Revisiting tumor patterns and penetrance in germline TP53 mutation carriers: temporal phases of Li-Fraumeni syndrome

Overview of the 2022 WHO Classification of Adrenal Cortical Tumors

The new WHO classification of adrenal cortical proliferations reflects translational advances in the fields of endocrine pathology, oncology and molecular biology. By adopting a question-answer framework, this review highlights advances in knowledge of histological features, ancillary studies, and associated genetic findings that increase the understanding of the adrenal cortex pathologies that are now reflected in the 2022 WHO classification. The pathological correlates of adrenal cortical proliferations include diffuse adrenal cortical hyperplasia, adrenal cortical nodular disease, adrenal cortical adenomas and adrenal cortical carcinomas. Understanding germline susceptibility and the clonal-neoplastic nature of individual adrenal cortical nodules in primary bilateral macronodular adrenal cortical disease, and recognition of the clonal-neoplastic nature of incidentally discovered non-functional subcentimeter benign adrenal cortical nodules has led to redefining the spectrum of adrenal cortical nodular disease. As a consequence, the most significant nomenclature change in the field of adrenal cortical pathology involves the refined classification of adrenal cortical nodular disease which now includes (a) sporadic nodular adrenocortical disease, (b) bilateral micronodular adrenal cortical disease, and (c) bilateral macronodular adrenal cortical disease (formerly known primary bilateral macronodular adrenal cortical hyperplasia). This group of clinicopathological entities are reflected in functional adrenal cortical pathologies. Aldosterone producing cortical lesions can be unifocal or multifocal, and may be bilateral with no imaging-detected nodule(s). Furthermore, not all grossly or radiologically identified adrenal cortical lesions may be the source of aldosterone excess. For this reason, the new WHO classification endorses the nomenclature of the HISTALDO classification which uses CYP11B2 immunohistochemistry to identify functional sites of aldosterone production to help predict the risk of bilateral disease in primary aldosteronism. Adrenal cortical carcinomas are subtyped based on their morphological features to include conventional, oncocytic, myxoid, and sarcomatoid subtypes. Although the classic histopathologic criteria for diagnosing adrenal cortical carcinomas have not changed, the 2022 WHO classification underscores the diagnostic and prognostic impact of angioinvasion (vascular invasion) in these tumors. Microscopic angioinvasion is defined as tumor cells invading through a vessel wall and forming a thrombus/fibrin-tumor complex or intravascular tumor cells admixed with platelet thrombus/fibrin. In addition to well-established Weiss and modified Weiss scoring systems, the new WHO classification also expands on the use of other multiparameter diagnostic algorithms (reticulin algorithm, Lin-Weiss-Bisceglia system, and Helsinki scoring system) to assist the workup of adrenal cortical neoplasms in adults. Accordingly, conventional carcinomas can be assessed using all multiparameter diagnostic schemes, whereas oncocytic neoplasms can be assessed using the Lin-Weiss-Bisceglia system, reticulin algorithm and Helsinki scoring system. Pediatric adrenal cortical neoplasms are assessed using the Wieneke system. Most adult adrenal cortical carcinomas show > 5 mitoses per 10 mm² and > 5% Ki67. The 2022 WHO classification places an emphasis on an accurate assessment of tumor proliferation rate using both the mitotic count (mitoses per 10 mm²) and Ki67 labeling index which play an essential role in the dynamic risk stratification of affected patients. Low grade carcinomas have mitotic rate of ≤ 20 mitoses per 10 mm², whereas high-grade carcinomas show > 20 mitoses per 10 mm². Ki67-based tumor grading has not been endorsed in the new WHO classification, since the proliferation indices are continuous variables rather than being static thresholds in tumor biology. This new WHO classification emphasizes the role of diagnostic and predictive biomarkers in the workup of adrenal cortical neoplasms. Confirmation of the adrenal cortical origin of a tumor remains a critical requirement when dealing with non-functional lesions in the adrenal gland which may be mistaken for a primary adrenal cortical neoplasm. While SF1 is the most reliable biomarker in the confirmation of adrenal cortical origin, paranuclear IGF2 expression is a useful biomarker in the distinction of malignancy in adrenal cortical neoplasms. In addition to adrenal myelolipoma, the new classification of adrenal cortical tumors has introduced new sections including adrenal ectopia, based on the potential role of such ectopic tissue as a possible source of neoplastic proliferations as well as a potential mimicker of metastatic disease. Adrenal cysts are also discussed in the new classification as they may simulate primary cystic adrenal neoplasms or even adrenal cortical carcinomas in the setting of an adrenal pseudocyst.

Inherited TP53 Variants and Risk of Prostate Cancer

BACKGROUND

Inherited germline TP53 pathogenic and likely pathogenic variants (gTP53) cause autosomal dominant multicancer predisposition including Li-Fraumeni syndrome (LFS). However, there is no known association of prostate cancer with gTP53.

OBJECTIVE

To determine whether gTP53 predisposes to prostate cancer.

DESIGN, SETTING, AND PARTICIPANTS

This multi-institutional retrospective study characterizes prostate cancer incidence in a cohort of LFS males and gTP53 prevalence in a prostate cancer cohort.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

We evaluated the spectrum of gTP53 variants and clinical features associated with prostate cancer.

RESULTS AND LIMITATIONS

We identified 31 prostate cancer cases among 163 adult LFS males, including 26 of 54 aged ≥50 yr. Among 117 LFS males without prostate cancer at the time of genetic testing, six were diagnosed with prostate cancer over a median (interquartile range [IQR]) of 3.0 (1.3-7.2) yr of follow-up, a 25-fold increased risk (95% confidence interval [CI] 9.2-55; p < 0.0001). We identified gTP53 in 38 of 6850 males (0.6%) in the prostate cancer cohort, a relative risk 9.1-fold higher than that of population controls (95% CI 6.2-14; p < 0.0001; gnomAD). We observed hotspots at the sites of attenuated variants not associated with classic LFS. Two-thirds of available gTP53 prostate tumors had somatic inactivation of the second TP53 allele. Among gTP53 prostate cancer cases in this study, the median age at diagnosis was 56 (IQR: 51-62) yr, 44% had Gleason ≥8 tumors, and 29% had advanced disease at diagnosis.

CONCLUSIONS

Complementary analyses of prostate cancer incidence in LFS males and gTP53 prevalence in prostate cancer cohorts suggest that gTP53 predisposes to aggressive prostate cancer. Prostate cancer should be considered as part of LFS screening protocols and TP53 considered in germline prostate cancer susceptibility testing.

PATIENT SUMMARY

Inherited pathogenic variants in the TP53 gene are likely to predispose men to aggressive prostate cancer.

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.

The spectrum of sex differences in cancer

Sex differences in cellular and systems biology have been evolutionarily selected to optimize reproductive success in all species with little (sperm) and big (ova) gamete producers. They are evident from the time of fertilization and accrue throughout development through genetic, epigenetic, and circulating sex hormone-dependent mechanisms. Among other effects, they significantly impact on chromatin organization, metabolism, cell cycle regulation, immunity, longevity, and cancer risk and survival. Sex differences in cancer should be expected and accounted for in basic, translational, and clinical oncology research.

Molecular Features and Clinical Management of Hereditary Pancreatic Cancer Syndromes and Familial Pancreatic Cancer

Hereditary pancreatic cancers are caused by several inherited genes. Familial pancreatic cancer is defined as pancreatic cancer arising in a patient with at least two first-degree relatives with pancreatic cancer in the absence of an identified genetic cause. Hereditary pancreatic cancer syndromes and familial pancreatic cancers account for about 10% of pancreatic cancer cases. Germline mutations in BRCA1, BRCA2, ATM, PALB2, CDKN2A, STK11, and TP53 and mismatch repair genes (MLH1, MSH2, MSH6, PMS2, and EPCAM) are among the well-known inherited susceptibility genes. Currently available targeted medications include poly (ADP-ribose) polymerase inhibitors (PARP) for cases with mutant BRCA and immune checkpoint inhibitors for cases with mismatch repair deficiency. Loss of heterozygosity of hereditary pancreatic cancer susceptibility genes such as BRCA1/2 plays a key role in carcinogenesis and sensitivity to PARP inhibitors. Signature 3 identified by whole genome sequencing is also associated with homologous recombination deficiency and sensitivity to targeted therapies. In this review, we summarize molecular features and treatments of hereditary pancreatic cancer syndromes and surveillance procedures for unaffected high-risk cases. We also review transgenic murine models to gain a better understanding of carcinogenesis in hereditary pancreatic cancer.

TP53_PROF: a machine learning model to predict impact of missense mutations in TP53

Correctly identifying the true driver mutations in a patient’s tumor is a major challenge in precision oncology. Most efforts address frequent mutations, leaving medium- and low-frequency variants mostly unaddressed. For TP53, this identification is crucial for both somatic and germline mutations, with the latter associated with the Li-Fraumeni syndrome (LFS), a multiorgan cancer predisposition. We present TP53_PROF (prediction of functionality), a gene specific machine learning model to predict the functional consequences of every possible missense mutation in TP53, integrating human cell- and yeast-based functional assays scores along with computational scores. Variants were labeled for the training set using well-defined criteria of prevalence in four cancer genomics databases. The model’s predictions provided accuracy of 96.5%. They were validated experimentally, and were compared to population data, LFS datasets, ClinVar annotations and to TCGA survival data. Very high accuracy was shown through all methods of validation. TP53_PROF allows accurate classification of TP53 missense mutations applicable for clinical practice. Our gene specific approach integrated machine learning, highly reliable features and biological knowledge, to create an unprecedented, thoroughly validated and clinically oriented classification model. This approach currently addresses TP53 mutations and will be applied in the future to other important cancer genes.

Case Report : Li-Fraumeni Syndrome with Central Nervous System Tumors in Two Siblings

Background

Li-Fraumeni syndrome (LFS) is a rare autosomal dominant cancer predisposition syndrome caused by germline TP53 gene mutations. It is characterized by high risk of early-onset cancer, and has been confirmed as associated with multiple tumors clinically. So pediatricians should be more alert to LFS in children with tumors. Choroid plexus carcinoma (CPC) is a rare, malignant tumor which account for less than 1% of all central nervous system (CNS) tumors. However, when such tumorigenesis occurs, it is important to be vigilant for the presence of LFS.

Case presentation

The first patient is a 32-month-old boy admitted for convulsions and then was found intracranial space-occupying lesion. Underwent operation, he was diagnosis as choroid plexus carcinoma (WHO Grade III). After 5 months, his elder sister, a 13-year-old girl, was brought to emergency department for confusion and intermittent convulsions. Surgery was performed immediately after head CT examination found the lesion. The pathology result indicated glioblastoma. Because the siblings of the same family have successively suffered from malignant tumors, we performed genetic testing on this family. TP53 gene mutation occurred in both children of these two cases from their father, and their other brother was not spared either. So the two siblings both met the diagnostic criteria of LFS. Then they all received systematic anti-tumor therapy, and follow-up hitherto.

Conclusion

Here we reported a rare LFS case that two siblings were inherited the same TP53 germline mutations from their father. They suffered from choroid plexus carcinoma and glioblastoma and were finally diagnosed with LFS. In this LFS family, the primary tumors of the two children were both central nervous system tumors, which were not reported in the previous literature. It is suggested that clinicians should be alert to LFS related tumors, which is helpful for early diagnosis. Timely detection of TP53 gene is an important way for early diagnosis of LFS, especially in children with tumor. The incidence of secondary tumor in LFS patients is significantly higher, and other family members of the LFS patient also have an increased risk of suffering from the tumors. Therefore, early diagnosis and timely tumor surveillance can obtain better therapeutic effect and prognosis for both proband and their family.

Early Onset Colorectal Cancer: An Emerging Cancer Risk in Patients with Diamond Blackfan Anemia

Diamond Blackfan anemia (DBA) is a rare inherited bone marrow failure syndrome, the founding member of a class of disorders known as ribosomopathies. Most cases result from loss of function mutations or deletions in 1 of 23 genes encoding either a small or large subunit-associated ribosomal protein (RP), resulting in RP haploinsufficiency. DBA is characterized by red cell hypoplasia or aplasia, poor linear growth and congenital anomalies. Small case series and case reports demonstrate DBA to be a cancer predisposition syndrome. Recent analyses from the Diamond Blackfan Anemia Registry of North America (DBAR) have quantified the cancer risk in DBA. These studies reveal the most prevalent solid tumor, presenting in young adults and in children and adolescents, to be colorectal cancer (CRC) and osteogenic sarcoma, respectively. Of concern is that these cancers are typically detected at an advanced stage in patients who, because of their constitutional bone marrow failure, may not tolerate full-dose chemotherapy. Thus, the inability to provide optimal therapy contributes to poor outcomes. CRC screening in individuals over the age of 50 years, and now 45 years, has led to early detection and significant improvements in outcomes for non-DBA patients with CRC. These screening and surveillance strategies have been adapted to detect familial early onset CRC. With the recognition of DBA as a moderately penetrant cancer risk syndrome a rational screening and surveillance strategy will be implemented. The downstream molecular events, resulting from RP haploinsufficiency and leading to cancer, are the subject of significant scientific inquiry.

Melanoma in patients with Li-Fraumeni syndrome (Review)

Li-Fraumeni syndrome (LFS) is a cancer-prone, autosomal dominant syndrome caused by underlying germline gene mutations of TP53, a tumor-suppressor gene encoding the p53 protein with a major role in apoptosis, DNA repair and cell cycle regulation. Cumulative cancer incidence for LFS patients by the age of 70 years is 80-100%, mostly involving adrenocortical carcinoma, brain tumors, bone and soft tissue sarcomas, leukemia and female breast cancer from the age of 20 years. Dominant negative TP53 variant is correlated with an increased tumorigenesis risk in LFS. Sporadic TP53 mutations are related to almost half of global cancers since p53 in addition to p73 protein represent essential players in anticancer cellular protection. Epidemiological aspects concerning skin cancers, especially malignant melanoma (MM), in LFS are less clear. A low level of statistical evidence demonstrates LFS cases with pediatric MM, multiple MM, spitzoid MM, atypical presentations, mucosal and uveal MM. Retrospective cohorts indicate a higher cumulative risk than the general population by the age of 70 years for MM and basal cell carcinoma. Non-syndromic and syndromic TP53 mutations are a major pathway of metastasis, including MM. In LHS, an important level of awareness involves skin cancers despite not being a part of the typical malignancy-containing picture. Additional data are crucially needed. However, at least one dermatologic control is a step in the multidisciplinary panel of surveillance of these patients; but in cases with benign and pre-malign pigmentations, serial dermatoscopy and full body photography are recommended for early melanoma detection in order to improve the prognosis and to reduce the overall malignancy burden.

Cancer incidence, patterns, and genotype-phenotype associations in individuals with pathogenic or likely pathogenic germline TP53 variants: an observational cohort study

BACKGROUND

Li-Fraumeni syndrome, caused primarily by pathogenic or likely pathogenic germline TP53 variants, is a rare, variably penetrant, cancer predisposition syndrome with very high risks of cancer starting in childhood, including the risk of multiple primary malignancies over an individual's lifespan. We aimed to characterise and quantify cancer incidence, patterns, and genotype-phenotype associations in individuals with pathogenic or likely pathogenic germline TP53 variants.

METHODS

This observational cohort study was done in 480 carriers of pathogenic or likely pathogenic germline TP53 variants enrolled in the National Cancer Institute's referral-based longitudinal Li-Fraumeni syndrome study between Aug 1, 2011, and March 24, 2020. Data on personal and family history of cancer were obtained through study questionnaires and validated by medical records. Variants were categorised on the basis of both loss-of-function (LOF) and dominant-negative effect (DNE) properties. Cancer incidence associated with Li-Fraumeni syndrome was compared with that of the general population using the Surveillance, Epidemiology, and End Results (SEER) 1975-2017 registry. Cancer incidence was evaluated with family-clustered Cox regression models and competing risk methods. This study is registered with ClinicalTrials.gov, NCT01443468.

FINDINGS

Individuals with Li-Fraumeni syndrome had a nearly 24 times higher incidence of any cancer than the general population (standardised incidence ratio 23·9; 95% CI 21·9-26·0), with the highest comparative incidence from childhood to 30 years of age. The overall cancer incidence remained 10·3 (95% CI 7·9-13·2) times higher than that of the general population after age 50 years. In women, when considering breast cancer as a competing risk, the probability of a first diagnosis of a non-breast cancer malignancy was substantially lower than that of any first cancer (24·4% [95% CI 19·6-30·5] vs 50·4% [43·5-56·5] by age 33·7 years). Overall, DNE_LOF and notDNE_LOF variants were associated with earlier age at first and second cancer compared with notDNE_notLOF and DNE_notLOF variants. The time interval from first to second cancer was shorter among carriers whose first cancer diagnoses were later in life. Multiple cancers were diagnosed within a short timeframe in some individuals, regardless of the order of cancer occurrence.

INTERPRETATION

This study adds granularity to the understanding of cancer incidence and patterns in individuals with pathogenic or likely pathogenic germline TP53 variants. Integration of age range-specific cancer incidence estimates, cancer-free survival by functional variant group, the potential impact of risk-reducing mastectomy on female cancer incidence, and data on subsequent malignancies will be important for the development of strategies to optimise cancer screening and management for these individuals.

FUNDING

Intramural Research Program, Division of Cancer Epidemiology and Genetics, National Institutes of Health.

Mitotic Errors Promote Genomic Instability and Leukemia in a Novel Mouse Model of Fanconi Anemia

Fanconi anemia (FA) is a disease of genomic instability and cancer. In addition to DNA damage repair, FA pathway proteins are now known to be critical for maintaining faithful chromosome segregation during mitosis. While impaired DNA damage repair has been studied extensively in FA-associated carcinogenesis in vivo, the oncogenic contribution of mitotic abnormalities secondary to FA pathway deficiency remains incompletely understood. To examine the role of mitotic dysregulation in FA pathway deficient malignancies, we genetically exacerbated the baseline mitotic defect in Fancc-/- mice by introducing heterozygosity of the key spindle assembly checkpoint regulator Mad2. Fancc-/-;Mad2+/- mice were viable, but died from acute myeloid leukemia (AML), thus recapitulating the high risk of myeloid malignancies in FA patients better than Fancc-/-mice. We utilized hematopoietic stem cell transplantation to propagate Fancc-/-; Mad2+/- AML in irradiated healthy mice to model FANCC-deficient AMLs arising in the non-FA population. Compared to cells from Fancc-/- mice, those from Fancc-/-;Mad2+/- mice demonstrated an increase in mitotic errors but equivalent DNA cross-linker hypersensitivity, indicating that the cancer phenotype of Fancc-/-;Mad2+/- mice results from error-prone cell division and not exacerbation of the DNA damage repair defect. We found that FANCC enhances targeting of endogenous MAD2 to prometaphase kinetochores, suggesting a mechanism for how FANCC-dependent regulation of the spindle assembly checkpoint prevents chromosome mis-segregation. Whole-exome sequencing revealed similarities between human FA-associated myelodysplastic syndrome (MDS)/AML and the AML that developed in Fancc-/-; Mad2+/- mice. Together, these data illuminate the role of mitotic dysregulation in FA-pathway deficient malignancies in vivo, show how FANCC adjusts the spindle assembly checkpoint rheostat by regulating MAD2 kinetochore targeting in cell cycle-dependent manner, and establish two new mouse models for preclinical studies of AML.

Sexual Differentiation Specifies Cellular Responses to DNA Damage

Significant sex differences exist across cellular, tissue organization, and body system scales to serve the distinct sex-specific functions required for reproduction. They are present in all animals that reproduce sexually and have widespread impacts on normal development, aging, and disease. Observed from the moment of fertilization, sex differences are patterned by sexual differentiation, a lifelong process that involves mechanisms related to sex chromosome complement and the epigenetic and acute activational effects of sex hormones. In this mini-review, we examine evidence for sex differences in cellular responses to DNA damage, their underlying mechanisms, and how they might relate to sex differences in cancer incidence and response to DNA-damaging treatments.

Analysis of the Li-Fraumeni Spectrum Based on an International Germline TP53 Variant Data Set: An International Agency for Research on Cancer TP53 Database Analysis

Questions

What is the phenotypic spectrum associated with variants in TP53, the gene variant in persons with Li-Fraumeni syndrome, and what mechanisms underlie phenotypic differences?

Findings

In this cohort study, the phenotypes within the classification Li-Fraumeni spectrum were defined, and data from 3034 persons from 1282 families with data available in the International Agency for Research on Cancer TP53 Database were analyzed and classified to reveal meaningful differences in the TP53 variant distribution between patients who met vs those who did not meet Li-Fraumeni syndrome testing criteria.

Meaning

The study results suggest that this classification is a potential step toward understanding the factors that lead to phenotypic differences in the Li-Fraumeni spectrum and may serve as a model for the reclassification of other hereditary conditions with an increased cancer risk.

Importance

Li-Fraumeni syndrome is a cancer predisposition syndrome that is associated with a high, lifelong risk of a broad spectrum of cancers that is caused by pathogenic TP53 germline variants. A definition that reflects the broad phenotypic spectrum that has evolved since the gene discovery is lacking, and mechanisms leading to phenotypic differences remain largely unknown.

Objective

To define the phenotypic spectrum of Li-Fraumeni syndrome and conduct phenotype-genotype associations across the phenotypic spectrum.

Design, Setting, and Participants

We analyzed and classified the germline variant data set of the International Agency for Research on Cancer TP53 database that contains data on a cohort of 3034 persons from 1282 families reported in the scientific literature since 1990. We defined the term Li-Fraumeni spectrum to encompass (1) phenotypic Li-Fraumeni syndrome, defined by the absence of a pathogenic/likely pathogenic TP53 variant in persons/families meeting clinical Li-Fraumeni syndrome criteria; (2) Li-Fraumeni syndrome, defined by the presence of a pathogenic/likely pathogenic TP53 variant in persons/families meeting Li-Fraumeni syndrome testing criteria; (3) attenuated Li-Fraumeni syndrome, defined by the presence of a pathogenic/likely pathogenic TP53 variant in a person/family with cancer who does not meet Li-Fraumeni syndrome testing criteria; and (4) incidental Li-Fraumeni syndrome, defined by the presence of a pathogenic/likely pathogenic TP53 variant in a person/family without a history of cancer. Data analysis occurred from November 2020 to March 2021.

Main Outcomes and Measures

Differences in variant distribution and cancer characteristics in patients with a germline TP53 variant who met vs did not meet Li-Fraumeni syndrome testing criteria.

Results

Tumor spectra showed significant differences, with more early adrenal (n = 166, 6.5% vs n = 0), brain (n = 360, 14.17% vs n = 57, 7.46%), connective tissue (n = 303, 11.92% vs n = 56, 7.33%), and bone tumors (n = 279, 10.98% vs n = 3, 0.39%) in patients who met Li-Fraumeni syndrome genetic testing criteria (n = 2139). Carriers who did not meet Li-Fraumeni syndrome genetic testing criteria (n = 678) had more breast (n = 292, 38.22% vs n = 700, 27.55%) and other cancers, 45% of them occurring after age 45 years. Hotspot variants were present in both groups. Several variants were exclusively found in patients with Li-Fraumeni syndrome, while others where exclusively found in patients with attenuated Li-Fraumeni syndrome. In patients who met Li-Fraumeni syndrome genetic testing criteria, most TP53 variants were classified as pathogenic/likely pathogenic (1757 of 2139, 82.2%), whereas 40.4% (404 of 678) of TP53 variants identified in patients who did not meet the Li-Fraumeni syndrome genetic testing criteria were classified as variants of uncertain significance, conflicting results, likely benign, benign, or unknown.

Conclusions and Relevance

The findings of this cohort study suggest that this new classification, Li-Fraumeni spectrum, is a step toward understanding the factors that lead to phenotypic differences and may serve as a model for other cancer predisposition syndromes.

TP53 in Acute Myeloid Leukemia: Molecular Aspects and Patterns of Mutation

Mutation of the tumor suppressor gene, TP53, is associated with abysmal survival outcomes in acute myeloid leukemia (AML). Although it is the most commonly mutated gene in cancer, its occurrence is observed in only 5–10% of de novo AML, and in 30% of therapy related AML (t-AML). TP53 mutation serves as a prognostic marker of poor response to standard-of-care chemotherapy, particularly in t-AML and AML with complex cytogenetics. In light of a poor response to traditional chemotherapy and only a modest improvement in outcome with hypomethylation-based interventions, allogenic stem cell transplant is routinely recommended in these cases, albeit with a response that is often short lived. Despite being frequently mutated across the cancer spectrum, progress and enthusiasm for the development of p53 targeted therapeutic interventions is lacking and to date there is no approved drug that mitigates the effects of TP53 mutation. There is a mounting body of evidence indicating that p53 mutants differ in functionality and form from typical AML cases and subsequently display inconsistent responses to therapy at the cellular level. Understanding this pathobiological activity is imperative to the development of effective therapeutic strategies. This review aims to provide a comprehensive understanding of the effects of TP53 on the hematopoietic system, to describe its varying degree of functionality in tumor suppression, and to illustrate the need for the adoption of personalized therapeutic strategies to target distinct classes of the p53 mutation in AML management.

Choroid Plexus Carcinomas With TP53 Germline Mutations: Management and Outcome

BACKGROUND

Choroid plexus carcinomas (CPCs) are rare pediatric tumors commonly associated with Li-Fraumeni syndrome (LFS), which involves a germline mutation of the tumor suppressor gene TP53.

MATERIALS AND METHODS

We retrospectively analyzed the corresponding information of 12 cases, including the effects of surgery and radiotherapy and TP53 germline mutations, to analyse the management strategies. Kaplan-Meier curves and the log-rank test were used to evaluate the progression-free survival (PFS).

RESULTS

Twelve CPC patients were included, of which TP53 germline mutations were found in eight cases. All patients underwent surgical resection, and six patients received radiotherapy following with operation after initial diagnosis, one patient received radiotherapy following relapse. It was significantly different (P=0.012 and 0.028) that patients with TP53 germline mutation receiving the gross total resection (GTR) without radiotherapy showed survival advantages. Without TP53 germline mutations also showed survival advantages, but there is no statistical significance (P=0.063).

CONCLUSIONS

These findings provide evidence for the therapeutic strategy that radiotherapy should not be considered for patients with TP53 germline mutations.

Psychosocial interventions and needs among individuals and families with Li-Fraumeni syndrome: A scoping review

Li-Fraumeni syndrome (LFS), a rare cancer predisposition syndrome caused by germline mutations in the TP53 gene, is associated with significant lifetime risk of developing cancer and warrants extensive and long-term surveillance. There are psychosocial impacts on individuals and families living with this condition, from the initial diagnosis throughout multiple stages across the lifespan, but these impacts have not been systematically reviewed and organized. The objective of this scoping review was to synthesize and characterize the literature on psychosocial screening and outcomes, educational needs, support services, and available interventions for patients and families with LFS. A systematic search of six databases was most recently conducted in August 2020: (PubMed/MEDLINE (NLM), EMBASE (Elsevier), Cochrane Library (Wiley), CINAHL (EBSCO), PsycINFO (OVID), and Web of Science (Clarivate Analytics). A total of 15 757 titles were screened, and 24 articles included. Several important themes were identified across studies: factors associated with TP53 genetic testing, LFS surveillance, psychological outcomes, and communication. Findings related to these themes were organized into age-specific categories (age agnostic/across the lifespan, childhood, adolescence and young adulthood, and adulthood).

Colorectal cancer screening and surveillance strategy for patients with Diamond Blackfan anemia: Preliminary recommendations from the Diamond Blackfan Anemia Registry

Diamond Blackfan anemia (DBA) is a rare inherited bone marrow failure syndrome characterized by red cell failure, congenital anomalies, poor linear growth, and cancer predisposition. Two previous analyses from the Diamond Blackfan Anemia Registry have quantified DBA as a cancer predisposition syndrome of moderate cancer penetrance. Patients with DBA have a 4.8-fold higher relative risk of developing cancer with an overall cumulative incidence of 13.7% by age 45 years. The two most prevalent solid tumors are colorectal cancer (CRC) and osteogenic sarcoma. Current and evolving data support the institution of cancer screening and surveillance strategies for CRC in DBA.

Genetic modifiers regulating DNA replication and double-strand break repair are associated with differences in mammary tumors in mouse models of Li-Fraumeni syndrome

Breast cancer is the most common tumor among women with inherited variants in the TP53 tumor suppressor, but onset varies widely suggesting interactions with genetic or environmental factors. Rodent models haploinsufficent for Trp53 also develop a wide variety of malignancies associated with Li-Fraumeni Syndrome, but BALB/c mice are uniquely susceptible to mammary tumors and is genetically linked to the Suprmam1 locus on chromosome 7. To define mechanisms that interact with deficiencies in p53 to alter susceptibility to mammary tumors, we fine-mapped the Suprmam1 locus in females from an N2 backcross of BALB/cMed and C57BL/6J mice. A major modifier was localized within a 10 cM interval on chromosome 7. The effect of the locus on DNA damage responses was examined in the parental strains and mice that are congenic for C57BL/6J alleles on the BALB/cMed background (SM1-Trp53^+/−). The mammary epithelium of C57BL/6J-Trp53^+/− females exhibited little radiation-induced apoptosis compared to BALB/cMed-Trp53^+/− and SM1-Trp53^+/− females indicating that the Suprmam1^B6/B6 alleles could not rescue repair of radiation-induced DNA double-strand breaks mostly relying on non-homologous end joining. In contrast, the Suprmam1^B6/B6 alleles in SM1-Trp53+/− mice were sufficient to confer the C57BL/6J-Trp53^+/− phenotypes in homology-directed repair and replication fork progression. The Suprmam1^B6/B6 alleles in SM1-Trp53^+/− mice appear to act in trans to regulate a panel of DNA repair and replication genes which lie outside the locus.

Association between Predicted Effects of TP53 Missense Variants on Protein Conformation and Their Phenotypic Presentation as Li-Fraumeni Syndrome or Hereditary Breast Cancer

Rare germline pathogenic TP53 missense variants often predispose to a wide spectrum of tumors characterized by Li-Fraumeni syndrome (LFS) but a subset of variants is also seen in families with exclusively hereditary breast cancer (HBC) outcomes. We have developed a logistic regression model with the aim of predicting LFS and HBC outcomes, based on the predicted effects of individual TP53 variants on aspects of protein conformation. A total of 48 missense variants either unique for LFS (n = 24) or exclusively reported in HBC (n = 24) were included. LFS-variants were over-represented in residues tending to be buried in the core of the tertiary structure of TP53 (p = 0.0014). The favored logistic regression model describes disease outcome in terms of explanatory variables related to the surface or buried status of residues as well as their propensity to contribute to protein compactness or protein-protein interactions. Reduced, internally validated models discriminated well between LFS and HBC (C-statistic = 0.78−0.84; equivalent to the area under the ROC (receiver operating characteristic) curve), had a low risk for over-fitting and were well calibrated in relation to the known outcome risk. In conclusion, this study presents a phenotypic prediction model of LFS and HBC risk for germline TP53 missense variants, in an attempt to provide a complementary tool for future decision making and clinical handling.

Utility of interim blood tests for cancer screening in Li-Fraumeni syndrome

Comprehensive annual screening reduces cancer-related mortality in Li-Fraumeni syndrome (LFS), a cancer-prone disorder caused by pathogenic germline TP53 variants. Blood tests at months 4 and 8 between annual screening are recommended but their effectiveness in early cancer detection has not been established. Interim blood counts and inflammatory biomarkers were evaluated in 132 individuals with LFS (112 adults, 87 female, median age 36 years [range 3-68], median follow-up 37 months [range 2-70]) and test abnormalities were observed in 225 (35%). Thirteen cancers in 12 individuals were diagnosed between annual screenings but only one cancer (colorectal adenocarcinoma) was diagnosed due to an abnormal interim blood test. Fisher's exact test and generalized estimating equation models found no statistical associations between cancer diagnoses and any test abnormality. Four- and 8-monthly interim screening blood tests may not be of independent benefit for cancer detection in LFS, but annual cancer screening and personalized follow-up remain essential.

Pediatric Head and Neck Tumors Associated with Li-Fraumeni Syndrome

INTRODUCTION

Cancer predisposition syndromes are germline pathogenic variants in genes that greatly raise the risk of developing neoplastic diseases. One of the most well-known is Li-Fraumeni syndrome (LFS), which is due to pathogenic variants in the TP53 gene. Children with LFS have higher risks for multiple malignancies before adulthood, often with rare and aggressive subtypes.

OBJECTIVE

To examine head and neck manifestations of LFS in children treated at a tertiary children's hospital over a 20-year period.

METHODS

A retrospective review of LFS children with neoplastic disease presenting in traditional Otolaryngologic head and neck subsites from 2000 to 2019, with patient charts reviewed for relevant clinical, imaging, and operative data.

RESULTS

Of the 40 LFS patients initially identified, 27 neoplastic tumors were identified in 20 children within this cohort (20 primary, 7 second primary). Head and neck subsites aside from the brain or orbit were involved in 22% (6/27) of these tumors, representing 20% (4/20) of primary tumors and 29% (2/7) of second primary tumors. Both second primaries within the head and neck were within the radiation fields of the first primary tumor. The mean ages at primary and second primary diagnosis were 4.6 years (SD 3.5) and 12 years (SD 1.4), respectively. The male/female ratio was 1:6 among all patients with head and neck tumors. All 6 head and neck tumors were sarcomas. Rhabdomyosarcoma (N = 3, 50%) was the most common pathology, and the other 3 demonstrated rare tumor pathological subtypes (synovial cell sarcoma, pleomorphic myxoid liposarcoma, mandibular osteosarcoma). The neck was the most common subsite (75%) within this group for primary tumor presentation.

CONCLUSION

This study identifies a high potential for head and neck involvement in children with LFS, which has not been previously described in the literature. Otolaryngological care should be included in a multidisciplinary care team surveilling these patients.

Oncologically Relevant Findings Reporting and Data System (ONCO-RADS): Guidelines for the Acquisition, Interpretation, and Reporting of Whole-Body MRI for Cancer Screening

Acknowledging the increasing number of studies describing the use of whole-body MRI for cancer screening, and the increasing number of examinations being performed in patients with known cancers, an international multidisciplinary expert panel of radiologists and a geneticist with subject-specific expertise formulated technical acquisition standards, interpretation criteria, and limitations of whole-body MRI for cancer screening in individuals at higher risk, including those with cancer predisposition syndromes. The Oncologically Relevant Findings Reporting and Data System (ONCO-RADS) proposes a standard protocol for individuals at higher risk, including those with cancer predisposition syndromes. ONCO-RADS emphasizes structured reporting and five assessment categories for the classification of whole-body MRI findings. The ONCO-RADS guidelines are designed to promote standardization and limit variations in the acquisition, interpretation, and reporting of whole-body MRI scans for cancer screening. Published under a CC BY 4.0 license Online supplemental material is available for this article.

Revisiting multiple erroneous genetic testing results and clinical misinterpretations in a patient with Li-Fraumeni syndrome: lessons for translational medicine

BACKGROUND

Many cancer patients undergo sophisticated laboratory testing, which requires proper interpretation and interaction between different specialists.

CASE PRESENTATION

We describe a patient with an extensive family history of cancer, who was diagnosed with bilateral breast cancer and two lung cancer lumps by the age of 40 years. She submitted a lung cancer specimen to a genetic profiling service, which reported the presence of the EGFR mutation (a combination of G719S and L833V substitutions) and the TP53 с.322_327del (p.G108_F109del) mutation in the tumor tissue. Possible therapeutic options were discussed at a medical conference, where one of the discussants raised a concern that the identified TP53 mutation may not necessarily be somatic, but reflect the germ-line status of the gene. Review of clinical records and follow-up dialog with the patient revealed, that she previously provided her blood for DNA analysis in two laboratories. The first laboratory utilized a custom NGS assay and did not detect the TP53 mutation, instead pointed to a potential pathogenic significance of the MSH6 c.2633 T > C (p.V878A) allele. The second laboratory revealed the TP53 с.322_327del (p.G108_F109del) allele but stated in the written report that it has an unknown pathogenic significance. To resolve the possible uncertainty regarding the role of the TP53 с.322_327del (p.G108_F109del) variant, we suggested that the patient invite her second cousin for genetic testing, as she was affected by neuroblastoma at the age of 3 years. This analysis revealed the presence of the same TP53 variant.

CONCLUSION

We provide point-by-point discussion, reviewing multiple laboratory mistakes and clinical misinterpretations occurred with this patient. This case report exemplifies the need to involve rigorous clinical expertise in the daily practice of medical laboratory facilities.

Spontaneous and inherited TP53 genetic alterations

The p53 protein is a transcription factor that prevents tumors from developing. In spontaneous and inherited cancers there are many different missense mutations in the DNA binding domain of the TP53 gene that contributes to tumor formation. These mutations produce a wide distribution in the transcriptional capabilities of the mutant p53 proteins with over four logs differences in the efficiencies of forming cancers in many diverse tissue types. These inherited and spontaneous TP53 mutations produce proteins that interact with both genetic and epigenetic cellular modifiers of p53 function and their inherited polymorphisms to produce a large number of diverse phenotypes in individual patients. This manuscript reviews these variables and discusses how the combinations of TP53 genetic alterations interact with genetic polymorphisms, epigenetic alterations, and environmental factors to begin predicting and modifying patient outcomes and provide a better understanding for new therapeutic opportunities.

In cis TP53 and RAD51C pathogenic variants may predispose to sebaceous gland carcinomas

Pathogenic variants in TP53 have been classically thought to cause Li-Fraumeni syndrome (LFS), a cancer predisposition with high risks for various childhood- and adult-onset malignancies. However, increased genetic testing has lately revealed, that pathogenic variant carriers exhibit a broader range of phenotypes and that penetrance may be dependent both on variant type and modifiers. Using next generation sequencing and short tandem repeat analysis, we identified germline pathogenic variants in TP53 and RAD51C located in cis on chromosome 17 in a 43-year-old male, who has developed a rare sebaceous gland carcinoma (SGC) but so far no tumors of the LFS spectrum. This course mirrors a Trp53-Rad51c-double-mutant cis mouse-model, which similarly develops SGC, while the characteristic Trp53-associated tumor spectrum occurs with significantly lower frequency. Therefore, we propose that co-occurent pathogenic variants in RAD51C and TP53 may predispose to SGC, reminiscent of Muir-Torre syndrome. Further, this report supports the diversity of clinical presentations associated with germline TP53 alterations, and thus, the proposed expansion of LFS to heritable TP53-related cancer syndrome.

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.

Family Health Leaders: Lessons on Living with Li-Fraumeni Syndrome across Generations

Li-Fraumeni Syndrome (LFS) is a hereditary disorder that confers an approximately 90% lifetime risk of cancer and requires comprehensive lifetime cancer screening. We explored healthcare roles for managing LFS-related cancer risks and treatments that were assumed by parents, adolescents, and adult children. Semi-structured interviews were conducted with 23 families. Family groupings were comprised of 2-5 members, with the younger generation in each family ranging in age from 7 to 40 years. Using grounded theory methods, we conducted open and focused coding of interview transcript content. Family members described how the role of health leader was implemented in their family, as well as factors such as maturation of a child or death of a member that determined who assumed particular roles and how these roles shifted over time. They often expressed collective responsibility for helping relatives understand LFS and implement appropriate cancer risk management. Members demonstrated their health role by attending others' medical appointments for support or information gathering. The health leader role was intergenerational and provided the family necessary support in navigating complicated healthcare decisions. Our findings provide insight into healthcare providers regarding how LFS patients and their relatives develop unique medical decision-making and caring roles influenced by the hereditary nature of LFS, and how these roles change over time. Providers who are attuned to family role dynamics may be better able to meet relatives' psychosocial and medical needs by understanding how living with LFS influences the family system's functioning and facilitating members' support for each other.

Upper Gastrointestinal Cancer Risk and Surveillance Outcomes in Li-Fraumeni Syndrome

INTRODUCTION

To assess the upper gastrointestinal (UGI) cancer risk and surveillance outcomes in Li-Fraumeni syndrome (LFS).

METHODS

Analysis of the International Agency for Research on Cancer database and a single-center adult LFS cohort.

RESULTS

UGI cancer was present in 7.2% of families and 3.9% of individuals with a pathogenic/likely pathogenic TP53 mutation in International Agency for Research on Cancer; 29% occurred before age 30. Our institutional cohort had 35 individuals (31% of the LFS cohort) with 48 cumulative upper endoscopies; 3 (8.5%) individuals had concerning UGI findings.

DISCUSSION

UGI cancer is observed in LFS. Upper endoscopy should be part of a comprehensive LFS surveillance program.

Pre- and Post-Zygotic TP53 De Novo Mutations in SHH-Medulloblastoma

Simple Summary

Medulloblastoma is the most common malignant brain tumor in children. In a subset of cases, a causal factor is a constitutive mutation of the TP53 gene, which may be inherited or arise for the first time in a patient (de novo). Using an immunohistochemistry assay as a screening tool, we selected patients suspected of harboring a TP53 mutation and offered genetic counseling and germline testing. Our study, which was the first to investigate the parental origin of TP53 mutations in medulloblastoma, allowed the identification of two additional cases with de novo mutations. Moreover, we demonstrated that in one patient the mutation originated at a post-zygotic stage, resulting in somatic mosaicism. These findings have important implications for genetic counseling since they highlight the occurrence of both pre- and post-zygotic TP53 de novo mutations in medulloblastoma, pointing out that in a specific subgroup of patients genetic testing should be offered regardless of family history.

Abstract

Li-Fraumeni syndrome (LFS) is an autosomal dominant disorder caused by mutations in the TP53 gene, predisposing to a wide spectrum of early-onset cancers, including brain tumors. In medulloblastoma patients, the role of TP53 has been extensively investigated, though the prevalence of de novo mutations has not been addressed. We characterized TP53 mutations in a monocentric cohort of consecutive Sonic Hedgehog (SHH)-activated medulloblastoma patients. Germline testing was offered based on tumor p53 immunostaining positivity. Among 24 patients, three (12.5%) showed tumor p53 overexpression, of whom two consented to undergo germline testing and resulted as carriers of TP53 mutations. In the first case, family history was uneventful and the mutation was not found in either of the parents. The second patient, with a family history suggestive of LFS, unexpectedly resulted as a carrier of the mosaic mutation c.742=/C>T p.(Arg248=/Trp). The allele frequency was 26% in normal tissues and 42–77% in tumor specimens. Loss of heterozygosity (LOH) in the tumor was also confirmed. Notably, the mosaic case has been in complete remission for more than one year, while the first patient, as most TP53-mutated medulloblastoma cases from other cohorts, showed a severe and rapidly progressive disease. Our study reported the first TP53 mosaic mutation in medulloblastoma patients and confirmed the importance of germline testing in p53 overexpressed SHH-medulloblastoma, regardless of family history.

Implementation of Germline Testing for Prostate Cancer: Philadelphia Prostate Cancer Consensus Conference 2019

PURPOSE

Germline testing (GT) is a central feature of prostate cancer (PCA) treatment, management, and hereditary cancer assessment. Critical needs include optimized multigene testing strategies that incorporate evolving genetic data, consistency in GT indications and management, and alternate genetic evaluation models that address the rising demand for genetic services.

METHODS

A multidisciplinary consensus conference that included experts, stakeholders, and national organization leaders was convened in response to current practice challenges and to develop a genetic implementation framework. Evidence review informed questions using the modified Delphi model. The final framework included criteria with strong (> 75%) agreement (Recommend) or moderate (50% to 74%) agreement (Consider).

RESULTS

Large germline panels and somatic testing were recommended for metastatic PCA. Reflex testing-initial testing of priority genes followed by expanded testing-was suggested for multiple scenarios. Metastatic disease or family history suggestive of hereditary PCA was recommended for GT. Additional family history and pathologic criteria garnered moderate consensus. Priority genes to test for metastatic disease treatment included BRCA2, BRCA1, and mismatch repair genes, with broader testing, such as ATM, for clinical trial eligibility. BRCA2 was recommended for active surveillance discussions. Screening starting at age 40 years or 10 years before the youngest PCA diagnosis in a family was recommended for BRCA2 carriers, with consideration in HOXB13, BRCA1, ATM, and mismatch repair carriers. Collaborative (point-of-care) evaluation models between health care and genetic providers was endorsed to address the genetic counseling shortage. The genetic evaluation framework included optimal pretest informed consent, post-test discussion, cascade testing, and technology-based approaches.

CONCLUSION

This multidisciplinary, consensus-driven PCA genetic implementation framework provides novel guidance to clinicians and patients tailored to the precision era. Multiple research, education, and policy needs remain of importance.

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.

Frequency of radiation-induced malignancies post-adjuvant radiotherapy for breast cancer in patients with Li-Fraumeni syndrome

PURPOSE

Women with Li-Fraumeni syndrome (LFS), a cancer predisposition syndrome caused by germline mutations in TP53, have an over 50% risk of developing breast cancer by age 70. Patients with LFS are at risk for radiation-induced malignancies; however, only small case series have prior investigated radiation risks in the treatment of breast cancer. We therefore aimed to investigate the risk of malignancy in breast cancer patients with LFS following adjuvant radiotherapy.

METHODS

A single-institution retrospective chart review was conducted for female breast cancer patients with confirmed germline TP53 mutation. The frequency of radiation-induced malignancies in LFS patients was compared to non-LFS breast cancer cases reported in the Penn Medicine Cancer Registry via statistical analyses.

RESULTS

We identified 51 female LFS breast cancer patients with 74 primary diagnoses. Fifty-seven% had a history of breast cancer only, and 25% had breast cancer as their presenting diagnosis of LFS. LFS-associated breast cancers were predominantly invasive ductal carcinoma (48%) and HER2+ (58%). Twenty patients underwent adjuvant radiotherapy with a median follow-up of 12.5 (2-20) years. Of 18 patients who received radiation in a curative setting, one (6%) patient developed thyroid cancer, and one (6%) patient developed sarcoma in the radiation field. This risk for radiation-induced malignancy associated with LFS was higher for both sarcoma and thyroid cancer in comparison with the control cohort.

CONCLUSIONS

We found a lower risk of radiation-induced secondary malignancies in LFS breast cancer patients than previously reported in the literature (33% risk of radiation-induced sarcoma). These findings suggest that LFS may not be an absolute contraindication for radiotherapy in breast cancer. The potential risk for locoregional recurrence without radiotherapy must be weighed against the long-term risk for radiation-induced malignancies in consideration of adjuvant radiotherapy for LFS breast cancer patients.

Psychosocial effects of whole-body MRI screening in adult high-risk pathogenic TP53 mutation carriers: a case-controlled study (SIGNIFY)

BACKGROUND

Germline TP53 gene pathogenic variants (pv) cause a very high lifetime risk of developing cancer, almost 100% for women and 75% for men. In the UK, annual MRI breast screening is recommended for female TP53 pv carriers. The SIGNIFY study (Magnetic Resonance Imaging screening in Li Fraumeni syndrome: An exploratory whole body MRI) study reported outcomes of whole-body MRI (WB-MRI) in a cohort of 44 TP53 pv carriers and 44 matched population controls. The results supported the use of a baseline WB-MRI screen in all adult TP53 pv carriers. Here we report the acceptability of WB-MRI screening and effects on psychosocial functioning and health-related quality of life in the short and medium terms.

METHODS

Psychosocial and other assessments were carried out at study enrolment, immediately before MRI, before and after MRI results, and at 12, 26 and 52 weeks' follow-up.

RESULTS

WB-MRI was found to be acceptable with high levels of satisfaction and low levels of psychological morbidity throughout. Although their mean levels of cancer worry were not high, carriers had significantly more cancer worry at most time-points than controls. They also reported significantly more clinically significant intrusive and avoidant thoughts about cancer than controls at all time-points. There were no clinically significant adverse psychosocial outcomes in either carriers with a history of cancer or in those requiring further investigations.

CONCLUSION

WB-MRI screening can be implemented in TP53 pv carriers without adverse psychosocial outcomes in the short and medium terms. A previous cancer diagnosis may predict a better psychosocial outcome. Some carriers seriously underestimate their risk of cancer. Carriers of pv should have access to a clinician to help them develop adaptive strategies to cope with cancer-related concerns and respond to clinically significant depression and/or anxiety.

Imaging features of adrenal gland masses in the pediatric population

The spectrum of adrenal masses in the pediatric population markedly differs from that in the adult population. Imaging plays a crucial role in detecting adrenal masses, differentiating malignant from benign lesions, recognizing extra-adrenal lesions in the suprarenal fossa, and directing further management. Ultrasound is the primary imaging modality of choice for the evaluation of adrenal masses in the neonatal period, whereas MRI or CT is used as a problem-solving tool. In older children, computed tomography or magnetic resonance imaging is often required after initial sonographic evaluation for further characterization of a lesion. Herein, we discuss the salient imaging features along with pathophysiology and clinical features of pediatric adrenal masses.

The first pancreatic neuroendocrine tumor in Li-Fraumeni syndrome: a case report

Background

Li-Fraumeni syndrome is a cancer predisposition syndrome caused by germline TP53 tumor suppressor gene mutations, with no previous association with pancreatic neuroendocrine tumors (PNETs). Here we present the first case of PNET associated with Li-Fraumeni syndrome.

Case presentation

This is a 43-year-old female who underwent laparoscopic distal pancreatectomy at age 39 for a well-differentiated grade 2 cystic PNET. When the patient was 41 years old, her seven-year-old daughter was found to have an astrocytoma and a germline TP53 mutation. While undergoing surveillance with ⁶⁸Gallium-DOTATATE positron emission tomography/computed tomography for her PNET, the patient was found to have a large choroid plexus papilloma in her right temporal lobe. She underwent genetic counseling and testing that identified a germline pathogenic variant in TP53, leading to the diagnosis of Li-Fraumeni syndrome. Her PNET had a hemizygous pathogenic TP53 mutation with loss of the wild-type alternate allele, consistent with loss of heterozygosity and the two-hit hypothesis. She was enrolled in a Li-Fraumeni syndrome protocol and continues surveillance screening with our service.

Conclusions

This is the first PNET reported in association with Li-Fraumeni syndrome. Pancreatic cancer risk is elevated in this syndrome, and our case highlights the need for vigilance in screening for pancreatic neoplasms in these patients.

Risk of Contralateral Breast Cancer in Women with and without Pathogenic Variants in BRCA1, BRCA2, and TP53 Genes in Women with Very Early-Onset (<36 Years) Breast Cancer

Early age at diagnosis of breast cancer is a known risk factor for hereditary predisposition and some studies show a high risk of contralateral breast cancer in BRCA1 carriers diagnosed at very young ages. However, little is published on the risk of TP53 carriers. 397 women with breast cancer diagnosed <36 years of age were obtained from three sources: (i) a population-based study of 283 women diagnosed sequentially from 1980-1997 in North-West England, (ii) referrals to the Genomic Medicine Department at St Mary's Hospital from 1990-2018, and (iii) individuals from (i) and the Family History Clinic at Wythenshawe Hospital South Manchester who tested negative for pathogenic variants (PV) in all three genes. Sequencing of BRCA1, BRCA2, and TP53 genes was carried out alongside tests for copy number for PV on all referred women. Rates of contralateral breast cancer were censored at death, last assessment, or risk-reducing mastectomy. In total, 47 TP53, 218 BRCA1, and 132 BRCA2 PV carriers were identified with breast cancer diagnosed aged 35 years and under, as well as a representative sample of 261 not known to carry a PV in BRCA1, BRCA2, and TP53. Annual rates of contralateral breast cancer (and percentage of synchronous breast cancers) were TP53: 7.03% (4.3%), BRCA1: 3.57% (1.8%), and BRCA2: 2.63% (1.5%). In non-PV carriers, contralateral rates in isolated presumed/tested non-carrier cases with no family history were 0.56%, and for those with a family history, 0.69%. Contralateral breast cancer rates are substantial in TP53, BRCA1, and BRCA2 PV carriers diagnosed with breast cancer aged 35 and under. Women need to be advised to help make informed decisions on contralateral mastectomy, guided by life expectancy from their index tumor.

Identifying multi-hit carcinogenic gene combinations: Scaling up a weighted set cover algorithm using compressed binary matrix representation on a GPU

Despite decades of research, effective treatments for most cancers remain elusive. One reason is that different instances of cancer result from different combinations of multiple genetic mutations (hits). Therefore, treatments that may be effective in some cases are not effective in others. We previously developed an algorithm for identifying combinations of carcinogenic genes with mutations (multi-hit combinations), which could suggest a likely cause for individual instances of cancer. Most cancers are estimated to require three or more hits. However, the computational complexity of the algorithm scales exponentially with the number of hits, making it impractical for identifying combinations of more than two hits. To identify combinations of greater than two hits, we used a compressed binary matrix representation, and optimized the algorithm for parallel execution on an NVIDIA V100 graphics processing unit (GPU). With these enhancements, the optimized GPU implementation was on average an estimated 12,144 times faster than the original integer matrix based CPU implementation, for the 3-hit algorithm, allowing us to identify 3-hit combinations. The 3-hit combinations identified using a training set were able to differentiate between tumor and normal samples in a separate test set with 90% overall sensitivity and 93% overall specificity. We illustrate how the distribution of mutations in tumor and normal samples in the multi-hit gene combinations can suggest potential driver mutations for further investigation. With experimental validation, these combinations may provide insight into the etiology of cancer and a rational basis for targeted combination therapy.

Inherited lung cancer: a review

Lung cancer is the most common cancer worldwide and has high rates of mortality. The major risk factor associated with this disease is tobacco smoke, but approximately 10%-25% of all lung cancer cases occur in patients who have never smoked. Data suggest that lung cancer in never-smokers has a different molecular profile, tumour microenvironment and epidemiology than that in smokers. Several risk factors have been associated with its occurrence, and the possibility of inherited predisposition is becoming clearer. A better understanding of this disease is essential for the future development of personalised screening, diagnosis and treatment approaches, with consequent reduction of mortality. In this review, we discuss historical studies of lung cancer in never-smokers and the currently available evidence of inherited predisposition to this disease.

Li-Fraumeni syndrome heterogeneity

Clinical variability is commonly seen in Li-Fraumeni syndrome. Phenotypic heterogeneity is present among different families affected by the same pathogenic variant in TP53 gene and among members of the same family. However, causes of this huge clinical spectrum have not been studied in depth. TP53 type mutation, polymorphic variants in TP53 gene or in TP53-related genes, copy number variations in particular regions, and/or epigenetic deregulation of TP53 expression might be responsible for clinical heterogeneity. In this review, recent advances in the understanding of genetic and epigenetic aspects influencing Li-Fraumeni phenotype are discussed.

Chemotherapy and Risk of Subsequent Malignant Neoplasms in the Childhood Cancer Survivor Study Cohort

PURPOSE

Therapeutic radiation in childhood cancer has decreased over time with a concomitant increase in chemotherapy. Limited data exist on chemotherapy-associated subsequent malignant neoplasm (SMN) risk.

PATIENTS AND METHODS

SMNs occurring > 5 years from diagnosis, excluding nonmelanoma skin cancers, were evaluated in survivors diagnosed when they were < 21 years old, from 1970 to 1999 in the Childhood Cancer Survivor Study (median age at diagnosis, 7.0 years; median age at last follow-up, 31.8 years). Thirty-year SMN cumulative incidence and standardized incidence ratios (SIRs) were estimated by treatment: chemotherapy-only (n = 7,448), chemotherapy plus radiation (n = 10,485), radiation only (n = 2,063), or neither (n = 2,158). Multivariable models were used to assess chemotherapy-associated SMN risk, including dose-response relationships.

RESULTS

Of 1,498 SMNs among 1,344 survivors, 229 occurred among 206 survivors treated with chemotherapy only. Thirty-year SMN cumulative incidence was 3.9%, 9.0%, 10.8%, and 3.4% for the chemotherapy-only, chemotherapy plus radiation, radiation-only, or neither-treatment groups, respectively. Chemotherapy-only survivors had a 2.8-fold increased SMN risk compared with the general population (95% CI, 2.5 to 3.2), with SIRs increased for subsequent leukemia/lymphoma (1.9; 95% CI, 1.3 to 2.7), breast cancer (4.6; 95% CI, 3.5 to 6.0), soft-tissue sarcoma (3.4; 95% CI, 1.9 to 5.7), thyroid cancer (3.8; 95% CI, 2.7 to 5.1), and melanoma (2.3; 95% CI, 1.5 to 3.5). SMN rate was associated with > 750 mg/m² platinum (relative rate [RR] 2.7; 95% CI, 1.1 to 6.5), and a dose response was observed between alkylating agents and SMN rate (RR, 1.2/5,000 mg/m²; 95% CI, 1.1 to 1.3). A linear dose response was also demonstrated between anthracyclines and breast cancer rate (RR, 1.3/100 mg/m²; 95% CI, 1.2 to 1.6).

CONCLUSION

Childhood cancer survivors treated with chemotherapy only, particularly higher cumulative doses of platinum and alkylating agents, face increased SMN risk. Linear dose responses were seen between alkylating agents and SMN rates and between anthracyclines and breast cancer rates. Limiting cumulative doses and consideration of alternate chemotherapies may reduce SMN risk.

A substantial proportion of apparently heterozygous TP53 pathogenic variants detected with a next-generation sequencing hereditary pan-cancer panel are acquired somatically

Previous analysis of next‐generation sequencing (NGS) hereditary pan‐cancer panel testing demonstrated that approximately 40% of TP53 pathogenic and likely pathogenic variants (PVs) detected have NGS allele frequencies between 10% and 30%, indicating that they likely are acquired somatically. These are seen more frequently in older adults, suggesting that most result from normal aging‐related clonal hematopoiesis. For this analysis, apparent heterozygous germline TP53 PV carriers (NGS allele frequency 30–70%) were offered follow‐up testing to confirm variant origin. Ninety‐eight probands had samples submitted for follow‐up family member testing, fibroblast testing, or both. The apparent heterozygous germline TP53 PV was not detected in 32.6% (15/46) of submitted fibroblast samples, indicating that it was acquired somatically, either through clonal hematopoiesis or via constitutional mosaicism. Notably, no individuals with confirmed germline or likely germline TP53 PVs met classic Li–Fraumeni syndrome (LFS) criteria, only 41% met Chompret LFS criteria, and 59% met neither criteria, based upon provider‐reported personal and family cancer history. Comprehensive reporting of TP53 PVs detected using NGS, combined with follow‐up analysis to confirm variant origin, is advised for clinical testing laboratories. These findings underscore the investment required to provide individuals and family members with clinically accurate genetic test results pertaining to their LFS risk.

TP53 germline mutation testing in early-onset breast cancer: findings from a nationwide cohort

Early-onset breast cancer may be due to Li-Fraumeni Syndrome (LFS). Current national and international guidelines recommend that TP53 genetic testing should be considered for women with breast cancer diagnosed before the age of 31 years. However, large studies investigating TP53 mutation prevalence in this population are scarce. We collected nationwide laboratory records for all young breast cancer patients tested for TP53 mutations in the Netherlands. Between 2005 and 2016, 370 women diagnosed with breast cancer younger than 30 years of age were tested for TP53 germline mutations, and eight (2.2%) were found to carry a (likely) pathogenic TP53 sequence variant. Among BRCA1/BRCA2 mutation negative women without a family history suggestive of LFS or a personal history of multiple LFS-related tumours, the TP53 mutation frequency was < 1% (2/233). Taking into consideration that TP53 mutation prevalence was comparable or even higher in some studies selecting patients with breast cancer onset at older ages or HER2-positive breast cancers, raises the question of whether a very early age of onset is an appropriate single TP53 genetic testing criterion.