Prevalence of germline TP53 variants among early-onset breast cancer patients from Polish population

HER2 status and response to neoadjuvant anti-HER2 treatment among patients with breast cancer and Li-Fraumeni syndrome

BACKGROUND

Breast cancer (BC) is the most common cancer among females with Li-Fraumeni syndrome (LFS), but available data on LFS-related BC characteristics are derived from small retrospective cohorts. Prior work has demonstrated a high proportion of HER2-positive BCs, but our understanding of how HER2-positive LFS BCs respond to anti-HER2 treatments is limited.

METHODS

BCs diagnosed in patients with germline TP53 variants between 2002-2022 were assembled from three institutions. Hormone receptor (HR) and HER2 expression were retrieved from pathology records. Pathologic complete response (pCR) was defined as ypT0/is ypN0.

RESULTS

A total of 264 BCs were identified among 232 patients with LFS: 211 (79.9 %) were invasive carcinomas, of which 106 were HER2-positive. Among HER2-positive BCs, most tumors co-expressed HRs (72.6 %) and were more frequent among those diagnosed at younger age (p < 0.001). Mastectomy was the preferred surgical approach among women with nonmetastatic cancers (77.8 %) and most received anti-HER2 targeted therapy (74.7 %). Among 38 patients receiving neoadjuvant therapy with available post-treatment pathology reports, 27 (71.1 %) achieved pCR: 18/26 (69.2 %) among HR-positive and 7/10 (70.0 %) HR-negative. The rate of pCR was 84.6 % among patients treated with an anthracycline-free regimen (all received trastuzumab). Among classifiable HER2-negative BCs (n = 77), 31 (40.3 %) were HER2-low and 46 (59.7 %) HER2-zero.

CONCLUSIONS

Among females with LFS and BC, HER2-positive subtype was associated with younger age at diagnosis and a predominant HR-positivity. Favorable pCR rates were observed among those receiving neoadjuvant HER2-directed therapies, for both HR-positive and negative tumors. These data may inform the counseling and care of patients with LFS.

Current insights and future directions of Li-Fraumeni syndrome

Li-Fraumeni syndrome is a rare yet serious hereditary cancer predisposition syndrome, marked by a significant early-life increased risk of developing cancer. Primarily caused by germline mutations in the TP53 tumor suppressor gene, Li-Fraumeni syndrome is associated with a wide range of malignancies. Clinical management of Li-Fraumeni syndrome could be challenging, especially the lifelong surveillance and follow-up of patients which requires a multidisciplinary approach. Emerging insights into the molecular and clinical basis of Li-Fraumeni syndrome, coupled with advances in genomic technologies and targeted therapies, offer promise in optimizing risk assessment, early detection, and treatment strategies tailored to the unique clinical and molecular profiles of affected individuals. This review discusses Li-Fraumeni syndrome in more depth, reviewing molecular, genomic, epidemiological, clinical, and therapeutic aspects of this disease.

Construction of a prognostic model for breast cancer based on moonlighting genes

Breast cancer (BRCA) is a highly heterogeneous disease, with significant differences in prognosis among patients. Existing biomarkers and prognostic models have limited ability to predict BRCA prognosis. Moonlighting genes regulate tumor progression and are associated with cancer prognosis. This study aimed to construct a moonlighting gene-based prognostic model for BRCA. We obtained differentially expressed genes (DEGs) in BRCA from The Cancer Genome Atlas and intersected them with moonlighting genes from MoonProt to acquire differential moonlighting genes. GO and KEGG results showed main enrichment of these genes in the response of BRCA cells to environmental stimuli and pentose phosphate pathway. Based on moonlighting genes, we conducted drug prediction and validated results through cellular experiments. After ABCB1 knockdown, viability and proliferation of BRCA cells were significantly enhanced. Based on differential moonlighting genes, BRCA was divided into three subgroups, among which cluster2 had the highest survival rate and immunophenoscore and relatively low tumor mutation burden. TP53 had the highest mutation frequency in cluster2 and cluster3, while PIK3CA had a higher mutation frequency in cluster1, with the majority being missense mutations. Subsequently, we established an 11-gene prognostic model in the training set based on DEGs among subgroups using univariate Cox regression, LASSO regression, and multivariable Cox regression analyses. Model prognostic performance was verified in GEO, METABRIC and ICGC validation sets. In summary, this study obtained three BRCA moonlighting gene-related subtypes and constructed an 11-gene prognostic model. The 11-gene BRCA prognostic model has good predictive performance, guiding BRCA prognosis for clinical doctors.

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

INTRODUCTION

Cancer 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 METHODS: Clinicopathological 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 RESULTS: Hereditary 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 CONCLUSION: Our 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.

Emerging insights into ethnic-specific TP53 germline variants

The recent expansion of human genomics repositories has facilitated the discovery of novel TP53 variants in populations of different ethnic origins. Interpreting TP53 variants is a major clinical challenge because they are functionally diverse, confer highly variable predisposition to cancer (including elusive low-penetrance alleles), and interact with genetic modifiers that alter tumor susceptibility. Here, we discuss how a cancer risk continuum may relate to germline TP53 mutations on the basis of our current review of genotype-phenotype studies and an integrative analysis combining functional and sequencing datasets. Our study reveals that each ancestry contains a distinct TP53 variant landscape defined by enriched ethnic-specific alleles. In particular, the discovery and characterization of suspected low-penetrance ethnic-specific variants with unique functional consequences, including P47S (African), G334R (Ashkenazi Jewish), and rs78378222 (Icelandic), may provide new insights in terms of managing cancer risk and the efficacy of therapy. Additionally, our analysis highlights infrequent variants linked to milder cancer phenotypes in various published reports that may be underdiagnosed and require further investigation, including D49H in East Asians and R181H in Europeans. Overall, the sequencing and projected functions of TP53 variants arising within ethnic populations and their interplay with modifiers, as well as the emergence of CRISPR screens and AI tools, are now rapidly improving our understanding of the cancer susceptibility spectrum, leading toward more accurate and personalized cancer risk assessments.

The APOBEC3B c.783delG Truncating Mutation Is Not Associated with an Increased Risk of Breast Cancer in the Polish Population

The APOBEC3B gene belongs to a cluster of DNA-editing enzymes on chromosome 22 and encodes an activation-induced cytidine deaminase. A large deletion of APOBEC3B was associated with increased breast cancer risk, but the evidence is inconclusive. To investigate whether or not APOBEC3B is a breast cancer susceptibility gene, we sequenced this gene in 617 Polish patients with hereditary breast cancer. We detected a single recurrent truncating mutation (c.783delG, p.Val262Phefs) in four of the 617 (0.65%) hereditary cases by sequencing. We then genotyped an additional 12,484 women with unselected breast cancer and 3740 cancer-free women for the c.783delG mutation. The APOBEC3B c.783delG allele was detected in 60 (0.48%) unselected cases and 19 (0.51%) controls (OR = 0.95, 95% CI 0.56-1.59, p = 0.94). The allele was present in 8 of 1968 (0.41%) familial breast cancer patients from unselected cases (OR = 0.80, 95% CI 0.35-1.83, p = 0.74). Clinical characteristics of breast tumors in carriers of the APOBEC3B mutation and non-carriers were similar. No cancer type was more frequent in the relatives of mutation carriers than in those of non-carriers. We conclude the APOBEC3B deleterious mutation p.Val262Phefs does not confer breast cancer risk. These data do not support the hypothesis that APOBEC3B is a breast cancer susceptibility gene.

Germline TP53 pathogenic variants and breast cancer: A narrative review

Approximately 10% of breast cancers are associated with the inheritance of a pathogenic variant (PV) in one of the breast cancer susceptibility genes. Multiple breast cancer predisposing genes, including TP53, are responsible for the increased breast cancer risk. Tumor protein-53 (TP53) germline PVs are associated with Li-Fraumeni syndrome, a rare autosomal dominant inherited cancer predisposition syndrome associated with early-onset pediatric and multiple primary cancers such as soft tissue and bone sarcomas, breast cancer, brain tumors, adrenocortical carcinomas and leukemias. Women harboring a TP53 PV carry a lifetime risk of developing breast cancer of 80-90%. The aim of the present narrative review is to provide a comprehensive overview of the criteria for offering TP53 testing, prevalence of TP53 carriers among patients with breast cancer, and what is known about its prognostic and therapeutic implications. A summary of the current indications of secondary cancer surveillance and survivorship issues are also provided. Finally, the spectrum of TP53 alteration and testing is discussed. The optimal strategies for the treatment of breast cancer in patients harboring TP53 PVs poses certain challenges. Current guidelines favor the option of performing mastectomy rather than lumpectomy to avoid adjuvant radiotherapy and subsequent risk of radiation-induced second primary malignancies, with careful consideration of radiation when indicated post-mastectomy. Some studies suggest that patients with breast cancer and germline TP53 PV might have worse survival outcomes compared to patients with breast cancer and wild type germline TP53 status. Annual breast magnetic resonance imaging (MRI) and whole-body MRI are recommended as secondary prevention.

Hereditary cancer syndromes

Hereditary cancer syndromes (HCSs) are arguably the most frequent category of Mendelian genetic diseases, as at least 2% of presumably healthy subjects carry highly-penetrant tumor-predisposing pathogenic variants (PVs). Hereditary breast-ovarian cancer and Lynch syndrome make the highest contribution to cancer morbidity; in addition, there are several dozen less frequent types of familial tumors. The development of the majority albeit not all hereditary malignancies involves two-hit mechanism, i.e. the somatic inactivation of the remaining copy of the affected gene. Earlier studies on cancer families suggested nearly fatal penetrance for the majority of HCS genes; however, population-based investigations and especially large-scale next-generation sequencing data sets demonstrate that the presence of some highly-penetrant PVs is often compatible with healthy status. Hereditary cancer research initially focused mainly on cancer detection and prevention. Recent studies identified multiple HCS-specific drug vulnerabilities, which translated into the development of highly efficient therapeutic options.

Prevalence of germline TP53 mutation among early onset middle eastern breast cancer patients

Background

The data on prevalence and clinical relevance of TP53 germline mutations in early onset Middle-Eastern breast cancer (BC) is limited.

Methods

We determined TP53 germline mutations in a cohort of 464 early onset BC patients from Saudi Arabia using capture sequencing based next generation sequencing.

Results

Germline TP53 pathogenic mutations were found in 1.5% (7/464) of early onset Saudi BC patients. A total of six pathogenic missense mutations, one stop gain mutation and two variants of uncertain significance (VUS) were detected in our cohort. No TP53 pathogenic mutations were detected among 463 healthy controls. TP53 mutations carriers were significantly more likely to have bilateral breast cancer (p = 0.0008). At median follow-up of 41 months, TP53 mutations were an unfavorable factor for overall survival in univariate analysis. All the patients carrying TP53 mutations were negative for BRCA1 and BRCA2 mutations. Majority of patients (85.7%; 6/7) carrying TP53 mutation had no family history suggestive of Li-Fraumeni Syndrome (LFS) or personal history of multiple LFS related tumors. Only one patient had a positive family history suggestive of LFS.

Conclusions

TP53 germline mutation screening detects a clinically meaningful risk of early onset BC from this ethnicity and should be considered in all early onset BC regardless of the family history of cancer, especially in young patients that are negative for BRCA mutations.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13053-021-00206-w.

Is Gestational Diabetes Mellitus a Risk Factor of Maternal Breast Cancer? A Systematic Review of the Literature

The association between gestational diabetes mellitus (GDM) and breast cancer (BC) risk is complex. We aimed to examine this association in a systematic review of the literature. This review was done using the PubMed/Medline and Web of Science databases, in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The Newcastle-Ottawa Scale was used for the assessment of bias and quality of studies. Only English-language articles published before 1 June 2021, were included. Fourteen studies were included in this systematic review. Among them, eight did not find statistically significant results. Three studies showed a statistically significant increased risk of BC after GDM, and they explained this potential increased risk by hyperinsulinemia, hyperglycemia, and low-grade inflammation. However, three studies showed a statistically significant decreased risk of BC after GDM, suggesting a possible protective effect of hormonal changes induced by GDM during pregnancy. These controversial results should be interpreted with caution due to both quantitative and qualitative methodological shortcomings. Further investigations are thus needed in order to gain a better understanding of the associations between GDM and BC, and their underlying mechanisms.

Analysis of 13 TP53 and WRAP53 polymorphism frequencies in russian populations

In the last decade the search for and annotation of human genome polymorphisms associated with phenotype have become particularly important concerning the opportunity of their use in medical and population genetics, pharmacogenomics and evolutionary biology. The study was aimed to calculate the frequencies and analyze the prevalence of 13 germline polymorphisms of two genes, ТР53 encoding the genome-keeper p53 protein and WRAP53 involved in regulation of p53 production, in 28 Russian populations. We obtained data on 9 exonic ТР53 variants (rs587781663, rs17882252, rs150293825, rs112431538, rs149633775, rs144340710, rs1042522, rs1800371, rs201753350), one intronic polymorphism (rs17881850), and three variants of WRAP53 (rs17880282, rs2287499, rs34067256). In the majority of populations the sample size was over 50 people (except five populations with 30–49 surveyed people). The alternative alleles’ population frequencies for studies genetic variants in most Russian populations were close to appropriate allele frequencies in European and Asian populations of similar origin taken from global databases. The exceptions were six populations ("Central Caucasus", "Dagestan", "northern Russians", "southeastern Russians", "Tatars" and "Transcaucasia") with increased alternative alleles’ population frequencies. All listed populations except the population of “southeastern Russians” are characterized by polymorphisms with high allele frequencies not satisfying the Hardy–Weinberg principle.