Allogeneic hematopoietic cell transplantation (HCT) remains the only cure for the hematologic manifestations of Fanconi anemia (FA). We performed retrospective predictor analyses for HCT outcomes in FA for pediatric and young adult patients transplanted between 2007 and 2020 across three large referral institutions. Eighty-nine patients, 70 with bone marrow failure +/− cytogenetic abnormalities, 19 with MDS/AML, were included. Five-year overall survival (OS) was 83.2% and event-free survival (EFS) was 74%. Age ≥19, HLA mismatch and year of HCT were multivariable predictors (MVPs) for OS, EFS and treatment-related mortality (TRM). In the pediatric group, TCD was a borderline MVP (P = 0.059) with 5-year OS of 73.0% in TCD vs. 100% for T-replete HCT. The cumulative incidence of day 100 grade II-IV aGvHD and 5-year cGvHD were 5.6% and 4.6%, respectively. Relapse in the MDS/AML subgroup occurred in 4 patients (16%). Graft failure was seen in 9 patients (TCD 6/37 [16%]; T-replete 3/52 [5.7%]). Six patients developed malignancy after HCT. Survival chances after HCT for FA are excellent and associated with high engrafted survival and low toxicity. Age ≥19, HLA mismatch, year of transplant and ‘TCD in the <19 years group’ (although borderline) were found to be negative predictors for survival.

Background Germline data have become widely available in paediatric oncology since the introduction of paired tumour-germline sequencing. To guide best practice in cancer predisposition syndrome (CPS) diagnostics, we aimed to assess the diagnostic yield of extensive germline analysis compared with clinical selection-based genetic testing among all children with cancer. Methods In this prospective diagnostic study, all children (aged 0-19 years) with newly diagnosed neoplasms treated in the Netherlands national centre, the Princess M & aacute;xima Center for Pediatric Oncology (Utrecht, Netherlands), between June 1, 2020, and July 31, 2022, were offered two approaches to identify CPSs. In a phenotype-driven approach, paediatric oncologists used the McGill Interactive Pediatric OncoGenetic Guidelines tool to select children for referral to a clinical geneticist, and for genetic testing. In a phenotype-agnostic approach, CPS gene panel sequencing (143 genes) was offered to all children. In children declining the research CPS gene panel, 49 CPS genes were still analysed as part of routine diagnostics by the pathologist. Children with a causative CPS identified before neoplasm diagnosis were excluded. The primary objective was to compare the number and type of patients diagnosed with a CPS between the two approaches. Findings 1052 children were eligible for this study, of whom 733 (70%) completed both the phenotype-driven approach and received phenotype-agnostic CPS gene panel sequencing (143 genes n=600; 49 genes n=133). In 53 children, a CPS was identified: 14 (26%) were diagnosed by the phenotype-driven approach only, 22 (42%) by CPS gene sequencing only, and 17 (32%) by both approaches. In 27 (51%) of the 53 children, the identified CPS was considered causative for the child's neoplasm. Only one (4%) of the 27 causative CPSs was missed by the phenotype-driven approach and was identified solely by phenotype-agnostic CPS gene sequencing. In 26 (49%) children, a CPS with uncertain causality was identified, including 14 adult-onset CPSs. The CPSs with uncertain causality were mainly detected by the phenotype-agnostic approach (21 [81%] of 26). Interpretation Phenotype-driven genetic testing and phenotype-agnostic CPS gene panel sequencing were complementary. The phenotype-driven approach identified the most causative CPSs. CPS gene panel sequencing identified additional CPSs, many of those with uncertain causality, but some with clinical utility. We advise clinical evaluation for CPSs in all children with neoplasms. Phenotype-agnostic testing of all CPS genes is preferably conducted only in research settings and should be paired with counseling. Copyright (c) 2024 Elsevier Ltd. All rights reserved, including those for text and data mining, AI training, and similar technologies.

Small cell osteosarcoma (SCOS), a variant of conventional high-grade osteosarcoma (COS), may mimic fusion-driven round cell sarcomas (FDRCS) by overlapping clinico-radiological and histomorphological/immunohistochemical characteristics, hampering accurate diagnosis and consequently proper therapy. We retrospectively analyzed decalcified formalin-fixed paraffin-embedded (FFPE) samples of 18 bone tumors primarily diagnosed as SCOS by methylation profiling, fusion gene analysis, and immunohistochemistry. In eight cases, the diagnosis of SCOS was maintained, and in 10 cases it was changed into FDRCS, including three Ewing sarcomas ( EWSR1::FLI1 in two cases and no identified fusion gene in the third case), two sarcomas with BCOR alterations ( KMT2D::BCOR, CCNB3::BCOR , respectively), three mesenchymal chondrosarcomas (HEY1::NCOA2 in two cases and one case with insufficient RNA quality), and two sclerosing epithelioid fibrosarcomas ( FUS::CREBL3 and EWSR1 rearrangement, respectively). Histologically, SCOS usually possessed more pleomorphic cells in contrast to the FDRCS showing mainly monomorphic cellular features. However, osteoid was seen in the latter tumors as well, often associated with slight pleomorphism. Also, the immunohistochemical profile (CD99, SATB2, and BCOR) overlapped. Clinically and radiologically, similarities between SCOS and FDRCS were observed, with by imaging only minimal presence or lack of (mineralized) osteoid in most of the SCOSs. In conclusion, discrimination of SCOS, epigenetically related to COS, versus FDRCS of bone can be challenging but is important due to different biology and therefore therapeutic strategies. Methylation profiling is a reliable and robust diagnostic test especially on decalcified FFPE material. Subsequent fusion gene analysis and/or use of specific immunohistochemical surrogate markers can be used to substantiate the diagnosis.

Purpose: Infantile myofibromatosis is characterized by the development of myofibroblastic tumors in young children. In most cases, the disease is caused by somatic gain-of-function variants in platelet-derived growth factor (PDGF) receptor beta (PDGFRB). Here, we reported a novel germline intronic PDGFRB variant, c.2905-8G>A, in 6 unrelated infants with multifocal myofibromatosis and their relatives. Methods: We performed constitutional and tumor DNA and RNA sequencing to identify novel variants, which were subsequently characterized in cellular assays. Results: All patients had multiple skin nodules, 4 had bone lesions, and 2 had aggressive disease with bowel obstruction. The c.2905-8G>A substitution creates an alternative acceptor splice site in intron 21, inserting 2 codons in the PDGFRB transcript. Functional studies revealed that the splice change induced a partial loss of function, contrasting with previously described variants. In 4 tumor samples, we identified a second somatic hit at position Asp850 in PDGFRB exon 18, triggering constitutive receptor activation and resistance to imatinib. In addition to vinblastine and methotrexate, 2 patients received imatinib without objective response. One of them switched to dasatinib with concomitant improvement. Conclusion: This splice-site PDGFRB variant favors the development of myofibroma, featuring an acquired oncogenic variant in the same gene and resistance to targeted therapy.

Importance:To improve diagnostics of cancer predisposition syndromes (CPSs) in children with cancer, it is essential to evaluate the effect of CPS gene sequencing among all children with cancer and compare it with genetic testing based on clinical selection. However, a reliable comparison is difficult because recent reports on a phenotype-first approach in large, unselected childhood cancer cohorts are lacking.Objective:To describe a national children's cancer center's experience in diagnosing CPSs before introducing routine next-generation sequencing.Design, Setting, and Participants:This retrospective cohort study was conducted at the National Retinoblastoma Treatment Center (Amsterdam, the Netherlands) and the Princess Máxima Center for Pediatric Oncology (Utrecht, Netherlands) and included Dutch pediatric patients with a new diagnosis of neoplasm between June 1, 2018, and December 31, 2019. Follow-up was at least 18 months after neoplasm diagnosis. Data analysis was conducted from July 2021 to February 2022.Exposures:As part of routine diagnostics, pediatric oncologists and ophthalmologists checked for characteristics of CPSs and selected children for referral to clinical geneticists and genetic testing.Main Outcomes and Measures:Detected cancer predisposition syndromes.Results:A total of 824 patients (median [range] age at diagnosis 7.5 [0-18.9] years; 361 girls [44%]) were assessed, including 335 children with a hematological neoplasm (41%) and 489 (59%) with a solid tumor. In 71 of 824 children (8.6%), a CPS was identified, of which most (96%) were identified by a phenotype-driven approach. Down syndrome and neurofibromatosis type 1 were the most common CPSs diagnosed. In 42 of 71 patients (59%), a CPS was identified after these children developed a neoplasm. The specific type of neoplasm was the most frequent indicator for genetic testing, whereas family history played a minor role.Conclusions and Relevance:In this cohort study of children with a neoplasm, the prevalence of CPSs identified by a phenotype-driven approach was 8.6%. The diagnostic approach for identifying CPSs is currently shifting toward a genotype-first approach. Future studies are needed to determine the diagnostic value, as well as possible disadvantages of CPS gene sequencing among all children with cancer compared with the phenotype-driven approach.

BACKGROUND:Distinguishing congenital pulmonary airway malformations (CPAMs) from pleuropulmonary blastoma (PPB) can be challenging. Previously diagnosed patients with CPAM may have been misdiagnosed and we may have missed DICER1-associated PPBs, a diagnosis with important clinical implications for patients and their families. To gain insight in potential misdiagnoses, we systematically assessed somatic DICER1 gene mutation status in an unselected, retrospective cohort of patients with a CPAM diagnosis. METHODS:In the Amsterdam University Medical Center (the Netherlands), it has been standard policy to resect CPAM lesions. We included all consecutive cases of children (age 0-18 years) with a diagnosis of CPAM between 2007 and 2017 at this center. Clinical and radiographic features were reviewed, and DICER1 gene sequencing was performed on DNA retrieved from CPAM tissue samples. RESULTS:Twenty-eight patients with a surgically removed CPAM were included. CPAM type 1 and type 2 were the most common subtypes (n = 12 and n = 13). For 21 patients a chest CT scan was available for reassessment by two pediatric radiologists. In 9 patients (9/21, 43%) the CPAM subtype scored by the radiologists did not correspond with the subtype given at pathology assessment. No pathogenic mutations and no copy number variations of the DICER1 gene were found in the DNA extracted from CPAM tissue (0/28). CONCLUSIONS:Our findings suggest that the initial CPAM diagnoses were correct. These findings should be validated through larger studies to draw conclusions regarding whether systematic DICER1 genetic testing is required in children with a pathological confirmed diagnosis of CPAM or not. LEVEL OF EVIDENCE:Level IV.

Background: Small-cell carcinoma of the ovary, hypercalcemic type (SCCOHT) is a rare aggressive ovarian malignancy mainly affecting children, adolescents, and young adults. Since the discovery of mutations in the SMARCA4 gene in 2014, SCCOHT has become the subject of extensive investigation. However, international uniform treatment guidelines for SCCOHT are lacking and the outcome remains poor. The aim of this systematic review is to generate an overview of all reported patients with SCCOHT from 1990 onwards, describing the clinical presentation, genetic characteristics, treatment, and outcome. Methods: A systematic search was performed in the databases Embase, Medline, Web of Science, and Cochrane for studies that focus on SCCOHT. Patient characteristics and treatment data were extracted from the included studies. Survival was estimated using Kaplan–Meier’s methodology. To assess the difference between survival, the log-rank test was used. To quantify the effect of the FIGO stage, the Cox proportional hazard regression model was estimated. The chi-squared test was used to study the association between the FIGO stage and the surgical procedures. Results: Sixty-seven studies describing a total of 306 patients were included. The median patient age was 25 years (range 1–60 years). The patients mostly presented with non-specific symptoms such as abdominal pain and sometimes showed hypercalcemia and elevated CA-125. A great diversity in the diagnostic work-up and therapeutic approaches was reported. The chemotherapy regimens were very diverse, all containing a platinum-based (cisplatin or carboplatin) backbone. Survival was strongly associated with the FIGO stage at diagnosis. Conclusions: SCCOHT is a rare and aggressive ovarian cancer, with a poor prognosis, and information on adequate treatment for this cancer is lacking. The testing of mutations in SMARCA4 is crucial for an accurate diagnosis and may lead to new treatment options. Harmonization and international collaboration to obtain high-quality data on diagnostic investigations, treatment, and outcome are warranted to be able to develop international treatment guidelines to improve the survival chances of young women with SCCOHT.

Infantile myofibromatosis (IM), which is typically diagnosed in young children, comprises a wide clinical spectrum ranging from inconspicuous solitary soft tissue nodules to multiple disseminated tumors resulting in life-threatening complications. Familial IM follows an autosomal dominant mode of inheritance and is linked to PDGFRB germline variants. Somatic PDGFRB variants were also detected in solitary and multifocal IM lesions. PDGFRB variants associated with IM constitutively activate PDGFRB kinase activity in the absence of its ligand. Germline variants have lower activating capabilities than somatic variants and, thus, require a second cis-acting hit for full receptor activation. Typically, these mutant receptors remain sensitive to tyrosine kinase inhibitors such as imatinib. The SIOPE Host Genome Working Group, consisting of pediatric oncologists, clinical geneticists and scientists, met in January 2020 to discuss recommendations for genetic testing and surveillance for patients who are diagnosed with IM or have a family history of IM/ PDGFRB germline variants. This report provides a brief review of the clinical manifestations and genetics of IM and summarizes our interdisciplinary recommendations.

For many years, inherited bone marrow failure (BMF) syndromes have been considered to be childhood diseases. However, due to next generation sequencing techniques, this viewpoint has been challenged. We report three siblings, who were diagnosed with myelodysplastic syndrome (MDS) or acute myeloid leukaemia (AML) in their 30s or 40s in the absence of prior symptoms (siblings 3, 5 and 6; Fig 1). Further family history showed the presence of MDS in mother, breast cancer in sibling 2 and mother, and both head and neck squamous cell carcinoma (HNSCC) and hepatocellular carcinoma in sibling 1 (Fig 1A). Because of the positive family history, this family was referred for genetic testing and counselling. In this setting, whole exome sequencing (WES, Data S1) was performed in order to identify a possible genetic defect underlying the increased risk for malignancies. WES revealed the presence of a homozygous FANCCc.67delG mutation in siblings 1, 3, 5 and 6, as well as the presence of a CHEK2c.1100delC mutation in this family (Table 1, Figure S1). FANCC CHEK2 c.67delG c.1100delC p.D23Ifs p.T367Mfs hom het FANCC CHEK2 c.67delG c.1100delC p.D23Ifs p.T367Mfs het het FANCC CHEK2 c.67delG c.1100delC p.D23Ifs p.T367Mfs hom het FANCC CHEK2 c.67delG c.1100delC p.D23Ifs p.T367Mfs hom hom FANCC CHEK2 IKZF1 IKZF1 ETV6 TP53 c.67delG c.1100delC c.949A>T c.950A>T c.809_810delinsA+823C>A c.892C>A p.D23Ifs p.T367Mfs p.N317Y p.N317I p.P270Tfs*4 p.R298S hom het – – – – 0·096 0·075 0·063 0·053 Fanconi anaemia (FA) is a rare DNA repair disorder caused by defects in one of the 21 currently identified FA genes. Mutations in FA genes result in a variety of clinical symptoms, including congenital malformations (60% of FA cases), development of progressive BMF (mean onset, 7 years of age; cumulative incidence, 90% at 40 years of age) and high risk of developing MDS/AML (median age 13 years, cumulative probability 30–40% at 40 years) (Shimamura & Alter, 2010; Quentin et al, 2011). BMF is considered to be the consequence of excess apoptosis in the haematopoietic stem and progenitor cells (HSPCs), creating a selective environment that favours the evolution of adapted clones, ultimately leading to leukaemic development (Alter, 2007). Besides haematological malignancies, FA strongly predisposes to solid tumour development, particularly HNSCCs and gynecological tumours (Shimamura & Alter, 2010). Although the median age at FA diagnosis was found to be 6·5 years (Shimamura & Alter, 2010), 9% of patients are reported to be diagnosed after 16 years of age (Alter, 2007). This percentage may be an underestimation, as recognition of FA in adult patients can be impeded by several factors. Firstly, a rare disease like FA that is classically regarded to be a childhood disease may not be taken into differential diagnostic consideration by doctors treating adult patients. Furthermore, the presentation of the FA phenotype can be very heterogeneous and tends to be milder in adult FA patients. The presentation of FA in these siblings is highly exceptional with regard to the late age of symptom onset and the absence of typical prior symptoms. The severity of the FA phenotype is thought to depend, at least partially, on the type of mutation. The FANCCc.67delG mutation has been described as resulting in a relatively mild phenotype, which could be explained by the finding that the resultant truncated protein retains partial—however highly imprecise—DNA repair activity (Donahue et al, 2004). However, the median age at FA diagnosis for patients affected by homozygous FANCCc.67delG mutations, based on clinical symptoms, was found to be 10·4 years (range 3·9–25·9) (S. Smetsers, unpublished observation). The observation that all FA patients in this family also carried the CHEK21100delC mutation may be of interest with regard to the delayed phenotype. This mutation results in reduced CHK2 (also termed CHEK2) expression, a protein that has important functions in the response to DNA damage, such as inducing cell cycle arrest (Antoni et al, 2007). CHEK21100delC heterozygosity is relatively common in the Netherlands, with a carrier frequency of 1%, and significantly increases the risk of developing breast cancer (Schmidt et al, 2016). Homozygosity for this mutation, also observed in sibling 5, is a rare condition that may further increase the risk for breast cancer (Adank et al, 2011). Although CHEK21100delC has not yet been associated with increased risk for leukaemia development, reduced levels of activated CHEK2 have been observed in AML (Popp et al, 2017). To our knowledge, the simultaneous presence of mutations in FANCC and CHEK2 has not been found before (Dr Q. Waisfisz, VU University Medical Centre, Amsterdam, the Netherlands, personal communication, 2017). Their co-occurrence in a family affected by several malignancies raises questions about whether the two mutations collaborated in inducing carcinogenesis, and if so, how. One possibility is that reduced CHEK2 protein levels could impede effective cell cycle checkpoint control, resulting in genomically-damaged cells that escape apoptosis. This hypothesis might also explain the absence of prior BMF, as HSPCs would not undergo excess apoptosis during cell cycle checkpoint control, but instead continue to cycle, thereby accumulating DNA damage. Supportive evidence comes from the finding that FA protein deficiency leads to hyper-activation of CHK1, another checkpoint kinase that shares many overlapping functions with CHK2 (Chen et al, 2009). However, the simultaneous occurrence of both mutations might be a coincidence given the high population frequency of CHEK21100delC. Additionally, the mutations may have had limited effect on each other as the biological mechanisms that underlie the risk for cancer development are already affected (Antoni et al, 2007). Another striking finding in this family is the high incidence of AML/MDS. FA-related leukaemias are characterized by specific chromosomal instability patterns, including gains of 1q and 3q and losses of chromosome 7 (Quentin et al, 2011). To determine additional hits that contributed to leukaemogenesis in the FA background, we performed targeted sequencing of 54 frequently mutated genes in myeloid malignancies (Table SII) on MDS BM material from sibling 6. Mutations were detected in IKZF1, ETV6 and TP53, although at low frequencies (Table 1). By screening for a set of 10 genes, others have also reported that mutations commonly found in MDS/AML were rare in FA-related leukaemia (Quentin et al, 2011). These results indicate that gene mutations that are involved in FA-related leukaemia differ from the ones that are recurrently observed in sporadic leukaemia. Furthermore, the presence of multiple low frequency mutations suggests the occurrence of highly clonal haematopoiesis in the context of FA. In summary, this family history illustrates the wide phenotypic variability that can be seen in FA patients. Timely recognition of FA underlying MDS or AML diagnosis is of utmost importance, as this will have extensive impact on treatment modalities, including tailored therapy and donor selection for transplantation, as well as the management of family members. G.B. and E.V. wrote the paper. E.v.d.B and K.M.A performed WES analysis. A.B.M. performed targeted sequencing panel. S.S., B.L. and R.H.S. provided patient material and clinical data, and discussed progress. All authors discussed the results and commented on the manuscript. The authors declare no conflict of interest. Data S1. Supplementary methods. Figure S1. Sangers sequencing. Table SI. Cytogenetic analysis. Table SII. TruSight Myeloid Sequencing Panel gene list (Illumina). Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

Case presentationAn 11-year-old girl, recently diagnosed with acute myeloid leukemia, was treated according to the NOPHO DBH AML 2012 protocol [1].After the third chemotherapy course, consisting of cytarabine, mitoxantrone, and intrathecal methotrexate, she was admitted to the Department of Pediatric Oncology because of septic shock during febrile neutropenia.She was treated with meropenem and vancomycin and blood cultures were positive for Streptococcus mitis.Because of persistent fever, the central venous catheter was removed.Nevertheless, the fever persisted and a chest CT was performed, which revealed multiple abnormalities suggestive of pulmonary aspergillosis, which was confirmed by bronchoalveolar lavage (BAL).On day 5 of admission, she was started on AmBisome® (liposomal amphotericin B; 5 mg/kg in glucose 5%).Because of her persisting neutropenia, granulocyte colony-stimulating factor (G-CSF) was administered.Fever disappeared with neutrophil recovery, approximately 5 days after the start of G-CSF and AmBisome®.Repeated blood tests showed normal renal function (creatinine 35 μmol/L, urea 3.7 mmol/L).Potassium supplementation was started because of hypokalemia.While phosphate concentrations were low at 0.54 mmol/L on day 5, they rose spontaneously and from day 7 onwards laboratory tests showed progressive hyperphosphatemia, with a maximum of 2.28 mmol/L (Fig. 1). QuestionWhat is the most likely cause of the hyperphosphatemia observed in this patient?

BRCA2 encodes a protein with a fundamental role in homologous recombination that is essential for normal development. Carrier status of mutations in BRCA2 is associated with familial breast and ovarian cancer, while bi-allelic BRCA2 mutations can cause Fanconi anemia (FA), a cancer predisposition syndrome with cellular cross-linker hypersensitivity. Cancers associated with BRCA2 mutations can acquire chemo-resistance on relapse. We modeled acquired cross-linker resistance with an FA-derived BRCA2- mutated acute myeloid leukemia (AML) platform. Associated with acquired cross-linker resistance was the expression of a functional BRCA2 protein variant lacking exon 5 and exon 7 ( BRCA2 ΔE5+7 ), implying a role for BRCA2 splicing for acquired chemo-resistance. Integrated network analysis of transcriptomic and proteomic differences for phenotyping of BRCA2 disruption infers impact on transcription and chromatin remodeling in addition to the DNA damage response. The striking overlap with transcriptional profiles of FA patient hematopoiesis and BRCA mutation associated ovarian cancer helps define and explicate the ‘ BRCAness’ profile.

Objectives/Hypothesis: Fanconi anemia is a hereditary chromosomal instability disorder. Hearing loss and ear abnormalities are among the many manifestations reported in this disorder. In addition, Fanconi anemia patients often complain about hearing difficulties in situations with background noise (speech perception in noise difficulties). Our study aimed to describe the prevalence of hearing loss and speech perception in noise difficulties in Dutch Fanconi anemia patients. Study Design: Retrospective chart review. Methods: A retrospective chart review was conducted at a Dutch tertiary care center. All patients with Fanconi anemia at clinical follow-up in our hospital were included. Medical files were reviewed to collect data on hearing loss and speech perception in noise difficulties. Results: In total, 49 Fanconi anemia patients were included. Audiograms were available in 29 patients and showed hearing loss in 16 patients (55%). Conductive hearing loss was present in 24.1%, sensorineural in 20.7%, and mixed in 10.3%. A speech in noise test was performed in 17 patients; speech perception in noise was subnormal in nine patients (52.9%) and abnormal in two patients (11.7%). Conclusions: Hearing loss and speech perception in noise abnormalities are common in Fanconi anemia. Therefore, pure tone audiograms and speech in noise tests should be performed, preferably already at a young age, because hearing aids or assistive listening devices could be very valuable in developing language and communication skills.

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.

Abstract LOH at chromosome arms 3p, 9p, 11q, and 17p are well-established oncogenetic aberrations in oral precancerous lesions and promising biomarkers to monitor the development of oral cancer. Noninvasive LOH screening of brushed oral cells is a preferable method for precancer detection in patients at increased risk for head and neck squamous cell carcinoma (HNSCC), such as patients with Fanconi anemia. We determined the prevalence of LOH in brushed samples of the oral epithelium of 141 patients with Fanconi anemia and 144 aged subjects, and studied the association between LOH and HNSCC. LOH was present in 14 (9.9%) nontransplanted patients with Fanconi anemia, whereas LOH was not detected in a low-risk group (n = 50, >58 years, nonsmoking/nonalcohol history) and a group with somewhat increased HNSCC risk (n = 94, >58 years, heavy smoking/excessive alcohol use); Fisher exact test, P = 0.023 and P = 0.001, respectively. Most frequent genetic alteration was LOH at 9p. Age was a significant predictor of LOH (OR, 1.13, P = 0.001). Five patients with Fanconi anemia developed HNSCC during the study at a median age of 39.6 years (range, 24.8–53.7). LOH was significantly associated with HNSCC (Fisher exact test, P = 0.000). Unexpectedly, the LOH assay could not be used for transplanted patients with Fanconi anemia because donor DNA in brushed oral epithelium, most likely from donor leukocytes present in the oral cavity, disturbed the analysis. Noninvasive screening using a LOH assay on brushed samples of the oral epithelium has a promising outlook in patients with Fanconi anemia. However, assays need to be adapted in case of stem cell transplantation, because of contaminating donor DNA. Cancer Prev Res; 8(11); 1102–11. ©2015 AACR.

Interstrand crosslinks (ICLs) are toxic DNA lesions that cause severe genomic damage during replication, especially in Fanconi anemia pathway-deficient cells. This results in progressive bone marrow failure and predisposes to acute myeloid leukemia (AML). The molecular mechanisms responsible for these defects are largely unknown. Using Ercc1-deficient mice, we show that Trp53 is responsible for ICL-induced bone marrow failure and that loss of Trp53 is leukemogenic in this model. In addition, Ercc1-deficient myeloid progenitors gain elevated levels of miR-139-3p and miR-199a-3p with age. These microRNAs exert opposite effects on hematopoiesis. Ectopic expression of miR-139-3p strongly inhibited proliferation of myeloid progenitors, whereas inhibition of miR-139-3p activity restored defective proliferation of Ercc1-deficient progenitors. Conversely, the inhibition of miR-199a-3p functions aggravated the myeloid proliferation defect in the Ercc1-deficient model, whereas its enforced expression enhanced proliferation of progenitors. Importantly, miR-199a-3p caused AML in a pre-leukemic mouse model, supporting its role as an onco-microRNA. Target genes include HuR for miR-139-3p and Prdx6, Runx1, and Suz12 for miR-199a-3p. The latter genes have previously been implicated as tumor suppressors in de novo and secondary AML. These findings show that, in addition to TRP53-controlled mechanisms, miR-139-3p and miR-199a-3p are involved in the defective hematopoietic function of ICL-repair deficient myeloid progenitors.

Fanconi anaemia (FA) is an inherited disease with congenital and developmental abnormalities characterised by cellular cross linker hypersensitivity. FA is caused by mutations in any of so far 15 identified FANC genes, which encode proteins that interact in a common DNA damage response (DDR) pathway. Individuals with FA have a high risk of developing acute myeloid leukaemia (AML) and squamous cell carcinoma. An increased cancer risk has been firmly established for carriers of mutations in FANCD1/BRCA2, FANCJ/BRIP1, FANCN/PALB2, RAD51C/FANCO and link the FA pathway to inherited breast and ovarian cancer. We describe a pedigree with FANCD2 mutations c.458T > C (p.Leu153Ser) and c.2715 + 1G > A (p.Glu906LeufsX4) with mild phenotype FA in the index case, T cell ALL in the Leu153Ser heterozygous brother and testicular seminoma in the p.Glu906LeufsX4 heterozygous father. Both FANCD2 alleles were present in the T Cell ALL and the seminoma. This links specific FANCD2 mutations to T cell ALL and seminoma without evidence of allelic loss in the tumour tissue.