Abstract Pediatric high-grade glioma (pedHGG) can occur as first manifestation of cancer predisposition syndromes resulting from pathogenic germline variants in the DNA mismatch repair (MMR) genes MSH2 , MSH6 , MLH1 , and PMS2 . The aim of this study was to establish a generalized screening for Lynch syndrome and constitutional MMR deficiency (CMMRD) in pedHGG patients, as the detection of MMR deficiencies (MMRD) may enable the upfront therapeutic use of checkpoint inhibitors and identification of variant carriers in the patients’ families. We prospectively enrolled 155 centrally reviewed primary pedHGG patients for MMR-immunohistochemistry (IHC) as part of the HIT-HGG-2013 trial protocol. MMR-IHC results were subsequently compared to independently collected germline sequencing data (whole exome sequencing or pan-cancer DNA panel next-generation sequencing) available in the HIT-HGG-2013, INFORM, and MNP2.0 trials. MMR-IHC could be successfully performed in 127/155 tumor tissues. The screening identified all present cases with Lynch syndrome or CMMRD (5.5%). In addition, MMR-IHC also detected cases with exclusive somatic MMR gene alterations (2.3%), including MSH2 hypermethylation as an alternative epigenetic silencing mechanism. Most of the identified pedHGG MMRD patients had no family history of MMRD, and thus, they represented index patients in their families. Cases with regular protein expression in MMR-IHC never showed evidence for MMRD in DNA sequencing. In conclusion, MMR-IHC presents a cost-effective, relatively widely available, and fast screening method for germline MMRD in pedHGG with high sensitivity (100%) and specificity (96%). Given the relatively high prevalence of previously undetected MMRD cases among pedHGG patients, we strongly recommend incorporating MMR-IHC into routine diagnostics.
Abstract STUDY QUESTION In children affected by rhabdoid tumors (RT), are there clinical, therapeutic, and/or (epi-)genetic differences between those conceived following ART compared to those conceived without ART? SUMMARY ANSWER We detected a significantly elevated female predominance, and a lower median age at diagnosis, of children with RT conceived following ART (RT_ART) as compared to other children with RT. WHAT IS KNOWN ALREADY Anecdotal evidence suggests an association of ART with RT. STUDY DESIGN, SIZE, DURATION This was a multi-institutional retrospective survey. Children with RT conceived by ART were identified in our EU-RHAB database (n = 11/311 children diagnosed between January 2010 and January 2018) and outside the EU-RHAB database (n = 3) from nine different countries. A population-representative German EU-RHAB control cohort of children with RTs conceived without ART (n = 211) (EU-RHAB control cohort) during the same time period was used as a control cohort for clinical, therapeutic, and survival analyses. The median follow-up time was 11.5 months (range 0–120 months) for children with RT_ART and 18.5 months (range 0–153 months) for the EU-RHAB control cohort. PARTICIPANTS/MATERIALS, SETTING, METHODS We analyzed 14 children with RT_ART diagnosed from January 2010 to January 2018. We examined tumors and matching blood samples for SMARCB1 mutations and copy number alterations using FISH, multiplex ligation-dependent probe amplification, and DNA sequencing. DNA methylation profiling of tumor and/or blood samples was performed using DNA methylation arrays and compared to respective control cohorts of similar age (n = 53 tumors of children with RT conceived without ART, and n = 38 blood samples of children with no tumor born small for gestational age). MAIN RESULTS AND THE ROLE OF CHANCE The median age at diagnosis of 14 individuals with RT_ART was 9 months (range 0–66 months), significantly lower than the median age of patients with RT (n = 211) in the EU-RHAB control cohort (16 months (range 0–253), P = 0.03). A significant female predominance was observed in the RT_ART cohort (M:F ratio: 2:12 versus 116:95 in EU-RHAB control cohort, P = 0.004). Eight of 14 RT_ART patients were diagnosed with atypical teratoid rhabdoid tumor, three with extracranial, extrarenal malignant rhabdoid tumor, one with rhabdoid tumor of the kidney and two with synchronous tumors. The location of primary tumors did not differ significantly in the EU-RHAB control cohort (P = 0.27). Six of 14 RT_ART patients presented with metastases at diagnosis. Metastatic stage was not significantly different from that within the EU-RHAB control cohort (6/14 vs 88/211, P = 1). The incidence of pathogenic germline variants was five of the 12 tested RT_ART patients and, thus, not significantly different from the EU-RHAB control cohort (5/12 versus 36/183 tested, P = 0.35). The 5-year overall survival (OS) and event free survival (EFS) rates of RT_ART patients were 42.9 ± 13.2% and 21.4 ± 11%, respectively, and thus comparable to the EU-RHAB control cohort (OS 41.1 ± 3.5% and EFS 32.1 ± 3.3). We did not find other clinical, therapeutic, outcome factors distinguishing patients with RT_ART from children with RTs conceived without ART (EU-RHAB control cohort). DNA methylation analyses of 10 tumors (atypical teratoid RT = 6, extracranial, extrarenal malignant RT = 4) and six blood samples from RT_ART patients showed neither evidence of a general DNA methylation difference nor underlying imprinting defects, respectively, when compared to a control group (n = 53 RT samples of patients without ART, P = 0.51, n = 38 blood samples of patients born small for gestational age, P = 0.1205). LIMITATIONS, REASONS FOR CAUTION RTs are very rare malignancies and our results are based on a small number of children with RT_ART. WIDER IMPLICATIONS OF THE FINDINGS This cohort of patients with RT_ART demonstrated a marked female predominance, and a rather low median age at diagnosis even for RTs. Other clinical, treatment, outcome, and molecular factors did not differ from those conceived without ART (EU-RHAB control cohort) or reported in other series, and there was no evidence for imprinting defects. Long-term survival is achievable even in cases with pathogenic germline variants, metastatic disease at diagnosis, or relapse. The female preponderance among RT_ART patients is not yet understood and needs to be evaluated, ideally in larger international series. STUDY FUNDING/COMPETING INTEREST(S) M.C.F. is supported by the ‘Deutsche Kinderkrebsstiftung’ DKS 2020.10, by the ‘Deutsche Forschungsgemeinschaft’ DFG FR 1516/4-1 and by the Deutsche Krebshilfe 70113981. R.S. received grant support by Deutsche Krebshilfe 70114040 and for infrastructure by the KinderKrebsInitiative Buchholz/Holm-Seppensen. P.D.J. is supported by the Else-Kroener-Fresenius Stiftung and receives a Max-Eder scholarship from the Deutsche Krebshilfe. M.H. is supported by DFG (HA 3060/8-1) and IZKF Münster (Ha3/017/20). BB is supported by the ‘Deutsche Kinderkrebsstiftung’ DKS 2020.05. We declare no competing interests. TRIAL REGISTRATION NUMBER N/A.
Abstract INTRODUCTION: Anecdotal case reports suggest an association between assisted reproduction technologies (ART) and malignant rhabdoid tumors (MRT). We performed a multi-institutional retrospective analysis of the EU-RHAB database, complemented by additional cases outside of EU-RHAB to compile clinical, (epi)genetic characteristics and outcome data of children with MRT following ART. METHODS: Data of 14 patients (from 311 patients with MRT) from 9 countries were analyzed (2010-2018). Tumors and matching blood samples were examined for SMARCB1 mutations using FISH, MLPA and sequencing. Molecular subgroups were determined using DNA methylation arrays and correlated with a validation cohort (n=22, tumor samples of MRT; n=39 blood samples of patients small for gestational age). RESULTS: The median age at diagnosis of the 13 girls and 1 boy was 9 months (0 – 66). 8 patients with ATRT, 3 with extracranial, extrarenal-, 1 with renal rhabdoid tumor and 2 with synchronous tumors were identified. Distant metastases at diagnosis were present in 6 patients. A germline mutation (GLM) was detected in 5 patients. In 11 tumors complete data on SMARCB1 mutational status were available. DNA methylation subgrouping was available in 10 tumors and 6 blood samples. A female predominance was noted as compared to the EU-RHAB cohort with MRT born without ART (n=213, p=0.009). A total of 8 patients received gross total resection, n=12 patients received conventional chemotherapy (EU-RHAB=9, Head Start II=2, IRS III=1). Radiotherapy was applied to 6 patients. 10 patients achieved CR, and 5 remain in continuing CR. Significant genome-wide DNA methylation differences (including imprinted genes) between patients born after ART and patients born without ART could not be demonstrated. CONCLUSIONS: Long-term survival is achievable in patients who develop MRT after ART, even in cases with GLM, metastatic disease at diagnosis, or relapse. Larger epidemiological studies are needed to confirm a potential association between MRT and ART.
Abstract Background Limited data on the prevalence and medical care of sickle cell disease (SCD) in Germany are available. Here, we make use of a patient registry to characterize the burden of disease and the treatment modalities for patients with SCD in Germany. Procedure A nationwide German registry for patients with SCD documents basic data on diagnosis and patient history retrospectively at the time of registration. A prospective annual documentation provides more details on complications and treatment of SCD. For the current analyses, data of 439 patients were available. Results Most patients had homozygous SCD (HbSS 75.1%, HbS/β‐thalassemia 13.2%, and HbSC 11.3%). The median age at diagnosis was 1.9 years (interquartile range, 0.6‐4.4 years), most patients were diagnosed when characteristic symptoms occurred. Sepsis and stroke had affected 3.2% and 4.2% of patients, respectively. During the first year of observation, 48.3% of patients were admitted to a hospital and 10.1% required intensive care. Prophylactic penicillin was prescribed to 95.6% of patients with homozygous SCD or HbS/β thalassemia below the age of six and hydroxycarbamide to 90.4% of patients above the age of two years. At least one annual transcranial Doppler ultrasound was documented for 74.8% of patients between 2 and 18 years. Conclusion With an estimated number of at least 2000, the prevalence of SCD in Germany remains low. Prospectively, we expect that the quality of care for children with SCD will be further improved by an earlier diagnosis after the anticipated introduction of a newborn screening program for SCD.
As the pathogenesis of rhabdoid tumors (RT) relies on epigenetic disturbances a potential link to assisted reproductive technologies (ART) deserves further analyses. We analyzed patients conceived by ART (egg donation, ICSI, ivF) from EU-RHAB (n=8), the US (n=2), Iran (n=1), Lithuania (n=1) and Spain (n=1). Genetic and clinical evaluation included SMARCB1 and/or SMARCA4 (FISH, MLPA, sequencing) mutation analysis and immunohistochemistry. Seven patients presented with AT/RT, four with extracranial RT and two demonstrated synchronous-, multifocal tumors. Metastases were present in 5 patients. Germline mutations (GLM) in SMARCB1 were detected in 4/9 (c.1110delG, c.141C>A, c.751delG, in one GLM not specified). Somatic mutations were analyzed in 8 children. The majority (69%) exhibited single nucleotide variants (c.1110delG, c.1148delC, c.197C>A, c.472C>T, c.141C>A, c.751delG), while partial/whole gene deletions (delTBX1_NIPSNAP1, delGNAZ_SMARCB1, delGNAZ_SEZ6L, delSMARCB1) were observed in 31%. A total resection (GTR) was achieved in 6/13. A total of 4 patients each received radiotherapy or HDCT. A CR was accomplished in 8 patients, three of them are alive 76, 72 and 10 months from diagnosis. Children born following ART appear to be at risk for the development of RT. Our data warrant evaluation whether this risk is increased when compared to the occurrence of RT in the general population and what the epi-, genetic mechanisms for this phenomenon might be. Supported by grants to MCF by the “Deutsche Kinderkrebsstiftung” DKKS 2010.03 and the parents organization Lichtblicke, Augsburg.
