ED (p = 0.008). This retrospective study suggests that the proposed CBC-score may provide better prognostic stratification of APL patients.

Therapy-related acute myeloid leukemia with favorable cytogenetics: still favorable?

Therapy-related acute myeloid leukemia (t-AML) is occasionally associated with favorable risk cytogenetics including core binding factor AML and acute promyelocytic leukemia (APL). It is unclear if these leukemias have the same favorable outcomes as their de novo counterparts. Interpretation of published data is difficult due to lack of data on the contribution of the original neoplasm as well as its treatment to overall mortality. Based on available evidence, we conclude that t-AML with favorable risk cytogenetics have superior outcomes among t-AMLs and should be treated similar to de novo AML in patients who are candidates for definitive therapy. Therapy-related APL has similar outcome as de novo APL. There is no evidence at the present time to support the routine use of allogeneic HSCT in first complete remission in t-AML with favorable cytogenetics.

DNA damage and repair in human cancer: molecular mechanisms and contribution to therapy-related leukemias

Most antitumour therapies damage tumour cell DNA either directly or indirectly. Without repair, damage can result in genetic instability and eventually cancer. The strong association between the lack of DNA damage repair, mutations and cancer is dramatically demonstrated by a number of cancer-prone human syndromes, such as xeroderma pigmentosum, ataxia-telangiectasia and Fanconi anemia. Notably, DNA damage responses, and particularly DNA repair, influence the outcome of therapy. Because DNA repair normally excises lethal DNA lesions, it is intuitive that efficient repair will contribute to intrinsic drug resistance. Unexpectedly, a paradoxical relationship between DNA mismatch repair and drug sensitivity has been revealed by model studies in cell lines. This suggests that connections between DNA repair mechanism efficiency and tumour therapy might be more complex. Here, we review the evidence for the contribution of carcinogenic properties of several drugs as well as of alterations in specific mechanisms involved in drug-induced DNA damage response and repair in the pathogenesis of therapy-related cancers.

Bleeding and thrombosis in acute promyelocytic leukemia

Acute promyelocytic leukemia (APL) has evolved from being a deadly to a highly curable disease, due to targeted molecular therapy with all-trans retinoic acid (ATRA). As a result, the incidence of early hemorrhagic deaths for which APL is notorious has reduced to 5-10% as reported in clinical trials. These results are not replicated outside of clinical trials as is evident from recent population-based registries. High incidence of early hemorrhagic deaths remains the greatest contributor to treatment failure in this otherwise curable leukemia. Additionally, thrombosis is now being increasingly recognized in APL patients and may be associated with ATRA usage.

Acute myeloid leukemia developing in patients with autoimmune diseases

Therapy-related acute myeloid leukemia is an unfortunate complication of cancer treatment, particularly for patients with highly curable primary malignancies and favorable life expectancy. The risk of developing therapy-related acute myeloid leukemia also applies to patients with non-malignant conditions, such as autoimmune diseases treated with cytotoxic and/or immunosuppressive agents. There is considerable evidence to suggest that there is an increased occurrence of hematologic malignancies in patients with autoimmune diseases compared to the general population, with a further increase in risk after exposure to cytotoxic therapies. Unfortunately, studies have failed to reveal a clear correlation between leukemia development and exposure to individual agents used for the treatment of autoimmune diseases. Given the dismal outcome of secondary acute myeloid leukemia and the wide range of available agents for treatment of autoimmune diseases, an increased awareness of this risk and further investigation into the pathogenetic mechanisms of acute leukemia in autoimmune disease patients are warranted. This article will review the data available on the development of acute myeloid leukemia in patients with autoimmune diseases. Possible leukemogeneic mechanisms in these patients, as well as evidence supporting the association of their primary immunosuppressive status and their exposure to specific therapies, will also be reviewed. This review also supports the idea that it may be misleading to label leukemias that develop in patients with autoimmune diseases who are exposed to cytotoxic agents as 'therapy-related leukemias'. A better understanding of the molecular defects in autoimmune disease patients who develop acute leukemia will lead to a better understanding of the association between these two diseases entities.

Therapy-related acute promyelocytic leukemia: observations relating to APL pathogenesis and therapy

Therapy-related acute promyelocytic leukemia (t-APL) is a well-recognized form of APL for which the underlying etiology has been well characterized. The pathogenesis of de novo (dn-APL) remains unknown; but epidemiologic studies have consistently identified increased body mass index (BMI), younger age, and ethnicity as possible risk factors. We analyzed demographics, clinical features, and treatment responses in a contemporary series of 64 patients treated with all-trans-retinoic acid and anthracycline-based therapy to assess for differences in these two etiologically distinct patient groups. Compared with patients with t-APL (n = 11), those with dn-APL (n = 53) had a greater median BMI (31.33 vs. 28.48), incidence of obesity (60.4% vs. 27.3%) (P = 0.04), and history of hyperlipidemia (45.3% vs. 18.2%) (P = 0.01). Fewer t-APL than dn-APL patients achieved complete remission at 63.6% vs. 92.5% respectively (P = 0.008). This was the result of a higher induction mortality rate of 36.4% vs. 7.5% respectively (P = 0.008). No cases of leukemic resistance were seen in either group. Overall survival (OS) was inferior in t-APL compared with dn-APL at 51% vs. 84%, respectively (P < 0.005), primarily as a result of higher induction mortality. Relapse occurred in nine patients (16.1%) overall, but no relapses occurred in the t-APL cohort. Our observations provide further support for the hypothesis that abnormalities in lipid homeostasis may in some way be of pathogenic importance in dn-APL. Therapy-related APL is sensitive to standard therapy with no cases of resistance or relapse seen. The inferior OS of the t-APL was due to induction mortality, possibly reflecting prior therapy.

Molecular pathogenesis of secondary acute promyelocytic leukemia

Balanced chromosomal translocations that generate chimeric oncoproteins are considered to be initiating lesions in the pathogenesis of acute myeloid leukemia. The most frequent is the t(15;17)(q22;q21), which fuses the PML and RARA genes, giving rise to acute promyelocytic leukemia (APL). An increasing proportion of APL cases are therapy-related (t-APL), which develop following exposure to radiotherapy and/or chemotherapeutic agents that target DNA topoisomerase II (topoII), particularly mitoxantrone and epirubicin. To gain insights into molecular mechanisms underlying the formation of the t(15;17) we mapped the translocation breakpoints in a series of t-APLs, which revealed significant clustering according to the nature of the drug exposure. Remarkably, in approximately half of t-APL cases arising following mitoxantrone treatment for breast cancer or multiple sclerosis, the chromosome 15 breakpoint fell within an 8-bp “hotspot” region in PML intron 6, which was confirmed to be a preferential site of topoII-mediated DNA cleavage induced by mitoxantrone. Chromosome 15 breakpoints falling outside the “hotspot”, and the corresponding RARA breakpoints were also shown to be functional topoII cleavage sites. The observation that particular regions of the PML and RARA loci are susceptible to topoII-mediated DNA damage induced by epirubicin and mitoxantrone may underlie the propensity of these agents to cause APL.

Acute promyelocytic leukemia with a smoldering course associated with therapy-related myelodysplastic syndrome

Acute promyelocytic leukemia (APL) may appear rarely as a late complication of the treatment of other primary cancers. Therapy-related APL (tAPL) differs from de novo APL in epidemiological and clinical parameters but shares common molecular signatures and does not differ in survival end- points. We describe a 67-year-old female patient who presented with an atypical course of tAPL. Atypical features in this patient's course included a preceding therapy-related myelodysplastic syndrome (MDS) with a slowly expanding pathological promyelocyte clone. Following treatment with all-trans-retinoic acid and arsenic trioxide, the patient achieved complete clinical, morphological and molecular remission. Review of the pertinent literature highlights the rarity of MDS transforming into APL, although dysplasia has been shown to be a possible feature of tAPL. MDS may be an underdiagnosed stage in tAPL leukomogenesis. This case also underscores the complexity of clinical decision-making in the context of tAPL.

Presenting features and treatment outcome of acute promyelocytic leukemia arising after multiple sclerosis

We report the clinical features and treatment outcome of 33 patients with multiple sclerosis who developed acute promyelocytic leukemia. Thirty patients were previously exposed to mitoxantrone. The median latency period between treatment initiation and acute promyelocytic leukemia diagnosis was 32 months. The PML-RARA bcr1 iso-form was identified in 87% of cases. Twenty-nine (90%) patients achieved hematologic remission after all-trans retinoic acid and chemotherapy (n = 31) or arsenic trioxide and all-trans retinoic acid. Consolidation included modified chemotherapy or arsenic trioxide. At a median follow up of 26 months, 23 patients are in complete remission, 4 relapsed and one developed secondary leukemia. The 5-year cumulative incidence of relapse and overall survival were 23% and 68%, respectively. Although treatment heterogeneity and suboptimal post-remission therapy must be taken into account, overall results and development of secondary leukemia in one patient suggest that effective and less toxic agents like arsenic trioxide warrants further investigation in this context.

[Mitoxantrone-related acute leukemia by multiple sclerosis. Case report and practical approach by unclear cytopenia]

BACKGROUND

Mitoxantrone is highly efficacious in the treatment of severe multiple sclerosis (MS). Mitoxantrone therapy-related acute leukemia (TRAL) has recently become the focus of interest.

METHODS

A case report of fatal TRAL following mitoxantrone therapy is presented with a discussion on the differential diagnosis and risk factors. The interdisciplinary development of diagnostic and therapeutic algorithms is presented from a haematological and neurological point of view.

RESULTS

We describe the case of a 34-year-old MS patient who developed TRAL following mitoxantrone therapy (cumulative dose 45 mg/m(2) body surface). The patient died from endocarditis. TRAL is a rare but potentially fatal complication of mitoxantrone therapy with a wide variation of reported incidence. Thus far, no specific risk factors relating for example to preceding therapy and treatment regimens have been identified. Frequent laboratory controls and early bone marrow aspiration are mandatory for suspected TRAL as the condition is potentially curable.

CONCLUSIONS

TRAL needs to be considered in the risk-benefit assessment of mitoxantrone therapy, however, the exact incidence and risk factors (e.g. dosage, treatment regimen) are still unclear. The risks are controllable under close surveillance and early diagnosis is important for prognosis. Future investigations need to concentrate on identification of potential risk factors.

Outcome of therapy-related acute promyelocytic leukemia with or without arsenic trioxide as a component of frontline therapy

BACKGROUND

Patients with therapy-related acute promyelocytic leukemia (t-APL) have been commonly exposed to topoisomerase inhibitors and may potentially benefit from induction regimens omitting anthracyclines.

METHODS

Retrospective analysis of the outcomes of 29 patients with t-APL who were either treated with arsenic trioxide (ATO) and all-trans-retinoic acid (ATRA) or with standard ATRA plus anthracycline-based chemotherapy was performed.

RESULTS

Prior therapy included chemotherapy alone, radiation alone, or a combination of the 2 in 19%, 33%, and 47% of patients, respectively. The combination of ATO and ATRA (n = 19) for induction resulted in a similar remission rate compared with ATRA plus chemotherapy (n = 10) (89% vs 70%; P = .35). The median overall survival for the patients treated with ATRA plus ATO was not reached compared with that for patients treated with ATRA plus chemotherapy (161 weeks; P = .79).

CONCLUSIONS

In this cohort of t-APL patients, outcomes with ATO and ATRA appeared to be comparable to anthracycline-containing induction regimens. This combination may be preferable in t-APL patients to avoid any risk of anthracycline-induced toxicities.

Hematopoietic stem cell transplantation for therapy-related myelodysplastic syndrome and acute leukemia: a single-center analysis of 47 patients

The prognosis of therapy-related myelodysplastic syndrome and acute leukemia (t-MDS/AL) remains poor. We retrospectively analyzed the data of 47 patients (31 AL and 16 MDS) who were treated at our institute. Thirty-three patients received disease-adapted chemotherapy, with a response rate of 73%, while 14 received no interventions due to an indolent course, such as MDS. The median follow-up of surviving patients was 1.9 years (range 0.1-10.5) after the diagnosis of t-MDS/AL, and the estimated 3-year overall survival (OS) for all patients was 55%. Twenty-seven patients underwent allogeneic hematopoietic stem cell transplantation (HCT), and the 3-year non-relapse mortality was 17%. Twenty patients did not undergo HCT due to various reasons including advanced age or comorbidities. The 3-year OS was better in patients who received HCT than in those who did not (71 vs. 31%; p = 0.018). A multivariate analysis revealed that HCT was associated with a better OS. Although this study has several limitations, including a potential selection bias due to the retrospective nature of the analysis and a small number of patients, the results show that modern HCT may be useful for inducing long-term survival in a fraction of patients suffering from t-MDS/AL. The present findings warrant future prospective studies.

Acute leukemia in women

The treatment and survival outcome of acute leukemia in women is generally similar to that of men. However, acute leukemia in women poses additional challenges in clinical practice. In addition to important precautions during therapy, such as prevention of abnormal uterine bleeding in premenopausal women and therapy during pregnancy, women who are survivors of acute leukemia face unique and potentially long-term health-related problems. In this review, we address the aforementioned issues, as well as the various health and psychosocial challenges faced by women who survive childhood leukemia during their path to adulthood. Finally, we address the issue of therapy-related acute leukemia in the category of women who are survivors of breast and ovarian cancer.

[Special issues related to the treatment of acute leukemias in women]

The treatment of acute leukemia is usually similar in women and men. The outcome is also generally the same. However, diagnosis in women poses additional challenges in clinical practice such as leukemia following breast or ovarian cancers, prevention of abnormal uterine bleeding in premenopausal females, treatment during pregnancy related-problems in long-term survivors. All these special issues are addressed in this review of the literature.