Hereditary Cancer in Clinical Practice最新文献

Background: Germline TP53 gene variants are intricately linked to Li-Fraumeni syndrome, a rare and aggressive hereditary cancer syndrome. This study investigated the frequency and spectrum of TP53 pathogenic variants associated with Li-Fraumeni syndrome in a large cohort of mainly breast cancer patients from Russia.

Methods: The study analyzed 3,455 genomic DNA samples from cancer patients using next-generation sequencing panels and whole-genome sequencing. Clinically significant TP53 variants were identified and validated using Sanger sequencing. The clinical and family history characteristics of patients with TP53 variants were analyzed.

Results: The analysis identified 13 (0.4%) individuals with clinically significant germline TP53 variants, all of whom were females with either unilateral breast cancer or breast cancer as part of multiple primary malignant neoplasms. The average age of breast cancer manifestation was 39.9 years, with a median of 36 years. Only 38.5% of the TP53 mutation carriers met the modified Chompret criteria for TP53 testing.

Conclusions: The findings underscore the necessity of thorough phenotype and family history analysis in genetic counseling to effectively diagnose LFS, and emphasize the importance of identifying TP53 variant carriers for developing treatment strategies, prognosis, and monitoring, as well as for identifying high-risk family members. The study also highlights that the current guidelines fail to identify over half of the TP53 mutation carriers, suggesting the need for a more comprehensive approach to genetic testing in suspected hereditary cancer cases.

Carcinogenesis encompasses processes that lead to increased mutation rates, enhanced cellular division (tumour growth), and invasive growth. Colorectal cancer (CRC) carcinogenesis in carriers of pathogenic APC (path_APC) and pathogenic mismatch repair gene (path_MMR) variants is initiated by a second hit affecting the corresponding wild-type allele. In path_APC carriers, second hits result in the development of multiple adenomas, with CRC typically emerging after an additional 20 years. In path_MLH1 and path_MSH2 carriers, second hits lead to the formation of microscopically detectable, microsatellite unstable (MSI) crypts, from which CRC develops in about half of carriers over their lifetime, often without progressing through a diagnosable adenoma stage. These divergent outcomes reflect the distinct functions of. the APC and MMR genes. In path_MLH1 and path_MSH2 carriers, a direct consequence of stochastic mutations may be the occurrence of invasive growth before tumour expansion, challenging the paradigm that an invasive cancer must always have an non-invasive precursor. In contrast to other path_ MMR carriers, path_PMS2 carriers who receive colonoscopic surveillance exhibit minimal increase in CRC incidence. This is consistent with a hybrid model: the initial mutation may cause an adenoma, and the second hit in the wild-type PMS2 allele may drive the adenoma towards become cancerous with MSI. Since all mutational events are stochastic, interventions aimed at preventing or curing cancer should ideally target the initial mutational events. Interventions focused on downstream events are external factors that influence which tumour clones survive Darwinian selection. In Lynch Syndrome, surveillance colonoscopy to remove adenomas may select for carcinogenetic pathways that bypass the adenoma stage.

Early identification of hereditary cancer predisposition in adolescents and young adults represents a unique opportunity to target cancer prevention and improve survival in a population at risk for adverse health outcomes. However, adolescents and young adults face challenges unique to their stage of life that can undermine their transition from pediatric to adult healthcare and lead to interruptions in preventative care. The purpose of this study was to understand expert perspectives on factors relevant to designing and implementing a transition clinic for adolescents and young adults with hereditary cancer predisposition. We used qualitative methods informed by human-centered design and implementation science to identify implementation considerations rooted in clinician experience. To understand clinic design and clinician experience at Geisinger transition clinics, we conducted a contextual inquiry using clinic observations and follow-up interviews of clinicians. To learn about designing and implementing a transition program, we also conducted in-depth interviews with national transition experts actively involved in developing, implementing, or participating in transition clinics around the United States. The contextual inquiry resulted in three diagrams depicting the following common elements of transition clinics at our institution: relationship building with patients, care coordination, stepwise transition education, communication between providers, and a sustainable clinic home. Interviews were analyzed deductively using thematic analysis to learn clinician perspectives about program implementation specific to each domain of the RE-AIM theoretical framework: reach, effectiveness, adoption, implementation, and maintenance.

Background: Familial adenomatous polyposis (FAP) is an autosomal dominant colorectal tumour syndrome characterised by the formation of multiple adenomatous polyps throughout the colon. It is important to understand the extracolonic phenotype that characterizes FAP. Most previous case reports of patients with both FAP and intellectual disability (ID) have described deletions in all or part of chromosome 5q, including the APC locus. However, it remains unclear whether the ID phenotype in patients with FAP is due to APC disruption or another genetic defect in the deleted 5q region.

Case presentation: Patient of family 1 is a 32-year-old woman presented with > 500 colorectal adenomatous polyps, gastric fundic gland polyposis, several duodenal adenomas, and mild intellectual disability (ID). She had no known family history of the FAP phenotype or ID. By copy number trio analysis, a 15.4 Mb interstitial heterozygous de novo deletion including APC region was observed in 5q21.2. q22.3. The patient in family 2 was a 29-year-old man with approximately 50 colorectal adenomatous polyps, fundic gland polyposis in the stomach, non-ampullary adenomas in the duodenum, and mild ID. He had no family history of the FAP phenotype or ID. Using copy number trio analysis, a de novo 9.8 Mb heterozygous deletion was identified on 5q22.1. q23.1 which includes the APC region.

Conclusions: Based on previous reports and the present study, we narrowed down the 5p deletion region associated with ID in FAP. Further investigation is required to understand ID due to 5q stromal deletion.

Background: BRCA2 germline mutations are known to predispose carriers to various cancer types, including breast, ovarian, pancreatic and prostate cancer. An association with melanoma has also been reported. However, the full tumour spectrum associated with BRCA2 mutations, particularly in patients with other concurrent pathogenetic mutations, is unexplored.

Case presentation: We present a 70-year-old female patient with a pathogenic BRCA2 c.5946del variant. Over a period of 15 years, she has developed two independent breast cancers, well-differentiated liposarcoma, clear cell renal cell carcinoma and myeloproliferative neoplasia. This unusual tumour spectrum and the staggered occurrence of these tumours required multiple rounds of genetic testing and led to a delayed diagnosis of the BRCA2-associated tumour predisposition. In addition to the BRCA2 mutation, extended germline testing revealed an APC c.3920T > A variant and variants of unknown significance in the BRIP1 and ATR genes. The molecular analysis of the tumours revealed distinct profiles with differences in HRD status and in copy number variations, indicating no common origin.

Conclusions: Our case study revealed that the pathogenic BRCA2 c.5946del germline variant can be associated with an unusual tumour spectrum, which may lead to a delayed diagnosis of a hereditary tumour predisposition. Thus, upfront genetic testing using large multigene panels or whole-genome sequencing in encouraged, especially in cases with a prominent family history.

Background: A complex inheritance has been suggested in families with colorectal-, gastric- and prostate cancer. Therefore, we conducted a genome-wide association study (GWAS) in colorectal cancer patients, who's relatives had prostate-, and/or gastric cancer.

Methods: The GWAS analysis consisted of 685 cases of colorectal cancer and 4780 healthy controls from Sweden. A sliding window haplotype analysis was conducted using a logistic regression model. Thereafter, we performed sequencing to find candidate variants, finally to be tested in a nested case-control study.

Results: Candidate loci/genes on ten chromosomal regions were suggested with odds ratios between 1.71-3.62 and p-values < 5 × 10-8 in the analysis. The regions suggested were 1q32.2, 3q29, 4q35.1, 4p15.31, 4q26, 8p23.1, 13q33.3, 13q13.3, 16q23.3 and 22q11.21. All regions, except one on 1q32.2, had protein coding genes, many already shown to be involved in cancer, such as ZDHHC19, SYNPO2, PCYT1A, MYO16, TXNRD2, COMT, and CDH13. Sequencing of DNA from 122 colorectal cancer patients with gastric- and/or prostate cancer in their families was performed to search for candidate variants in the haplotype regions. The identified candidate variants were tested in a nested case-control study of similar colorectal cancer cases and controls. There was some support for an increased risk of colorectal-, gastric-, and/or prostate cancer in all the six loci tested.

Conclusions: This study demonstrated a proof of principle strategy to identify risk variants found by GWAS, and identified ten candidate loci that could be associated with colorectal, gastric- and prostate cancer.

Genetic testing for breast cancer predisposing genes has expanded beyond BRCA1 and BRCA2 and now includes panels of 20 or more genes. It is now recommended that all women diagnosed with breast cancer at age 65 or below be offered testing for an extended gene panel. The rationale for testing includes personalizing the management of breast cancer according to the mutation found. For BRCA1 and BRCA2 carriers, the finding of a mutation has clear implications for cancer management, but for other genes, such as ATM, the management implications are less clear. Women with an ATM mutation have a lifetime risk of breast cancer of approximately 25%, the majority of which are ER-positive. The risk of ovarian cancer is approximately 5%. It is not yet clear how the identification of an ATM mutation in a patient newly diagnosed with breast cancer should impact on her treatment and follow-up. At present, these women are treated in the same way as women without a mutation. It is important that large prospective studies be conducted looking at various treatment modalities in women with breast cancer and an ATM mutation in order to optimize outcomes.

Background: Efficient and scalable solutions are needed to identify patients who qualify for germline cancer genetic testing. We evaluated the clinical validity of a brief, patient-administered hereditary cancer risk assessment digital tool programmed to assess if patients meet criteria for germline genetic testing, based on personal and family history, and in line with national guidelines.

Methods: We applied the tool to cases seen in a nationwide telehealth genetic counseling practice. Validity of the tool was evaluated by comparing the tool's assessment to that of the genetic counselor who saw the patient. Patients' histories were extracted from genetic counselor-collected pedigrees and input into the tool by the research team to model how a patient would complete the tool. We also validated the tool's assessment of which specific aspects of the personal and family history met criteria for genetic testing. Descriptive statistics were used.

Results: Of the 152 cases (80% female, mean age 52.3), 56% had a personal history of cancer and 66% met genetic testing criteria. The tool and genetic counselor agreed in 96% of cases. Most disagreements (4/6; 67%) occurred because the genetic counselor's assessment relied on details the tool was not programmed to collect since patients typically don't have access to the relevant information (pathology details, risk models). We also found complete agreement between the tool and research team on which specific aspects of the patient's history met criteria for genetic testing.

Conclusion: We observed a high level of agreement with genetic counselor assessments, affirming the tool's clinical validity in identifying individuals for hereditary cancer predisposition testing and its potential for increasing access to hereditary cancer risk assessment.