Allogeneic hematopoietic cell transplantation for fanconi anemia in patients with pretransplantation cytogenetic abnormalities, myelodysplastic syndrome, or acute leukemia

T-cell depleted allogeneic hematopoietic stem cell transplant for the treatment of Fanconi anemia and MDS/AML

The only curative approach for myelodysplastic syndrome (MDS) or acute myeloid leukemia (AML) arising in patients with Fanconi anemia (FA) is allogeneic hematopoietic stem cell transplantation (HCT); however, HCT approaches are inconsistent and limited data on outcomes exist. We retrospectively evaluated outcomes of thirty patients with FA and MDS/AML who underwent first allogeneic HCT with a T-cell depleted (TCD) graft at our institution. Patients were transplanted on successive protocols with stepwise changes in cytoreduction and GVHD prophylaxis. All but two patients (93%) experienced durable hematopoietic engraftment. With median follow-up of 8.7 years, 5-year OS was 66.8% and DFS 53.8%. No significant differences in survival were found in patients with high-risk prognostic features (age ≥20 years, AML diagnosis, alternative donor graft) or when stratified by conditioning regimen. The 5-year cumulative incidences of relapse and NRM were 24.3% and 21.9%, respectively. NRM was higher in patients ≥20 years at HCT but did not otherwise differ. We herein demonstrate promising outcomes following allogeneic HCT for patients with FA and MDS/AML using TCD grafts, particularly in a cohort of high-risk patients with 50% ≥20 years and a majority receiving mismatched grafts. Future prospective studies are needed to compare this approach with other HCT platforms.

Pediatric Bone Marrow Failure: A Broad Landscape in Need of Personalized Management

Irreversible severe bone marrow failure (BMF) is a life-threatening condition in pediatric patients. Most important causes are inherited bone marrow failure syndromes (IBMFSs) and (pre)malignant diseases, such as myelodysplastic syndrome (MDS) and (idiopathic) aplastic anemia (AA). Timely treatment is essential to prevent infections and bleeding complications and increase overall survival (OS). Allogeneic hematopoietic stem cell transplantation (HSCT) provides a cure for most types of BMF but cannot restore non-hematological defects. When using a matched sibling donor (MSD) or a matched unrelated donor (MUD), the OS after HSCT ranges between 60 and 90%. Due to the introduction of post-transplantation cyclophosphamide (PT-Cy) to prevent graft versus host disease (GVHD), alternative donor HSCT can reach similar survival rates. Although HSCT can restore ineffective hematopoiesis, it is not always used as a first-line therapy due to the severe risks associated with HSCT. Therefore, depending on the underlying cause, other treatment options might be preferred. Finally, for IBMFSs with an identified genetic etiology, gene therapy might provide a novel treatment strategy as it could bypass certain limitations of HSCT. However, gene therapy for most IBMFSs is still in its infancy. This review summarizes current clinical practices for pediatric BMF, including HSCT as well as other disease-specific treatment options.

RUNX1 mutations mitigate quiescence to promote transformation of hematopoietic progenitors in Fanconi anemia

Many inherited bone marrow failure syndromes (IBMFSs) present a high risk of transformation to myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML). During transformation of IBMFSs, hematopoietic stem and progenitor cells (HSPCs) with poor fitness gain ectopic, dysregulated self-renewal secondary to somatic mutations via undefined mechanisms. Here, in the context of the prototypical IBMFS Fanconi anemia (FA), we performed multiplexed gene editing of mutational hotspots in MDS-associated genes in human induced pluripotent stem cells (iPSCs) followed by hematopoietic differentiation. We observed aberrant self-renewal and impaired differentiation of HSPCs with enrichment of RUNX1 insertions and deletions (indels), generating a model of IBMFS-associated MDS. We observed that compared to the failure state, FA MDS cells show mutant RUNX1-mediated blunting of the G1/S cell cycle checkpoint that is normally activated in FA in response to DNA damage. RUNX1 indels also lead to activation of innate immune signaling, which stabilizes the homologous recombination (HR) effector BRCA1, and this pathway can be targeted to abrogate viability and restore sensitivity to genotoxins in FA MDS. Together, these studies develop a paradigm for modeling clonal evolution in IBMFSs, provide basic understanding of the pathogenesis of MDS, and uncover a therapeutic target in FA-associated MDS.

Fludarabine-Based Low-Intensity Conditioning for Fanconi Anemia is Associated with Good Outcomes in Aplastic Anemia but not in MDS - a Single-Center Experience

Background

Hematopoietic stem cell transplantation (HSCT) is the only curative option for patients with Fanconi Anemia (FA) with hematological abnormalities.

Materials and Methods

This is a retrospective analysis of patients with FA who underwent a matched-related donor HSCT.

Results

Sixty patients underwent 65 transplants between 1999-2021 using a fludarabine-based low-intensity conditioning regimen. The median age at transplant was 11 years (range: 3-37). Aplastic anemia (AA) was the underlying diagnosis in 55 (84.6%), while 8 (12.4%) had myelodysplastic syndrome (MDS) and 2 (3%) had acute myeloid leukemia (AML). The conditioning regimen used was Fludarabine with low-dose Cyclophosphamide for aplastic anemia and Fludarabine with low-dose Busulfan for MDS/AML. Graft versus host disease (GVHD) prophylaxis consisted of Cyclosporine and methotrexate. Peripheral blood was the predominant stem cell graft source (86.2%). Engraftment occurred in all but one patient. The median time to neutrophil and platelet engraftment was 13 days (range: 9-29) & 13 days (range: 5-31), respectively. Day 28 chimerism analysis showed complete chimerism in 75.4 % and mixed chimerism in 18.5%. Secondary graft failure was encountered in 7.7%. Grade II-IV acute GVHD occurred in 29.2%, while Grade III-IV acute GVHD occurred in 9.2%. Chronic GVHD was seen in 58.5% and was limited in most patients. The median follow-up is 55 months (range: 2-144) & the 5-year estimated overall survival (OS) is 80.2 ± 5.1%. Secondary malignancies were noted in 4 patients. The 5-year OS was significantly higher in patients undergoing HSCT for AA (86.6 + 4.7%) as compared to MDS/AML (45.7+16.6%) (p= 0.001).

Conclusion

SCT using a fully matched donor provides good outcomes with low-intensity conditioning regimens in patients with FA who have aplastic marrow.

Clinical observation on the safety and efficacy of umbilical cord mesenchymal stem cells in the treatment of bronchiolitis obliterans after allogeneic haematopoietic stem cell transplantation

Graft-versus-host disease (GVHD) is caused by a pathologic and destructive response of the organism as a result of the interaction between donor immunocompetent T lymphocytes and the recipient tisular antigens1. Graft-versus-host disease is considered a serious complication of hematopoietic stem cell transplantation. The skin, oral cavity and lungs are commonly affected organs. Among these complications bronchiolitis obliterans syndrome is a serious complication, which even can be life-threatening. Therefore, this research aims to do a clinical observation on the safety and efficacy of umbilical cord mesenchymal stem cells in the treatment of bronchiolitis obliterans after allogeneic haematopoietic stem cell transplantation. Fifteen patients were included in this study, who received allogeneic hematopoietic stem cell transplantation. Among these patients, both of them were treated with azithromycin, montelukast, glucocorticoid and pirfenidone. Two of them did not receive second line anti-rejection treatment due to economic reasons, and three of them were treated with mesenchymal stem cells. These bronchiolitis obliterans syndrome-related symptoms such as shortness of breath, chest tightness and wheezing have improved. Two of them died due to bronchiolitis obliterans syndrome related complications such as respiratory failure. Two of them not only improve the symptoms but also increased the FEV1/FVC, who were treated with mesenchymal stem cells. The comprehensive treatment regimen containing imatinib and ruxolitinib is safe and effective and mesenchymal stem cell is a promising treatment option to improve the prognosis of post-HSCT BOS.

Two decades of stem cell transplantation in patients with Fanconi anemia: Analysis of factors affecting transplant outcomes

Allogeneic hematopoietic stem cell transplantation (HSCT) is currently the only curative treatment for the hematological complications of patients with Fanconi anemia (FA). Over the last two decades, HSCT outcomes have improved dramatically following the development of regimens tailored for FA patients. In this study, we analyzed genetic, clinical, and transplant data of 41 patients with FA who underwent HSCT at Hadassah Medical Center between November 1996 and September 2020. Overall survival (OS) was 82.9% with a median follow-up time of 2.11-years (95% CI, .48-16.56). Thirteen patients (31.7%) developed acute graft-versus-host disease (GVHD), three of them with grades 3-4. Nine patients developed chronic GVHD, five had extensive disease. Twelve patients (29.3%) developed stable mixed-chimerism with complete resolution of bone marrow failure (BMF); none of them had acute nor chronic GVHD. Significantly higher GVHD rates were observed in transplants from peripheral blood stem cell grafts as compared to other stem cell sources (p = .002 for acute and p = .004 for chronic GVHD). Outcome parameters were comparable between HSCT from matched-sibling (n = 20) to other donors (n = 21), including survival rates (p = .1), time to engraftment (p = .69 and p = .14 for neutrophil and platelet engraftment time, respectively), chimerism status (p = .36 and p = .83 for full-donor and mixed chimerism, respectively), and GVHD prevalence (p = 1). Our results demonstrate the vast improvements in HSCT outcomes of patients with FA, narrowing the gap between matched-sibling versus alternative donor transplantations. Our data identifies factors that may significantly affect transplant outcomes such as graft source and chimerism status.

Modern management of Fanconi anemia

In this review, we present a clinical case report and discussion to outline the importance of long-term specific Fanconi anemia (FA) monitoring, and we discuss the main aspects of the general management of patients with FA and clinical complications. While several nontransplant treatments are currently under evaluation, hematopoietic stem cell transplantation (HSCT) remains the only therapeutic option for bone marrow failure (BMF). Although HSCT outcomes in patients with FA have remarkably improved over the past 20 years, in addition to the mortality intrinsic to the procedure, HSCT increases the risk and accelerates the appearance of late malignancies. HSCT offers the best outcome when performed in optimal conditions (moderate cytopenia shifting to severe, prior to transfusion dependence and before clonal evolution or myelodysplasia/acute myeloid leukemia); hence, an accurate surveillance program is vital. Haploidentical HSCT offers very good outcomes, although long-term effects on malignancies have not been fully explored. A monitoring plan is also important to identify cancers, particularly head and neck carcinomas, in very early phases. Gene therapy is still experimental and offers the most encouraging results when performed in early phases of BMF by infusing high numbers of corrected cells without genotoxic effects. Patients with FA need comprehensive monitoring and care plans, coordinated by centers with expertise in FA management, that start at diagnosis and continue throughout life. Such long-term follow-up is essential to detect complications related to the disease or treatment in this setting.

Cytogenetics in Fanconi Anemia: The Importance of Follow-Up and the Search for New Biomarkers of Genomic Instability

Fanconi Anemia (FA) is a disease characterized by genomic instability, increased sensitivity to DNA cross-linking agents, and the presence of clonal chromosomal abnormalities. This genomic instability can compromise the bone marrow (BM) and confer a high cancer risk to the patients, particularly in the development of Myelodysplastic Syndrome (MDS) and Acute Myeloid Leukemia (AML). The diagnosis of FA patients is complex and cannot be based only on clinical features at presentation. The gold standard diagnostic assay for these patients is cytogenetic analysis, revealing chromosomal breaks induced by DNA cross-linking agents. Clonal chromosome abnormalities, such as the ones involving chromosomes 1q, 3q, and 7, are also common features in FA patients and are associated with progressive BM failure and/or a pre-leukemia condition. In this review, we discuss the cytogenetic methods and their application in diagnosis, stratification of the patients into distinct prognostic groups, and the clinical follow-up of FA patients. These methods have been invaluable for the understanding of FA pathogenesis and identifying novel disease biomarkers. Additional evidence is required to determine the association of these biomarkers with prognosis and cancer risk, and their potential as druggable targets for FA therapy.

Unmanipulated haploidentical haematopoietic cell transplantation with radiation-free conditioning in Fanconi anaemia: A retrospective analysis from the Chinese Blood and Marrow Transplantation Registry Group

Haematopoietic cell transplantation (HCT) is the only curative treatment for haematological complications in patients with Fanconi anaemia (FA). Haploidentical (haplo-) HCT is a promising alternative for FA. We aimed to analyse the outcomes of unmanipulated haplo-HCT in patients with FA with radiation-free conditioning. A total of 56 patients from 11 centres between 2013 and 2021 in China were retrospectively analysed. The mean (SD) cumulative incidence was 96.4% (0.08%) for 30-day neutrophil engraftment and 85.5% (0.24%) for 100-day platelet engraftment. With a median (range) follow-up of 2.4 (0.2-5.8) years, favourable mean (SD) overall survival of 80.9% (5.5%) and event-free survival of 79.3% (5.6%) were achieved. The mean (SD) incidences of acute graft-versus-host disease (aGvHD) Grade II-IV and Grade III-IV were 55.4% (0.45%) and 42.9 (0.45%) respectively. The mean (SD) cumulative incidence of 3-year chronic graft-versus-host disease (cGvHD) was 34.7% (0.86%) and that of moderate-to-severe cGvHD was 9.0% (0.19%). Our data demonstrate that in unmanipulated haplo-HCT for patients with FA, radiation-free regimens based on fludarabine and low-dose cyclophosphamide ± busulfan achieved favourable engraftment and survival with relatively high incidences of aGvHD and cGvHD. These results prompt the use of low-intensity conditioning without radiation and intensive GvHD prophylaxis when considering unmanipulated haplo-HCT in patients with FA.

HLA - matched related donor hematopoietic stem cell transplantation in a patient with polynucleotide kinase 3-phosphatase mutation developed acute myeloid leukemia

BACKGROUND

PNPK gene mutations result in DNA repair disorders and have a spectrum of neurodevelopmental manifestations. To date, cancer predisposition has not been described in patients with PNKP mutations.

OBSERVATION

Here, we report a patient with PNKP mutation, who developed AML at age of five and underwent reduced-intensity HSCT.

CONCLUSION

Although many DNA repair disorders are known to have increased risk of malignancy, association between PNKP mutations and malignancy is not well-described. This report is the first description of a PNPK mutation patient developing a malignancy and undergoing curative HSCT.

Hematopoietic stem cell transplantation for classical inherited bone marrow failure syndromes: an update

INTRODUCTION

Inherited bone marrow failure syndromes (IBMFS) feature complex molecular pathophysiology resulting in ineffective hematopoiesis and increased risk of progression to myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML). Allogenic hematopoietic stem cell transplantation (HSCT) is the only well-established cure for the hematological manifestations of these diseases.

AREAS COVERED

In recent years, analysis of large series from international databases (mainly from the European Bone Marrow Transplantation [EBMT] database) has improved knowledge about HSCT in IBMFS. This review, following a thorough Medline search of the pertinent published studies, reports the most recent data on HSCT in IBMFS.

EXPERT OPINION

Despite the common features, IBMFS are very different in their manifestations and in the occurrence and management of HSCT complications. Thus, a 'disease-specific' HSCT using an optimized conditioning regimen based on the characteristics of the disease is essential for achieving long-term survival. The phenotypical heterogeneity associated with extramedullary abnormalities has to be carefully evaluated before HSCT because transplantation may only correct impaired hematopoiesis. HSCT may be associated with the risk of treatment-related mortality and with significant early and late morbidity. For these reasons, the benefits should be carefully weighed against the risks.

Survival and toxicity outcomes of hematopoietic stem cell transplantation for pediatric patients with Fanconi anemia: a unified multicentric national study from the Spanish Working Group for Bone Marrow Transplantation in Children

Hematopoietic stem cell transplantation (HSCT) is currently the only curative option for hematological manifestations in patients with Fanconi anemia (FA). We report the outcome of 34 patients with FA inside a collaborative multicenter national study based on recommendations of Spanish Working Group for Bone Marrow Transplantation in Children (GETMON) between 2009 and 2016. Fludarabine-based conditioning regimen was carried out in all patients, with low dose total body irradiation in unrelated transplants. Disease status before HSCT was bone marrow failure (BMF) in 30 patients and myelodysplastic syndrome (MDS) in four. Donors were matched siblings donors (MSD) in 18, matched unrelated donors (MUD) in 15, and one haploidentical donor. All except one patient engrafted. Cumulative incidence of grades II-IV acute graft-versus-host disease (GVHD) was 29% and 11% for chronic GVHD. Median follow-up after HSCT was 6.5 years. Seven patients (21%) died due to transplant-related causes, two (6%) because of MDS relapse, and one (3%) after a squamous cell carcinoma. Overall survival (OS) was 73% at 5 years post-transplant, with no differences between MSD and MUD transplants. OS for patients with BMF was 80% while for MDS was 25%. Our data suggest HSCT can cure hematologic manifestations of most FA patients with BMF.

Long-term outcome in patients with Fanconi anemia who received hematopoietic stem cell transplantation: a retrospective nationwide analysis

We retrospectively analyzed nationwide records of 163 Fanconi anemia (FA) patients [aplastic anemia (AA), n = 118; myelodysplastic syndrome (MDS), n = 30; acute leukemia, n = 15] who underwent first allogeneic hematopoietic stem cell transplantation (HSCT) between 1987 and 2015 in Japan. An alternative donor was used in 119 (73%) patients, and 160 (98%) patients received a non-T-cell-depleted graft. With an 8.7-year median follow-up, 5-year overall survival (OS) was 81%. The 5-year OS was significantly higher in AA patients than in MDS and acute leukemia patients (89%, 71%, and 44%, respectively). In the MDS/leukemia group, factors associated with poor outcome in univariate analysis were older age at HSCT (≥ 18 years), conditioning regimen without anti-thymocyte or lymphocyte globulin, and grade II-IV acute graft-versus-host disease. After 1 year, of 137 survivors, 15 developed subsequent malignancies, of whom 12 were diagnosed with head and neck (HN)/esophageal cancer. An irradiation regimen and older age were associated with the risk of HN/esophageal cancer. Five of seven deaths were attributed to subsequent malignancies more than 5 years after HSCT. On the basis of the risk factors for HSCT in MDS/leukemia patients and subsequent malignancies, a more effective HSCT approach is required.

Outcome of patients with Fanconi anemia developing myelodysplasia and acute leukemia who received allogeneic hematopoietic stem cell transplantation: A retrospective analysis on behalf of EBMT group

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is curative for bone marrow failure in patients with Fanconi anemia (FA), but the presence of a malignant transformation is associated with a poor prognosis and the management of these patients is still challenging. We analyzed outcome of 74 FA patients with a diagnosis of myelodysplastic syndrome (n = 35), acute leukemia (n = 35) or with cytogenetic abnormalities (n = 4), who underwent allo-HSCT from 1999 to 2016 in EBMT network. Type of diagnosis, pre-HSCT cytoreductive therapies and related toxicities, disease status pre-HSCT, donor type, and conditioning regimen were considered as main variables potentially influencing outcome. The 5-year OS and EFS were 42% (30-53%) and 39% (27-51%), respectively. Patients transplanted in CR showed better OS compared with those transplanted in presence of an active malignant disease (OS:71%[48-95] vs 37% [24-50],P = .04), while none of the other variables considered had an impact. Twenty-two patients received pre-HSCT cytoreduction and 9/22 showed a grade 3-4 toxicity, without any lethal event or negative influence on survival after HSCT(OS:toxicity pre-HSCT 48% [20-75%] vs no-toxicity 51% [25-78%],P = .98). The cumulative incidence of day-100 grade II-IV a-GvHD and of 5-year c-GvHD were 38% (26-50%) and 40% (28-52%). Non-relapse-related mortality and incidence of relapse at 5-years were 40% (29-52%) and 21% (11-30%) respectively, without any significant impact of the tested variables. Causes of death were transplant-related events in most patients (34 out of the 42 deaths, 81%). This analysis confirms the poor outcome of transformed FA patients and identifies the importance of achieving CR pre-HSCT, suggesting that, in a newly diagnosed transformed FA patient, a cytoreductive approach pre-HSCT should be considered if a donor have been secured.

Comprehensive analysis on phenotype and genetic basis of Chinese Fanconi anemia patients: dismal outcomes call for nationwide studies

Background

Fanconi anemia (FA) is the most common inherited bone marrow failure (BMF) syndrome with 22 related genes identified. The ALDH2 rs671variant has been proved related to accelerate the progression of BMF in FA patients. The phenotype and genetic basis of Chinese FA patients have not been investigated yet.

Methods

We analyzed the 22 FA-related genes of 63 BMF patients suspected to be FA. Clinical manifestations, morphological and cytogenetic feathers, ALDH2 genotypes, treatment, and outcomes of the definite cases were retrospectively studied.

Results

A total of 21 patients were confirmed the diagnosis of FA with the median age of BMF onset was 4-year-old. The number of patients manifested as congenital malformations and growth retardation were 20/21 and 14/21, respectively. BM dysplasia and cytogenetic abnormalities were found in 13/20 and 8/19 patients. All the patients with abnormal karyotypes also manifested as BM dysplasia or had evident blasts. Thirty-five different mutations were identified involving six genes and including twenty novel mutations. FANCA mutations contributed to 66.67% of cases. Eight patients harboring ALDH2-G/A genotype have a significantly younger age of BMF onset (p = 0.025). Within the 19 patients adhering to continuous follow-up, 15 patients underwent hematopoietic stem cell transplantations (HSCTs). During the 29 months of follow-up, 8/19 patients died, seven of which were HSCT-related, and one patient who did not receive HSCT died from severe infection.

Conclusions

The phenotypic and genetic spectrum of Chinese FA patients is broad. Bone marrow dysplasia and cytogenetic abnormalities are prevalent and highly consistent. The overall outcome of HSCTs is disappointing. Nationwide multicenter studies are needed for the rarity and adverse outcome of this disease.

Genetic Predisposition to Myelodysplastic Syndrome in Clinical Practice

Myelodysplastic syndromes (MDSs) are a heterogeneous group of marrow failure disorders that primarily affect older persons but also occur at a lower frequency in children and young adults. There is increasing recognition of an inherited predisposition to MDS as well as other myeloid malignancies for patients of all ages. Germline predisposition to MDS can occur as part of a syndrome or sporadic disease. The timely diagnosis of an underlying genetic predisposition in the setting of MDS is important. This article delineates germline genetic causes of MDS and provides a scaffold for the diagnosis and management of patients in this context.

Bone Marrow Failure in Fanconi Anemia: Clinical and Genetic Spectrum in a Cohort of 20 Pediatric Patients

Prognostic refinement in Fanconi anemia (FA) is needed, especially when considering allogeneic hematopoietic stem cell transplantation (HCT). We studied 20 children with FA and bone marrow failure from a single center. According to Hôpital Saint-Louis risk classification for FA, patients were classified in stage A (no or mild cytopenia/dysplasia), B (single non-high-risk cytogenetic abnormality), C (severe cytopenia and/or significant dysplasia and/or high-risk cytogenetic abnormality), and D (myelodysplastic syndrome with excess of blasts/acute myeloid leukemia) in 4, 2, 13, and 0 cases, respectively. Nine patients received androgens +/- steroids, with a response rate of 30%, and 11 patients underwent HCT. Ten-year cumulative incidence (CI) of myelodysplastic syndrome/acute myeloid leukemia and overall survival (OS) were 21.9% and 45.3%, respectively, in the entire cohort, whereas cumulative incidence of transplantation-related mortality and OS were 27% and 63%, respectively, in patients who underwent HCT. Patients with significant dysplasia at diagnosis (stages C and D) had significantly shorter OS post-HCT as compared with patients without dysplasia. All patients in stages C and D at diagnosis or during evolution died from their disease. HCT in recent years was associated with more favorable outcomes. Larger cohorts could validate homogenous reporting of risk and help decision-making, particularly for HCT.

Chromosome instability syndromes

Fanconi anaemia (FA), ataxia telangiectasia (A-T), Nijmegen breakage syndrome (NBS) and Bloom syndrome (BS) are clinically distinct, chromosome instability (or breakage) disorders. Each disorder has its own pattern of chromosomal damage, with cells from these patients being hypersensitive to particular genotoxic drugs, indicating that the underlying defect in each case is likely to be different. In addition, each syndrome shows a predisposition to cancer. Study of the molecular and genetic basis of these disorders has revealed mechanisms of recognition and repair of DNA double-strand breaks, DNA interstrand crosslinks and DNA damage during DNA replication. Specialist clinics for each disorder have provided the concentration of expertise needed to tackle their characteristic clinical problems and improve outcomes. Although some treatments of the consequences of a disorder may be possible, for example, haematopoietic stem cell transplantation in FA and NBS, future early intervention to prevent complications of disease will depend on a greater understanding of the roles of the affected DNA repair pathways in development. An important realization has been the predisposition to cancer in carriers of some of these gene mutations.

Myelodysplastic Syndrome, Acute Myeloid Leukemia, and Cancer Surveillance in Fanconi Anemia

Fanconi anemia (FA) is a DNA repair disorder associated with a high risk of cancer and bone marrow failure. Patients with FA may present with certain dysmorphic features, such as radial ray abnormalities, short stature, typical facies, bone marrow failure, or certain solid malignancies. Some patients may be recognized due to exquisite sensitivity after exposure to cancer therapy. FA is diagnosed by increased chromosomal breakage after exposure to clastogenic agents. It follows autosomal recessive and X-linked inheritance depending on the underlying genomic alterations. Recognizing patients with FA is important for therapeutic decisions, genetic counseling, and optimal clinical management.

Studies in an Early Development Window Unveils a Severe HSC Defect in both Murine and Human Fanconi Anemia

Fanconi anemia (FA) causes bone marrow failure early during childhood, and recent studies indicate that a hematopoietic defect could begin in utero. We performed a unique kinetics study of hematopoiesis in Fancg-/- mouse embryos, between the early embryonic day 11.5 (E11.5) to E12.5 developmental window (when the highest level of hematopoietic stem cells [HSC] amplification takes place) and E14.5. This study reveals a deep HSC defect with exhaustion of proliferative and self-renewal capacities very early during development, together with severe FA clinical and biological manifestations, which are mitigated at E14.5 due to compensatory mechanisms that help to ensure survival of Fancg-/- embryos. It also reports that a deep HSC defect is also observed during human FA development, and that human FA fetal liver (FL) HSCs present a transcriptome profile similar to that of mouse E12.5 Fancg-/- FL HSCs. Altogether, our results highlight that early mouse FL could represent a good alternative model for studying Fanconi pathology.

Associations of complementation group, ALDH2 genotype, and clonal abnormalities with hematological outcome in Japanese patients with Fanconi anemia

Fanconi anemia (FA) is a genetically and clinically heterogeneous disorder that predisposes patients to bone marrow failure (BMF), myelodysplastic syndromes (MDS), and acute myeloid leukemia (AML). To study which genetic and phenotypic factors predict clinical outcomes for Japanese FA patients, we examined the FA genes, bone marrow karyotype, and aldehyde dehydrogenase-2 (ALDH2) genotype; variants of which are associated with accelerated progression of BMF in FA. In 88 patients, we found morphologic MDS/AML in 33 patients, including refractory cytopenia in 16, refractory anemia with excess blasts (RAEB) in 7, and AML in 10. The major mutated FA genes observed in this study were FANCA (n = 52) and FANCG (n = 23). The distribution of the ALDH2 variant alleles did not differ significantly between patients with mutations in FANCA and FANCG. However, patients with FANCG mutations had inferior BMF-free survival and received hematopoietic stem cell transplantation (HSCT) at a younger age than those with FANCA mutations. In FANCA, patients with the c.2546delC mutation (n = 24) related to poorer MDS/AML-free survival and a younger age at HSCT than those without this mutation. All patients with RAEB/AML had an abnormal karyotype and poorer prognosis after HSCT; specifically, the presence of a structurally complex karyotype with a monosomy (n = 6) was associated with dismal prognosis. In conclusion, the best practice for a clinician may be to integrate the morphological, cytogenetic, and genetic data to optimize HSCT timing in Japanese FA patients.

Chromosomal Aberrations and Survival after Unrelated Donor Hematopoietic Stem Cell Transplant in Patients with Fanconi Anemia

Studies of chromosomal aberrations in blood or bone marrow of patients with Fanconi anemia (FA) have focused on their associations with leukemic transformation. The role of such abnormalities on outcomes after hematopoietic cell transplantation (HCT) is unclear. We used genome-wide single nucleotide polymorphism arrays to identify chromosomal aberrations in pre-HCT blood samples from 73 patients with FA who received unrelated donor HCT for severe aplastic anemia between 1991 and 2007. Outcome data and blood samples were available through the Center for International Blood and Marrow Transplant Research. For survival analyses, we used the Kaplan-Meier estimator to calculate the survival probabilities and the exact log-rank test to compare the survival differences across groups. Chromosomal aberrations were detected in 16 (22%) patients; most frequent were clonal copy loss in chromosome 7 (9.6%), clonal copy gains in the long arm (q) of chromosome 1 (chr1q⁺) (8.2%), and clonal or complete copy gains in the q arm of chromosome 3 (chr3q⁺) (8.2%). Seven (9.6%) patients had alterations in 3 or more chromosomes. Poor post-HCT overall survival (OS) was noted in patients with chr3q⁺ (P = .04), or those with abnormalities in ≥3 chromosomes (P = .03). The 1-year OS was 0% versus 45% in patients with either alteration versus its absence. No statistically significant differences in OS were noted in patients carrying deletions in chr7 (1-year OS = 29% versus 42%; log-rank P = .74). The study is limited by the small sample size. A larger, prospective study is warranted to validate our findings in light of recent improvement in transplant modalities and outcomes.

Evaluation of the Utility of Bone Marrow Morphology and Ancillary Studies in Pediatric Patients Under Surveillance for Myelodysplastic Syndrome

OBJECTIVES

To evaluate the utility of flow cytometry, karyotype, and a fluorescence in situ hybridization (FISH) panel in screening children for myelodysplastic syndrome (MDS).

METHODS

Bone marrow morphology, flow cytometry, karyotype, and FISH reports from 595 bone marrow specimens (246 patients) were analyzed.

RESULTS

By morphology, 8.7% of cases demonstrated at least unilineage dysplasia and/or increased blasts. Flow cytometry identified definitive abnormalities in 2.8% of cases, all of which had abnormal morphology. Of the 42 cases (7.2%) with acquired karyotypic abnormalities, 26 had no morphologic dysplasia. With a 98.2% concordance between karyotype and MDS FISH, FISH only identified two additional cases, both with low-level (<4%) abnormalities. Peripheral blood count evaluation only identified the absence of thrombocytopenia to correlate with an absence of abnormal ancillary tests.

CONCLUSIONS

The combination of morphologic evaluation and karyotype with judicious use of flow cytometry and MDS FISH is sufficient to detect abnormalities for these indications.

Transplant results in adults with Fanconi anaemia

The outcomes of adult patients transplanted for Fanconi anaemia (FA) have not been well described. We retrospectively analysed 199 adult patients with FA transplanted between 1991 and 2014. Patients were a median of 16 years of age when diagnosed with FA, and underwent transplantation at a median age of 23 years. Time between diagnosis and transplant was shortest (median 2 years) in those patients who had a human leucocyte antigen identical sibling donor. Fifty four percent of patients had bone marrow (BM) failure at transplantation and 46% had clonal disease (34% myelodysplasia, 12% acute leukaemia). BM was the main stem cell source, the conditioning regimen included cyclophosphamide in 96% of cases and fludarabine in 64%. Engraftment occurred in 82% (95% confidence interval [CI] 76-87%), acute graft-versus-host disease (GvHD) grade II-IV in 22% (95% CI 16-28%) and the incidence of chronic GvHD at 96 months was 26% (95% CI 20-33). Non-relapse mortality at 96 months was 56% with an overall survival of 34%, which improved with more recent transplants. Median follow-up was 58 months. Patients transplanted after 2000 had improved survival (84% at 36 months), using BM from an identical sibling and fludarabine in the conditioning regimen. Factors associated with improved outcome in multivariate analysis were use of fludarabine and an identical sibling or matched non-sibling donor. Main causes of death were infection (37%), GvHD (24%) and organ failure (12%). The presence of clonal disease at transplant did not significant impact on survival. Secondary malignancies were reported in 15 of 131 evaluable patients.

How I manage patients with Fanconi anaemia

Fanconi Anaemia is a rare, genetic heterogeneous multisystem disease that is the most common congenital syndrome of marrow failure. Twenty genes have been reported to cause the disease. Remarkable progress has been made over the last 20 years in the understanding of the genetic and pathophysiological mechanisms. Unfortunately, these advances have not been completely paralleled by advances in medical treatment, where the most important component remains stem cell transplantation. This therapy, although contributing to long-term negative effects, such as increased occurrence of late malignancies, is the only current option capable of prolonging the survival of patients. In spite of relevant recent progress in matched unrelated donor transplants, the largest studies with longer follow-up still show a superiority of matched sibling donor transplants with a success rate, in selected cohorts, of over 90%. This article reviews different aspects of the disease, including genetics, diagnosis and treatment options, with special focus on stem cell transplantation, comprehensive post-diagnosis management, decision-making processes and long-term follow-up.

Azacitidine as a bridge to allogeneic hematopoietic cell transplantation in a pediatric patient with Fanconi anemia and acute myeloid leukemia

HCT is the definitive therapy for patients with FA and AML. Conventional cytotoxic agents cause potential DNA damage, and currently, there is no established regimen for these patients prior to HCT. A 13-year-old male with FA and refractory AML was given azacitidine, achieved morphologic remission and underwent HCT. At 95 days after HCT, he relapsed. Azacitidine along with DLI was used as first salvage therapy. Azacitidine was overall well tolerated with minimal side effects. In patients with AML and FA, azacitidine can be considered an alternative to conventional chemotherapy.

Successful Treatment of Hepatocellular Carcinoma Complicated by Fanconi Anemia

A 42-year-old woman with liver tumors was referred to our hospital. Her condition was complicated by Fanconi anemia, and she had undergone total laryngectomy 8 years ago. On admission, contrast-enhanced computed tomography revealed hypervascular tumors in the right hepatic lobe. Ultrasound-guided tumor biopsy revealed that the tumor comprised moderately differentiated hepatocellular carcinoma. Although the patient exhibited preserved liver function (Child-Pugh A), complete blood count revealed severe pancytopenia. Eventually, the tumor was successfully treated by transcatheter arterial embolization (TAE). Both platelet transfusion and systemic administration of antibiotics were performed. She was discharged 35 days after TAE.

Hematopoietic cell transplantation in Fanconi anemia: current evidence, challenges and recommendations

INTRODUCTION

Hematopoietic cell transplantation for Fanconi Anemia (FA) has improved dramatically over the past 40 years. With an enhanced understanding of the intrinsic DNA-repair defect and pathophysiology of hematopoietic failure and leukemogenesis, sequential changes to conditioning and graft engineering have significantly improved the expectation of survival after allogeneic hematopoietic cell transplantation (alloHCT) with incidence of graft failure decreased from 35% to <10% and acute graft-versus-host disease (GVHD) from >40% to <10%. Today, five-year overall survival exceeds 90% in younger FA patients with bone marrow failure but remains about 50% in those with hematologic malignancy. Areas covered: We review the evolution of alloHCT contributing to decreased rates of transplant related complications; highlight current challenges including poorer outcomes in cases of clonal hematologic disorders, alloHCT impact on endocrine function and intrinsic FA risk of epithelial malignancies; and describe investigational therapies for prevention and treatment of the hematologic manifestations of FA. Expert commentary: Current methods allow for excellent survival following alloHCT for FA associated BMF irrespective of donor hematopoietic cell source. Alternative curative approaches, such as gene therapy, are being explored to eliminate the risks of GVHD and minimize therapy-related adverse effects.

Allogeneic Hematopoietic Stem Cell Transplantation for Adult Patients with Fanconi Anemia

BACKGROUND AND OBJECTIVES

Fanconi anemia (FA) is a rare genetic disorder caused by an impaired DNA repair mechanism which leads to an increased tendency toward malignancies and progressive bone marrow failure. The only curative management available for hematologic abnormalities in FA patients is hematopoietic stem cell transplantation (HSCT). This study aimed to report the results of HSCT in adult or adolescent FA patients.

PATIENTS AND METHODS

Twenty FA patients with ages of 16 or more who underwent HSCT between 2002 and 2015 enrolled in this study. The stem cell source was peripheral blood, and all patients had a full human leukocyte antigen (HLA) matched donor, 19 patients had a sibling donor, and one had full matched other related. Indications for HSCT were severe bone marrow failure or dependence on blood products transfusion and failure of medical treatment to sustain peripheral blood elements at an acceptable level.

RESULTS

Eleven patients were female and 9 male (55% and 45%). Mean age was 24.05 years. Mortality rate was 50% (n=10), and the leading cause of death was graft versus host disease (GVHD) which occurred in 5 patients (4 cases from acute GVHD and one from chronic GVHD). Survival analysis showed an overall 5-year survival of 53.63% (95% confidence interval: 29.53%-72.74%) and 13 year survival of 45.96 % (95% confidence interval: 22.08%-67.03%) among patients.

CONCLUSION

HSCT is the only curative management for bone marrow failure in FA patients. But the high rate of mortality and morbidity in adolescent and adult patients makes it a challenging issue.

Four decades of stem cell transplantation for Fanconi anaemia in the Netherlands

This article presents the haematopoietic stem cell transplantation (SCT) results of the complete Dutch Fanconi anaemia (FA) patient cohort. Sixty-eight Dutch FA patients have been transplanted since 1972. In total, 63 (93%) patients engrafted, 54 after first SCT and 9 after second SCT. Fludarabine (FLU)-based conditioning was associated with decreased graft failure (odds ratio 0·21, P = 0·01), decreased early mortality (hazard ratio 0·25, P = 0·01) and improved 5-year overall survival (FLU 87·8% [standard error (SE) 5·1%] versus non-FLU 59·3% [SE 9·5%], P = 0·01). Late mortality was mainly caused by squamous cell carcinoma. Twenty-two patients were treated with the current Dutch FA conditioning regimen (FLU 150 mg/m(2) and cyclophosphamide 30 mg/kg ± anti-thymocyte globulin - no irradiation). Stem cell donors were matched related (n = 8) or alternative donors (n = 14). Stable engraftment after first SCT was achieved in 19 (86%) patients. At a median follow-up of 3·9 years 20 (91%) patients are alive. Our study provides a unique overview of a nation-wide SCT cohort illustrating the major improvements in treatment regimen and patient outcome in recent years. It shows that a non-irradiation and busulfan-free conditioning regimen can be used successfully, also in alternative donor SCT. Furthermore, it underlines the importance of late cancer screening and comprehensive care for this complex disorder.

Somatic, hematologic phenotype, long-term outcome, and effect of hematopoietic stem cell transplantation. An analysis of 97 Fanconi anemia patients from the Italian national database on behalf of the Marrow Failure Study Group of the AIEOP (Italian Association of Pediatric Hematology-Oncology)

We analyzed 97 Fanconi anemia patients from a clinic/biological database for genotype, somatic, and hematologic phenotype, adverse hematological events, solid tumors, and treatment. Seventy-two patients belonged to complementation group A. Eighty percent of patients presented with mild/moderate somatic phenotype and most with cytopenia. No correlation was seen between somatic/hematologic phenotype and number of missense mutations of FANCA alleles. Over follow-up, 33% of patients improved or maintained mild/moderate cytopenia or normal blood count, whereas remaining worsened cytopenia. Eleven patients developed a hematological adverse event (MDS, AML, pathological cytogenetics) and three developed solid tumors. 10 years cumulative risk of death of the whole cohort was 25.6% with median follow-up 5.8 years. In patients eligible to hematopoietic stem cell transplantation because of moderate cytopenia, mortality was significantly higher in subjects transplanted from matched unrelated donor over nontransplanted subjects, whereas there was no significant difference between matched sibling donor transplants and nontransplanted patients. In patients eligible to transplant because of severe cytopenia and clonal disease, mortality risk was not significantly different in transplanted from matched unrelated versus matched sibling donor versus nontransplanted subjects. The decision to transplant should rely on various elements including, type of donor, HLA matching, patient comorbidities, impairment, and clonal evolution of hematopoiesis. Am. J. Hematol. 91:666-671, 2016. © 2016 Wiley Periodicals, Inc.

Addition of High-Dose Cytarabine to Fludarabine-Based Conditioning for Hematopoietic Stem Cell Transplantation for Treating Fanconi Anemia Patients with Advanced Myeloid Malignancy: A Single-Center Experience and Literature Review

The complication of Fanconi anemia (FA) with acute leukemia is rare and challenging to treat because of high relapse rates, despite the improved outcome of hematopoietic stem cell transplantation with fludarabine-based conditioning for treating FA patients with hematological abnormalities. We added high-dose cytarabine to fludarabine-based conditioning to promote an enhanced antitumor effect and successfully subjected 4 patients with FA, including 3 with acute leukemia, to hematopoietic stem cell transplantation. All patients remain alive without treatment-related mortality or evidence of disease. Adding high-dose cytarabine to fludarabine-based conditioning may be tolerable and effective for treating FA patients with acute leukemia.

How I treat MDS and AML in Fanconi anemia

Fanconi anemia (FA) is the most frequent inherited cause of bone marrow failure (BMF). Most FA patients experience hematopoietic stem cell attrition and cytopenia during childhood, which along with intrinsic chromosomal instability, favor clonal evolution and the frequent emergence in their teens or young adulthood of myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML). To early identify and further predict bone marrow (BM) clonal progression and enable timely treatment, the follow-up of FA patients includes regular BM morphological and cytogenetic examinations. Allogeneic hematopoietic stem cell transplantation (HSCT) remains the only curative treatment of FA patients with MDS or AML. Although questions remain concerning HSCT itself (including the need for pretransplant chemotherapy, the best conditioning regimen, and the optimal long-term follow-up of such patients especially regarding secondary malignancies), clonal evolution in the absence of significant BM dysplasia and blast cells can be difficult to address in FA patients, for whom the concept of preemptive HSCT is discussed. Illustrated by 3 representative clinical vignettes showing specific features of MDS and AML in FA patients, this paper summarizes our practical approach from diagnosis through treatment in this particular situation.

Androgen therapy in Fanconi anemia: A retrospective analysis of 30 years in Germany

A substantial number of individuals with Fanconi anemia (FA) develop bone marrow failure and are treated with androgen therapy in order to increase blood counts. The authors retrospectively identified 70 patients who received androgen therapy any time between July 1976 and September 2014. Among these patients, 37 had medical records for analysis. Twenty-five of the 37 (68%) patients had response in hemoglobin level (n = 25), platelet count (n = 21), and/or absolute neutrophil count (n = 13). The median rise in hemoglobin was 6.5 mg/dL, platelet count 70,000/mm(3), and absolute neutrophil count (ANC) 1530/μL. The majority of patients (n = 22) had a response in 2 or more blood parameters. Reasons for discontinuation of therapy included development of cytogenetic aberrations (n = 9), lack of response (n = 7), hepatic adenoma (n = 6), progression to myelodysplastic syndrome/acute myeloid leukemia (n = 3), stabilization of blood parameters (n = 3), resolution of cytopenia secondary to mosaicism (n = 1), virilization (n = 1), development of anogenital carcinoma (n = 1), inaccessibility of medication (n = 1), and unknown (n = 1). Four patients at last follow-up remain on androgen therapy. These results highlight that androgen therapy can significantly improve blood counts for many FA patients, but progression of underlying bone marrow disease and development of liver adenomas requires careful monitoring.

Genetic predisposition to myelodysplastic syndrome and acute myeloid leukemia in children and young adults

Myelodysplastic syndrome (MDS) is a clonal blood disorder characterized by ineffective hematopoiesis, cytopenias, dysplasia and an increased risk of acute myeloid leukemia (AML). With the growing availability of clinical genetic testing, there is an increasing appreciation that a number of genetic predisposition syndromes may underlie apparent de novo presentations of MDS/AML, particularly in children and young adults. Recent findings of clonal hematopoiesis in acquired aplastic anemia add another facet to our understanding of the mechanisms of MDS/AML predisposition. As more predisposition syndromes are recognized, it is becoming increasingly important for hematologists and oncologists to have familiarity with the common as well as emerging syndromes, and to have a systematic approach to diagnosis and screening of at risk patient populations. Here, we provide a practical algorithm for approaching a patient with a suspected MDS/AML predisposition, and provide an in-depth review of the established and emerging familial MDS/AML syndromes caused by mutations in the ANKRD26, CEBPA, DDX41, ETV6, GATA2, RUNX1, SRP72 genes. Finally, we discuss recent data on the role of somatic mutations in malignant transformation in acquired aplastic anemia, and review the practical aspects of MDS/AML management in patients and families with predisposition syndromes.

Preemptive Bone Marrow Transplantation for FANCD1/BRCA2

Children with biallelic mutations in FANCD1/BRCA2 are at uniquely high risks of leukemia and solid tumors. Preemptive bone marrow transplantation (PE-BMT) has been proposed to avoid the development of leukemia, but empirical study of PE-BMT is unlikely because of the rarity of these children and the unknown benefit of PE-BMT. We used survival analysis to estimate the risks of leukemia and the expected survival if leukemia could be eliminated by curative PE-BMT. We used the results in a decision analysis model to explore the plausibility of PE-BMT for children with variable ages at diagnosis and risks of transplantation-related mortality. For example, PE-BMT at 1 year of age with a 10% risk of transplantation-related mortality increased the mean survival by 1.7 years. The greatest benefit was for patients diagnosed between 1 and 3 years of age, after which the benefit of PE-BMT decreased with age at diagnosis, and the risk of death from solid tumors constituted a relatively greater burden of mortality. Our methods may be used to model survival for other hematologic disorders with limited empirical data and a pressing need for clinical guidance.

Recommendations on hematopoietic stem cell transplantation for inherited bone marrow failure syndromes

Allogeneic hematopoietic stem cell transplantation (HSCT) offers the potential to cure patients with an inherited bone marrow failure syndrome (IBMFS). However, the procedure involves the risk of treatment-related mortality and may be associated with significant early and late morbidity. For these reasons, the benefits should be carefully weighed against the risks. IBMFS are rare, whereas case reports and small series in the literature illustrate highly heterogeneous practices in terms of indications for HSCT, timing, stem cell source and conditioning regimens. A consensus meeting was therefore held in Vienna in September 2012 on behalf of the European Group for Blood and Marrow Transplantation to discuss HSCT in the setting of IBMFS. This report summarizes the recommendations from this expert panel, including indications for HSCT, timing, stem cell source and conditioning regimen.

Alternative donor hematopoietic cell transplantation for Fanconi anemia

Historically, alternative donor hematopoietic cell transplantation (HCT) for Fanconi anemia (FA) patients resulted in excessive morbidity and mortality. To improve outcomes, we made sequential changes to the HCT conditioning regimen. A total of 130 FA patients (median age, 9.0 years; range, 1-48) underwent alternative donor HCT at the University of Minnesota between 1995 and 2012. All patients received cyclophosphamide (CY), single fraction total body irradiation (TBI), and antithymocyte globulin (ATG) with or without fludarabine (FLU), followed by T-cell-depleted bone marrow or unmanipulated umbilical cord blood transplantation. The addition of FLU enhanced engraftment 3-fold. The incidence of grades 2-4 acute and chronic graft-versus-host disease was 20% and 10%, respectively. Severe toxicity was highest in patients >10 years of age or those with a history of opportunistic infections or transfusions before HCT. Mortality was lowest in patients without a history of opportunistic infection or transfusions and who received conditioning with TBI 300 cGy, CY, FLU, and ATG. These patients had a probability of survival of 94% at 5 years. Alternative donor HCT is now associated with excellent survival for patients without prior opportunistic infections or transfusions and should be considered for all FA patients after the onset of marrow failure. These studies were registered at http://www.clinicaltrials.gov as NCT00005898, NCT00167206, and NCT00352976.

Advances in unrelated and alternative donor hematopoietic cell transplantation for nonmalignant disorders

PURPOSE OF REVIEW

The role of hematopoietic cell transplantation in non-malignant disorders has increased exponentially with the recognition that multiple diseases can be controlled or cured if engrafted with donor-derived cells. This review provides an overview of advances made in alternative donor transplants for nonmalignant disorders.

RECENT FINDINGS

Stem cell sources, novel transplant methods, and sophisticated supportive care have simultaneously made giant strides toward improving the safety and efficacy of hematopoietic cell transplantation. This has led to the utilization of marrow, cord, peripheral blood stem cell and haploidentical stem cell sources, and novel reduced toxicity or reduced intensity conditioning regimens to transplant non-malignant disorders such as immune dysfunctions, marrow failure syndromes, metabolic disorders and hemoglobinopathies. Transplant complications such as graft rejection, infections, and graft versus host disease are better combated in this modern era of medicine, achieving better survival with decreased late effects. These aspects of transplant for non-malignant disorders are discussed.

SUMMARY

This review presents the progress made in the realm of hematopoietic cell transplantation for non-malignant disorders. It advocates the consideration of alternative donor transplants in the absence of human leukocyte antigen matched siblings when indicated by disease severity. The ultimate goal is to provide curative transplant options for more patients that can benefit from this intervention, prior to detrimental outcomes.

Haematopoietic cell transplantation for acute leukaemia and advanced myelodysplastic syndrome in Fanconi anaemia

Acute leukaemia or advanced myelodysplastic syndrome (MDS ≥ 5% blasts) in Fanconi anaemia (FA) patients is associated with a poor prognosis. We report 21 FA patients with acute leukaemia or advanced MDS who underwent haematopoietic cell transplantation (HCT) at the University of Minnesota between 1988 and 2011. Six patients had biallelic BRCA2 mutations. Eight patients received pre-transplant cytoreduction, with 3 achieving complete remission. HCT donor source included human leucocyte antigen-matched sibling (n = 2) or alternative donors (n = 19). Neutrophil engraftment was 95% for the entire cohort, and the incidence of acute graft-versus-host disease was 19%. 5-year overall survival (OS) was 33%, with a relapse rate of 24%, with similar OS in patients with biallelic BRCA2 mutations. Our study supports the use of HCT in the treatment of FA patients with acute leukaemia or advanced MDS, however, the role of chemotherapy prior to HCT remains unclear for this population. FA patients with biallelic BRCA2 are unique and may benefit from higher dose chemotherapy relative to other complementation groups.

Allogeneic hematopoietic stem cell transplantation in Fanconi anemia: the European Group for Blood and Marrow Transplantation experience

Although allogeneic hematopoietic stem cell transplantation (HSCT) remains the only curative treatment for patients with Fanconi anemia (FA), published series mostly refer to single-center experience with limited numbers of patients. We analyzed results in 795 patients with FA who underwent first HSCT between May 1972 and January 2010. With a 6-year median follow-up, overall survival was 49% at 20 years (95% confidence interval, 38-65 years). Better outcome was observed for patients transplanted before the age of 10 years, before clonal evolution (ie, myelodysplastic syndrome or acute myeloid leukemia), from a matched family donor, after a conditioning regimen without irradiation, the latter including fludarabine. Chronic graft-versus-host disease and secondary malignancy were deleterious when considered as time-dependent covariates. Age more than 10 years at time of HSCT, clonal evolution as an indication for transplantation, peripheral blood as source of stem cells, and chronic graft-versus-host disease were found to be independently associated with the risk for secondary malignancy. Changes in transplant protocols have significantly improved the outcome of patients with FA, who should be transplanted at a young age, with bone marrow as the source of stem cells.