Screening with whole-body magnetic resonance imaging in pediatric subjects with Li-Fraumeni syndrome: A single institution pilot study

Baseline surveillance in Li Fraumeni syndrome using whole-body MRI: a systematic review and updated meta-analysis

OBJECTIVES

Li-Fraumeni syndrome (LFS) is a cancer syndrome associated with early-onset neoplasias. The use of whole-body magnetic resonance imaging (WBMRI) is recommended for regular cancer screening, however, evidence supporting the benefits in asymptomatic LFS patients is limited. This study aims to assess the clinical utility of WBMRI in germline TP53 mutation carriers at baseline and follow-up.

MATERIALS AND METHODS

We systematically searched PubMed, Cochrane, and Embase databases for studies evaluating WBMRI as an early detection method for tumor screening in patients with LFS. We pooled the prevalence of the included variables along with their corresponding 95% confidence intervals (CIs). Statistical analyses were performed using R software, version 4.3.1.

RESULTS

From 1687 results, 11 comprising 703 patients (359 females (51%); with a median age of 32 years (IQR 1-74)) were included. An estimated detection rate of 31% (95% CI: 0.28, 0.34) for any suspicious lesions was found in asymptomatic TP53 carriers who underwent baseline WBMRI. A total of 277 lesions requiring clinical follow-up were identified in 215 patients. Cancer was confirmed in 46 lesions across 39 individuals. The estimated cancer diagnosis rate among suspicious lesions was 18% (95% CI: 0.13, 0.25). WBMRI detected 41 of the 46 cancers at an early-disease stage, with an overall detection rate of 6% (95% CI: 0.05, 0.08). The incidence rate was 2% per patient round of WBMRI (95% CI: 0.01, 0.04), including baseline and follow-up.

CONCLUSION

This meta-analysis provides evidence that surveillance with WBMRI is effective in detecting cancers in asymptomatic patients with LFS.

CLINICAL RELEVANCE STATEMENT

Our study demonstrates that whole-body MRI is an effective tool for early cancer detection in asymptomatic Li-Fraumeni Syndrome patients, highlighting its importance in surveillance protocols to improve diagnosis and treatment outcomes.

KEY POINTS

Current evidence for whole-body MRI screening of asymptomatic Li-Fraumeni Syndrome (LFS) patients remains scarce. Whole-body MRI identified 41 out of 46 cancers at an early stage, achieving an overall detection rate of 6%. Whole-body MRI surveillance is a valuable method for detecting cancers in asymptomatic LFS patients.

Feasibility of whole-body MRI for cancer screening in children and young people with ataxia telangiectasia: A mixed methods cross-sectional study

BACKGROUND/OBJECTIVES

Ataxia telangiectasia (A-T) is an inherited multisystem disorder with increased sensitivity to ionising radiation and elevated cancer risk. Although other cancer predisposition syndromes have established cancer screening protocols, evidence-based guidelines for cancer screening in A-T are lacking. This study sought to assess feasibility of a cancer screening protocol based on whole-body MRI (WB-MRI) in children and young people with A-T.

DESIGN/METHODS

Children and young people with A-T were invited to undergo a one-off non-sedated 3-Tesla WB-MRI. Completion rate of WB-MRI was recorded and diagnostic image quality assessed by two experienced radiologists, with pre-specified success thresholds for scan completion of >50% participants and image quality between acceptable to excellent in 65% participants. Positive imaging findings were classified according to the ONCO-RADS system. Post-participation interviews were performed with recruited families to assess the experience of participating and feelings about waiting for, and communication of, the findings of the scan.

RESULTS

Forty-six children and young people with A-T were identified, of which 36 were eligible to participate, 18 were recruited and 16 underwent WB-MRI. Nineteen parents participated in interviews. Fifteen participants (83%) completed the full WB-MRI scan protocol. The pre-specified image quality criterion was achieved with diagnostic images obtained in at least 93% of each MRI sequence. Non-malignant scan findings were present in 4 (25%) participants. Six themes were identified from the interviews: (1) anxiety is a familiar feeling, (2) the process of MRI scanning is challenging for some children and families, (3) preparation is essential to reduce stress, (4) WB-MRI provides the reassurance about the physical health that families need, (5) WB-MRI experience turned out to be a positive experience and (6) WB-MRI allows families to be proactive.

CONCLUSION

This study shows that WB-MRI for cancer screening is feasible and well-accepted by children and young people with A-T and their families.

Whole-body MRI in oncology: A comprehensive review

Whole-Body Magnetic Resonance Imaging (WB-MRI) has cemented its position as a pivotal tool in oncological diagnostics. It offers unparalleled soft tissue contrast resolution and the advantage of sidestepping ionizing radiation. This review explores the diverse applications of WB-MRI in oncology. We discuss its transformative role in detecting and diagnosing a spectrum of cancers, emphasizing conditions like multiple myeloma and cancers with a proclivity for bone metastases. WB-MRI's capability to encompass the entire body in a singular scan has ushered in novel paradigms in cancer screening, especially for individuals harboring hereditary cancer syndromes or at heightened risk for metastatic disease. Additionally, its contribution to the clinical landscape, aiding in the holistic management of multifocal and systemic malignancies, is explored. The article accentuates the technical strides achieved in WB-MRI, its myriad clinical utilities, and the challenges in integration into standard oncological care. In essence, this review underscores the transformative potential of WB-MRI, emphasizing its promise as a cornerstone modality in shaping the future trajectory of cancer diagnostics and treatment.

Whole-Body MRI Screening for Carriers of Germline TP53 Mutations-A Systematic Review and Meta-Analysis

PURPOSE

This systematic review evaluated whole-body MRI (WB-MRI) as a cancer screening tool for individuals carrying germline TP53 mutations, a population known to be at a significantly elevated risk of malignancy. The primary objective is to assess the diagnostic performance of WB-MRI in detecting cancer in this cohort.

METHODS

PubMed, MEDLINE, EMBASE and the Cochrane Central Registry of Controlled Trials were searched until 18 August 2023. Eligible studies were selected based on predefined inclusion criteria. The data extracted included information on study characteristics, patient demographics, and the WB-MRI diagnostic performance.

RESULTS

This systematic review identified eight eligible studies, comprising 506 TP53 mutation carriers. The mean age was 34.6 ± 16.3 (range 1-74) years. In total, 321/506 (63.4%) of the patients were female and 185/506 (36.6%) were male. In addition, 267/506 (52.8%) had a previous oncological diagnosis. Thirty-six new cancers were diagnosed with WB-MRI (36/506 (7.1%)). The overall pooled proportion of cancer detected on MRI was 7% (95% confidence interval 5-10). In total, 44 new lesions were picked up, as multiple lesions were found in some patients.

CONCLUSION

WB-MRI is an effective cancer screening tool for TP53 mutation carriers. While these findings suggest the potential for WB-MRI to contribute to early cancer detection in this high-risk population, further research and the standardisation of protocols internationally are warranted to optimise its clinical utility.

Surveillance imaging and early surgical intervention for improved CNS tumor outcomes in children with Li-Fraumeni syndrome: Children's National Hospital experience and literature review

OBJECTIVE

Li-Fraumeni syndrome (LFS) is a cancer predisposition syndrome caused by germline mutations in the TP53 gene. CNS tumors are the fourth most common tumor type in LFS, and recent screening guidelines demonstrate that early tumor detection is associated with improved long-term survival. However, there is a paucity of data regarding surgical intervention when lesions are identified in asymptomatic patients on surveillance imaging. The authors investigated this through their cohort and literature review.

METHODS

The cohort consisted of children seen in the Pediatric Cancer Genetics Program at Children's National Hospital between August 2012 and August 2021. The authors also include a PubMed (MEDLINE) literature search of articles from 2006 to 2021 related to surveillance and CNS tumors in patients with LFS. Studies in which CNS tumors were not identified or detailed patient information was not provided were excluded. Patients from the selected articles and the authors' cohort were added for further analysis.

RESULTS

Between August 2012 and August 2021, 10 children with LFS and CNS tumors were assessed at Children's National Hospital: 4 who were known carriers of the TP53 mutation had CNS lesions found on surveillance imaging, whereas 6 presented with symptomatic CNS lesions and were either known or subsequently found to have germline TP53 mutations. The literature search identified 148 articles, 7 of which were included in this review. Patients from the literature and the present cohort were added for a total of 56 CNS lesions. A majority of the low-grade CNS lesions (22/24, 92%) were found on surveillance protocols in asymptomatic patients, whereas the majority of the high-grade lesions (22/26, 85%) presented in symptomatic patients who were not undergoing routine surveillance or as the initial diagnosis of LFS. The authors noted a significant survival advantage in pediatric patients with low-grade lesions, with an overall survival of 100% at 30 months. Minor limitations of the study include patient sample size and limitations in the patient cohort due to this being a retrospective rather than a prospective study.

CONCLUSIONS

Data presented in this study support surveillance protocols in LFS and demonstrate the importance of dedicated CNS imaging and early surgical intervention when lesions are identified. Systematic review registration no.: CRD42022372610 (www.crd.york.ac.uk/prospero).

Imaging Recommendations for Diagnosis, Staging, and Management of Hereditary Malignancies

Hereditary cancer syndromes, characterized by genetically distinct neoplasms developing in specific organs in more than one family members, predispose an individual to early onset of distinct site-specific tumors. Early age of onset, multiorgan involvement, multiple and bilateral tumors, advanced disease at presentation, and aggressive tumor histology are few characteristic features of hereditary cancer syndromes. A multidisciplinary approach to hereditary cancers has led to a paradigm shift in the field of preventive oncology and precision medicine. Imaging plays a pivotal role in the screening, testing, and follow-up of individuals and their first- and second-degree relatives with hereditary cancers. In fact, a radiologist is often the first to apprise the clinician about the possibility of an underlying hereditary cancer syndrome based on pathognomonic imaging findings. This article focuses on the imaging spectrum of few common hereditary cancer syndromes with specific mention of the imaging features of associated common and uncommon tumors in each syndrome. The screening and surveillance recommendations for each condition with specific management approaches, in contrast to sporadic cases, have also been described.

Diagnostic accuracy of imaging approaches for early tumor detection in children with Li-Fraumeni syndrome

BACKGROUND

The Toronto protocol for cancer surveillance in children with Li-Fraumeni syndrome has been adopted worldwide.

OBJECTIVE

To assess the diagnostic accuracy of the imaging used in this protocol.

MATERIALS AND METHODS

We conducted a blinded retrospective review of imaging modalities in 31 pediatric patients. We compared imaging findings with the reference standards, which consisted of (1) histopathological diagnosis, (2) corresponding dedicated imaging or subsequent surveillance imaging or (3) clinical outcomes. We individually analyzed each modality's diagnostic performance for cancer detection and assessed it on a per-study basis for chest and abdominal regional whole-body MRI (n=115 each), brain MRI (n=101) and abdominal/pelvic US (n=292), and on a per-lesion basis for skeleton/soft tissues on whole-body MRI (n=140).

RESULTS

Of 763 studies/lesions, approximately 80% had reference standards that identified 4 (0.7%) true-positive, 523 (85.3%) true-negative, 5 (0.8%) false-positive, 3 (0.5%) false-negative and 78 (12.7%) indeterminate results. There were 3 true-positives on whole-body MRI and 1 true-positive on brain MRI as well as 3 false-negatives on whole-body MRI. Sensitivities and specificities of tumor diagnosis using a worst-case scenario analysis were, respectively, 40.0% (95% confidence interval [CI]: 7.3%, 83.0%) and 38.2% (95% CI: 29.2%, 48.0%) for skeleton/soft tissues on whole-body MRI; sensitivity non-available and 97.8% (95% CI: 91.4%, 99.6%) for chest regional whole-body MRI; 100.0% (95% CI: 5.5%, 100.0%) and 96.8% (95% CI: 90.2%, 99.2%) for abdominal regional whole-body MRI; sensitivity non-available and 98.3% (95% CI: 95.3, 99.4) for abdominal/pelvic US; and 50.0% (95% CI: 2.7%, 97.3%) and 93.8% (95% CI: 85.6%, 97.7%) for brain MRI.

CONCLUSION

Considerations for optimizing imaging protocol, defining criteria for abnormalities, developing a structured reporting system, and practicing consensus double-reading may enhance the diagnostic accuracy for tumor surveillance.

Screening of cancer predisposition syndromes

Pediatric patients with cancer predisposition syndromes are at increased risk of developing malignancies compared with their age-matched peers, necessitating regular surveillance. Screening protocols differ among syndromes and are composed of a number of elements, imaging being one. Surveillance can be initiated in infants, children and adolescents with a tumor known or suspected of being related to a cancer predisposition syndrome or where genetic testing identifies a germline pathogenic gene variant in an asymptomatic child. Pre-symptomatic detection of malignant neoplasms offers potential to improve treatment options and survival outcomes, but the benefits and risks of screening need to be weighed, particularly with variable penetrance in many cancer predisposition syndromes. In this review we discuss the benefits and risks of surveillance imaging and the importance of integrating imaging and non-imaging screening elements. We explore the principles of surveillance imaging with particular reference to whole-body MRI, considering the strategies to minimize false-negative and manage false-positive whole-body MRI results, the value of standardized nomenclature when reporting risk stratification to better guide patient management, and the need for timely communication of results to allay anxiety. Cancer predisposition syndrome screening is a multimodality, multidisciplinary and longitudinal process, so developing formalized frameworks for surveillance imaging programs should enhance diagnostic performance while improving the patient experience.

Medical guidelines for Li-Fraumeni syndrome 2019, version 1.1

Li–Fraumeni syndrome (LFS) is a hereditary tumor that exhibits autosomal dominant inheritance. LFS develops in individuals with a pathogenic germline variant of the cancer-suppressor gene, TP53 (individuals with TP53 pathogenic variant). The number of individuals with TP53 pathogenic variant among the general population is said to be 1 in 500 to 20,000. Meanwhile, it is found in 1.6% (median value, range of 0–6.7%) of patients with pediatric cancer and 0.2% of adult patients with cancer. LFS is diagnosed by the presence of germline TP53 pathogenic variants. However, patients can still be diagnosed with LFS even in the absence of a TP53 pathogenic variant if the familial history of cancers fit the classic LFS diagnostic criteria. It is recommended that TP53 genetic testing be promptly performed if LFS is suspected. Chompret criteria are widely used for the TP53 genetic test. However, as there are a certain number of cases of LFS that do not fit the criteria, if LFS is suspected, TP53 genetic testing should be performed regardless of the criteria. The probability of individuals with TP53 pathogenic variant developing cancer in their lifetime (penetrance) is 75% for men and almost 100% for women. The LFS core tumors (breast cancer, osteosarcoma, soft tissue sarcoma, brain tumor, and adrenocortical cancer) constitute the majority of cases; however, various types of cancers, such as hematological malignancy, epithelial cancer, and pediatric cancers, such as neuroblastoma, can also develop. Furthermore, approximately half of the cases develop simultaneous or metachronous multiple cancers. The types of TP53 pathogenic variants and factors that modify the functions of TP53 have an impact on the clinical presentation, although there are currently no definitive findings. There is currently no cancer preventive agent for individuals with TP53 pathogenic variant. Surgical treatments, such as risk-reducing bilateral mastectomy warrant further investigation. Theoretically, exposure to radiation could induce the onset of secondary cancer; therefore, imaging and treatments that use radiation should be avoided as much as possible. As a method to follow-up LFS, routine cancer surveillance comprising whole-body MRI scan, brain MRI scan, breast MRI scan, and abdominal ultrasonography (US) should be performed immediately after the diagnosis. However, the effectiveness of this surveillance is unknown, and there are problems, such as adverse events associated with a high rate of false positives, overdiagnosis, and sedation used during imaging as well as negative psychological impact. The detection rate of cancer through cancer surveillance is extremely high. Many cases are detected at an early stage, and treatments are low intensity; thus, cancer surveillance could contribute to an improvement in QOL, or at least, a reduction in complications associated with treatment. With the widespread use of genomic medicine, the diagnosis of LFS is unavoidable, and a comprehensive medical care system for LFS is necessary. Therefore, clinical trials that verify the feasibility and effectiveness of the program, comprising LFS registry, genetic counseling, and cancer surveillance, need to be prepared.

Whole-body magnetic resonance imaging (WB-MRI) for cancer screening: recommendations for use

Whole-body magnetic resonance imaging (WB-MRI) is currently recommended for cancer screening in adult and paediatric subjects with cancer predisposition syndromes, representing a substantial aid for prolonging health and survival of these subjects with a high oncological risk. Additionally, the number of studies exploring the use of WB-MRI for cancer screening in asymptomatic subjects from the general population is growing. The primary aim of this review was to analyse the acquisition protocols found in the literature, in order to identify common sequences across published studies and to discuss the need of additional ones for specific populations. The secondary aim of this review was to provide a synthesis of current recommendations regarding the use of WB-MRI for cancer screening.

Whole-body magnetic resonance imaging in children - how and why? A systematic review

Whole-body magnetic resonance imaging (MRI) is increasingly being used for a number of indications. Our aim was to review and describe indications and scan protocols for diagnostic value of whole-body MRI for multifocal disease in children and adolescents, we conducted a systematic search in Medline, Embase and Cochrane for all published papers until November 2018. Relevant subject headings and free text words were used for the following concepts: 1) whole-body, 2) magnetic resonance imaging and 3) child and/or adolescent. Included were papers in English with a relevant study design that reported on the use and/or findings from whole-body MRI examinations in children and adolescents. This review includes 54 of 1,609 papers identified from literature searches. Chronic nonbacterial osteomyelitis, lymphoma and metastasis were the most frequent indications for performing a whole-body MRI. The typical protocol included a coronal STIR (short tau inversion recovery) sequence with or without a coronal T1-weighted sequence. Numerous studies lacked sufficient data for calculating images resolution and only a few studies reported the acquired voxel volume, making it impossible for others to reproduce the protocol/images. Only a minority of the included papers assessed reliability tests and none of the studies documented whether the use of whole-body MRI affected mortality and/or morbidity. Our systematic review confirms significant variability of technique and the lack of proven validity of MRI findings. The information could potentially be used to boost attempts towards standardization of technique, reporting and guidelines development.

Germline TP53 Testing in Breast Cancers: Why, When and How?

Simple Summary

TP53 variants detected in blood represent a main genetic cause of breast cancers occurring before 31 years of age. TP53 being included in most of the cancer gene panels, patients with breast cancer are offered germline TP53 testing, independently of the age of tumour onset and familial history. Interpretation of TP53 variants is remarkably complex, and detection of a germline disease-causing TP53 variant in a breast cancer patient has drastic medical consequences: radiotherapy contributing to the development of subsequent tumours should be, if possible, avoided. In her family, variant carriers should be offered annual follow-up, including whole-body MRI. Therefore, we consider that, in breast cancer patients, germline TP53 testing should be performed before treatment and that the decision of TP53 testing should not be systematic but based on the age of tumour onset, type of breast cancer, personal and familial history of cancer.

Abstract

Germline TP53 variants represent a main genetic cause of breast cancers before 31 years of age. Development of cancer multi-gene panels has resulted in an exponential increase of germline TP53 testing in breast cancer patients. Interpretation of TP53 variants, which are mostly missense, is complex and requires excluding clonal haematopoiesis and circulating tumour DNA. In breast cancer patients harbouring germline disease-causing TP53 variants, radiotherapy contributing to the development of subsequent tumours should be, if possible, avoided and, within families, annual follow-up including whole-body MRI should be offered to carriers. We consider that, in breast cancer patients, germline TP53 testing should be performed before treatment and offered systematically only to patients with: (i) invasive breast carcinoma or ductal carcinoma in situ (DCIS) before 31; or (ii) bilateral or multifocal or HER2+ invasive breast carcinoma/DCIS or phyllode tumour before 36; or (iii) invasive breast carcinoma before 46 and another TP53 core tumour (breast cancer, soft-tissue sarcoma, osteosarcoma, central nervous system tumour, adrenocortical carcinoma); or (iv) invasive breast carcinoma before 46 and one first- or second-degree relative with a TP53 core tumour before 56. In contrast, women presenting with breast cancer after 46, without suggestive personal or familial history, should not be tested for TP53.

Li-Fraumeni Syndrome and Whole-Body MRI Screening: Screening Guidelines, Imaging Features, and Impact on Patient Management

OBJECTIVE

Li-Fraumeni syndrome (LFS) is a rare autosomal-dominant inherited syndrome containing a germline mutation in the TP53 gene, which predisposes to oncogenesis. Leukemia and tumors of the brain, soft tissues, breasts, adrenal glands, and bone are the most common cancers associated with this syndrome. Patients with LFS are very susceptible to radiation, therefore the use of whole-body MRI is recommended for regular cancer screening. It is important to recognize the common tumors associated with LFS on MRI, and it is also important to be aware of the high rate of false-positive lesions.

CONCLUSION

Whole-body MRI is useful for the detection of cancer in patients who come for regular screening; however, it is associated with pitfalls about which the radiologist must remain aware.

Blood functional assay for rapid clinical interpretation of germline TP53 variants

BACKGROUND

The interpretation of germline TP53 variants is critical to ensure appropriate medical management of patients with cancer and follow-up of variant carriers. This interpretation remains complex and is becoming a growing challenge considering the exponential increase in TP53 tests. We developed a functional assay directly performed on patients' blood.

METHODS

Peripheral blood mononuclear cells were cultured, activated, exposed to doxorubicin and the p53-mediated transcriptional response was quantified using reverse transcription-multiplex ligation probe amplification and RT-QMPSF assays, including 10 p53 targets selected from transcriptome analysis, and two amplicons to measure p53 mRNA levels. We applied this blood functional assay to 77 patients addressed for TP53 analysis.

RESULTS

In 51 wild-type TP53 individuals, the mean p53 functionality score was 12.7 (range 7.5-22.8). Among eight individuals harbouring likely pathogenic or pathogenic variants, the scores were reduced (mean 4.8, range 3.1-7.1), and p53 mRNA levels were reduced in patients harbouring truncating variants. We tested 14 rare unclassified variants (p.(Pro72His), p.(Gly105Asp), p.(Arg110His), p.(Phe134Leu), p.(Arg158Cys), p.(Pro191Arg), p.(Pro278Arg), p.(Arg283Cys), p.(Leu348Ser), p.(Asp352Tyr), p.(Gly108_Phe109delinsVal), p.(Asn131del), p.(Leu265del), c.-117G>T) and 12 yielded functionally abnormal scores. Remarkably, the assay revealed that the c.*1175A>C polymorphic variant within TP53 poly-adenylation site can impact p53 function with the same magnitude as a null variant, when present on both alleles, and may act as a modifying factor in pathogenic variant carriers.

CONCLUSION

This blood p53 assay should therefore be a useful tool for the rapid clinical classification of germline TP53 variants and detection of non-coding functional variants.

Solitary myofibroma preceding the development of multicentric myofibromatosis: A report of two cases with surveillance recommendations

Infantile myofibroma is the most common fibrous tumor of infancy. Despite the frequency of these tumors, the natural history is incompletely understood. We present two cases with a unique pattern of disease: solitary myofibromas with subsequent progression to diffuse myofibromatosis. Given the variable spectrum of disease and the corresponding difference in morbidity and potential mortality based on the extent of disease, we propose surveillance recommendations.

Whole-Body MRI Surveillance of Cancer Predisposition Syndromes: Current Best Practice Guidelines for Use, Performance, and Interpretation

OBJECTIVE. Whole-body MRI is a valuable tool in the surveillance of cancer predisposition syndromes (CPSs). Because it allows wide-FOV imaging without ionizing radiation, whole-body MRI is ideal in pediatric patients, enabling efficient assessment of different organ systems for multifocal disease. This article summarizes the use of whole-body MRI in pediatric patients with CPSs for earlier detection of malignancy, provides evidence where available, and offers guidance where lacking because of the rarity of CPSs. Protocol modifications and technique performance in specific CPSs are also considered. CONCLUSION. Whole-body MRI is the preferred imaging modality for surveillance of pediatric patients with CPSs, and the growing literature supports its importance in presymptomatic cancer detection.

Whole-body magnetic resonance imaging as surveillance for subsequent malignancies in preadolescent, adolescent, and young adult survivors of germline retinoblastoma: An update

BACKGROUND

Germline retinoblastoma (Rb) survivors are at lifelong risk for developing subsequent malignancies (SMNs). Optimal surveillance modalities are needed to detect SMN at an early stage in this high-risk cohort. We investigated the use of rapid whole-body magnetic resonance imaging (WB-MRI) as a noninvasive screening modality in this cohort.

PROCEDURE

WB-MRI was performed in asymptomatic preadolescent, adolescent, or young adult survivors of germline Rb from February 1, 2008 to December 31, 2018 at a tertiary cancer center. We calculated sensitivity and specificity of WB-MRI and rate of false-positive findings requiring additional evaluation.

RESULTS

Overall, 110 WB-MRI were performed in 47 germline Rb survivors (51% female; median age at initial WB-MRI: 15.5 years [range 8-25.3]). Patients received 1-10 annual WB-MRI examinations (median: two). Thirteen patients had an abnormal WB-MRI; three findings were deemed to be likely benign and were not evaluated further. Ten patients required dedicated imaging and three required biopsy; two patients were diagnosed with localized high-grade osteosarcoma, while the other eight had benign findings. One patient was diagnosed with secondary osteosarcoma 3 months after normal WB-MRI. In total, there were 96 true negatives, 11 false positives, two true positives, and one false negative. The sensitivity of WB-MRI in this cohort was 66.7% (95% confidence interval [CI], 14.2-96.0) and the specificity was 89.7% (95% CI, 83.6-93.7).

CONCLUSIONS

Based on our 10-year experience, surveillance WB-MRI appears to have limited utility as a surveillance modality for SMN in germline Rb survivors. Alternate screening modalities should be investigated.

Germline genetic landscape of pediatric central nervous system tumors

Central nervous system (CNS) tumors are the second most common type of cancer among children. Depending on histopathology, anatomic location, and genomic factors, specific subgroups of brain tumors have some of the highest cancer-related mortality rates or result in considerable lifelong morbidity. Pediatric CNS tumors often occur in patients with genetic predisposition, at times revealing underlying cancer predisposition syndromes. Advances in next-generation sequencing (NGS) have resulted in the identification of an increasing number of cancer predisposition genes. In this review, the literature on genetic predisposition to pediatric CNS tumors is evaluated with a discussion of potential future targets for NGS and clinical implications. Furthermore, we explore potential strategies for enhancing the understanding of genetic predisposition of pediatric CNS tumors, including evaluation of non-European populations, pan-genomic approaches, and large collaborative studies.

Guidelines for the Li-Fraumeni and heritable TP53-related cancer syndromes

Fifty years after the recognition of the Li-Fraumeni syndrome (LFS), our perception of cancers related to germline alterations of TP53 has drastically changed: (i) germline TP53 alterations are often identified among children with cancers, in particular soft-tissue sarcomas, adrenocortical carcinomas, central nervous system tumours, or among adult females with early breast cancers, without familial history. This justifies the expansion of the LFS concept to a wider cancer predisposition syndrome designated heritable TP53-related cancer (hTP53rc) syndrome; (ii) the interpretation of germline TP53 variants remains challenging and should integrate epidemiological, phenotypical, bioinformatics prediction, and functional data; (iii) the penetrance of germline disease-causing TP53 variants is variable, depending both on the type of variant (dominant-negative variants being associated with a higher cancer risk) and on modifying factors; (iv) whole-body MRI (WBMRI) allows early detection of tumours in variant carriers and (v) in cancer patients with germline disease-causing TP53 variants, radiotherapy, and conventional genotoxic chemotherapy contribute to the development of subsequent primary tumours. It is critical to perform TP53 testing before the initiation of treatment in order to avoid in carriers, if possible, radiotherapy and genotoxic chemotherapies. In children, the recommendations are to perform clinical examination and abdominal ultrasound every 6 months, annual WBMRI and brain MRI from the first year of life, if the TP53 variant is known to be associated with childhood cancers. In adults, the surveillance should include every year clinical examination, WBMRI, breast MRI in females from 20 until 65 years and brain MRI until 50 years.

Whole-body magnetic resonance imaging in pediatric oncology - recommendations by the Oncology Task Force of the ESPR

The purpose of this recommendation of the Oncology Task Force of the European Society of Paediatric Radiology (ESPR) is to indicate reasonable applications of whole-body MRI in children with cancer and to address useful protocols to optimize workflow and diagnostic performance. Whole-body MRI as a radiation-free modality has been increasingly performed over the last two decades, and newer applications, as in screening of children with germ-line mutation cancer-related gene defects, are now widely accepted. We aim to provide a comprehensive outline of the diagnostic value for use in daily practice. Based on the results of our task force session in 2018 and the revision in 2019 during the ESPR meeting, we summarized our group's experiences in whole-body MRI. The lack of large evidence by clinical studies is challenging when focusing on a balanced view regarding the impact of whole-body MRI in pediatric oncology. Therefore, the final version of this recommendation was supported by the members of Oncology Task Force.

Penetrance of Different Cancer Types in Families with Li-Fraumeni Syndrome: A Validation Study Using Multicenter Cohorts

Li-Fraumeni syndrome (LFS) is a rare hereditary cancer syndrome associated with an autosomal-dominant mutation inheritance in the TP53 tumor suppressor gene and a wide spectrum of cancer diagnoses. The previously developed R package, LFSPRO, is capable of estimating the risk of an individual being a TP53 mutation carrier. However, an accurate estimation of the penetrance of different cancer types in LFS is crucial to improve the clinical characterization and management of high-risk individuals. Here, we developed a competing risk-based statistical model that incorporates the pedigree structure efficiently into the penetrance estimation and corrects for ascertainment bias while also increasing the effective sample size of this rare population. This enabled successful estimation of TP53 penetrance for three LFS cancer types: breast (BR), sarcoma (SA), and others (OT), from 186 pediatric sarcoma families collected at MD Anderson Cancer Center (Houston, TX). Penetrance validation was performed on a combined dataset of two clinically ascertained family cohorts with cancer to overcome internal bias in each (total number of families = 668). The age-dependent onset probability distributions of specific cancer types were different. For breast cancer, the TP53 penetrance went up at an earlier age than the reported BRCA1/2 penetrance. The prediction performance of the penetrance estimates was validated by the combined independent cohorts (BR = 85, SA = 540, and OT = 158). Area under the ROC curves (AUC) were 0.92 (BR), 0.75 (SA), and 0.81 (OT). The new penetrance estimates have been incorporated into the current LFSPRO R package to provide risk estimates for the diagnosis of breast cancer, sarcoma, or other cancers. SIGNIFICANCE: These findings provide specific penetrance estimates for LFS-associated cancers, which will likely impact the management of families at high risk of LFS.See related article by Shin et al., p. 347.

Cost-effectiveness of early cancer surveillance for patients with Li-Fraumeni syndrome

INTRODUCTION

Patients with germline TP53 pathogenic variants (Li-Fraumeni syndrome [LFS]) are at extremely high lifetime risk of developing cancer. Recent data suggest that tumor surveillance for patients with LFS may improve survival through early cancer detection. The objective of this study was to assess the cost-effectiveness of a cancer surveillance strategy for patients with LFS compared with those whose tumors present clinically.

METHODS

A Markov decision analytic model was developed from a third-party payer perspective to estimate cost-effectiveness of routine cancer surveillance over a patient's lifetime. The model consisted of four possible health states: no cancer, cancer, post-cancer survivorship, and death. Model outcomes were costs (2015 United States Dollars [USD]), effectiveness (life years [LY] gained), and incremental cost-effectiveness ratio (ICER; change in cost/LY gained). One-way sensitivity analyses and probabilistic sensitivity analyses examined parameter uncertainty.

RESULTS

The model showed a mean cost of $46 496 and $117 102 and yielded 23 and 27 LY for the nonsurveillance and surveillance strategies, respectively. The ICER for early cancer surveillance versus no surveillance was $17 125 per additional LY gained. At the commonly accepted willingness to pay threshold of $100 000/life-year gained, surveillance had a 98% probability of being the most cost-effective strategy for early cancer detection in this high-risk population.

CONCLUSIONS

Presymptomatic cancer surveillance is cost-effective for patients with germline pathogenic variants in TP53. Lack of insurance coverage or reimbursement in this population may have significant consequences and leads to undetected cancers presenting in later stages of disease with worse clinical outcomes.

Translating genomic risk into an early detection strategy for sarcoma

Sarcomas have a strong genetic etiology, and the study of families affected by sarcomas has informed much of what we now understand of modern cancer biology. The recent emergence of powerful genetic technologies has led to astonishing reductions in costs and increased throughput. In the clinic, these technologies are revealing a previously unappreciated and rich landscape of genetic cancer risk. In addition to both known and new cancer risk mutations, genomic tools are cataloguing complex and polygenic risk patterns, collectively explaining between 15-25% of apparently sporadic sarcoma cases. The impact on clinical management is exemplified by Li-Fraumeni Syndrome, the most penetrant sarcoma syndrome. Whole body magnetic resonance imaging can identify surgically resectable cancers in up to one in ten individuals with Li-Fraumeni Syndrome. Taken together, parallel developments in genomics, therapeutics and imaging technologies will drive closer engagement between genetics and multidisciplinary care of the sarcoma patient in the 21st century.

Surveillance Screening in Li-Fraumeni Syndrome: Raising Awareness of False Positives

Li-Fraumeni syndrome (LFS) is a rare cancer predisposition syndrome inherited in an autosomal dominant fashion that involves a germline mutation of tumor protein 53 (TP53). With the advent of more accessible and accurate genetic testing methods, along with more widespread knowledge of LFS, asymptomatic carriers can now be more easily identified. No general surveillance protocols were previously recommended other than routine physical exams and breast and colon cancer screening at younger ages, primarily due to questions involving efficacy, cost, and clinical benefits. With more data now available to support the implementation of a surveillance protocol for cancer predisposition syndromes such as LFS, preventative screening has become a national standard of care. However, as surveillance becomes more integrated into patient care, the benefits and risks must be further evaluated. We briefly describe our institutional experience with surveillance screening in LFS and describe two patients in depth where surveillance imaging brought to light false positives that led to increased utilization of resources and concern for new malignancy. Though the benefits of surveillance are clear, it is important to understand the potential for false positives involved with instituting this practice. Continued research of this topic is thus warranted, perhaps with larger prospective studies, to better capture the survival benefits of patients undergoing surveillance screening and more comprehensively understand the incidence of false positives.