Li-Fraumeni Research Articles

The Clinical and Molecular Profile of Lung Cancer Patients Harboring the TP53 R337H Germline Variant in a Brazilian Cancer Center: The Possible Mechanism of Carcinogenesis.

In southern and southeastern Brazil, the TP53 founder variant c.1010G>A (R337H) has been previously documented with a prevalence of 0.3% within the general population and linked to a heightened incidence of lung adenocarcinomas (LUADs). In the present investigation, we cover clinical and molecular characterizations of lung cancer patients from the Brazilian Li-Fraumeni Syndrome Study (BLISS) database. Among the 175 diagnosed malignant neoplasms, 28 (16%) were classified as LUADs, predominantly occurring in females (68%), aged above 50 years, and never-smokers (78.6%). Significantly, LUADs manifested as the initial clinical presentation of Li-Fraumeni Syndrome in 78.6% of cases. Molecular profiling was available for 20 patients, with 14 (70%) revealing EGFR family alterations. In total, 23 alterations in cancer driver genes were identified, comprising 7 actionable mutations and 4 linked to resistance against systemic treatments. In conclusion, the carriers of TP53 R337H demonstrate a predisposition to LUAD development. Furthermore, our results indicate that environmental pollution potentially impacts the carcinogenesis of lung tumors in the carriers of TP53 R337H.

FRI256 The Clinical Impacts Of Bi-allelic Germline Pathogenic Variant In TP53 In Two Patients With Li-Fraumeni Syndrome

Abstract Disclosure: V. Petry: None. D. Cohn: None. R.R. Oppenheimer: None. M.D. Estevez-Diz: None. A. Latronico: None. B.B. Mendonca: None. M.Q. Almeida: None. M.C. Fragoso: None. Background: Li-Fraumeni syndrome is an autosomal dominant cancer predisposition due to a heterozygous germline TP53 mutation. This mutation is related to different types of cancer; mainly adrenocortical carcinomas (ACC), soft tissues and bone sarcomas, breast cancer, choroid plexus carcinoma and leukemias at early ages. Although little is known about the impact of this TP53 variant in the homozygous form. Methods: We described the clinical presentation and the follow-up of 2 patients with a TP53 (p.R337H) homozygous pathogenic variant inherited from their parents. Case 1: A two year old patient presented with a headache, vomiting and nuchal stiffness, and was taken to the ER where she had a CNS CT scan. The CT scan revealed a mass located at left intraventricular region She then had surgery to remove the tumor and the histological finding confirmed the diagnosis of choroid plexus carcinoma. She underwent adjuvant systemic chemotherapy Headstart III protocol. This was the first case of cancer within this family. The child was seen by a medical geneticist and a genetic test revealed a homozygous pathogenic variant (p.R337H) in TP53. Afterwards her parents were tested and both were heterozygous for the p.R337H mutation. The patient is now 4 years old and free of oncologic disease. Case 2: A 9 months old female patient presented with Cushing´s syndrome and heterosexual precocious puberty. The MRI revealed a right adrenal tumor and she underwent laparoscopic adrenalectomy. Oral hydrocortisone was initiated postoperatively as glucocorticoid replacement therapy and was gradually tapered off over 6 months. Both parents of the patient were heterozygous for the p.R337H mutation in TP53 and they reported several cases of cancer within the family. The patient inherited both mutated alleles TP53 p.R337H. She had normal puberty development and she reached the target height. The patient did not develop further neoplasms during long-term follow-up (23 years). Conclusions: We described 2 cases with a biallelic pathogenic variant in TP53 (p.R337H) who were diagnosed with cancer at early ages and who did not develop further neoplasms during the follow-up period. There is a previous case description in the literature of a patient with a homozygous p.R337H mutation in TP53 who developed ACC at an early age and he did not develop other neoplasms during 8 years of follow-up. These two cases draw your attention to the early age for the development of choroid plexus carcinoma and adrenocortical tumors as well as the published case by Giacomazzi et al. Whether the bi-allelic pattern of the TP53 variant influences the tumor’s behavior remains unclear, there are potentially broad implications for clinical surveillance and genetic counseling for patients and their families. Presentation: Friday, June 16, 2023

FRI193 Early Presentation Of Pediatric Oncocytic Adrenal Tumor Associated With Germline TP53 Pathogenic Variant—Report Of Three Cases

Abstract Disclosure: R.R. Oppenheimer: None. L.P. Lins: None. C.P. Oliveira: None. I.P. Magalhaes: None. A. Latronico: None. B.B. Mendonca: None. M.Q. Almeida: None. A.W. Kuhn: None. H. Charchar: None. M.C. Fragoso: None. Oncocytic adrenal tumors (OAT) are uncommon and usually nonfunctional. In the pediatric age group, OAT are extremely rare and less than 20 cases have been reported. Herein we report the clinical presentation and follow up of 3 non-related children with Li-Fraumeni syndrome with a germline TP53 pathogenic variant (PV) (p.R337H) who developed secreting OAT. Case 1. A 19 month old male presented with moon face, weight gain, irritability and pubic hair (Tanner stage P3) for over 4 months. He had no family history of neoplasms and his parents were unrelated to each other. Hormonal data revealed serum cortisol 33 mcg/dL with a suppressed ACTH. Testosterone was elevated (242 ng/dL - RR <12 ng/dL) with low plasma gonadotropins. Androstenedione 3,08 (RR<0,5ng/mL). Abdominal CT revealed a left adrenal tumor (5.0 x 4.4 x 4.0cm). He underwent a left laparoscopic adrenalectomy and histopathologic analysis confirmed OAT Wieneke score 2/9. Immunohistochemistry was positive for inhibin, p53 and Ki67 (10-15%). The postoperative clinical course was uneventful. The TP53 p.R337H PV was inherited from his father. He is now prepubertal and there is no evidence of relapse in 14 months of monitoring. Case 2. An 18 month old female presented with acne, clitoromegaly, pubic hair (Tanner stage 2), axillary odor, axillary hair and weight gain. Hormonal study showed elevated total testosterone of 624.7 ng/dL, androstenedione, DHEA-S and prepubertal gonadotropins. 17OHP and cortisol were normal. Abdominal CT confirmed a heterogeneous solid nodule of 5.5 x 4.5 x 3.7 cm in the right adrenal topography. The patient underwent a right adrenalectomy and OAT was identified by histopathology (Wieneke score 3/9). Immunohistochemistry was positive for p53, inhibin and Ki67 (30%). The TP53 p.R337H PV was inherited from her mother. She had remission of secondary sexual characteristics and he is now prepubertal. Case 3. A 2 years and 8 months old girl was referred with precocious pubarche and clitoromegaly (2,6cm). She had a right flank palpable mass and tanner 1 breasts. Hormonal studies showed elevated testosterone (70ng/dL), androstenedione (3.81ng/mL) and DHEA-S (13490ng/mL), with LH 0.3IU/L and FSH 3.4IU/L. The cortisol after DST was 5.8mcg/dL and ACTH was suppressed. Abdominal MRI revealed a 5 cm tumor at the right adrenal gland. She underwent laparoscopic adrenalectomy. The histopathologic analysis revealed an OAT Wieneke score 1/9. Immunohistochemistry was positive for p53 and Ki67 (13%). The TP53 p.R337H PV was inherited from her father. Conclusion: Although rare, functional OATs have been reported in children. Herein we describe the first patients with the TP53 p.R337H PV to present with OATs. These are the youngest cases of OAT published so far. The clinical presentation, hormonal data and follow-up were not different from those of other pediatric adrenal tumors. So far there is no evidence of disease relapse during follow-up. Presentation: Friday, June 16, 2023

SAT274 Multilocus Imprinting Disorder Due To Genome-wide Paternal Uniparental Disomy Associated With Adrenocortical Tumors

Abstract Disclosure: E.M. Pinto: None. E. Lalli: None. G. Wu: None. R. Ribeiro: None. G. Zambetti: None. Pediatric adrenocortical tumor (ACT) is an uncommon malignancy frequently associated with Li-Fraumeni syndrome, a familial cancer predisposition disorder caused by germline mutations in the tumor suppressor TP53. ACT is also associated with other genetic constitutional disorders, such as Beckwith-Wiedemann syndrome (BWS) which results from the deregulation of a gene cluster on chromosome 11p15. We report here the identification of three pediatric patients with ACT and additional tumors, two of which received a clinical diagnosis of BWS. Family histories of these two probands include multiple unsuccessful pregnancies. All patients have wild-type TP53 sequence and no evidence for germline chromosome 11p15 alterations. Molecular analyses by whole genome sequencing revealed genome-wide copy neutral loss of heterozygosity (cnLOH) in all tumors. Microsatellite STR and MS-MLPA confirmed genome-wide cnLOH with the selective loss of all maternal chromosomes and duplication of paternal chromosomes in each tumor. Analysis of skin fibroblasts showed mosaic paternal uniparental disomy with partial LOH for all chromosomes, while no LOH was detected in blood DNA. The most prominent clinical feature of genome-wide cnLOH is an unbalanced monoallelic and parent-of-origin specific expression of imprinted genes known as multilocus imprinting disorder (MID). MID has been associated with maternal-effect variants that alter the maintenance of methylation at germline-derived differentially methylated regions (DMRs) in early embryogenesis. In addition, causative trans-acting factors in imprinting disorders, including the subcortical maternal complex (SCMC), have the potential to affect multiple DMRs across the genome, resulting in a multilocus imprinting disorder. Our study identifies three pediatric patients who developed ACT and other tumors that have undergone genome wide cnLOH that specifically selected against all maternal chromosomes. None of three patients presented with germline alterations in TP53 or 11p15, typical of pediatric ACT. WGS data revealed a germline mutation (p.M573T) in the histone methyltransferase NSD1 in the mother of patient #2. NSD1 mutations are reportedly associated with recurrent miscarriages, tissue overgrowth and increased cancer risk. Alterations in other epigenetic regulators, such as SETD1B (p.R226C), a component of a histone methyltransferase complex and TNRC18 (p.P454L), that enables chromatin binding activity were observed in both mother and child in each family. Further analysis of maternal-effect variants associated with abnormal pregnancies and MID will be important for understanding the mechanisms underlying genome-wide cnLOH. Our results support the molecular testing of multiple loci in atypical clinical presentations of patients with pediatric ACT. Presentation: Saturday, June 17, 2023

SAT322 Case report: Impact Of Combined Treatment To Prolong Overall Survival In Advanced Adrenocortical Pediatric Cancer Associated With Li-Fraumeni Syndrome

Abstract Disclosure: I.P. de Magalhães: None. N.C. de Sousa: None. H.L. Charchar: None. A.W. Kuhn: None. M.Y. Nishi: None. F.L. Ledesma: None. R.I. Lopes: None. F.T. Dénes: None. P. Herman: None. M.R. Menezes: None. A. Latronico: None. B.B. Mendonca: None. M.Q. Almeida: None. M.B. Fragoso: None. Background: Adrenocortical cancer (ACC) in pediatric patients (<15 years of age) are even rarer compared to the general population it is a classic presentation of Li-Fraumeni syndrome (LFS). ACC incidence in this subgroup is limited to 0.3 cases per million per year with a high incidence in Sothwest of Brazil. Furthermore, the overall five-year survival of pediatric ACC cases is better than in adult with a rate of approximately 50%, considering a complete resection required for cure. However, prognosis of childhood ACC is highly variable and difficult to predict in clinical practice. Clinical Case: We present the case of a 3-year-old girl who was diagnosed with metastatic adrenocortical carcinoma with classical signs of virilization and Cushing's syndrome. The patient underwent transperitoneal right adrenalectomy in May 2011. During surgery, there was rupture of the tumor capsule and the inferior vena cava. She was referred to our service after 8 months due to the presence of locoregional recurrence and maintained hormonal secretion. Histological data confirmed ACC and the tumor was classified as Weiss score 5, Wieneke: 4, Ki67 40%. Genetic analysis identified germline confirmed p-R337H on TP53, XAF1-E134. Imaging exams documented suspected liver metastasis and peritoneal implants. She underwent palliative treatment with mitotane (M) and systemic chemotherapy EDP+M with partial response. A new surgical approach to the residual lesions was proposed. The patient underwent right partial hepatectomy and peritoneal implant removed in September 2012. After metastasectomy, the patient presented persistence of the disease. The patient was exposed to a new cycle of EDP+M, but the disease progressed. She underwent radiofrequency ablation of abdominal lesions in July 2013 without success. A new surgical approach was indicated in July 2013. The histological analysis confirmed metastases of ACC. She underwent a new chemotherapy regimen with gemcitabine, docetaxel and fluorouracil + M. She presented a complete response confirmed by radiological exams and hormonal data. Mitotane was discontinued in 2016 due to bladder bleeding. She presented an excellent response with combined treatment, without recurrence up to now with 10 years of recurrence free survival and 12 years of overall survival. She developed normal puberty and reached the target height and maintains primary adrenal insufficiency with glico and mineralocorticoid replacement. Although the tumor spillage, histological and molecular data predicted a dismal outcome this patient surprisingly is presenting an excellent evolution under continuous surveillance. Clinical Lesson: This report described a challenging pediatric advanced ACC which the combined treatment strategy provided successful outcome Presentation: Saturday, June 17, 2023

Emerging evidence on the role of breast microbiota on the development of breast cancer in high-risk patients.

Cancer is a multi-factorial disease, and the etiology of breast cancer (BC) is due to a combination of both genetic and environmental factors. Breast tissue shows a unique microbiota, Proteobacteria and Firmicutes are the most abundant bacteria in breast tissue, and several studies have shown that the microbiota of healthy breast differs from that of BC. Breast microbiota appears to be correlated with different characteristics of the tumor, and prognostic clinicopathologic features. It also appears that there are subtle differences between the microbial profiles of the healthy control and high-risk patients. Genetic predisposition is an extremely important risk factor for BC. BRCA1/2 germline mutations and Li-Fraumeni syndrome are DNA repair deficiency syndromes inherited as autosomal dominant characters that substantially increase the risk of BC. These syndromes exhibit incomplete penetrance of BC expression in carrier subjects. The action of breast microbiota on carcinogenesis might explain why women with a mutation develop cancer and others do not. Among the potential biological pathways through which the breast microbiota may affect tumorigenesis, the most relevant appear to be DNA damage caused by colibactin and other bacterial-derived genotoxins, β-glucuronidase-mediated estrogen deconjugation and reactivation, and HPV-mediated cancer susceptibility. In conclusion, in patients with a genetic predisposition, an unfavorable breast microbiota may be co-responsible for the onset of BC. Prospectively, the ability to modulate the microbiota may have an impact on disease onset and progression in patients at high risk for BC.

NCCN Guidelines® Insights: Genetic/Familial High-Risk Assessment: Breast, Ovarian, and Pancreatic, Version 2.2024.

The NCCN Guidelines for Genetic/Familial High-Risk Assessment: Breast, Ovarian, and Pancreatic focus primarily on assessment of pathogenic/likely pathogenic (P/LP) variants associated with increased risk of breast, ovarian, pancreatic, and prostate cancer, including BRCA1, BRCA2, CDH1, PALB2, PTEN, and TP53, and recommended approaches to genetic counseling/testing and care strategies in individuals with these P/LP variants. These NCCN Guidelines Insights summarize important updates regarding: (1) a new section for transgender, nonbinary and gender diverse people who have a hereditary predisposition to cancer focused on risk reduction strategies for ovarian cancer, uterine cancer, prostate cancer, and breast cancer; and (2) testing criteria and management associated with TP53 P/LP variants and Li-Fraumeni syndrome.

Prédispositions génétiques au cancer bronchopulmonaire: Genetic predisposition to lung cancer

While thoracic oncologists are familiar with somatic pathogenic variants in lung cancer, they only have limited knowledge of genetic predisposition to the disease. Genetic predisposition refers to the presence of a germline pathogenic variant (present in the patient’s DNA) that is the main cause of the lung cancer diagnosis. This review article presents the major lung cancer predisposition syndromes, such as EFGR-associated syndrome and Li-Fraumeni. Identifying a genetic predisposition has consequences for the patient, for whom long-term lung cancer screening is warranted. Additionally, if the risk of other cancers is increased, as in Li-Fraumeni syndrome, the patient is offered multiorgan screening, including annual whole-body MRI. There are also implications for the family, as it then becomes necessary to identify other carriers among relatives, and offer them personalized surveillance.1877-1203/© 2023 SPLF. Published by Elsevier Masson SAS. All rights reserved.

328P Frequency of radiotherapy-induced malignancies in Li-Fraumeni syndrome patients with early breast cancer and influence of the radiotherapy technique

328P Frequency of radiotherapy-induced malignancies in Li-Fraumeni syndrome patients with early breast cancer and influence of the radiotherapy technique

542P Drug screening in Li-Fraumeni syndrome brain tumor models

542P Drug screening in Li-Fraumeni syndrome brain tumor models

Risk of Radiation-Associated Secondary Malignancies among Patients with Breast Cancer Harboring TP53 Germline Variants

Radiation-associated malignancies are rare and poorly understood. TP53 encodes a multifunctional protein that maintains genome integrity and is the most common somatically mutated gene in cancer. Germline pathogenic variants of TP53 predispose carriers to several cancers comprising the Li-Fraumeni syndrome. It is hypothesized that carriers are also at increased risk of radiotherapy (RT)-associated secondary malignancies; however, reports are mixed. We evaluated the risk of secondary malignancies after breast RT among patients with Li-Fraumeni syndrome. This multi-institutional cohort study included carriers of TP53 germline variants who underwent surgical treatment for breast cancer between 1980 and 2020. Patients were stratified based on germline TP53 classification (pathogenic variants [PV] vs variants of uncertain significance [VUS]). The primary outcome of interest was the cumulative incidence risk of developing an in-field secondary cancer after radiotherapy for primary breast carcinoma. Ninety-one patients (57 PV and 34 VUS) were evaluated with a median age of 36 years (interquartile range [IQR] 31, 42) and a median follow up of 7.9 years (IQR 4.7, 14.4). Among those with PV who received RT (n = 22), 4 secondary non-breast cancers developed in the radiation field (15-year cumulative incidence 19% [95% CI: 4-43%]), whereas, among those with PV who did not receive RT (n = 35), 0 secondary non-breast cancers were observed in the treated breast (15-year cumulative incidence 0%; p = 0.043). We observed 3 radiation-associated sarcomas among patients with PV who received RT (15-year risk 12% [95% CI 2-33%]) compared with 0 among those who did not receive RT (p = 0.08). No RT-associated sarcomas were observed among 18 patients with TP53 VUS who received RT. RT was not associated with overall survival, despite higher T and N breast cancer stage among those receiving RT (p = 0.33). As expected, patients with PV were more likely than those with VUS to develop any secondary cancer following breast cancer treatment (15-year risk: 54% [95% CI: 33-72%] vs. 14% [95% CI: 3-36%]). Carriers of pathogenic variants of TP53 are at elevated risk of developing secondary malignancies after breast cancer treatment. This population is at particular risk of developing in-field secondary cancers following RT. This iatrogenic risk must be weighed against the anticipated therapeutic benefit of tumor control. Shared decision making is crucial in the radiotherapeutic management of breast cancer patients harboring the Li-Fraumeni syndrome.

Genome-first approach of the prevalence and cancer phenotypes of pathogenic or likely pathogenic germline TP53 variants

Pathogenic or likely pathogenic (P/LP) germline TP53 variants are the primary cause of Li-Fraumeni syndrome (LFS), a hereditary cancer predisposition disorder characterized by early-onset cancers. The population prevalence of P/LP germline TP53 variants is estimated to be approximately one in every 3,500 to 20,000 individuals. However, these estimates are likely impacted by ascertainment biases and lack of clinical and genetic data to account for potential confounding factors, such as clonal hematopoiesis. Genome-first approaches of cohorts linked to phenotype data can further refine these estimates by identifying individuals with variants of interest and then assessing their phenotypes. This study evaluated P/LP germline (variant allele fraction ≥30%) TP53 variants in three cohorts: UK Biobank (UKB, n= 200,590), Geisinger (n= 170,503), and Penn Medicine Biobank (PMBB, n= 43,731). A total of 109 individuals were identified with P/LP germline TP53 variants across the three databases. The TP53 p.R181H variant was the most frequently identified (9 of 109 individuals, 8%). A total of 110 cancers, including 47 hematologic cancers (47 of 110, 43%), were reported in 71 individuals. The prevalence of P/LP germline TP53 variants was conservatively estimated as 1:10,439 in UKB, 1:3,790 in Geisinger, and 1:2,983 in PMBB. These estimates were calculated after excluding related individuals and accounting for the potential impact of clonal hematopoiesis by excluding heterozygotes who ever developed a hematologic cancer. These varying estimates likely reflect intrinsic selection biases of each database, such as healthcare or population-based contexts. Prospective studies of diverse, young cohorts are required to better understand the population prevalence of germline TP53 variants and their associated cancer penetrance.

The evaluation of the possibility of Li-Fraumeni syndrome in cancer patients in East Azarbaijan Province of Iran

Introduction: In 1969, Li-Fraumeni syndrome (LFS), which is a rare cancer predisposition syndrome, was reported for the first time. The main problem in LFS is the mutation in the TP53 gene, which is a crucial tumor suppressor gene in the cell cycle. A hereditary syndrome is inherited in an autosomal dominant pattern. There is a significant correlation between this syndrome and various cancers such as sarcoma, breast cancer, brain tumors, and different other types of malignancies. This study aimed to identify the possibility of LFS in cancer patients in the East Azarbaijan, Iran. Methods: In this experimental study, 45 children with cancer in the Northwest of Iran were investigated for LFS. DNA was extracted from the whole blood cells using the salting-out method. The region within the exons 5-8 of the TP53 gene has been replicated via Polymerase Chain Reaction (PCR) method. The PCR products were sent for Sanger sequencing, and finally, the data were analyzed by Chromas software. Results: In the studied probands, in 12 (26.67%) cases, polymorphisms in Exon 6 and Introns 6 and Intron 7 were identified, and no mutation was observed in exons 5-8 of the TP53 gene. Conclusion: Our results show that there were no mutations in exons 5-8 of the TP53 gene as an indication of LFS possibility in these families. Further studies are needed to be done in a bigger population, and Next-Generation Sequencing (NGS) needs to be done to evaluate the whole genome of these patients to complete our data.

Interpretation of ambiguous TP53 test results: Mosaicism, clonal hematopoiesis, and variants of uncertain significance.

The increased use of next-generation sequencing has led to the detection of pathogenic TP53 variants in the germline setting in patients without a personal or family history consistent with Li-Fraumeni syndrome (LFS). These variants can represent low-penetrance LFS, mosaic LFS, or clonal hematopoiesis of indeterminate potential. Additionally, TP53 variants of uncertain significance can be detected in patients with a history suspicious for LFS. The interpretation of the significance of these variants can be challenging but is crucial for an accurate diagnosis and appropriate medical management. This retrospective case review provides illustrative examples of the interpretation of challenging TP53 results through multidisciplinary expertise and use of a flowchart. The authors describe eight patients with TP53 variants associated with ambiguous diagnoses and, for each case, describe how the results were interpreted and the medical care that was implemented. This report presents illustrative cases to help guide clinicians to reach definitive diagnoses for patients when confronted with TP53 variants that are inconsistent with the clinical picture and to add to the body of literature regarding interpretation and medical management of TP53 variants discovered on germline testing.

Spectrum and Excess Risk of Gastrointestinal Tumors in Li-Fraumeni Syndrome

Li-Fraumeni syndrome (LFS), linked to heterozygous germline pathogenic/likely pathogenic variants in TP53, confers exceptionally high cancer risk, including core cancers (sarcoma, breast, adrenocortical, and brain cancer) among many other cancer types.1 Colorectal cancer (CRC) is most common after the core and hematologic cancers, accounting for ∼2.8% of diagnoses. Stomach and esophageal cancers constitute another 1.3% (TP53 Database; R20, July 2019: https://tp53.isb-cgc.org).2.

99 Characterization of the Radiation Response and Prevention of Radiation-Induced Malignancies in Li-Fraumeni Syndrome

99 Characterization of the Radiation Response and Prevention of Radiation-Induced Malignancies in Li-Fraumeni Syndrome

Adrenocortical carcinoma in the face of Li-Fraumeni syndrome - a case report

Adrenocortical carcinoma (ACC) is a rare malignancy with a dismal prognosis. ACCs are caused by a cumulation of sporadic mutations, however, some inherited mutations may predispose to ACC. This paper presents a case of a 12-years-old child diagnosed with TP53 mutation, preceded by ACC diagnosis.

Challenging interpretation of germline TP53 variants based on the experience of a national comprehensive cancer centre

TP53 variant interpretation is still challenging, especially in patients with attenuated Li–Fraumeni syndrome (LFS). We investigated the prevalence of pathogenic/likely pathogenic (P/LP) variants and LFS disease in the Hungarian population of cancer patients. By testing 893 patients with multiplex or familial cancer, we identified and functionally characterized novel splice variants of TP53 helping accurate variant classification. The differences among various semi-automated interpretation platforms without manual curation highlight the importance of focused interpretation as the automatic classification systems do not apply the TP53-specific criteria. The predicted frequency of the TP53 P/LP variants in Hungary is 0.3 per million which most likely underestimates the real prevalence. The higher detection rate of disease-causing variants in patients with attenuated LFS phenotype compared to the control population (OR 12.5; p < 0.0001) may raise the potential benefit of the TP53 genetic testing as part of the hereditary cancer panels of patients with multiple or familial cancer even when they do not meet Chompret criteria. Tumours developed at an earlier age in phenotypic LFS patients compared to the attenuated LFS patients which complicates genetic counselling as currently there are no different recommendations in surveillance protocols for LFS, phenotypic LFS, and attenuated LFS patients.

A systematic review of the prevalence of pathogenic or likely pathogenic germline variants in individuals with FOXO1 fusion-positive rhabdomyosarcoma.

Several cancer predisposition syndromes (CPS) are reported to predispose to rhabdomyosarcoma, most frequently in children with embryonal rhabdomyosarcoma. There are lingering questions over the role of CPS in individuals with alveolar rhabdomyosarcoma (ARMS), which are frequently driven by FOXO1 fusion oncoproteins. We conducted a systematic review to identify patients with FOXO1 fusion-positive ARMS (FP-ARMS) who underwent germline DNA sequencing. We estimated the prevalence of pathogenic/likely pathogenic (P/LP) variants in cancer predisposing genes (CPGs) and of CPSs. We included 19 publications reporting on 191 patients with FP-ARMS. P/LP variants in CPGs were identified in 26/191 (13.6%) patients, nine (4.9%) of which were associated with a CPS diagnosis. Evidence for causal associations between CPSs and FP-ARMS could not be assessed with available data from this review. Only one patient was affected with a CPS known to predispose to rhabdomyosarcoma, Li-Fraumeni syndrome. Typical CPS associations with rhabdomyosarcoma are rare, but not nonexistent, in patients with FP-ARMS. FOXO1 fusion status, alone, is insufficient for clinicians to rely on to distinguish between patients with/without CPS.

Factors affecting adherence to a high-risk surveillance protocol among patients with Li-Fraumeni syndrome

BackgroundHigh-risk surveillance for patients with Li-Fraumeni syndrome (LFS) has shown a stage shift and improved overall survival, but is demanding. Our objective was to evaluate surveillance adherence in a population of patients with LFS presenting for high-risk care.MethodsA retrospective analysis of surveillance adherence of adult patients with LFS at a single institution was performed. Adherence was defined by the duration from initial University of Virginia (UVA) LFS clinic visit to the time of first missed surveillance test. Two-sample t-tests and ANOVA tests were used to identify factors associated with duration of adherence.ResultsA total of 42 patients were evaluated in the UVA LFS clinic between 2017 and 2021. Of these, 21 patients met inclusion criteria. At the time of review, 6 patients (29%) were up to date with high-risk surveillance recommendations. The mean duration of adherence was 17 months. Female sex was found to be associated with longer duration of adherence (mean 21 mo vs. 3.5 mo for males, p = 0.02). A personal history or active diagnosis of cancer was also associated with increased adherence (p = 0.02). However, neither age (p = 0.89), geography (p = 0.84), or known family history of LFS (p = 0.08) were associated with duration of adherence.ConclusionFemale sex as well as a personal history of cancer were associated with longer duration of adherence to recommended high-risk surveillance among patients with LFS. Identification of barriers to surveillance will be essential moving forward to increase adherence and promote early detection of cancer, thereby reducing the morbidity and mortality of LFS.