New surveillance guidelines for Li-Fraumeni and hereditary TP53 related cancer syndrome: implications for germline TP53 testing in breast cancer

Update on Cancer Screening Recommendations for Individuals with Li-Fraumeni Syndrome

Li-Fraumeni syndrome (LFS) is an autosomal dominant cancer predisposition condition characterized by a high lifetime risk for a wide spectrum of malignancies associated with germline pathogenic/likely pathogenic variants in the TP53 tumor suppressor gene. Secondary malignant neoplasms are particularly common. Early cancer detection through surveillance enables early intervention and leads to improved clinical outcomes with reduced tumor-related mortality and treatment-related morbidity. Since the 2017 publication of LFS tumor surveillance guidelines from the inaugural American Association for Cancer Research Childhood Cancer Predisposition Workshop, understanding the genotype-phenotype relationships in LFS has evolved, and adaptations of the guidelines have been implemented in institutions worldwide. The "Toronto Protocol" remains the current standard for lifelong surveillance; however, as outlined in this perspective, modifications should be considered about the use of certain modalities to target organs in an age-dependent manner. The Working Group's recommendations have also been extended to include a more detailed outline for surveillance in the adult TP53 pathogenic/likely pathogenic variant carrier population, based on the recognition that early education of both practitioners and patients on what to expect after the transition from childhood/adolescence to young adulthood is important in preparing them for changes in surveillance strategies. In this perspective, we provide an up-to-date clinical overview of LFS and present our updated consensus tumor surveillance recommendations from the 2023 American Association for Cancer Research Childhood Cancer Predisposition Workshop.

Li-Fraumeni Syndrome : Current Strategies and Future Perspectives

Li-Fraumeni syndrome (LFS) is a rare inherited cancer predisposition syndrome caused by germline mutations in the TP53 tumor suppressor gene. It predisposes affected individuals to a wide spectrum of early-onset malignancies, including sarcomas, breast cancer, brain tumors, and adrenocortical carcinoma. Advances in genetic testing and risk management strategies have enhanced the identification and clinical management of LFS patients. Comprehensive surveillance has demonstrated increased survival rates through proactive screening. Beyond surveillance, research is exploring novel approaches such as liquid biopsy for early cancer detection and chemoprevention strategies, including metformin trials, to mitigate cancer risk. This review discusses the molecular basis, clinical spectrum, surveillance strategies, and emerging research in LFS.

EMQN best practice guidelines for genetic testing in hereditary breast and ovarian cancer

Hereditary Breast and Ovarian Cancer (HBOC) is a genetic condition associated with increased risk of cancers. The past decade has brought about significant changes to hereditary breast and ovarian cancer (HBOC) diagnostic testing with new treatments, testing methods and strategies, and evolving information on genetic associations. These best practice guidelines have been produced to assist clinical laboratories in effectively addressing the complexities of HBOC testing, while taking into account advancements since the last guidelines were published in 2007. These guidelines summarise cancer risk data from recent studies for the most commonly tested high and moderate risk HBOC genes for laboratories to refer to as a guide. Furthermore, recommendations are provided for somatic and germline testing services with regards to clinical referral, laboratory analyses, variant interpretation, and reporting. The guidelines present recommendations where 'must' is assigned to advocate that the recommendation is essential; and 'should' is assigned to advocate that the recommendation is highly advised but may not be universally applicable. Recommendations are presented in the form of shaded italicised statements throughout the document, and in the form of a table in supplementary materials (Table S4). Finally, for the purposes of encouraging standardisation and aiding implementation of recommendations, example report wording covering the essential points to be included is provided for the most common HBOC referral and reporting scenarios. These guidelines are aimed primarily at genomic scientists working in diagnostic testing laboratories.

Risk for Hereditary Neoplastic Syndromes in Women with Mismatch Repair-Proficient Endometrial Cancer

Endometrial cancer (EC) is a prevalent malignancy in women, and those who are proficient in the DNA mismatch repair (pMMR) pathway may have a family history (FH) that meets the criteria for a hereditary neoplastic condition (HNS). This study aimed to estimate the risk of HNS in women with pMMR endometrial tumors by analyzing their FH. To achieve this, we collaborated with a primary study and collected FH information by telephone. The final sample comprised 42 women who responded to the Primary Screening Questionnaire. Their family pedigrees were drawn and categorized according to internationally standardized criteria for the risk of HNS. Results showed that 26 women (61%) were found to be at risk for HNS, with Bethesda criteria being met by 23%, Amsterdam criteria by 15%, and 4% met the attenuated familial adenomatous polyposis criteria. Our results emphasize the importance of FH and the need to encourage healthcare professionals to collect and document FH more frequently, even if it is self-reported. By identifying individuals with HNS, we can improve their outcomes and reduce the burden of cancer in families with a predisposition to cancer.

30 year experience of index case identification and outcomes of cascade testing in high-risk breast and colorectal cancer predisposition genes

It is 30 years since the first diagnostic cancer predisposition gene (CPG) test in the Manchester Centre for Genomic Medicine (MCGM), providing opportunities for cancer prevention, early detection and targeted treatments in index cases and at-risk family members. Here, we present time trends (1990-2020) of identification of index cases with a germline CPG variant and numbers of subsequent cascade tests, for 15 high-risk breast and gastro-intestinal tract cancer-associated CPGs: BRCA1, BRCA2, PALB2, PTEN, TP53, APC, BMPR1a, CDH1, MLH1, MSH2, MSH6, PMS2, SMAD4, STK11 and MUTYH. We recorded 2082 positive index case diagnostic screening tests, generating 3216 positive and 3140 negative family cascade (non-index) tests. This is equivalent to an average of 3.05 subsequent cascade tests per positive diagnostic index test, with 1.54 positive and 1.51 negative non-index tests per family. The CPGs with the highest numbers of non-index positive cases identified on cascade testing were BRCA1/2 (n = 1999) and the mismatch repair CPGs associated with Lynch Syndrome (n = 731). These data are important for service provision and health economic assessment of CPG diagnostic testing, in terms of cancer prevention and early detection strategies, and identifying those likely to benefit from targeted treatment strategies.

Pathological and Genetic Stratification for Management of Adrenocortical Carcinoma

CONTEXT

Adrenocortical carcinoma (ACC) is a rare endocrine malignancy that affects patients across the age spectrum. Although the overall survival in patients with ACC is poor, there is significant heterogeneity in terms of outcomes, presentation, and underlying genetic drivers.

EVIDENCE ACQUISITION

This review is based on the evidence collected from primary research studies, expert reviews, and published guidelines. The studies were identified through PubMed search with key words "adrenocortical carcinoma," "prognosis," "pathology," and "genetics." The PubMed search was complemented by authors' expertise, research, and clinical experience in the field of ACC.

EVIDENCE SYNTHESIS

Identification of biomarkers has been critical to gain better insight into tumor behavior and to guide therapeutic approach to patients. Tumor stage, resection status, and Ki67 are pathological tumor characteristics that have been identified as prognosticators in patients with ACC. Cortisol excess also correlates with worse prognosis. Clinical and histopathological characteristics help stratify patient outcomes, yet still up to 25% of patients have a different outcome than predicted. To bridge this gap, comprehensive genomic profiling studies have characterized additional profiles that correlate with clinical outcomes. In addition, studies of clinically applicable molecular markers are under way to further stratify outcomes in patients with ACC tumors.

CONCLUSIONS

Clinical predictors in combination with pathological markers play a critical role in the approach to patients with ACC. Recent advances in genetic prognosticators will help extend the stratification of these tumors and contribute to a personalized therapeutic approach to patients with ACC.

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.

Revisiting the indication for prophylactic contralateral mastectomy in patients with Li-Fraumeni syndrome and breast cancer. Case report

Objective

To describe the case of a patient with Li-Fraumeni syndrome (LFS) and breast cancer in whom the benefit of contralateral prophylactic mastectomy (CPM) was challenged; and to offer a critical discussion regarding the evidence supporting this procedure in this patient population.

Case presentation

A 37-year-old woman with breast cancer and a family history of multiple early onset cancer of the LFS spectrum in whom a pathogenic variant of the TP53 gene was confirmed during adjuvant hormonal therapy. The case was presented during the multidisciplinary meeting of the Breast Service of a referral oncology center in Colombia, in order to discuss the benefit of CPM. The decision of the board meeting was not to perform CPM. After 30 months of follow-up, the patient is disease-free.

Conclusion

There is no evidence on the impact of CPM on survival of patients with LFS and breast cancer in particular. However, in light of the current knowledge, it is not possible to generalize the approach of withholding this prophylactic surgery. It is important to report those cases in which the decision is made to either perform or omit this procedure in order to increase the body of evidence, considering the limitations that make it difficult to build large cohorts or conduct trials exclusively for this genetic disorder.

Breast cancer characteristics and surgery among women with Li-Fraumeni syndrome in Germany-A retrospective cohort study

Background

Women with Li‐Fraumeni syndrome (LFS) have elevated breast cancer (BC) risk. Optimal BC treatment strategies in this population are yet unknown.

Methods

BC subtypes and treatment were retrospectively investigated between December 2016 and January 2019 in a multicentre study. BC risks were evaluated according to the type of surgery.

Results

Thirty‐five women of our study population (35/44; 79.5%) had developed 36 breast lesions at first diagnosis at a mean age of 34 years. Those breast lesions comprised 32 invasive BCs (89%), three ductal carcinoma in situ alone (8%) and one malignant phyllodes tumour (3%). BCs were mainly high‐grade (18/32), of no special type (NST; 31/32), HER2‐enriched (11/32) or luminal‐B‐(like)‐type (10/32). Affected women (n = 35) received breast‐conserving surgery (BCS, n = 17) or a mastectomy (ME, n = 18) including seven women with simultaneous contralateral prophylactic mastectomy (CPM) at first diagnosis. Nineteen women suffered 20 breast or locoregional axillary lesions at second diagnosis with mean age of 36. Median time between first and second diagnosis was 57 months; median time to contra‐ and ipsilateral recurrence depended on surgical strategies (BCS: 46 vs. unilateral ME: 93 vs. bilateral ME > 140 months). Women with a primary treatment of solitaire therapeutic ME suffered from contralateral BC earlier compared to those with therapeutic ME and CPM (median: 93 vs. >140 months).

Conclusion

Aggressive BC subtypes occur among women with LFS. Surgical treatment, i.e. ME and CPM, may prolong time to a second BC diagnosis. Conclusion on long‐term survival benefit is pending. Individual competing tumour risks and long‐term outcomes need to be taken into consideration.

From BRCA1 to Polygenic Risk Scores: Mutation-Associated Risks in Breast Cancer-Related Genes

Background

There has been huge progress over the last 30 years in identifying the familial component of breast cancer.

Summary

Currently around 20% is explained by the high-risk genes BRCA1 and BRCA2, a further 2% by other high-penetrance genes, and around 5% by the moderate risk genes ATM and CHEK2. In contrast, the more than 300 low-penetrance single-nucleotide polymorphisms (SNP) now account for around 28% and they are predicted to account for most of the remaining 45% yet to be found. Even for high-risk genes which confer a 40-90% risk of breast cancer, these SNP can substantially affect the level of breast cancer risk. Indeed, the strength of family history and hormonal and reproductive factors is very important in assessing risk even for a BRCA carrier. The risks of contralateral breast cancer are also affected by SNP as well as by the presence of high or moderate risk genes. Genetic testing using gene panels is now commonplace.

Key-Messages

There is a need for a more parsimonious approach to panels only testing those genes with a definite 2-fold increased risk and only testing those genes with challenging management implications, such as CDH1 and TP53, when there is strong clinical indication to do so. Testing of SNP alongside genes is likely to provide a more accurate risk assessment.