Li-Fraumeni Research Articles

Abstract 1124: Prevention of radiation-induced malignancies in Li-Fraumeni syndrome

Abstract PURPOSE: Li-Fraumeni Syndrome (LFS) is a genetic disorder associated with a significant risk of early-onset cancer. This condition is driven by germline mutations in the TP53 gene which plays a primary role in the regulation of the radiation response. Aberrant TP53 function contributes to radiation vulnerability and a greater risk of secondary, radiation-induced malignancies (RIMs). As a result, therapeutic options for LFS patients are often limited to exclude radiotherapy (RT), which may otherwise be beneficial for the treatment of certain primary tumors. Data from our lab demonstrate an aberrant transcriptomic response to irradiation (IR) in mutant p53 patient skin fibroblasts compared to wildtype; however, it is unknown whether reprogramming this radiation response can decrease the risk of RIM in LFS. Metformin, a commonly prescribed anti-diabetic drug, is associated with lower cancer incidence and may decrease cancer-related mortality in murine LFS models. In addition to its potential anti-tumorigenicity, studies have shed light on the ability of metformin to prevent IR-induced damage in normal tissue; hence, we hypothesize that metformin can reprogram the radiation response to protect against radiation injury and delay the onset of RIM in LFS. METHODS: To establish a murine model of RIM in LFS, and to investigate whether metformin can delay tumor onset in this model, whole-body or localized IR were administered to mice harboring a hotspot Trp53R172H/+ mutation in the presence and absence of metformin. Serial MRI was conducted to monitor for tumor development. To understand the effect of metformin on the mutant p53 radiation response in vivo, a similar murine workflow was established and irradiated skin was collected longitudinally from untreated and metformin-treated cohorts for whole transcriptome sequencing. Sequencing data were functionally validated in a separate cohort of mice using flow cytometry. In parallel, we performed RNA sequencing on LFS patient fibroblasts to characterize the effect of metformin on the human radiation response. RESULTS: We demonstrate that IR decreases tumor latency in TP53R172H/+ mice, and that metformin significantly delays tumor onset within the radiation field. Moreover, transcriptomic data revealed that metformin upregulates apoptosis following IR in TP53R172H/+ mice. Flow cytometry analysis of the radiation response validated these findings, demonstrating that metformin promotes the apoptosis-driven clearance of damaged, potentially tumorigenic cells following IR. Transcriptomic data from patient cell lines will be presented. CONCLUSIONS: Overall, we show that metformin may delay RIM in LFS mice, and have begun to characterize the biology underpinning this reprogrammed response to IR. This study is the first to highlight metformin as a radioprotective agent in the context of germline mutant p53, with the potential to broaden RT treatment options for LFS patients. Citation Format: Pamela Psarianos, Nicholas Fischer, David Malkin. Prevention of radiation-induced malignancies in Li-Fraumeni syndrome [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1124.

Abstract 3018: Transcriptional dysregulation in germline TP53-driven breast cancers

Abstract Background: Pathogenic germline variants (PGVs) in TP53 is associated with multicancer risk syndrome known as Li-Fraumeni Syndrome (LFS) and females have 80-90% risk of breast cancer at very early age compared to sporadic breast cancers. The mechanism of p53 tumor suppression relies on its function as a transcriptional activator; however, there is little data on the specific transcriptional defects in human breast tumors driven by germline mutant p53. Methods: To investigate the specific transcriptional defects due to TP53 PGVs in human breast, we performed bulk RNA-seq on invasive ductal carcinoma (IDC), ductal carcinoma in situ (DCIS) and surrounding and contralateral normal breast tissue in LFSBC compared to non-LFS sporadic BC. We also compared our results to breast tumors from The Cancer Genome Atlas (TCGA) with and without acquired TP53 mutations. Results: Our RNA-seq analysis revealed significant changes in the expression of key pathways in LFSBC compared to non-LFS breast cancer. Notably, cancer hallmark pathways such as apoptosis and reactive oxygen species were downregulated, while androgen response and cholesterol homeostasis pathways were upregulated in LFSBC compared to non-LFSBC. Expression of downstream targets of p53 such as BAX, tumor suppressors such as CDKN1A (p21) and BTG2, were significantly down in LFSBC suggesting impaired transcriptional activity of mutated TP53 in LFS patients. We also observed downregulation of cell cycle regulators in LFS breast tumors compared to their surrounding and contralateral tissues. Although, there were no significant transcriptional differences as the tumor progressed from LFS DCIS to IDC, indicating that the damage caused by the mutated p53 had already occurred at the early stage. Additionally, we also investigated the immune cell composition in LFS-BC and non-LFSBC. LFSBC exhibited a higher relative proportion of CD4+ T cells, CD20+ B cells, NK cells, macrophages and monocytes compared to all sporadic non-LFSBC subtypes (TCGA) and age matched non-LFSBC. This providing novel insights into the immune landscape associated with LFS-driven breast cancer. Conclusion: Our findings suggest that breast tissues with an inherited TP53 mutation undergo a defective transcriptional state, shifting away from apoptosis, and experiencing dysregulation of cell cycle at an early stage as DCIS, potentially contributing to the early onset of LFS breast cancer. The preliminary analysis of immune repertoire in LFSBC opens avenues for deeper investigations into spatial transcriptomic profiles of germline TP53-mutated breast tumors also the immune cells. Overall, this study provides valuable insights into the TP53 mutation driven breast cancers in humans. Citation Format: Nabamita Boruah, Renyta Moses, Ryan Hausler, Heena Desai, Anh Le, Gregory Kelly, Ashvathi Raghavakaimal, Mohana Narasimhamurthy, Anupma Nayak, Arnold J. Levine, Kara N. Maxwell. Transcriptional dysregulation in germline TP53-driven breast cancers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3018.

Abstract 1533: Characterizing tumor-immune surveillance in Li-Fraumeni syndrome

Abstract Li-Fraumeni Syndrome (LFS) is a cancer predisposition syndrome associated with germline TP53 mutations and increased lifetime risk of developing multiple cancers. p53, the protein encoded by TP53, plays a role in regulating various aspects of immune cell biology. Accordingly, inactivation of p53 in tumor cells shapes interactions with the immune system and influences the anti-tumor immune response. Mutation or deletion of p53 in immune cells also favors tumor development and progression. However, to date, a comprehensive study of immune cell populations and the anti-tumor immune response has not been undertaken in the context of LFS. We hypothesized that germline TP53 mutation carriers possess dysfunctional immune cells and/or immune responses, supporting LFS-associated tumor progression. Our preliminary data indicate a profound defect in tumor-immune surveillance in an LFS murine model. We observed that MC38 cancer cells develop significantly faster into tumors when injected into LFS mice (harboring a gain-of-function mutation Trp53R172H/WT) compared to wildtype (WT) control mice. Importantly, we identified significant alterations in immune cell compositions and phenotypes within the tumor microenvironment as well as immune organs using flow cytometry. We are currently using ex vivo proliferation assays and cytotoxicity assays to investigate the impact of mutant p53 on the tumor-killing ability of immune effector cells. Altogether, an improved understanding of anti-tumor immune dysfunction in the context of germline TP53 mutation may reveal the potential for innovative therapies to target different facets of the immune system to intercept cancer progression in LFS patients. Citation Format: Camilla Giovino, Nicholas Fischer, Noel Ong, Ashby Kissoondoyal, Ran Kafri, David Malkin. Characterizing tumor-immune surveillance in Li-Fraumeni syndrome [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1533.

Abstract 3025: Germline p53 R181 variants and DNA binding cooperativity in tumorigenesis

Abstract TP53 is the most frequently mutated gene in cancer, and its encoded protein p53 has many tumor-suppressive functions. There are several different classes of mutant p53 acquired in human cancer and inherited in cancer-prone families with Li-Fraumeni Syndrome, where individuals have an 80-90% increased risk of cancer. These include structural mutations that are generally (e.g R175H) or locally (e.g Y220C) misfolded, DNA contact mutations (e.g R273H); and oligomerization mutations (A347D). Cooperativity mutations affect binding of the p53 tetramer to DNA via disruption of a salt bridge formed by the negatively charged glutamic acid (E) 180 residue of one p53 monomer and the positively charged arginine (R) 181 residue of another. p53 “cooperativity” mutations at the R181 residue (R181H and R181C) have been increasingly identified in cancer-prone families undergoing genetic testing; however, the mechanism by which these variants disrupt p53 tumor suppression in humans is not understood. We show that the purified DNA binding domains of p53 variants R181H and R181C bind less cooperatively to the p53 binding site in the CDKN1A (p21) promoter, despite retaining wild-type levels of structural stability. RNA-sequencing of CRISPR knock-in colorectal and breast cancer cell lines shows reduced ability of R181H and R181C to transactivate a curated set of ~300 known p53 target genes. Upon treatment with p53 activating molecule Nutlin-3a, the R181-mutant cells fail to cell cycle arrest in the G1 phase and maintain high proliferative rates. Interestingly, we observe some residual apoptotic activity in R181H and R181C mutant cells treated with DNA-damaging agent 5-fluorouracil, despite losing the transactivation of proapoptotic p53 targets; this suggests that these mutants retain the p53 transcription-independent mechanism of apoptosis which is observed in other p53 variants such as P47S and A347D. These studies will define the pathogenicity of R181 variants and guide therapeutic intervention for patients that harbor these p53 mutations. Citation Format: Renyta Moses, Ryan Hausler, Gregory Kelly, Alexandra Indeglia, Sven Miller, John Karanicolas, Maureen Murphy, Kara Maxwell. Germline p53 R181 variants and DNA binding cooperativity in tumorigenesis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3025.

Abstract 3564: Survival-based grouping of genetic variants: A novel statistical framework with an application to TP53 mutations

Abstract Advancements in genotyping and sequencing techniques, coupled with the growing magnitude of genome databases, have led to comprehensive investigations into the impact of genetic variants on human diseases, including cancers. It is commonly acknowledged that genetic variants have homogeneous effects on clinical outcomes, i.e., variants exhibit similar effects within a certain group but are distinct from those in other groups. However, such grouping information is typically unknown, and identification of the underlying genetic variation groups is crucial for understanding their functional consequences, facilitating patient management, and improving risk prediction. To resolve this challenge, we introduce a novel statistical framework called Survival-based Clustering of Predictors (SCP) in Cox regression to group genetic variants based on patient survival outcomes. Built upon a penalized Cox regression model, SCP considers different genetic variants, as well as additional patient-specific features if needed, as survival predictors and then searches for homogeneity among the coefficients for individual variants to recover the underlying grouping structure. Focusing on TP53, the most frequently mutated gene in cancer that has resulted in a wide range of functions and clinical outcomes, we apply SCP to group TP53 germline mutations with the age of cancer diagnosis as the time-to-event. Using datasets from four Li-Fraumeni syndrome (LFS) cohorts at MD Anderson, NCI, and DFCI, we obtained 75 recurring TP53 germline mutations from 513 patients and clustered these mutations into high-, medium-, and low-risk groups. Hotspot mutations such as R175H, R248Q, G245S, and R273C are in the high-risk group as supported in many TP53 studies, while several non-hotspot mutations such as R290H, V218G, and G244D also exhibit strong positive effects and are grouped together with hotspot mutations. Overall, mutations in all three risk groups, obtained through applying SCP, are highly consistent with a yeast functional assay-based approach for grouping TP53 mutations, supporting the utility of SCP for survival-based grouping of genetic variants. The contribution of our study is three-fold. Statistically, our method fills a critical gap in the survival analysis literature, offering a novel statistical framework for clustering predictors in Cox regression based on survival outcomes. Clinically, we provide a timely solution to the patient outcome-based grouping of TP53 mutations, facilitating clinical management of TP53 mutation carriers. Biologically, we bring fresh insights into knowledge for the most frequently observed genetic variants in cancer, providing new hypotheses to TP53-related biological research. Citation Format: Xiaoqian Liu, Haoming Shi, Emilie Montellier, Pierre Hainaut, Wenyi Wang. Survival-based grouping of genetic variants: A novel statistical framework with an application to TP53 mutations [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3564.

Abstract 6376: Establishment of the Consortium for Childhood Cancer Predisposition and the Childhood Cancer Predisposition Study

Abstract Background: Genetic predisposition contributes to a much higher proportion of cancer in children than previously appreciated. This creates a unique opportunity to develop improved methods to identify children at increased risk for cancer, enable early detection or prevention of tumors, and improve cure rates with decreased morbidity. However, several challenges have impeded successful research and systematic approaches to the care of children with cancer predisposition. Methods: We established the Consortium for Childhood Cancer Predisposition (C3P), currently comprised of seven large pediatric institutions in North America. The long-term goal of C3P is to improve outcomes for children with genetic susceptibility to cancer through collaborative research and data sharing. To this end, we have developed the Childhood Cancer Predisposition Study (CCPS), a multicenter registry and biorepository, to achieve three main aims: 1) Establish and maintain the infrastructure for recruitment, participation, collection and sharing of clinical data and biological samples for children with cancer predisposition syndromes (CPS); 2) Define the spectrum of disease in children with CPS and explore the unique characteristics and management approaches of CPS-related tumors compared to their sporadic counterparts; and 3) Evaluate the clinical impact and effectiveness of standard and emerging tumor surveillance strategies. Results: The CCPS opened to enrollment in May, 2021 and is currently recruiting at 3 member sites. To date, 276 primary subjects and 44 family members have been enrolled, 211 in the last year. In total, 37 different cancer predisposition diagnoses are represented among participants, including those that are more prevalent, e.g., Li-Fraumeni syndrome (n=42), DICER1 syndrome (n=27), and PTEN Hamartoma Syndrome (n=21), and those which are very rare, e.g., Rothmund-Thomson syndrome (n=2). There is excellent uptake on obtaining samples, with the CCPS Biorepository at Emory University receiving biospecimens from 261 subjects to date, including constitutional DNA (n=261), frozen peripheral blood mononuclear cells (n=32), and plasma samples for ctDNA analysis (n= 26). Conclusions: C3P has established the infrastructure to facilitate comprehensive collaborative work to improve outcomes for children with cancer predisposition, which represent a wide variety of disorders. Future efforts will include the development of innovative strategies to promote recruitment beyond the primary C3P sites and the support of additional clinical and biological studies of specific CPS. Citation Format: Anita Villani, Garrett M. Brodeur, Lisa R. Diller, Chloe Edgerton, Junne Kamihara, Wendy Kohlmann, Suzanne P. MacFarland, Luke Maese, David Malkin, Kim E. Nichols, Melissa R. Perrino, Sharon E. Plon, Surya Rednam, Christopher C. Porter. Establishment of the Consortium for Childhood Cancer Predisposition and the Childhood Cancer Predisposition Study [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6376.

Abstract 6198: TP53 mutational clusters stratify the Li-Fraumeni syndrome spectrum

Abstract Li-Fraumeni syndrome (LFS) is a highly penetrant cancer predisposition disorder caused by germline variants in the TP53 tumor suppressor gene. LFS has recently been redefined as a ‘spectrum’ disorder to reflect the highly variable cancer types with largely unpredictable ages-of-onset and disease severity. The broad functional gradient associated with different TP53 variants is thought to contribute to LFS heterogeneity, although it is still poorly understood and there is an unmet clinical need for risk stratification strategies to improve variant interpretation and patient care. Here, we performed an unsupervised cluster analysis leveraging p53 mutagenesis datasets (Kato et al., 2003 & Giacomelli et al., 2018) that revealed five TP53 mutational clusters with unique mutation patterns, structural features, and functional consequences. Stratifying germline carriers based on the five clusters exposed important clinical characteristics to consider for patient management, such as ages-of-onset, tumor type development, and survival outcomes. In particular, we discovered an osteosarcoma-prone subgroup comprised of monomeric mutant p53 carriers with aggressive cancer phenotypes. We also identified a cluster of TP53 variants found more often in non-cancer and healthy older populations, and carriers of these variants that developed cancer had less “LFS-like” phenotypes including an older age-of-onset and a significantly higher frequency of colorectal cancers. Remarkably, our TP53 variant clustering strategy could also stratify breast cancer survival among germline carriers. This work provides a new framework to delineate the LFS spectrum toward the development of machine learning-based approaches for personalized cancer surveillance plans. Citation Format: Nicholas W. Fischer, Brianne Laverty, Ran Kafri, Kara N. Maxwell, Emma R. Woodward, Christian Kratz, David Malkin. TP53 mutational clusters stratify the Li-Fraumeni syndrome spectrum [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6198.

Gender-Affirming Care in a Transgender Young Woman With Li-Fraumeni Syndrome: A Case Report

The number of youths who identify with a gender different from their sex designated at birth is increasing. Youth account for about 4% of all cancer diagnoses in the United States. Some youths may want gender-affirming medical treatment, such as puberty blockers and/or hormone therapy, which may exacerbate cancer and/or increase cancer development risk. No studies assess the impact of estrogen-based treatment in gender-diverse youth with a history of Li-Fraumeni syndrome. This case report will discuss gender-affirming care and shared decision-making in a youth with a history of Li-Fraumeni syndrome and increased risk for breast cancer.

Genetic testing for hereditary cancer syndromes in Tunisian patients: Impact on health system

IntroductionCancer management in Africa faces diverse challenges due to limited resources, health system challenges, and other matters. Identifying hereditary cancer syndromic cases is crucial to improve clinical management and preventive care in these settings. This study aims to explore the clinicopathological features and genetic factors associated with hereditary cancer in Tunisia, a North African country with a rising cancer burden Materials and methodsClinicopathological features and personal/family history of cancer were explored in 521 patients. Genetic analysis using Sanger and next-generation sequencing was performed for a set of patients ResultsHereditary breast and ovarian cancer syndrome was the most frequent cluster in which 36 BRCA mutations were identified. We described a subgroup of patients with likely ‘’breast cancer-only syndrome’’ among this cluster. Two cases of Li-Fraumeni syndrome with distinct TP53 mutations namely c.638G>A and c.733G>A have been identified. Genetic investigation also allowed the identification of a new BLM homozygous mutation (c.3254dupT) in one patient with multiple primary cancers. Phenotype-genotype correlation suggests the diagnosis of Bloom syndrome. A recurrent MUTYH mutation (c.1143_1144dup) was identified in three patients with different phenotypes ConclusionOur study calls for comprehensive genetic education and the implementation of genetic screening in Tunisia and other African countries health systems, to reduce the burden of hereditary diseases and improve cancer outcomes in resource-stratified settings.

Health-related quality of life and fear of progression in individuals with Li-Fraumeni syndrome.

Li-Fraumeni syndrome (LFS) is a rare autosomal dominant cancer predisposition syndrome associated with a highly elevated lifetime cancer risk. This and the recommended intense surveillance program represent a large psychological burden on families. In order to develop targeted psychosocial interventions, we conducted a needs assessment. Adults (≥18 years) with LFS were included via regular hospital visits and online support groups and newsletters. Individuals filled out a questionnaire addressing among others: fear of progression (FoP-questionnaire, short-form), health-related quality of life (HRQoL, Short-Form Health Survey-12), distress (National Comprehensive Cancer Network distress thermometer), perceived cancer risk, and aspects of surveillance adherence. Collecting data over a 14-month period (March 2020 - June 2021), 70 adults were recruited (female = 58, 82.9%; mean age = 41.53 years). With mean mental component scores (MCS) of 42.28 (SD = 10.79), and physical component scores (PCS) of 48.83 (SD = 10.46), HRQoL was low in 34.8% (physical) and 59.4% (mental) of individuals when applying a mean cut-off of 45.4 (PCS) and 47.5 (MCS) to indicate poor HRQoL. High levels of FoP and distress were present in 68.6% and 69.1% of the participants, respectively. Performing a multiple linear regression on MCS and PCS, no sociodemographic variable was shown to be significant. FoP (β = -0.33, p < 0.05) and distress (β = -0.34, p < 0.05) were significantly associated with MCS. Individuals in our sample were burdened more than expected, with the majority reporting low levels of (mental) HRQoL, high distress, and FoP. Psychosocial support is necessary to help individuals with LFS (survivors as well as "previvors") increase their HRQoL, as it is crucial to survival.

Correlation between choroid plexus carcinoma and Li-Fraumeni syndrome: implications of TP53 mutations and management strategies-a case-based narrative review.

Choroid plexus carcinomas (CPCs) are rare, aggressive grade 3 tumors of the central nervous system associated with Li-Fraumeni syndrome (LFS) in a notable percentage of cases due to TP53 germline mutations. Understanding the correlation between CPCs and LFS is crucial for tailored management strategies. However, distinguishing CPCs from benign choroid plexus papillomas (CPPs) remains challenging, relying largely on histologic features. This study aimed to explore the association between CPCs and LFS, emphasizing the impact of TP53 mutations on diagnosis, treatment, and clinical outcomes. Scientific databases such as PubMed, Scopus, and Web of Science were systematically searched up to January 2024 using keywords related to CPCs, LFS, TP53 mutation, and central nervous system tumors. Selection criteria included studies investigating the link between CPCs and LFS, their management approaches, and genetic implications of TP53 mutations. Ten relevant studies were selected for analysis after screening titles, abstracts, and full-text articles. Data extraction focused on clinical, genetic, and management factors related to CPCs associated with LFS. The review highlighted the strong association (36%) between CPCs and LFS, primarily due to TP53 germline mutations. Studies emphasized the need for genetic testing in patients with CPCs, especially in pediatric cases, to identify LFS implications. Furthermore, the impact of TP53 mutations on treatment strategies was emphasized, recommending irradiation-sparing therapies due to inferior survival rates associated with radiotherapy in LFS patients with CPCs. Cases illustrated the challenges in diagnosing CPCs and the importance of immunohistochemistry and genetic testing for TP53 mutations. CPCs pose challenges in diagnosis and management, particularly in distinguishing them from benign tumors. The association with LFS, often due to TP53 germline mutations, underscores the importance of genetic testing for early detection and tailored treatment strategies. Irradiation-sparing therapies are recommended for LFS-associated CPCs to mitigate the risk of secondary malignancies. Comprehensive profiling of CPC patients, especially in pediatric cases, is crucial for early detection and management of potential secondary cancers associated with LFS.

Laser interstitial thermal therapy as a radiation-sparing approach for central nervous system tumors in children with cancer predisposition syndromes: report of a child with Li-Fraumeni syndrome. Illustrative case.

Ionizing radiation and alkylating chemotherapies increase secondary malignancy risk in patients with cancer predisposition syndromes (CPSs), such as Li-Fraumeni syndrome. Laser interstitial thermal therapy (LITT) is a minimally invasive ablation technique that has not been associated with mutagenic risks. We describe the case of a child with LFS and a history of treated choroid plexus carcinoma (CPC) who developed a second primary glial tumor that was safely treated with magnetic resonance imaging (MRI)-guided LITT. A 4-year-old male with left parietal World Health Organization grade III CPC associated with a TP53 germline mutation was evaluated. The patient underwent neoadjuvant platinum-based chemotherapy before near-total resection, followed by 131I-8H9 immunotherapy and 30 fractions of 54-Gy proton radiotherapy. He remained without evidence of disease for 2 years before developing a slow-growing mass adjacent to the left frontal ventricular horn. Stereotactic biopsy revealed a glial neoplasm. Given the nonsuperficial location and focality of the lesion, MRI-guided LITT was performed for ablative therapy. There were no complications, and 2 years of surveillance revealed continued retraction of the ablated tumor focus and no subsequent disease. Alternatives to mutagenic therapies for brain tumors should be explored for patients with CPS. LITT paired with imaging surveillance is a logical strategy to ensure durable outcomes and mitigate treatment-related secondary neoplasms.

Cancer Precision-Prevention trial of Metformin in adults with Li Fraumeni syndrome (MILI) undergoing yearly MRI surveillance: a randomised controlled trial protocol

BackgroundLi-Fraumeni syndrome (LFS) is a rare autosomal dominant disease caused by inherited or de novo germline pathogenic variants in TP53. Individuals with LFS have a 70–100% lifetime risk of developing cancer. The current standard of care involves annual surveillance with whole-body and brain MRI (WB-MRI) and clinical review; however, there are no chemoprevention agents licensed for individuals with LFS. Preclinical studies in LFS murine models show that the anti-diabetic drug metformin is chemopreventive and, in a pilot intervention trial, short-term use of metformin was well-tolerated in adults with LFS. However, metformin’s mechanism of anticancer activity in this context is unclear.MethodsMetformin in adults with Li-Fraumeni syndrome (MILI) is a Precision-Prevention phase II open-labelled unblinded randomised clinical trial in which 224 adults aged ≥ 16 years with LFS are randomised 1:1 to oral metformin (up to 2 mg daily) plus annual MRI surveillance or annual MRI surveillance alone for up to 5 years. The primary endpoint is to compare cumulative cancer-free survival up to 5 years (60 months) from randomisation between the intervention (metformin) and control (no metformin) arms. Secondary endpoints include a comparison of cumulative tumour-free survival at 5 years, overall survival at 5 years and clinical characteristics of emerging cancers between trial arms. Safety, toxicity and acceptability of metformin; impact of metformin on quality of life; and impact of baseline lifestyle risk factors on cancer incidence will be assessed. Exploratory end-points will evaluate the mechanism of action of metformin as a cancer preventative, identify biomarkers of response or carcinogenesis and assess WB-MRI performance as a diagnostic tool for detecting cancers in participants with LFS by assessing yield and diagnostic accuracy of WB-MRI.DiscussionAlongside a parallel MILI study being conducted by collaborators at the National Cancer Institute (NCI), MILI is the first prevention trial to be conducted in this high-risk group. The MILI study provides a unique opportunity to evaluate the efficacy of metformin as a chemopreventive alongside exploring its mechanism of anticancer action and the biological process of mutated P53-driven tumourigenesis.Trial registrationISRCTN16699730. Registered on 28 November 2022. URL: https://www.isrctn.com/ EudraCT/CTIS number 2022-000165-41.

Frequency of Radiation Therapy-Induced Malignancies in Patients With Li-Fraumeni Syndrome and Early-Stage Breast Cancer and the Influence of Radiation Therapy Technique

IntroductionBreast cancer (BC) is the most common malignancy in female patients with Li-Fraumeni Syndrome (LFS), a condition associated with an increased risk of various malignancies, including radiotherapy-induced malignancies (RIM) within previously irradiated areas. Our study aimed to assess the incidence of RIM in LFS patients with early-stage breast cancer (eBC) treated with adjuvant radiotherapy (RT), including the impact of RT dose and technique. MethodsWe examined patients with a germline pathogenic/likely pathogenic TP53 variant diagnosed with eBC and monitored by a Hereditary Cancer Team at a single cancer center. The study endpoints included RIM frequency, the association of RIM with the dose and type of radiotherapy (2D RT, 3D RT, and IMRT), and BC recurrence. ResultsWe analyzed 48 patients with a median age of 39 years (range 21 - 62). A majority (71%) had the TP53 R337H variant, and 87% were unaware of their LFS diagnosis at the time of BC treatment. Treatment modalities included mastectomy (62%), (neo)adjuvant chemotherapy (66%), and RT (62%), with RT being more common after breast-conserving surgery (87% vs. 46% with mastectomy, P=0.010). Among the 30 patients treated with RT, 10% developed RIM in the irradiated field, consisting of three soft tissue malignancies. RT dose (≤40.8 or >40.8 Gy) did not influence RIM occurrence, but the type of RT did. RIM was observed in 100% of cases with 2D RT (2/2), 50% with IMRT (1/2), and 0% with 3D RT (0/16) (P=0.004). ConclusionOur study underscores a concerning rate of RIM following adjuvant RT, emphasizing the importance of a thorough risk-benefit evaluation before recommending RT, with preference for its avoidance if possible. Although subgroup sizes were limited, the risk of RIM appeared to be influenced by the RT technique, with higher rates observed with 2D RT and IMRT compared to 3D RT. Early TP53 testing is essential to guide the BC treatment plan.

Therapeutic Strategies for Gliomas Associated With Cancer Predisposition Syndromes.

The purpose of this article was to provide an overview of syndromic gliomas. The authors conducted a nonsystematic literature review. Cancer predisposition syndromes (CPSs) are genetic conditions that increase one's risk for certain types of cancer compared with the general population. Syndromes that can predispose one to developing gliomas include neurofibromatosis, Li-Fraumeni syndrome, Lynch syndrome, and tuberous sclerosis complex. The standard treatment for sporadic glioma may involve resection, radiation therapy, and/or alkylating chemotherapy. However, DNA-damaging approaches, such as radiation and alkylating agents, may increase the risk of secondary malignancies and other complications in patients with CPSs. In some cases, depending on genetic aberrations, targeted therapies or immunotherapeutic approaches may be considered. Data on clinical characteristics, therapeutic strategies, and prognosis of syndromic gliomas remain limited. In this review, we provide an overview of syndromic gliomas with a focus on management for patients with CPSs and the role of novel treatments that can be considered.

LFSPROShiny: An Interactive R/Shiny App for Prediction and Visualization of Cancer Risks in Families With Deleterious Germline TP53 Mutations.

LFSPRO is an R library that implements risk prediction models for Li-Fraumeni syndrome (LFS), a genetic disorder characterized by deleterious germline mutations in the TP53 gene. To facilitate the use of these models in clinics, we developed LFSPROShiny, an interactive R/Shiny interface of LFSPRO that allows genetic counselors (GCs) to perform risk predictions without any programming components and further visualize the risk profiles of their patients to aid the decision-making process. LFSPROShiny implements two models that have been validated on multiple LFS patient cohorts: a competing risk model that predicts cancer-specific risks for the first primary and a recurrent-event model that predicts the risk of a second primary tumor. Starting with a visualization template, we keep regular contact with GCs, who ran LFSPROShiny in their counseling sessions, to collect feedback and discuss potential improvement. On receiving the family history as input, LFSPROShiny renders the family into a pedigree and displays the risk estimates of the family members in a tabular format. The software offers interactive overlaid side-by-side bar charts for visualization of the patients' cancer risks relative to the general population. We walk through a detailed example to illustrate how GCs can run LFSPROShiny in clinics from data preparation to downstream analyses and interpretation of results with an emphasis on the utilities that LFSPROShiny provides to aid decision making. Since December 2021, we have applied LFSPROShiny to over 100 families from counseling sessions at the MD Anderson Cancer Center. Our study suggests that software tools with easy-to-use interfaces are crucial for the dissemination of risk prediction models in clinical settings, hence serving as a guideline for future development of similar models.

Epithelioid angiomyolipoma of the liver in a patient with Li-Fraumeni syndrome: a case report

BackgroundEpithelioid angiomyolipoma (EAML) is a rare variant of angiomyolipoma that predominantly consists of epithelioid cells and belongs to the perivascular epithelioid cell neoplasm (PEComa) family. The majority of EAMLs arise in the kidneys, and primary hepatic EAML appears to be much less common than renal EAML. Most PEComas arise sporadically, but may be associated with tuberous sclerosis complex (TSC), an autosomal dominant genetic disorder characterized by germline mutations in the TSC1 or TSC2 genes. However, PEComas have previously been reported in five patients with Li-Fraumeni syndrome (LFS), which is an inherited cancer susceptibility disorder resulting from germline mutations in the TP53 tumor suppressor gene.Case presentationWe report a 49-year-old female patient with hepatic EAML and pancreatic cancer. Because she had previously been diagnosed with bilateral breast cancer at the age of 30, we performed a comprehensive genetic analysis to identify genetic alterations associated with any cancer predisposition syndrome. Whole-exome sequencing of a blood sample identified a heterozygous germline variant of TP53 (NM_000546.5):c.708C>A, and targeted next-generation sequencing of liver EAML and pancreatic cancer tissue samples demonstrated the same TP53 (NM_000546.5):c.708C>A variant in both. This, plus the patient’s history of early-onset breast cancer, met the 2015 version of the Chompret criteria for diagnosis of LFS.ConclusionsThere have been very few case reports regarding the presence of PEComa in LFS, and to the best of our knowledge, this is the first report of EAML of the liver in a patient with LFS.

Li-Fraumeni syndrome presenting with de novo TP53 mutation, severe phenotype and advanced paternal age: a case report

BackgroundLi-Fraumeni syndrome (LFS) is an autosomal dominant hereditary cancer syndrome caused by pathogenic variants in the gene TP53. This gene codes for the P53 protein, a crucial player in genomic stability, which functions as a tumor suppressor gene. Individuals with LFS frequently develop multiple primary tumors at a young age, such as soft tissue sarcomas, breast cancer, and brain tumors.Case presentationA 38 years-old female with a history of femur osteosarcoma, ductal carcinoma of the breast, high-grade breast sarcoma, pleomorphic sarcoma of the left upper limb, infiltrating lobular carcinoma of the breast, gastric adenocarcinoma, leiomyosarcoma of the right upper limb, and high-grade pleomorphic renal sarcoma. Complete molecular sequencing of the TP53 gene showed c.586 C > T (p.R196X) in exon 6, which is a nonsense mutation that produces a shorter and malfunctioning P53. Family history includes advanced father’s age at the time of conception (75 years), which has been associated with an increased risk of de novo germline mutations. The patient had seven paternal half-siblings with no cancer history. The patient received multiple treatments including surgery, systemic therapy, and radiotherapy, but died at the age of 38.ConclusionsAdvanced paternal age is a risk factor to consider when hereditary cancer syndrome is suspected. Early detection of hereditary cancer syndromes and their multi-disciplinary surveillance and treatment is important to improve clinical outcomes for these patients. Further investigation of the relationship between the pathogenic variant of TP53 and its phenotype may guide the stratification of surveillance and treatment.

Phenotype analysis of families with TP53 germline variants at the Center for Familial Breast and Ovarian Cancer, Cologne.

Tumor protein p53 (TP53) pathogenic variant (PV) carriers are identified during genetic testing for hereditary causes of cancer. PVs in TP53 are associated with the Li-Fraumeni syndrome (LFS), and thus, surveillance and preventive measures are important for TP53 PV carriers. However, the penetrance of TP53 PVs can be low if the Chompret criteria are not fulfilled. In this study, we compared the phenotypic characteristics of families that did and did not fulfill the LFS criteria according to Chompret. The German Consortium for Hereditary Breast and Ovarian Cancer (GC-HBOC) database was used to identify index patients with a likely pathogenic/pathogenic TP53 variant and their family members. The study investigated the type of variant, pedigree, age of onset, number of primary tumors, and histological type of BC. TP53 PV were present in the index cases of 35 families, 57% (20/35) of which fulfilled the Chompret criteria. The median age of onset at first BC diagnosis was lower in families that fulfilled the Chompret criteria compared to those who did not. Four of all diseased individuals were minors (4%; 4/105) when malignancy was first diagnosed. Sarcomas and brain tumors occurred in 10% (10/105) and in 7% (7/105) of all diseased persons, respectively. BC was the most frequently occurring first tumor (60%; 62/105) and additional malignancy (45%; 20/44) in this cohort. Subsequent malignancies developed in 31% (20/65) of the individuals who fulfilled the Chompret criteria compared with 15% (6/40) of those who did not. The tumor spectrum and age of onset found in this study showed that tumors other than BC had low disease penetrance in TP53 PV carriers identified using the GC-HBOC criteria for genetic testing.

O-11 A rare cause of thyroid cancer - Li Fraumeni 2 syndrome

Abstract Introduction Thyroid cancer often originates from follicular cells, and papillary thyroid cancer (PTC) is the most common type. There is a familial predisposition in some cases of thyroid cancer. However, a minority of cases have thyroid cancer syndrome (e.g., familial polyposis, MEN 2, or Cowden syndrome). Many known genetic susceptibility genes are RET/PTC, BRAF, RAS, TERT, and TP53. We want to present a case of Li Fraumeni type 2 syndrome as a rare cause of thyroid cancer. Clinical Case A 69-year-old female patient with a history of PTC is admitted to the endocrinology department for follow-up. In 1976, this patient had a thyroid lobectomy, but the pathology result is unknown, and she takes 75 mcg of levothyroxine daily. In 1999, she was diagnosed with rectal cancer. The patient had a completion thyroidectomy in 2002, and the pathology was compatible with PTC. In 2014, she was diagnosed with right breast noninvasive ductal cancer. Cases of cancer were also quite common in her family history. The results of laboratory tests revealed normal TSH levels with negative thyroglobulin and anti-thyroglobulin levels. Neck ultrasonography showed no rest gland and pathological LAP. We requested genetic analysis (55 genes) for familial cancer syndromes. As a result of the analysis, 2 genes were found to be heterozygous. The c.599T&amp;gt;c heterozygous variant in the CHEK 2 gene was found (Figure 1). It was evaluated as pathogenic in the database review. Another heterozygous mutation in the BRIP1 gene, which was evaluated as a VUS also detected. Conclusion The CHEK 2 gene is a DNA-repairing protein kinase at position 22.q12.1. It is responsible for TP53 stabilization, genome maintenance, and apoptosis. CHEK2 phosphorylates p53 in response to DNA damage, leading to cell cycle arrest and stabilization (Figure 2). The mutation(CHEK 2 c.599T&amp;gt;c) we detected in this case has been considered possibly pathogenic in the academic databases. There are reported CHEK 2 c.599T&amp;gt;c cases on the CLINVAR site; the first report is from 2013. Classic Li-Fraumeni syndrome is a rare autosomal dominant syndrome caused by TP53 gene mutation. The chromosome location on classical Li fraumeni is 17p13.1. Li-Fraumeni type 2 develops due to the CHEK 2 gene mutation on chromosome 22q12.1. The results of a mutation of the CHEK2 gene are breast cancer, prostate cancer, PTC, colon cancer, kidney cancer, adrenocortical cancer, lung cancer, and rare cases of myelodysplastic syndromes. There are no data on thyroid-specific mortality in carriers of the CHEK2 mutations, and it is not yet known whether thyroid cancer in this population is more aggressive or has a better outcome.The familial syndromes should also be considered if PTC is detected in breast, colon, and prostate cancer patients. Studies on Li-Fraumeni type 2 syndrome are scarce, and considering the prevalence in European countries, further investigations of this syndrome and screening in patients with multiple cancers in the family should be warranted.Figure 1.Genetic sequencing image of the case