Diagnostic magnetic resonance imaging characteristics of congenital mesoblastic nephroma: a retrospective multi-center International Society of Pediatric Oncology-Renal Tumor Study Group (SIOP-RTSG) radiology panel study.

BACKGROUND: Congenital mesoblastic nephroma is the most common solid renal tumor in neonates. Therefore, patients <3 months of age are advised to undergo upfront nephrectomy, whereas invasive procedures at diagnosis in patients ≥3 months of age are discouraged by the International Society of Pediatric Oncology-Renal Tumor Study Group (SIOP-RTSG). Nevertheless, discriminating congenital mesoblastic nephroma, especially from the more common Wilms tumor, solely based on imaging remains difficult. Recently, magnetic resonance imaging (MRI) has become the preferred modality. Studies focusing on MRI characteristics of congenital mesoblastic nephroma are limited. OBJECTIVE: This study aims to identify diagnostic MRI characteristics of congenital mesoblastic nephroma in the largest series of patients to date. MATERIALS AND METHODS: In this retrospective multicenter study, five SIOP-RTSG national review radiologists identified 52 diagnostic MRIs of histologically proven congenital mesoblastic nephromas. MRI was performed following SIOP-RTSG protocols, while radiologists assessed their national cases using a validated case report form. RESULTS: Patients (24/52 classic, 11/52 cellular, and 15/52 mixed type congenital mesoblastic nephroma, 2/52 unknown) had a median age of 1 month (range 1 day-3 months). Classic type congenital mesoblastic nephroma appeared homogeneous with a lack of hemorrhage, necrosis and/or cysts, showing a concentric ring sign in 14 (58.3%) patients. Cellular and mixed type congenital mesoblastic nephroma appeared more heterogeneous and were larger (311.6 and 174.2 cm3, respectively, versus 41.0 cm3 for the classic type (P<0.001)). All cases were predominantly T2-weighted isointense and T1-weighted hypointense, and mean overall apparent diffusion coefficient values ranged from 1.05-1.10×10-3 mm2/s. CONCLUSION: This retrospective international collaborative study showed classic type congenital mesoblastic nephroma predominantly presented as a homogeneous T2-weighted isointense mass with a typical concentric ring sign, whereas the cellular type appeared more heterogeneous. Future studies may use identified MRI characteristic of congenital mesoblastic nephroma for validation and for exploring the discriminative non-invasive value of MRI, especially from Wilms tumor.

Different subtypes of chronic fatigue in childhood cancer survivors: A DCCSS LATER study.

INTRODUCTION: The aim of the current study was to investigate whether subtypes of chronic fatigue (CF) can be identified in childhood cancer survivors (CCS), and if so, to determine the characteristics of participants with a specific subtype. METHODS: Participants were included from the nationwide DCCSS LATER cohort. The Checklist Individual Strength (CIS) was completed to assess fatigue. Participants with CF (scored ≥35 on the fatigue severity subscale and indicated to suffer from fatigue for ≥6 months) were divided into subgroups using two-step cluster analysis based on the CIS concentration, motivation, and physical activity subscales. Differences between groups on demographics, psychosocial, lifestyle, and treatment-related variables were determined using ANOVA and chi-square analyses (univariable) and multinomial regression analysis (multivariable). RESULTS: A total of 1910 participants participated in the current study (n = 450 with CF; n = 1460 without CF). Three CF subgroups were identified: Subgroup 1 (n = 133, 29% of participants) had CF with problems in physical activity; Subgroup 2 (n = 111, 25% of participants) had CF with difficulty concentrating; and Subgroup 3 (n = 206, 46% of participants) had multi-dimensional CF. Compared to Subgroup 1, Subgroup 2 more often reported sleep problems, limitations in social functioning, and less often have more than two comorbidities. Subgroup 3 more often reported depression, sleep problems, a lower self-esteem, and limitations in social functioning and a lower educational level compared to Subgroup 1. CONCLUSION: Different subgroups of CCS with CF can be identified based on fatigue dimensions physical activity, motivation and concentration. Results suggest that different intervention strategies, tailored for each subgroup, might be beneficial.

Long-term neurocognitive, psychosocial, and physical outcomes after prenatal exposure to radiotherapy: a multicentre cohort study of the International Network on Cancer, Infertility, and Pregnancy.

BACKGROUND: The main data available on the safety of radiation during pregnancy originate from animal studies and from studies of survivors of atomic or nuclear disasters. The effect of radiotherapy to treat maternal cancer on fetal development is uncertain. This report presents a unique cohort and aims to determine the long-term neurocognitive, psychosocial and physical outcomes of offspring of mothers treated with radiotherapy during pregnancy. METHODS: In this international, multicentre, mixed retrospective-prospective cohort study, we recruited participants between Aug 5, 2006, and Aug 24, 2023, aged between 1·5 and 46 years, at three referral centres in Belgium, the Netherlands, and the USA. Participants were eligible if they were born from mothers treated with radiotherapy during pregnancy. Fetal radiation doses were obtained from medical records and participants were followed up at predefined ages (1·5, 3, 6, 9, 12, 15, and 18 years) and 5-yearly in adulthood, based on age at enrolment, using a neurocognitive test battery (measuring intelligence, attention, and memory), parent-reported executive function and psychosocial questionnaires, and a medical assessment. Results were compared with test-specific normative data. Linear regression models investigated associations between radiotherapy factors (fetal radiation dose, gestational age at the start and end of radiotherapy, and radiotherapy duration) and outcomes. FINDINGS: 68 maternal cases of radiotherapy during pregnancy were registered by the three participating centres, of which 61 resulted in a livebirth and were therefore eligible to participate in the child follow-up study. After excluding those who did not give consent, 43 participants born from 42 mothers treated with radiotherapy during pregnancy were included in the study (median age at first assessment 3 years [IQR 2-11]; median age at last assessment 12 years [9-18]; median number of assessments two [1-4]). 18 (42%) of the included participants were female and 25 (58%) male, and 37 (86%) were of White ethnicity. Mean neurocognitive outcomes of the entire cohort were within normal ranges. No associations were found with fetal radiation dose or timing of radiotherapy during pregnancy. Six (16%) of 38 participants with neurocognitive outcomes scored lower than one SD on at least one neurocognitive outcome, three (7%) reported chronic medical conditions (spasmophilia, spastic diplegia, and IgG deficiency), and three (7%) were diagnosed with attention-deficit hyperactivity disorder (of whom two scored lower on attention). Of ten (23%) participants with lower neurocognitive score(s), a chronic medical condition, or attention-deficit hyperactivity disorder, eight were born preterm. The remaining 33 (77%) participants showed no neurocognitive, psychosocial, or chronic physical problems. INTERPRETATION: We show on average normal neurocognitive, psychosocial, and physical outcomes after prenatal exposure to radiotherapy. Differences in outcomes could not be explained by exposure to radiotherapy during pregnancy. These results suggest that extra-abdomino-pelvic radiotherapy exposure during pregnancy in general does not adversely affect outcomes of liveborn children. Further research with a larger sample is necessary to confirm these findings. FUNDING: Kom Op Tegen Kanker, KWF Kankerbestrijding, Stichting Tegen Kanker, Research Foundation Flanders.

Prevention of cisplatin-induced hearing loss in children: achievements and challenges for evidence-based implementation of sodium Thiosulfate.

Ototoxicity is a devastating direct, irreversible side effect of platinum use in children with cancer, with its consequent effect on speech, language and social development, quality of life and adult productivity. Cisplatin, an essential chemotherapeutic agent for the treatment of solid tumors in children, is a DNA cross-linking agent. Which causes hearing loss in 50-70% of cisplatin treated children. Fortunately, to prevent hearing loss, sodium thiosulfate (STS), which binds to cisplatin, and reduces the superoxides in both tumor and outer hair cells of the cochlea has now been discovered to be an effective and safe otoprotectant if administered correctly. The aim of this perspective paper is to explore the key safety issues and challenges important for pediatric oncologists and pharmacists when considering the clinical use of STS as an otoprotectant for children and adolescents receiving cisplatin. These include: the choice of the formulation; the timing, both that of the STS in relation to cisplatin as well as the timing of the cisplatin infusion itself; the dosing; the challenge left by the definition of localized versus disseminated disease and the difference in indication for STS, between cisplatin treated patients and those receiving another platinum chemotherapeutic agent, carboplatin.

Efficacy and safety of azacitidine in pediatric patients with newly diagnosed advanced myelodysplastic syndromes before hematopoietic stem cell transplantation in the AZA-JMML-001 trial.

Here we report efficacy, pharmacokinetics, and safety data obtained in treatment-naive, pediatric patients with newly diagnosed advanced MDS receiving azacitidine in the AZA-JMML-001 study. The primary endpoint was response rate (proportion of patients with complete response [CR], partial response [PR], or marrow CR, sustained for ≥4 weeks). Of the 10 patients enrolled, one had an unconfirmed marrow CR and none had confirmed responses after three cycles; the study was therefore closed after stage 1. Azacitidine was well tolerated. The lack of efficacy of azacitidine in pediatric patients with newly diagnosed advanced MDS highlights the need for effective new treatments in these patients.

Experiences of pediatric cancer patients (age 12-18 years) with extensive germline sequencing for cancer predisposition: a qualitative study.

This study explored the experiences and needs of adolescents, ranging from 12 to 18 years old, who have recently been diagnosed with cancer and participated in a nationwide germline genetic sequencing study within the context of pediatric oncology. The 21 adolescents in this qualitative interview study viewed genetic sequencing as an integral part of their cancer journey. They often characterized germline sequencing as "good-to-know" without specifying immediate utility. While the adolescents comprehended the significance of germline genetic sequencing, they were less focused on its potential long-term implications. Adolescents expressed a strong desire to be actively engaged in decisions related to genetics. They advocated for a participatory role in genetic decision-making from a young age onwards. They recommended that re-consent should be sought before re-analysis of their genetic data is performed and believe that patients should have the opportunity to provide (re-)consent once they reach adulthood. Moreover, the adolescents emphasized the importance of developing counseling materials that are not only concise but also visually attractive. In conclusion, this study underscores the positive perception that adolescents diagnosed with cancer hold regarding germline genetic sequencing. They articulate a strong interest in being actively involved in genetic decision-making. To address these articulated needs and preferences, we recommend the development of visually engaging counseling materials. These materials should effectively convey both the immediate and long-term implications of genetic sequencing, enabling adolescents with cancer to make informed decisions about genetic sequencing.

The role of the mineralocorticoid receptor in steroid-induced cytotoxicity in pediatric acute lymphoblastic leukemia.

Not available.

Reproductive outcomes and reproductive health care utilization among male survivors of childhood cancer: A DCCSS-LATER study.

BACKGROUND: Treatment-related gonadal dysfunction leading to fertility problems is a frequently encountered late effect in childhood cancer survivors (CCSs). This study evaluated reproductive outcomes and reproductive health care utilization among male CCSs compared with male siblings. METHODS: A nationwide cohort study was conducted as part of the Dutch Childhood Cancer Survivor LATER study part 1, a questionnaire and linkage study. A questionnaire addressing reproductive outcomes and reproductive health care was completed by 1317 male CCSs and 407 male siblings. A total of 491 CCSs and 185 siblings had a previous or current desire for children and were included in this study. RESULTS: Fewer CCSs had biological children compared with siblings (65% vs. 88%; p < .001). The type of conception by men who fathered a child was comparable between CCSs and siblings (spontaneous conception of 90% of both groups; p = .86). The percentage of men who had consulted a reproductive specialist because of not siring a pregnancy was higher in CCSs compared with siblings (34% vs. 12%; p < .001). Following consultation, fewer CCSs underwent assisted reproductive techniques (ART) compared with siblings (41% vs. 77%; p = .001). After ART, fewer CCSs fathered a child compared with siblings (49% vs. 94%; p = .001). CONCLUSIONS: More male survivors consult a reproductive specialist, but fewer survivors undergo ART and father a child after ART compared with siblings. This insight is important for understanding potential problems faced by survivors regarding family planning and emphasizes the importance of collaboration between oncologists and reproductive specialists.

Leptin Increase During Dexamethasone and Its Association With Hunger and Fat in Pediatric Acute Lymphoblastic Leukemia.

CONTEXT: During treatment, children with acute lymphoblastic leukemia (ALL) receive high doses dexamethasone, which induce acute side effects. OBJECTIVE: To determine the influence of a 5-day dexamethasone course on changes in leptin, fat mass, BMI, hunger, sleep, and fatigue and to explore associations between these changes. METHODS: Pediatric ALL patients were included during maintenance treatment. Data were collected before (T1) and after (T2) a 5-day dexamethasone course (6 mg/m2/day). At both time points, BMI, fat mass (bioelectrical impedance analysis), and leptin were assessed, as well as parent-reported questionnaires regarding hunger, fatigue, and sleep problems. Changes between T1 and T2 were assessed using paired tests. Correlation coefficients were calculated to assess associations between these changes (Delta scores: T2-T1). Univariable regression models were estimated to study associations between covariates and elevated leptin. RESULTS: We included 105 children, with median age 5.4 years (range, 3.0-18.8). Leptin and fat mass, as well as hunger scores, fatigue, and sleep deteriorated after 5 days of dexamethasone (P < .001), in contrast to BMI (P = .12). No correlations between delta leptin and delta fat mass, BMI, hunger, fatigue, or sleep were found. Elevated leptin on T1 was associated with older age (odds ratio [OR] 1.51; 95% CI, 1.28-1.77), higher fat mass (OR 1.19; 95% CI, 1.07-1.33), and earlier maintenance week (OR 0.96; 95% CI, 0.92-0.99). CONCLUSION: Five days of high-dose dexamethasone treatment led to direct and significant changes in leptin, hunger scores, and fat mass. Since children with ALL are at increased risk for metabolic adverse events, understanding underlying mechanisms is important, and a dexamethasone-induced state of acute leptin resistance might play a role.

The cumulative burden of self-reported, clinically relevant outcomes in long-term childhood cancer survivors and implications for survivorship care: A DCCSS LATER study.

BACKGROUND: The aim of this study is to evaluate how cumulative burden of clinically relevant, self-reported outcomes in childhood cancer survivors (CCSs) compares to a sibling control group and to explore how the burden corresponds to levels of care proposed by existing risk stratifications. METHODS: The authors invited 5925 5-year survivors from the Dutch Childhood Cancer Survivor Study (DCCSS LATER) cohort and their 1066 siblings to complete a questionnaire on health outcomes. Health outcomes were validated by self-reported medication use or medical record review. Missing data on clinically relevant outcomes in CCSs for whom no questionnaire data were available were imputed with predictive mean matching. We calculated the mean cumulative count (MCC) for clinically relevant outcomes. Furthermore, we calculated 30-year MCC for groups of CCSs based on primary cancer diagnosis and treatment, ranked 30-year MCC, and compared the ranking to levels of care according to existing risk stratifications. RESULTS: At median 18.5 years after 5-year survival, 46% of CCSs had at least one clinically relevant outcome. CCSs experienced 2.8 times more health conditions than siblings (30-year MCC = 0.79; 95% confidence interval [CI], 0.74-0.85 vs. 30-year MCC = 0.29; 95% CI, 0.25-0.34). CCSs' burden of clinically relevant outcomes consisted mainly of endocrine and vascular conditions and varied by primary cancer type. The ranking of the 30-year MCC often did not correspond with levels of care in existing risk stratifications. CONCLUSIONS: CCSs experience a high cumulative burden of clinically relevant outcomes that was not completely reflected by current risk stratifications. Choices for survivorship care should extend beyond primary tumor and treatment parameters, and should consider also including CCSs' current morbidity.

Physical frailty deteriorates after a 5-day dexamethasone course in children with acute lymphoblastic leukemia, results of a national prospective study.

BACKGROUND: Dexamethasone is important in the treatment for pediatric acute lymphoblastic leukemia (ALL) but induces muscle atrophy with negative consequences for muscle mass, muscle strength, and functional abilities. The aim of this study was to establish the effect of a dexamethasone course on sarcopenia and physical frailty in children with ALL, and to explore prognostic factors. METHODS: Patients with ALL aged 3-18 years were included during maintenance therapy. Patients had a sarcopenia/frailty assessment on the first day of (T1) and on the day after (T2) a 5-day dexamethasone course. Sarcopenia was defined as low muscle strength in combination with low muscle mass. Prefrailty and frailty were defined as having two or ≥three of the following components, respectively: low muscle mass, low muscle strength, fatigue, slow walking speed, and low physical activity. Chi-squared and paired t-tests were used to assess differences between T1 and T2. Logistic regression models were estimated to explore patient- and therapy-related prognostic factors for frailty on T2. RESULTS: We included 105 patients, 61% were boys. Median age was 5.3 years (range: 3-18.8). At T1, sarcopenia, prefrailty, and frailty were observed in respectively 2.8%, 23.5%, and 4.2% of patients. At T2, the amount of patients with frailty had increased to 17.7% (p = 0.002), whereas the number of patients with sarcopenia and prefrailty remained similar. Higher ASMM (odds ratio [OR]: 0.49, 95% CI: 0.28-0.83), stronger handgrip strength (OR: 0.41, 95% CI: 0.22-0.77) and more physical activity minutes per day (OR: 0.98, 95% CI: 0.96-0.99) decreased the risk of frailty at T2. Slower walking performance (OR: 2, 95% CI: 1.2-3.39) increased the risk. Fatigue levels at T1 were not associated with frailty at T2. CONCLUSION: Physical frailty increased strikingly after a 5-days dexamethasone course in children with ALL. Children with poor physical state at start of the dexamethasone course were more likely to be frail after the course.

Prevalence, risk factors, and optimal way to determine overweight, obesity, and morbid obesity in the first Dutch cohort of 2338 long-term survivors of childhood cancer: a DCCSS-LATER study.

BACKGROUND: Overweight and obesity are common challenges among childhood cancer survivors. Overweight may be disguised, as survivors can have normal weight but high fat percentage (fat%) on dual-energy X-ray absorptiometry (DXA). We aimed to assess prevalence, identify determinants and biomarkers, and assess which method captures overweight best, in a nationwide cohort. METHODS: The prevalence of overweight and obesity, primarily defined by body mass index (BMI), was assessed in the DCCSS-LATER cohort of adult survivors treated from 1963-2002, with the LifeLines cohort as reference. The associations between risk factors and overweight metrics were investigated using logistic regression. Additional overweight metrics included DXA fat%, waist circumference (WC), waist/hip ratio (WHR), waist/height ratio (WHtR), and high-molecular-weight (HMW) adiponectin. RESULTS: A total of 2338 (mean age 35.5 years, follow-up 28.3 years) survivors participated. The overweight prevalence was 46.3% in men and 44.3% in women (obesity 11.2% and 15.9%, morbid obesity 2.4% and 5.4%), with highest rates among brain tumor survivors. Compared to controls, there was no overall increased overweight rate, but this was higher in women > 50 years, morbid obesity in men > 50 years. Overweight at cancer diagnosis (adjusted odds ratio [aOR] = 3.83, 95% CI 2.19-6.69), cranial radiotherapy (aOR = 3.21, 95% CI 1.99-5.18), and growth hormone deficiency (separate model, aOR = 1.61, 95% CI 1.00-2.59) were associated with overweight. Using BMI, WC, WHR, and WHtR, overweight prevalence was similar. Low HMW adiponectin, present in only 4.5% of survivors, was an insensitive overweight marker. Dual-energy X-ray absorptiometry-based classification identified overweight in an additional 30%, particularly after abdominal radiotherapy, total body irradiation, anthracyclines, and platinum. CONCLUSIONS: Overweight occurs in almost half of long-term survivors. There was no overall increased incidence of overweight compared to controls. We identified factors associated with overweight, as well as subgroups of survivors in whom DXA can more reliably assess overweight.

The Value of IgM Memory B-Cells in the Assessment of Splenic Function in Childhood Cancer Survivors at Risk for Splenic Dysfunction: A DCCSS-LATER Study.

Background: Childhood cancer survivors (CCS) who received radiotherapy involving the spleen or total body irradiation (TBI) might be at risk for splenic dysfunction. A comprehensive screening test for examining splenic dysfunction is lacking. Objective: We investigated whether IgM memory B-cells could be used to assess splenic dysfunction in CCS who received a splenectomy, radiotherapy involving the spleen, or TBI. Methods: All CCS were enrolled from the DCCSS-LATER cohort. We analyzed differences in IgM memory B-cells and Howell-Jolly bodies (HJB) in CCS who had a splenectomy (n = 9), received radiotherapy involving the spleen (n = 36), or TBI (n = 15). IgM memory B-cells < 9 cells/µL was defined as abnormal. Results: We observed a higher median number of IgM memory B-cells in CCS who received radiotherapy involving the spleen (31 cells/µL, p=0.06) or TBI (55 cells/µL, p = 0.03) compared to CCS who received splenectomy (20 cells/µL). However, only two CCS had IgM memory B-cells below the lower limit of normal. No difference in IgM memory B-cells was observed between CCS with HJB present and absent (35 cells/µL vs. 44 cells/µL). Conclusion: Although the number of IgM memory B-cells differed between splenectomized CCS and CCS who received radiotherapy involving the spleen or TBI, only two CCS showed abnormal values. Therefore, this assessment cannot be used to screen for splenic dysfunction.

Hallmark discoveries in the biology of Wilms tumour.

The modern study of Wilms tumour was prompted nearly 50 years ago, when Alfred Knudson proposed the 'two-hit' model of tumour development. Since then, the efforts of researchers worldwide have substantially expanded our knowledge of Wilms tumour biology, including major advances in genetics - from cloning the first Wilms tumour gene to high-throughput studies that have revealed the genetic landscape of this tumour. These discoveries improve understanding of the embryonal origin of Wilms tumour, familial occurrences and associated syndromic conditions. Many efforts have been made to find and clinically apply prognostic biomarkers to Wilms tumour, for which outcomes are generally favourable, but treatment of some affected individuals remains challenging. Challenges are also posed by the intratumoural heterogeneity of biomarkers. Furthermore, preclinical models of Wilms tumour, from cell lines to organoid cultures, have evolved. Despite these many achievements, much still remains to be discovered: further molecular understanding of relapse in Wilms tumour and of the multiple origins of bilateral Wilms tumour are two examples of areas under active investigation. International collaboration, especially when large tumour series are required to obtain robust data, will help to answer some of the remaining unresolved questions.

MRI-based inter- and intrafraction motion analysis of the pancreatic tail and spleen as preparation for adaptive MRI-guided radiotherapy in neuroblastoma.

BACKGROUND: In pediatric radiotherapy treatment planning of abdominal tumors, dose constraints to the pancreatic tail/spleen are applied to reduce late toxicity. In this study, an analysis of inter- and intrafraction motion of the pancreatic tail/spleen is performed to estimate the potential benefits of online MRI-guided radiotherapy (MRgRT). MATERIALS AND METHODS: Ten randomly selected neuroblastoma patients (median age: 3.4 years), irradiated with intensity-modulated arc therapy at our department (prescription dose: 21.6/1.8 Gy), were retrospectively evaluated for inter- and intrafraction motion of the pancreatic tail/spleen. Three follow-up MRIs (T2- and T1-weighted ± gadolinium) were rigidly registered to a planning CT (pCT), on the vertebrae around the target volume. The pancreatic tail/spleen were delineated on all MRIs and pCT. Interfraction motion was defined as a center of gravity change between pCT and T2-weighted images in left-right (LR), anterior-posterior (AP) and cranial-caudal (CC) direction. For intrafraction motion analysis, organ position on T1-weighted ± gadolinium was compared to T2-weighted. The clinical radiation plan was used to estimate the dose received by the pancreatic tail/spleen for each position. RESULTS: The median (IQR) interfraction motion was minimal in LR/AP, and largest in CC direction; pancreatic tail 2.5 mm (8.9), and spleen 0.9 mm (3.9). Intrafraction motion was smaller, but showed a similar motion pattern (pancreatic tail, CC: 0.4 mm (1.6); spleen, CC: 0.9 mm (2.8)). The differences of Dmean associated with inter- and intrafraction motions ranged from - 3.5 to 5.8 Gy for the pancreatic tail and - 1.2 to 3.0 Gy for the spleen. In 6 out of 10 patients, movements of the pancreatic tail and spleen were highlighted as potentially clinically significant because of ≥ 1 Gy dose constraint violation. CONCLUSION: Inter- and intrafraction organ motion results into unexpected constrain violations in 60% of a randomly selected neuroblastoma cohort, supporting further prospective exploration of MRgRT.

Cellular senescence in kidney biopsies is associated with tubular dysfunction and predicts CKD progression in childhood cancer patients with karyomegalic interstitial nephropathy.

Karyomegalic interstitial nephropathy (KIN) has been reported as an incidental finding in patients with childhood cancer treated with ifosfamide. It is defined by the presence of tubular epithelial cells (TECs) with enlarged, irregular, and hyperchromatic nuclei. Cellular senescence has been proposed to be involved in kidney fibrosis in hereditary KIN patients. We report that KIN could be diagnosed 7-32 months after childhood cancer diagnosis in 6/6 consecutive patients biopsied for progressive chronic kidney disease (CKD) of unknown cause between 2018 and 2021. The morphometry of nuclear size distribution and markers for DNA damage (γH2AX), cell-cycle arrest (p21+, Ki67-), and nuclear lamina decay (loss of lamin B1), identified karyomegaly and senescence features in TECs. Polyploidy was assessed by chromosome fluorescence in situ hybridization (FISH). In all six patients the number of p21-positive TECs far exceeded the typically small numbers of truly karyomegalic cells, and p21-positive TECs contained less lysozyme, testifying to defective resorption, which explains the consistently observed low-molecular-weight (LMW) proteinuria. In addition, polyploidy of TEC was observed to correlate with loss of lysozyme staining. Importantly, in the five patients with the largest nuclei, the percentage of p21-positive TECs tightly correlated with estimated glomerular filtration rate loss between biopsy and last follow-up (R2 = 0.93, p < 0.01). We conclude that cellular senescence is associated with tubular dysfunction and predicts CKD progression in childhood cancer patients with KIN and appears to be a prevalent cause of otherwise unexplained CKD and LMW proteinuria in children treated with DNA-damaging and cell stress-inducing therapy including ifosfamide. © 2023 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Minimal Infiltrative Disease Identification in Cryopreserved Ovarian Tissue of Girls with Cancer for Future Use: A Systematic Review.

BACKGROUND: Ovarian tissue cryopreservation and transplantation are the only available fertility techniques for prepubertal girls with cancer. Though autotransplantation carries a risk of reintroducing malignant cells, it can be avoided by identifying minimal infiltrative disease (MID) within ovarian tissue. METHODS: A broad search for peer-reviewed articles in the PubMed database was conducted in accordance with PRISMA guidelines up to March 2023. Search terms included 'minimal residual disease', 'cryopreservation', 'ovarian', 'cancer' and synonyms. RESULTS: Out of 542 identified records, 17 were included. Ovarian tissues of at least 115 girls were evaluated and categorized as: hematological malignancies (n = 56; 48.7%), solid tumors (n = 42; 36.5%) and tumors of the central nervous system (n = 17; 14.8%). In ovarian tissue of 25 patients (21.7%), MID was detected using RT-qPCR, FISH or multicolor flow cytometry: 16 of them (64%) being ALL (IgH rearrangements with/without TRG, BCL-ABL1, EA2-PBX1, TEL-AML1 fusion transcripts), 3 (12%) Ewing sarcoma (EWS-FLI1 fusion transcript, EWSR1 rearrangements), 3 (12%) CML (BCR-ABL1 fusion transcript, FLT3) and 3 (12%) AML (leukemia-associated immunophenotypes, BCR-ABL1 fusion transcript) patients. CONCLUSION: While the majority of malignancies were found to have a low risk of containing malignant cells in ovarian tissue, further studies are needed to ensure safe implementation of future fertility restoration in clinical practice.