Concise handbook of familial cancer susceptibility syndromes - second edition

Advances in diagnosis and management of cancer of the esophagus

Esophageal cancer is the seventh most common malignancy worldwide, with over 470 000 new cases diagnosed each year. Two distinct histological subtypes predominate, and should be considered biologically separate disease entities.1 These subtypes are esophageal adenocarcinoma (EAC) and esophageal squamous cell carcinoma (ESCC). Outcomes remain poor regardless of subtype, with most patients presenting with late stage disease.2 Novel strategies to improve early detection of the respective precursor lesions, squamous dysplasia, and Barrett's esophagus offer the potential to improve outcomes. The introduction of a limited number of biologic agents, as well as immune checkpoint inhibitors, is resulting in improvements in the systemic treatment of locally advanced and metastatic esophageal cancer. These developments, coupled with improvements in minimally invasive surgical and endoscopic treatment approaches, as well as adaptive and precision radiotherapy technologies, offer the potential to improve outcomes still further. This review summarizes the latest advances in the diagnosis and management of esophageal cancer, and the developments in understanding of the biology of this disease.

Medical imaging utilization and associated radiation exposure in children with down syndrome

OBJECTIVE

To evaluate the frequency of medical imaging or estimated associated radiation exposure in children with Down syndrome.

METHODS

This retrospective cohort study included 4,348,226 children enrolled in six U.S. integrated healthcare systems from 1996-2016, 3,095 of whom were diagnosed with Down syndrome. We calculated imaging rates per 100 person years and associated red bone marrow dose (mGy). Relative rates (RR) of imaging in children with versus without Down syndrome were estimated using overdispersed Poisson regression.

RESULTS

Compared to other children, children with Down syndrome received imaging using ionizing radiation at 9.5 times (95% confidence interval[CI] = 8.2-10.9) the rate when age <1 year and 2.3 times (95% CI = 2.0-2.5) between ages 1-18 years. Imaging rates by modality in children <1 year with Down syndrome compared with other children were: computed tomography (6.6 vs. 2.0, RR = 3.1[95%CI = 1.8-5.1]), fluoroscopy (37.1 vs. 3.1, RR 11.9[95%CI 9.5-14.8]), angiography (7.6 vs. 0.2, RR = 35.8[95%CI = 20.6-62.2]), nuclear medicine (6.0 vs. 0.6, RR = 8.2[95% CI = 5.3-12.7]), radiography (419.7 vs. 36.9, RR = 11.3[95%CI = 10.0-12.9], magnetic resonance imaging(7.3 vs. 1.5, RR = 4.2[95% CI = 3.1-5.8]), and ultrasound (231.2 vs. 16.4, RR = 12.6[95% CI = 9.9-15.9]). Mean cumulative red bone marrow dose from imaging over a mean of 4.2 years was 2-fold higher in children with Down syndrome compared with other children (4.7 vs. 1.9mGy).

CONCLUSIONS

Children with Down syndrome experienced more medical imaging and higher radiation exposure than other children, especially at young ages when they are more vulnerable to radiation. Clinicians should consider incorporating strategic management decisions when imaging this high-risk population.

[Prepubertal gynecomastia at the debut of hereditary tumors predisposition syndrome (clinical case reports)]

Peutz-Jeghers Syndrome (Peutz-Jeghers Syndrome, PJS) refers to syndromes of hereditary tumor predisposition and is caused by pathological variants of the STK11 gene, leading to a defect in the synthesis of serine/threonine kinase 11 protein, which acts as a tumor suppressor.Clinical symptoms of the syndrome are combination of hamartomatous polyposis of the gastrointestinal tract and specific skin-mucosal hyperpigmentation. Also, this disease is characterized by a high risk of developing gastrointestinal and extra-intestinal tumors, including benign or malignant tumors of the reproductive system.One of the first signs of the disease in male patients may be prepubertal gynecomastia associated with large-cell calcifying Sertoli cells tumors expressing aromatase. In contrast to from pubertal gynecomastia, prepubertal is extremely rare, and it is often based on pathological causes. Early diagnosis of patients with pre-pubertal gynecomastia, including Peitz-Jaegers syndrome, defines the tactics of gynecomastia management and protocols for monitoring the development of other components of the disease in the future.This article describes two patients with pre-pubertal gynecomastia and Peitz-Jaegers syndrome with different molecular genetic defects: in one case associated with duplication of the STK11 gene site, in the other - with microdeletion of the short arm of chromosome 19 containing this gene.

Somatic and germline ATM variants in non-small-cell lung cancer: Therapeutic implications

ATM is an apical kinase of the DNA damage response involved in the repair of DNA double-strand breaks. Germline ATM variants (gATM) have been associated with an increased risk of developing lung adenocarcinoma (LUAD), and approximately 9% of LUAD tumors harbor somatic ATM mutations (sATM). Biallelic carriers of pathogenic gATM exhibit a plethora of immunological abnormalities, but few studies have evaluated the contribution of immune dysfunction to lung cancer susceptibility. Indeed, little is known about the clinicopathological characteristics of lung cancer patients with sATM or gATM alterations. The introduction of targeted therapies and immunotherapies, and the increasing number of clinical trials evaluating treatment combinations, warrants a careful reexamination of the benefits and harms that different therapeutic approaches have had in lung cancer patients with sATM or gATM. This review will discuss the role of ATM in the pathogenesis of lung cancer, highlighting potential therapeutic approaches to manage ATM-deficient lung cancers.

Genomics-Driven Precision Medicine in Pediatric Solid Tumors

Over the past decades, several study programs have conducted genetic testing in cancer patients to identify potential genetic targets for the development of precision therapeutic strategies. These biomarker-driven trials have demonstrated improved clinical outcomes and progression-free survival rates in various types of cancers, especially for adult malignancies. However, similar progress in pediatric cancers has been slow due to their distinguished mutation profiles compared to adults and the low frequency of recurrent genomic alterations. Recently, increased efforts to develop precision medicine for childhood malignancies have led to the identification of genomic alterations and transcriptomic profiles of pediatric patients which presents promising opportunities to study rare and difficult-to-access neoplasms. This review summarizes the current state of known and potential genetic markers for pediatric solid tumors and provides perspectives on precise therapeutic strategies that warrant further investigations.

STK11 Causative Variants and Copy Number Variations Identified in Thai Patients With Peutz-Jeghers Syndrome

Introduction Peutz-Jeghers syndrome (PJS) is a rare autosomal dominant inherited disorder caused by germline mutations in the serine-threonine kinase 11 (STK11) tumor suppressor gene. This syndrome is characterized by hamartomatous gastrointestinal polyps, mucocutaneous melanin pigmentation, and a higher risk of developing various cancers. Methods We summarized the clinical and molecular characteristics of five unrelated Thai patients with PJS. Denaturing high-performance liquid chromatography (DHPLC) screening, coupled with direct DNA sequencing and multiplex ligation-dependent probe amplification (MLPA), were applied for the molecular analysis of STK11. Results A total of four STK11 pathogenic changeswere identified in the five PJS patients, including two frameshift variants (a novel c.199dup, p.Leu67ProfsTer96 and a known c.834_835del, p.Cys278TrpfsTer6) and two types of copy number variations (CNV), exon 1 deletion and exons 2-3 deletion. Among reported STK11 exonic deletions, exon 1 and exons 2-3 deletions were found to be the two most commonly deleted exons. Conclusion All identified STK11 mutations were null mutations that were associated with more severe PJS phenotypes and cancers. This study broadens the phenotypic and mutational spectrum of STK11 in PJS.

Occurrence of variants of unknown clinical significance in genetic testing for hereditary breast and ovarian cancer syndrome and Lynch syndrome: a literature review and analytical observational retrospective cohort study

BACKGROUND AND PURPOSE

Over the last decade, the implementation of multigene panels for hereditary tumor syndrome has increased at our institution (Inselspital, University Hospital Berne, Switzerland). The aim of this study was to determine the prevalence of variants of unknown significance (VUS) in patients with suspected Lynch syndrome and suspected hereditary breast and ovarian cancer syndrome, the latter in connection with the trend toward ordering larger gene panels.

RESULTS

Retrospectively collected data from 1057 patients at our institution showed at least one VUS in 126 different cases (11.9%). In patients undergoing genetic testing for BRCA1/2, the prevalence of VUS was 6%. When < 10 additional genes were tested in addition to BRCA1/2, the prevalence increased to 13.8%, and 31.8% for > 10 additional genes, respectively. The gene most frequently affected with a VUS was ATM. 6% of our patients who were tested for Lynch syndrome had a VUS result in either MLH1, MSH2 or MSH6.

CONCLUSIONS

Our data demonstrate that panel testing statistically significantly increases VUS rates due to variants in non-BRCA genes. Good genetic counseling before and after obtaining results is therefore particularly important when conducting multigene panels to minimize patient uncertainty due to VUS results.

From the patient to the population: Use of genomics for population screening

Genomic medicine is expanding from a focus on diagnosis at the patient level to prevention at the population level given the ongoing under-ascertainment of high-risk and actionable genetic conditions using current strategies, particularly hereditary breast and ovarian cancer (HBOC), Lynch Syndrome (LS) and familial hypercholesterolemia (FH). The availability of large-scale next-generation sequencing strategies and preventive options for these conditions makes it increasingly feasible to screen pre-symptomatic individuals through public health-based approaches, rather than restricting testing to high-risk groups. This raises anew, and with urgency, questions about the limits of screening as well as the moral authority and capacity to screen for genetic conditions at a population level. We aimed to answer some of these critical questions by using the WHO Wilson and Jungner criteria to guide a synthesis of current evidence on population genomic screening for HBOC, LS, and FH.

Cancer Effects of Low to Moderate Doses of Ionizing Radiation in Young People with Cancer-Predisposing Conditions: A Systematic Review

Moderate to high doses of ionizing radiation (IR) are known to increase the risk of cancer, particularly following childhood exposure. Concerns remain regarding risks from lower doses and the role of cancer-predisposing factors (CPF; genetic disorders, immunodeficiency, mutations/variants in DNA damage detection or repair genes) on radiation-induced cancer (RIC) risk. We conducted a systematic review of evidence that CPFs modify RIC risk in young people. Searches were performed in PubMed, Scopus, Web of Science, and EMBASE for epidemiologic studies of cancer risk in humans (&lt;25 years) with a CPF, exposed to low-moderate IR. Risk of bias was considered. Fifteen articles focusing on leukemia, lymphoma, breast, brain, and thyroid cancers were included. We found inadequate evidence that CPFs modify the risk of radiation-induced leukemia, lymphoma, brain/central nervous system, and thyroid cancers and limited evidence that BRCA mutations modify radiation-induced breast cancer risk. Heterogeneity was observed across studies regarding exposure measures, and the numbers of subjects with CPFs other than BRCA mutations were very small. Further studies with more appropriate study designs are needed to elucidate the impact of CPFs on RIC. They should focus either on populations of carriers of specific gene mutations or on common susceptible variants using polygenic risk scores.

What can we learn from more than 1,000 Brazilian patients at risk of hereditary cancer?

Background

Identifying individuals at a higher risk of developing cancer is a major concern for healthcare providers. Cancer predisposition syndromes are the underlying cause of cancer aggregation and young-onset tumors in many families. Germline genetic testing is underused due to lack of access, but Brazilian germline data associated with cancer predisposition syndromes are needed.

Methods

Medical records of patients referred for genetic counseling at the Oncogenetics Department at the Hospital Sírio-Libanês (Brasília, DF, Brazil) from July 2017 to January 2021 were reviewed. The clinical features and germline findings were described. Detection rates of germline pathogenic/likely pathogenic variant (P/LPV) carriers were compared between international and Brazilian guidelines for genetic testing.

Results

A total of 1,091 individuals from 985 families were included in this study. Most patients (93.5%) had a family history of cancer, including 64% with a family member under 50 with cancer. Sixty-six percent of patients (720/1091) had a personal history of cancer. Young-onset cancers (&lt;50 years old) represented 62% of the patients affected by cancer and 17% had multiple primary cancers. The cohort included patients with 30 different cancer types. Breast cancer was the most prevalent type of cancer (52.6%). Germline testing included multigene panel (89.3%) and family variant testing (8.9%). Approximately 27% (236/879) of the tested patients harbored germline P/LPVs in cancer susceptibility genes. BRCA2, BRCA1, and TP53 were the most frequently reported genes, corresponding to 18.6%, 14.4%, and 13.5% of the positive results, respectively. Genetic testing criteria from international guidelines were more effective in identifying carriers than the Brazilian National Agency of Supplementary Health (ANS) criteria (92% vs. 72%, p&lt;0.001). Forty-six percent of the cancer-unaffected patients who harbored a germline P/LPV (45/98) would not be eligible for genetic testing according to ANS because they did not have a family variant previously identified in a cancer-affected relative.

Conclusion

The high detection rate of P/LPVs in the present study is possibly related to the genetic testing approach with multigene panels and cohort’s characteristics, represented mainly by individuals with a personal or family history of young-onset cancer. Testing asymptomatic individuals with suspicious family history may also have contributed to a higher detection rate. A significant number of carriers would not have been identified using ANS criteria for genetic testing.

The Mutation of CD27 Deficiency Presented With Familial Hodgkin Lymphoma and a Review of the Literature

This study aimed to report 4 siblings with CD27 deficiency presented with Hodgkin lymphoma. The father of the family, his 2 wives, and 17 children born from these wives were included into the study. CD27 mutation of all the family members with, and without Hodgkin lymphoma were studied. The variants detected by the exome sequencing analysis were verified by Sanger sequencing and analyzed using SeqScape Software 3. It was determined that both the father of the family and his 2 wives carried the same variant heterozygously. Of the children born to the first mother, 2 children were normal, 3 were heterozygous and 5 were homozygous. Four of these 5 homozygous children were diagnosed with Hodgkin lymphoma. Of the children born to the second mother, 1 child was normal, 3 children were heterozygous and 2 children were homozygous, and none of them had developed a malignant event. We also showed that CD27 deficiency may enhance Treg differentiation. According to our information, this study augmented the relationship of Hodgkin lymphoma and CD27 deficiency. The detection of homozygous CD27 variant in all siblings who developed lymphoma strengthened the place of this mutation in the etiology of Hodgkin lymphoma. In contrast, the presence of homozygous siblings with no malignant event suggested the possible contributions of environmental factors on the etiology.

Geospatial Assessment of Pesticide Concentration in Ambient Air and Colorectal Cancer Incidence in Arkansas, 2013-2017

Exposure to various agricultural pesticides has been linked to colorectal cancer (CRC), mostly among farmworkers and applicators. Given the potential pesticide drift in ambient air, residents near farmland may be exposed to carcinogenic pesticides even if they are not actively engaged in pesticide application. Pesticide air pollution at the county level was estimated using the 2014 National Air Toxics Assessment. CRC incidence data were acquired from the Arkansas Central Cancer Registry for 2013-2017. We ran ordinary least squares (OLS) regression models, finding significant spatial autocorrelation of residuals for most models. Using geographically weighted regression (GWR) we found age-adjusted CRC incidence rates vary in an increasing west-to-east gradient, with the highest rates in the Arkansas Delta region. A similar gradient was observed in the distribution of the population living below the poverty line and the population percentage of Black people. Significant associations between Trifluralin (crude model only), Carbon Tetrachloride, and Ethylene Dibromide with CRC incidence rates in OLS models only explained 5-7% of the variation and exhibited spatial autocorrelation of residuals. GWR models explained 24-32% (adjusted r² 9-16%) of CRC incidence rate variation, suggesting additional factors may contribute to the association between pesticides and CRC.

Update on Management of Squamous Cell Esophageal Cancer

PURPOSE OF THE REVIEW

Esophageal cancer is the sixth most common cause of cancer death globally. Squamous cell carcinoma of the esophagus (ESCC) is the predominant histologic type in the world. Treatment strategies have evolved in the last decade and new paradigms are replacing traditional approaches at all stages of cancer. This review will summarize the epidemiology, diagnosis, staging, and treatment of esophageal squamous cell carcinoma.

RECENT FINDINGS

Novel approaches to screening may be cost-effective in regions with a high incidence of ESCC. Multi-disciplinary evaluation and treatment has become the standard of care. Endoscopic resection may be an option for early stage ESCC. Minimally invasive esophagectomy can be performed safely as a primary therapy or after-induction chemoradiation. Several recent studies have found a survival benefit to immunotherapy for patients with metastatic or persistent disease. Multi-disciplinary evaluation and multi-modal therapy including cytotoxic chemotherapy, radiation, surgery, and immunotherapy have improved survival compared to surgery alone.

The need for tumor surveillance of children and adolescents with cancer predisposition syndromes: a retrospective cohort study in a tertiary-care children's hospital

Expert recommendations for the management of tumor surveillance in children with a variety of cancer predisposition syndromes (CPS) are available. We aimed (1) at identifying and characterizing children who are affected by a CPS and (2) at comparing current practice and consensus recommendations of the American Association for Cancer Research workshop in 2016. We performed a database search in the hospital information system of the University Children's Hospital for CPS in children, adolescents, and young adults and complemented this by review of electronic patients' charts. Between January 1, 2017, and December 3, 2019, 272 patients with 41 different CPS entities were identified in 20 departments (144 [52.9%] male, 128 [47.1%] female, median age 9.1 years, range, 0.4-27.8). Three (1.1%) patients died of non-malignancy-associated complications of the CPS; 49 (18.0%) patients were diagnosed with malignancy and received regular follow-up. For 209 (95.0%) of the remaining 220 patients, surveillance recommendations were available: 30/220 (13.6%) patients received CPS consultations according to existing consensus recommendations, 22/220 (10.0%) institutional surveillance approaches were not complying with recommendations, 84/220 (38.2%) patients were seen for other reasons, and 84/220 (38.2%) were not routinely cared for. Adherence to recommendations differed extensively among CPS entities.

CONCLUSION

The spectrum of CPS patients at our tertiary-care children's hospital is manifold. For most patients, awareness of cancer risk has to be enhanced and current practice needs to be adapted to consensus recommendations. Offering specialized CPS consultations and establishing education programs for patients, relatives, and physicians may increase adherence to recommendations.

WHAT IS KNOWN

• A wide spectrum of rare syndromes manifesting in childhood is associated with an increased cancer risk. • For many of these syndromes, expert recommendations for management and tumor surveillance are available, although based on limited evidence.

WHAT IS NEW

• Evaluating current practice, our data attest significant shortcomings in tumor surveillance of children and adolescents with CPS even in a tertiary-care children's hospital. • We clearly advocate a systematic and consistent integration of tumor surveillance into daily practice.

Peutz-Jeghers Syndrome and the Role of Imaging: Pathophysiology, Diagnosis, and Associated Cancers

Simple Summary

The Peutz-Jeghers Syndrome is a rare autosomal dominant syndrome characterized by mucocutaneous pigmentations, multiple gastrointestinal hamartomatous polyps, and an elevated risk of malignancy. Awareness of various Peutz-Jeghers Syndrome imaging patterns, associated malignancies, and their complications is crucial for accurate imaging interpretation and patient management. In this manuscript, we provide an overview of this condition, associated malignancies, and imaging surveillance protocols.

Abstract

The Peutz-Jeghers Syndrome (PJS) is an autosomal dominant neoplastic syndrome defined by hamartomatous polyps through the gastrointestinal tract, development of characteristic mucocutaneous pigmentations, and an elevated lifetime cancer risk. The majority of cases are due to a mutation in the STK11 gene located at 19p13.3. The estimated incidence of PJS ranges from 1:50,000 to 1:200,000. PJS carries an elevated risk of malignancies including gastrointestinal, breast, lung, and genitourinary (GU) neoplasms. Patients with PJS are at a 15- to 18-fold increased malignancy risk relative to the general population. Radiologists have an integral role in the diagnosis of these patients. Various imaging modalities are used to screen for malignancies and complications associated with PJS. Awareness of various PJS imaging patterns, associated malignancies, and their complications is crucial for accurate imaging interpretation and patient management. In this manuscript, we provide a comprehensive overview of PJS, associated malignancies, and surveillance protocols.

A Case of Peutz-Jeghers Syndrome Presenting With an Inoperable Periampullary Tumor

Peutz-Jeghers syndrome (PJS) is a syndrome characterized by multiple hamartomatous polyps in the gastrointestinal system and melanin pigments accumulating in the skin and mucous membranes. Patients with PJS have an increased risk of gastrointestinal malignancies. In this syndrome, pancreatic cancer is primarily detected in older ages. In this article, we present a case of a patient with an unresectable periampullary tumor and PJS.

A pilot randomized trial of an educational intervention to increase genetic counseling and genetic testing among Latina breast cancer survivors

Latinas are less likely to participate in genetic counseling (GC) and genetic testing (GT) than non-Hispanic Whites. A multisite, randomized pilot study tested a culturally targeted educational intervention to increase uptake of GC/GT among Latina breast cancer (BC) survivors (N = 52). Participants were recruited in Tampa, FL and Ponce, PR and randomized to: (a) fact sheet about BC survivorship (control) or (b) a culturally targeted educational booklet about GC/GT (intervention). Participants in the intervention condition were also offered no-cost telephone GC followed by free GT with mail-based saliva sample collection. Participants self-reported hereditary breast and ovarian cancer (HBOC) knowledge and emotional distress at baseline and 1- and 3-month follow-ups. We used logistic regression to examine differences in GC/GT uptake by study arm (primary outcome) and repeated measures ANOVA to examine the effects of study arm and time on HBOC knowledge and emotional distress (secondary outcomes). Compared to the control arm, intervention participants were more likely to complete GC (ORIntervention  = 13.92, 95% CI = 3.06-63.25, p < .01) and GT (ORIntervention  = 12.93, 95% CI = 2.82-59.20, p < .01). Study site did not predict uptake of GC (p = .08) but Ponce participants were more likely to complete GT (ORPonce  = 4.53, 95% CI = 1.04-19.72, p = .04). ANOVAs demonstrated an increase in HBOC knowledge over time across both groups (F(2,88) = 12.24, p < .01, ηp2  = 0.22). We also found a significant interaction of study arm and time, such that intervention participants demonstrated a greater and sustained (to the 3-month follow-up) increase in knowledge than control participants (F(2,88) = 3.66, p = .03, ηp2  = 0.08). No other main or interaction effects were significant (all p's> .15). Study findings demonstrate the potential of our culturally targeted print intervention. Lessons learned from this multisite pilot study for enhancing GC/GT in Latinas include the need to attend to both access to GC/GT and individual factors such as attitudes and knowledge.

Tissue gene mutation profiles in patients with colorectal cancer and their clinical implications

Colorectal cancer (CRC) is one of the most common types of cancer in the world, and targeted therapy is frequently used in the clinical management of the disease. A complete and accurate picture of tissue gene mutations is therefore critical. Tissue specimens from 117 patients with CRC were used for high throughput DNA next-generation sequencing (NGS) analysis. Hotspots from 50 genes frequently associated with the development and progression of solid tumors were targeted for sequencing. Characterization of tissue gene mutations was performed; the tissue mutation positive rates of KRAS, KIT, PIK3CA, MET and EGFR were 52.1, 19.7, 29.9, 15.4 and 14.5%, respectively. The mutation positive rates of TP53, APC, CDKN2A, STK11 and FBXW7 were 65.8, 39.3, 32.5, 19.7 and 19.7%, respectively. The most frequent KRAS mutations were G12A/C/D/S/V, accounting for 61.2% of all KRAS mutations. The most frequent TP53 mutations were R273C/G/H/L, accounting for 8.5% of all TP53 mutations. The most frequent APC mutation was E1554fs, accounting for 19.7% of all APC mutations. IDH1 R132C/H, KIT M541L, MET N375S, and SMAD4 R361C/H were also frequently identified. TP53 mutations were more common in patients ≥60 years old (P<0.05), and IDH1 mutations were more common in male patients (P<0.05). NGS 50 gene panel sequencing provides a comprehensive tissue gene mutation profile which may significantly improve clinical management.

An update on the CNS manifestations of brain tumor polyposis syndromes

Cancer predisposition syndromes are associated with an increased risk of developing primary malignancies. Here we discuss those which are associated with an increased risk of tumors of the central nervous system (CNS) and gastrointestinal (GI) tract. These can be grouped into those in which the CNS tumors predominate versus those in which the GI cancers predominate. The former include constitutional mismatch repair deficiency (CMMRD) syndrome, Li-Fraumeni syndrome (LFS), and Cowden syndrome (CS) while the latter include familial adenomatosis polyposis 1 (FAP1), Lynch syndrome and polymerase proofreading-associated polyposis syndrome (PPAP). Tumor specificity does exist as medulloblastoma occur in FAP, LFS and CMMRD while glioma are most commonly seen in all replication repair-deficient genes and LFS. Choroid plexus carcinoma is strictly observed in LFS while Cowden syndrome patients develop Lhermitte Duclos disease or meningioma. In each syndrome, specific types of low-grade and high-grade gastrointestinal cancers can occur, but these will be discussed elsewhere. Underlying cancer predisposition syndromes are important to consider when faced with brain tumors, particularly in the pediatric and young adult age groups, as identification of an underlying germ line mutation may change the upfront management of the patient and has implications for future cancer surveillance for both the patient and potentially affected family members. Considerations of family history, presence of skin lesions and consanguinity provide valuable information in identifying patients at potential increased risk.

Heterozygous Tumor Suppressor Microenvironment in Cancer Development

Hereditary cancer syndromes are typically caused by mutations of a tumor suppressor gene that lead to the early development of multifocal benign neoplasms followed by their malignant progression. However, the term 'hereditary cancer syndrome' may be misleading, as a large subgroup of syndromes are characterized by highly penetrant benign tumors. The reason why these cardinal tumors rarely progress to malignancy has been an elusive question in cancer biology. In this opinion article, we propose a framework where a heterozygous tumor suppressor gene microenvironment has antagonistic roles in tumorigenesis, by accelerating development of benign tumors while restraining further progression to malignant cancers.

Genetic and molecular epidemiology of adult diffuse glioma

The WHO 2007 glioma classification system (based primarily on tumour histology) resulted in considerable interobserver variability and substantial variation in patient survival within grades. Furthermore, few risk factors for glioma were known. Discoveries over the past decade have deepened our understanding of the molecular alterations underlying glioma and have led to the identification of numerous genetic risk factors. The advances in molecular characterization of glioma have reframed our understanding of its biology and led to the development of a new classification system for glioma. The WHO 2016 classification system comprises five glioma subtypes, categorized by both tumour morphology and molecular genetic information, which led to reduced misclassification and improved consistency of outcomes within glioma subtypes. To date, 25 risk loci for glioma have been identified and several rare inherited mutations that might cause glioma in some families have been discovered. This Review focuses on the two dominant trends in glioma science: the characterization of diagnostic and prognostic tumour markers and the identification of genetic and other risk factors. An overview of the many challenges still facing glioma researchers is also included.

Familial aggregation of early-onset cancers

This registry‐linkage study evaluates familial aggregation of cancer among relatives of a population‐based series of early‐onset (≤40 years) cancer patients in Finland. A cohort of 376,762 relatives of early‐onset cancer patients diagnosed between 1970 and 2012 in 40,538 families was identified. Familial aggregation of early‐onset breast, colorectal, brain and other central nervous system (CNS) cancer and melanoma was explored by standardized incidence ratios (SIR), stratified by relatedness. Gender‐, age‐ and period‐specific population cancer incidences were used as reference. Cumulative risks for siblings and offspring of the proband up to age ≤40 years were also estimated. Almost all early‐onset cancers were sporadic (98% or more). Among first‐degree relatives, SIR was largest in colorectal cancer (14, 95% confidence interval 9.72–18), and lowest in melanoma (1.93, 1.05–3.23). Highest relative‐specific SIRs were observed for siblings in families, where also parent had concordant cancer, 90 (43–165) for colorectal cancer and 29 (11–64) for CNS cancer. In spouses, all SIRs were at population level. Cumulative risk of colorectal cancer by age 41 was 0.98% in siblings and 0.10% in population, while in breast cancer the corresponding risks were 2.05% and 0.56%. In conclusion, early‐onset cancers are mainly sporadic. Findings support high familial aggregation in early‐onset colorectal and CNS cancers. Familial aggregation in multiplex families with CNS cancers was mainly attributed to neurofibromatosis and in colorectal cancer to FAP‐ and HNPCC‐syndromes. The pattern of familial aggregation of early‐onset breast cancer could be seen to support very early exposure to environmental factors and/or rare genetic factors.

What's new?

The tendency for certain cancer types to cluster in families generally is explained by shared environmental exposures or inherited mutations. In particular, early‐onset cancer, diagnosed between ages 0 and 40, is considered indicative of familial factors. Here, investigation of cancer risk among more than 376,760 relatives of probands, or individuals with early‐onset cancer, shows that the likelihood of early‐onset cancer affecting even just one other relative in addition to the proband is exceedingly rare. Nearly all early‐onset cancers in the study population were sporadic. Estimated cumulative risks observed for specific cancers may prove useful in the context of genetic counseling.

Clinical interpretation of pathogenic ATM and CHEK2 variants on multigene panel tests: navigating moderate risk

Comprehensive genomic cancer risk assessment (GCRA) helps patients, family members, and providers make informed choices about cancer screening, surgical and chemotherapeutic risk reduction, and genetically targeted cancer therapies. The increasing availability of multigene panel tests for clinical applications allows testing of well-defined high-risk genes, as well as moderate-risk genes, for which the penetrance and spectrum of cancer risk are less well characterized. Moderate-risk genes are defined as genes that, when altered by a pathogenic variant, confer a 2 to fivefold relative risk of cancer. Two such genes included on many comprehensive cancer panels are the DNA repair genes ATM and CHEK2, best known for moderately increased risk of breast cancer development. However, the impact of screening and preventative interventions and spectrum of cancer risk beyond breast cancer associated with ATM and/or CHEK2 variants remain less well characterized. We convened a large, multidisciplinary, cross-sectional panel of GCRA clinicians to review challenging, peer-submitted cases of patients identified with ATM or CHEK2 variants. This paper summarizes the inter-professional case discussion and recommendations generated during the session, the level of concordance with respect to recommendations between the academic and community clinician participants for each case, and potential barriers to implementing recommended care in various practice settings.

Radiogenomic Predictors of Adverse Effects following Charged Particle Therapy

Radiogenomics is the study of genomic factors that are associated with response to radiation therapy. In recent years, progress has been made toward identifying genetic risk factors linked with late radiation-induced adverse effects. These advances have been underpinned by the establishment of an international Radiogenomics Consortium with collaborative studies that expand cohort sizes to increase statistical power and efforts to improve methodologic approaches for radiogenomic research. Published studies have predominantly reported the results of research involving patients treated with photons using external beam radiation therapy. These studies demonstrate our ability to pool international cohorts to identify common single nucleotide polymorphisms associated with risk for developing normal tissue toxicities. Progress has also been achieved toward the discovery of genetic variants associated with radiation therapy-related subsequent malignancies. With the increasing use of charged particle therapy (CPT), there is a need to establish cohorts for patients treated with these advanced technology forms of radiation therapy and to create biorepositories with linked clinical data. While some genetic variants are likely to impact toxicity and second malignancy risks for both photons and charged particles, it is plausible that others may be specific to the radiation modality due to differences in their biological effects, including the complexity of DNA damage produced. In recognition that the formation of patient cohorts treated with CPT for radiogenomic studies is a high priority, efforts are underway to establish collaborations involving institutions treating cancer patients with protons and/or carbon ions as well as consortia, including the Proton Collaborative Group, the Particle Therapy Cooperative Group, and the Pediatric Proton Consortium Registry. These important radiogenomic CPT initiatives need to be expanded internationally to build on experience gained from the Radiogenomics Consortium and epidemiologists investigating normal tissue toxicities and second cancer risk.

Survival patterns and cancer determinants in families with myotonic dystrophy type 1

BACKGROUND AND PURPOSE

Research indicates that patients with myotonic dystrophy type 1 (DM1) are at increased risk of cancer and early death. Family data may provide insights given DM1 phenotypic heterogeneity, the broad range of non-muscular manifestations and the usual delays in the diagnosis of DM1.

METHOD

Family history data were collected from 397 genetically and/or clinically confirmed DM1 patients (respondents) enrolled in the US or UK myotonic dystrophy registries. Standardized mortality ratios were calculated for DM1 first-degree relatives (parents, siblings and offspring) by their reported DM1 status (affected, unaffected or unknown). For cancer-related analyses, mixed effects logistic regression models were used to evaluate factors associated with cancer development in DM1 families, including familial clustering.

RESULTS

A total of 467 deaths and 337 cancers were reported amongst 1737 first-degree DM1 relatives. Mortality risk amongst relatives reported as DM1-unaffected was comparable to that of the general population [standardized mortality ratio (SMR) 0.82, P = 0.06], whilst significantly higher mortality risks were noted in DM1-affected relatives (SMR = 2.47, P < 0.0001) and in those whose DM1 status was unknown (SMR = 1.60, P < 0.0001). In cancer risk analyses, risk was higher amongst families in which the DM1 respondent had cancer (odds ratio 1.95, P = 0.0001). Unknown DM1 status in the siblings (odds ratio 2.59, P = 0.004) was associated with higher cancer risk.

CONCLUSION

There is an increased risk of death, and probably cancer, in relatives with DM1 and in those whose DM1 status is unknown. This suggests a need to perform a careful history and physical examination, supplemented by genetic testing, to identify family members at risk for DM1 and who might benefit from disease-specific clinical care and surveillance.

Risk, Risk Factors, and Surveillance of Subsequent Malignant Neoplasms in Survivors of Childhood Cancer: A Review

Subsequent malignant neoplasms (SMNs) in childhood cancer survivors cause substantial morbidity and mortality. This review summarizes recent literature on SMN epidemiology, risk factors, surveillance, and interventions. Survivors of childhood cancer experience long-term increased SMN risk compared with the general population, with a greater than twofold increased solid tumor risk extending beyond age 40 years. There is a dose-dependent increased risk for solid tumors after radiotherapy, with the highest risks for tumors occurring in or near the treatment field (eg, greater than fivefold increased risk for breast, brain, thyroid, skin, bone, and soft tissue malignancies). Alkylating and anthracycline chemotherapies increase the risk for development of several solid malignancies in addition to acute leukemia/myelodysplasia, and these risks may be modified by other patient characteristics, such as age at exposure and, potentially, inherited genetic susceptibility. Strategies for identifying survivors at risk and initiating long-term surveillance have improved and interventions are underway to improve knowledge about late-treatment effects among survivors and caregivers. Better understanding of treatment-related risk factors and genetic susceptibility holds promise for refining surveillance strategies and, ultimately, upfront cancer therapies.

Recognizing and Managing Children with a Pediatric Cancer Predisposition Syndrome: A Guide for the Pediatrician

It is estimated that at least 8% to 10% of children diagnosed with cancer have an inherited cancer predisposition syndrome. Pediatricians may be called upon to (1) identify children with symptoms suggestive of cancer that require further diagnostic testing, (2) identify children who should be referred to cancer genetics based on their personal and family histories, and (3) provide primary care to children who have an inherited cancer syndrome. This review article provides a list of clinical warning signs suggestive of childhood malignancy, discusses the personal and family history "red flags" suggestive of hereditary cancer, offers checklists to help identify patients who are candidates for cancer genetics evaluation, and describes features of the major pediatric cancer syndromes involving solid tumors and surveillance guidelines. This review aims to provide the pediatrician with the tools needed to recognize, refer, and help manage children at risk for pediatric cancer syndromes. [Pediatr Ann. 2018;47(5):e204-e216.].

Peutz-Jeghers Syndrome Presenting as Colonic Intussusception: A Rare Entity

Peutz-Jeghers syndrome is an autosomal dominant inherited medical condition characterized by hyperpigmented mucocutaneous macules, hamartomatous polyps in the digestive tract, and with a greater risk of gastrointestinal and non-gastrointestinal cancers. In fact, without appropriate medical surveillance, the lifetime risk for all cancers combined may be as high as 93%. The syndrome is rare, with estimates of incidence varying between 1 in 8,300 and 1 in 280,000 live births. Infrequently, individuals present for the first time with bowel obstruction secondary to intussusception. Here, we present an interesting case of a young Burmese man who, early on, showed traits of Peutz-Jeghers syndrome, including the characteristic hyperpigmented areas on the fingers and lips. Unfortunately, the diagnosis was not made until he later developed bowel obstruction caused by an intussusception, requiring exploratory laparoscopic bowel resection. A high index of suspicion is needed to diagnose accurately. However, early identification and close surveillance can lead to excellent prognosis in these individuals.

Evidence for genetic anticipation in vonHippel-Lindau syndrome

BACKGROUND

von Hippel-Lindau (vHL) syndrome is a rare autosomal-dominant disorder that confers a lifelong risk for developing both benign and malignant tumours in multiple organs. Recent evidence suggests that vHL may exhibit genetic anticipation (GA). The aim of this study was to determine if GA occurs in vHL, and if telomere shortening may be a factor in GA.

METHODS

A retrospective chart review of vHL families seen at The Hospital for Sick Children between 1984 and 2016 was performed. Age of onset (AOO, defined as the age of first physician-diagnosed vHL-related manifestation) was confirmed for 96 patients from 20 unrelated families (80 clinically affected and 16 unaffected carriers). Flow-FISH(flow cytometry sorting of cells whose telomeres are labeled by Fluorescence In Situ Hybridization) was used to measure mean telomere length of six white blood cell subtypes from 14 known VHL pathogenic variant carriers.

RESULTS

The median AOO for generations I, II and III were 32.5, 22.5 and 12.0 years, respectively. The differences in the AOO between generations were highly significant using a Cox proportional hazards model (P=6.00×10^-12). Telomere lengths were significantly different for granulocytes and natural killer lymphocytes of patients with vHL compared with age-matched controls. For six vHL parent-child pairs, median white blood cell telomere lengths between parent and child were not significantly different.

CONCLUSIONS

Our results suggest that vHL telomere abnormalities may be primarily somatic in origin rather than a cause of GA. As tumour development exhibits GA in our cohort, vHL surveillance guidelines may need to account for a patient's generational position within a vHL pedigree.

Multi-gene Panel Testing in Breast Cancer Management

Hereditary predisposition accounts for approximately 10% of all breast cancers and is mostly associated with germline mutations in high-penetrance genes encoding for proteins participating in DNA repair through homologous recombination (BRCA1 and BRCA2). With the advent of massive parallel next-generation DNA sequencing, simultaneous analysis of multiple genes with a short turnaround time and at a low cost has become possible. The clinical validity and utility of multi-gene panel testing is getting better characterized as more data on the significance of moderate-penetrance genes are collected from large, cancer genetic testing studies. In this chapter, we attempt to provide a general guide for interpretation of panel gene testing in breast cancer and use of the information obtained for clinical decision-making.

Genetic analysis and clinical description of Greek patients with Peutz-Jeghers syndrome: Creation of a National Registry

Peutz-Jeghers syndrome (PJS) is a rare autosomal dominant disorder caused by germline mutations in the STK11 tumor suppressor gene. PJS patients face a cumulative cancer risk as high as 93% for all sites combined. The present study reports the spectrum of STK11 mutations in eight families with clinical diagnosis of PJS, summarizes the clinical characteristics of sixteen mutation carriers and launches a National Registry for PJS in Greece. STK11 loss-of-function (LoF) mutations were detected in 87.5% of index patients. Carriers presented with their first manifestation at a median age of 24.9 years, while early-onset breast cancer was the most frequent malignancy observed, highlighting the need for breast surveillance. Out of the deleterious STK11 mutations identified, two were novel: c.375_376delGT and c.676_679dupAACG, with 57.2% of these potentially occurring de novo. Using all available clinical and genetic data, the National Registry for Greek PJS was established in an attempt to better characterize the syndrome and raise awareness among patients and clinicians (available at https://www.peutzjeghersgreece.org). This is the first comprehensive genetic analysis and clinical characterization of Greek PJS patients, where a high incidence of breast cancer was observed and the first attempt to centralize all data in a National Registry.

Genomic Disparities in Breast Cancer Among Latinas

BACKGROUND

Breast cancer is the most common cancer diagnosed among Latinas in the United States and the leading cause of cancer-related death among this population. Latinas tend to be diagnosed at a later stage and have worse prognostic features than their non-Hispanic white counterparts. Genetic and genomic factors may contribute to observed breast cancer health disparities in Latinas.

METHODS

We provide a landscape of our current understanding and the existing gaps that need to be filled across the cancer prevention and control continuum.

RESULTS

We summarize available data on mutations in high and moderate penetrance genes for inherited risk of breast cancer and the associated literature on disparities in awareness of and uptake of genetic counseling and testing in Latina populations. We also discuss common genetic polymorphisms and risk of breast cancer in Latinas. In the treatment setting, we examine tumor genomics and pharmacogenomics in Latina patients with breast cancer.

CONCLUSIONS

As the US population continues to diversify, extending genetic and genomic research into this underserved and understudied population is critical. By understanding the risk of breast cancer among ethnically diverse populations, we will be better positioned to make treatment advancements for earlier stages of cancer, identify more effective and ideally less toxic treatment regimens, and increase rates of survival.

Mosaic chromosome Y loss and testicular germ cell tumor risk

Studies have suggested mosaic loss of chromosome Y (mLOY) in blood-derived DNA is common in older men. Cohort studies investigating mLOY and mortality have reported contradictory results. Previous work found a 1.6 Mb deletion of the AZFc region on the Y chromosome (the “gr/gr” deletion) is associated with both male infertility and increased risk of testicular germ cell tumors (TGCT). We investigated whether mosaic loss across the entire Y chromosome was associated with TGCT. We obtained blood and buccal-derived DNA from two case-control studies: the NCI Familial Testicular Cancer Study (FTC; cases=172, controls=163) and the NCI US Servicemen's Testicular Tumor Environmental and Endocrine Determinants Study (STEED; cases=506, controls=611). We utilized 15 quantitative polymerase chain reactions (qPCR) spanning the Y chromosome to assess mLOY. Multivariate logistic regression models adjusted for study batch effects detected no significant overall relationship between mean chromosome Y T/R ratio and TGCT (OR=0.34, 95% CI=0.10–1.17, P=0.09). When restricted to familial TGCT cases, a significantly lower T/R ratio was observed in cases compared with controls (0.993 vs 1.014, P-value=0.01). Our study suggests mLOY, as measured by 15 probes spanning the Y chromosome, could be associated with familial TGCT, but larger studies are required to confirm this observation.

Familial risk for lung cancer

Lung cancer, which has a low survival rate, is a leading cause of cancer-associated mortality worldwide. Smoking and air pollution are the major causes of lung cancer; however, numerous studies have demonstrated that genetic factors also contribute to the development of lung cancer. A family history of lung cancer increases the risk for the disease in both smokers and never-smokers. This review focuses on familial lung cancer, in particular on the familial aggregation of lung cancer. The development of familial lung cancer involves shared environmental and genetic factors among family members. Familial lung cancer represents a good model for investigating the association between environmental and genetic factors, as well as for identifying susceptibility genes for lung cancer. In addition, studies on familial lung cancer may help to elucidate the etiology and mechanism of lung cancer, and may identify novel biomarkers for early detection and diagnosis, targeted therapy and improved prevention strategies. This review presents the aetiology and molecular biology of lung cancer and then systematically introduces and discusses several aspects of familial lung cancer, including the characteristics of familial lung cancer, population-based studies on familial lung cancer and the genetics of familial lung cancer.

Confounding of the association between radiation exposure from CT scans and risk of leukemia and brain tumors by cancer susceptibility syndromes

Recent studies linking radiation exposure from pediatric computed tomography (CT) to increased risks of leukemia and brain tumors lacked data to control for cancer susceptibility syndromes (CSS). These syndromes might be confounders because they are associated with an increased cancer risk and may increase the likelihood of pediatric CT scans. We identify CSS predisposing to leukemia and brain tumors through a systematic literature search and summarize prevalence and risk. Since empirical evidence is lacking in published literature on patterns of CT use for most types of CSS, we estimate confounding bias of relative risks (RR) for categories of radiation exposure based on expert opinion about patterns of CT scans among CSS patients. We estimate that radiation-related RRs for leukemia are not meaningfully confounded by Down syndrome, Noonan syndrome and other CSS. Moreover, tuberous sclerosis complex, von Hippel-Lindau disease, neurofibromatosis type 1 and other CSS do not meaningfully confound RRs for brain tumors. Empirical data on the use of CT scans among CSS patients is urgently needed. Our assessment indicates that associations with radiation exposure from pediatric CT scans and leukemia or brain tumors reported in previous studies are unlikely to be substantially confounded by unmeasured CSS.

RECQL: a new breast cancer susceptibility gene

Identifying and characterizing novel genetic risk factors for BRCA1/2 negative breast cancers is highly relevant for early diagnosis and development of a management plan. Mutations in a number of DNA repair genes have been associated with genomic instability and development of breast and various other cancers. Whole exome sequencing efforts by 2 groups have led to the discovery in distinct populations of multiple breast cancer susceptibility mutations in RECQL, a gene that encodes a DNA helicase involved in homologous recombination repair and response to replication stress. RECQL pathogenic mutations were identified that truncated or disrupted the RECQL protein or introduced missense mutations in its helicase domain. RECQL mutations may serve as a useful biomarker for breast cancer. Targeting RECQL associated tumors with novel DNA repair inhibitors may provide a new strategy for anti-cancer therapy.

Self-reported cancer family history is a useful tool for identification of individuals at risk of hereditary cancer predisposition syndrome at primary care centers in middle-income settings: a longitudinal study

Analysis of cancer family history (CFH) offers a low-cost genetic tool to identify familial cancer predisposition. In middle-income settings, the scarcity of individual records and database-linked records hinders the assessment of self-reported CFH consistency as an indicator of familial cancer predisposition. We used self-reported CFH to identify those families at risk for hereditary cancer syndromes in community-based primary care centers of a low-income Brazilian area. We also evaluated the consistency of the information collected by reassessing CFH five years later. We interviewed 390 families and constructed their pedigrees for genetic cancer risk assessment. We found 125 families affected by cancer, 35.2% with moderate to high risk of familial susceptibility to cancer, a number that represents a relatively high prevalence of potential hereditary cancer syndromes in the overall study sample. Upon reassessment of CFH in 14/20 families that were previously identified as having at least one first-degree and one second-degree relative affected by cancer, and presented moderate to high risk for developing cancer, 90% of initial pedigrees were confirmed. These results demonstrate the reliability of self-reports as a means of early identification of healthy individuals at risk, encouraging the wider use of this method in low- and middle-income primary care settings.

Retinoblastoma in a pediatric oncology reference center in Southern Brazil

Background

Retinoblastoma (Rb) is the most common intraocular tumor diagnosed in children in Brazil. However, detailed information is lacking regarding patient clinical demographics. This study aimed to determine the clinical profile of patients with Rb who were treated in a public university hospital in southern Brazil from 1983 to 2012. Methods: Patients’ medical records were reviewed to retrospectively identify patients with a principal diagnosis of Rb. Rb was classified as hereditary or non-hereditary. Clinical staging was reviewed by an ophthalmologist. Statistical analysis was performed using SPSS.

Results

Of 165 patients with a diagnosis of Rb during this period, 140 were included in the study. Disease was unilateral in 65.0 % of patients, bilateral in 32.9 %, and trilateral in 2.1 %. The mean age at onset of the first sign/symptom was 18.1 month, and 35.7 % of patients were diagnosed during the first year of life. The most common presenting signs were leukocoria (73.6 %) and strabismus (20.7 %). The mean age at diagnosis was 23.5 months, and time to diagnosis was 5.4 months. In patients with clinical features of hereditary Rb, both onset of the first sign/symptom and diagnosis were at an earlier age than in patients without these features (12.3 vs 21.6 months [P = 0.001] and 15.9 vs 28.0 months [P < 0.001], respectively). However, there was no significant difference in overall survival between the two groups. Ocular stage at diagnosis was advanced in 76.5 % (Reese V) and 78.1 % (International Classification D or E). Of patients with unilateral and bilateral disease, 35.2 % and 34.8 %, respectively, had extraocular disease at diagnosis; 10.7 % had metastatic disease at diagnosis. Enucleation was observed in 88.1 % and exenteration in 11.9 % of patients; 93.6 % patients were followed until 2012, and 22.9 % relapsed. Overall survival was 86.4 %.

Conclusions

Most Rb diagnoses are still diagnosed in advanced stages of the disease, considerably reducing overall survival time and the rate of eye and vision preservation.

Electronic supplementary material

The online version of this article (doi:10.1186/s12887-016-0579-9) contains supplementary material, which is available to authorized users.

Should multi-gene panel testing replace limited BRCA1/2 testing? A review of genetic testing for hereditary breast and ovarian cancers

Clinical testing of patients for hereditary breast and ovarian cancer syndromes began in the mid-1990s with the identification of the BRCA1 and BRCA2 genes. Since then, mutations in dozens of other genes have been correlated to increased breast, ovarian, and other cancer risk. The following decades of data collection and patient advocacy allowed for improvements in medical, legal, social, and ethical advances in genetic testing. Technological advances have made it possible to sequence multiple genes at once in a panel to give patients a more thorough evaluation of their personal cancer risk. Panel testing increases the detection of mutations that lead to increased risk of breast, ovarian, and other cancers and can better guide individualized screening measures compared to limited BRCA testing alone. At the same time, multi-gene panel testing is more time-and cost-efficient. While the clinical application of panel testing is in its infancy, many problems arise such as lack of guidelines for management of newly identified gene mutations, high rates of variants of uncertain significance, and limited ability to screen for some cancers. Through on-going concerted efforts of pooled data collection and analysis, it is likely that the benefits of multi-gene panel testing will outweigh the risks in the near future.

Partial KCNQ1OT1 hypomethylation: A disguised familial Beckwith-Wiedemann syndrome as a sporadic adrenocortical tumor

Beckwith-Wiedemann syndrome has a wide spectrum of complications such as embryonal tumors, namely adrenocortical tumor. Tumor predisposition is one of the most challenging manifestations of this syndrome. A 45-day old female with a family history of adrenocortical tumor presented with adrenocortical tumor. The case raised suspicion of a hereditary Beckwith-Wiedemann syndrome, therefore molecular analysis was undertaken. The results revealed partial KCNQ1OT1 hypomethylation in the infant's blood DNA which was associated with a complete loss of methylation in the infant's adrenocortical tumor tissue. It is unique for familial Beckwith-Wiedemann syndrome caused by KCNQ1OT1 partial hypomethylation to manifest solely through adrenocortical tumor. Incomplete penetrance and specific tissue mosaicism could provide explanations to this novel hereditary Beckwith-Wiedemann syndrome presentation.

Childhood CT scans and cancer risk: impact of predisposing factors for cancer on the risk estimates

To investigate the role of cancer predisposing factors (PFs) on the associations between paediatric computed tomography (CT) scan exposures and subsequent risk of central nervous system (CNS) tumours and leukaemia. A cohort of children who underwent a CT scan in 2000-2010 in 23 French radiology departments was linked with the national childhood cancers registry and national vital status registry; information on PFs was retrieved through hospital discharge databases. In children without PF, hazard ratios of 1.07 (95% CI 0.99-1.10) for CNS tumours (15 cases) and 1.16 (95% CI 0.77-1.27) for leukaemia (12 cases) were estimated for each 10 mGy increment in CT x-rays organ doses. These estimates were similar to those obtained in the whole cohort. In children with PFs, no positive dose-risk association was observed, possibly related to earlier non-cancer mortality in this group. Our results suggest a modifying effect of PFs on CT-related cancer risks, but need to be confirmed by longer follow-up and other studies.

Relationship between paediatric CT scans and subsequent risk of leukaemia and brain tumours: assessment of the impact of underlying conditions

BACKGROUND

We previously reported evidence of a dose-response relationship between ionising-radiation exposure from paediatric computed tomography (CT) scans and the risk of leukaemia and brain tumours in a large UK cohort. Underlying unreported conditions could have introduced bias into these findings.

METHODS

We collected and reviewed additional clinical information from radiology information systems (RIS) databases, underlying cause of death and pathology reports. We conducted sensitivity analyses excluding participants with cancer-predisposing conditions or previous unreported cancers and compared the dose-response analyses with our original results.

RESULTS

We obtained information from the RIS and death certificates for about 40% of the cohort (n∼180 000) and found cancer-predisposing conditions in 4 out of 74 leukaemia/myelodysplastic syndrome (MDS) cases and 13 out of 135 brain tumour cases. As these conditions were unrelated to CT exposure, exclusion of these participants did not alter the dose-response relationships. We found evidence of previous unreported cancers in 2 leukaemia/MDS cases, 7 brain tumour cases and 232 in non-cases. These previous cancers were related to increased number of CTs. Exclusion of these cancers reduced the excess relative risk per mGy by 15% from 0.036 to 0.033 for leukaemia/MDS (P-trend=0.02) and by 30% from 0.023 to 0.016 (P-trend<0.0001) for brain tumours. When we included pathology reports we had additional clinical information for 90% of the cases. Additional exclusions from these reports further reduced the risk estimates, but this sensitivity analysis may have underestimated risks as reports were only available for cases.

CONCLUSIONS

Although there was evidence of some bias in our original risk estimates, re-analysis of the cohort with additional clinical data still showed an increased cancer risk after low-dose radiation exposure from CT scans in young patients.