The association between non-breast and ovary cancers and BRCA mutation in first- and second-degree relatives of high-risk breast cancer patients: a large-scale study of Koreans

Possible link between familial susceptibility to cancer and the level of oxidative stress in thyroid cancer patients

BACKGROUND

Hereditary cancer is estimated to account for up to 10% of the worldwide cancer burden; 5% of all thyroid cancers are thought to be genetic. Inheritance of a deleterious mutation in genes associated with a high lifetime risk of developing cancer. Cancer-predisposing genes can promote the initiation and progression of thyroid cancer by enhancing the activation of major signaling pathways through oxidative stress mechanisms.

AIM

Identification of the possible link between familial susceptibility to cancer and the level of oxidative stress in thyroid cancer patients.

METHODS

Patients with thyroid cancer (with and without genetic predisposition) were investigated. Study participants were treated in Limited Liability Company (LLC) "Oncology Scientific Research Center" (Tbilisi, Georgia). The study group was collected between 2020 and 2021. In patients' blood, the thyroid hormones content (free Triiodothyronine (fFT3), free Thyroxine (fFT4), bound Triiodothyronine (FT3), bound Thyroxine (FT4), Thyroid-stimulating hormone (TSH)), and oxidative stress intensity (total activity of non-enzymatic antioxidant system (TAA) and the lipid peroxidation product, malondialdehyde (MDA), content) were investigated.

RESULTS

The difference in free and bound forms of T3 and T4 levels in the blood serum between patients with thyroid cancer (Group 2 and Group 3) and the control group (Group 1) was not statistically significant (F1,2=0.5, p1,2=0.8, F1,3=2.31, p1,3=0.16). In patients with thyroid cancer the TSH level significantly increased compared to the control group (Group 1) (TSH (mean ± Std error): Group 1- 1.21 ± 0.12, Group 2-2.45 ± 0.11 (F1,2=107, p1,2<0.001), Group 3-2.47 ± 0.17 (F1,3=150, p1,3<0.001)) and the MDA levels increased by 4-5 fold. In patients with thyroid cancer from families with cancer aggregation(Group 2), the level of TAA statistically significantly decreased (F1 - 2=200; p1 - 2<0.001), in patients without genetic predisposition to cancer(Group 3), the level of TAA did not change compared to the control (F1 - 3= 2.13; p1 - 3=0.15), CONCLUSIONS: Oxidative stress plays a critical role in tumorigenesis, and antioxidant/oxidant imbalance may contribute to the malignant transformation of normal tissue. In patients with familial susceptibility to cancer mutations of several genes, which are involved in the regulation of oxidative metabolism, may contribute to the disruption of the redox balance, increase the level of oxidative stress, and contribute to the development of thyroid cancer.

Cancer risks among first-degree relatives of women with a genetic predisposition to breast cancer

BACKGROUND

Associations between germline alterations in women and cancer risks among their relatives are largely unknown.

METHODS

We identified women from 2 Swedish cohorts Karolinska Mammography Project for Risk Prediction of Breast Cancer (KARMA) and prevalent KARMA (pKARMA), including 28 362 women with genotyping data and 13 226 with sequencing data. Using Swedish Multi-Generation Register, we linked these women to 133 389 first-degree relatives. Associations between protein-truncating variants in 8 risk genes and breast cancer polygenic risk score in index women and cancer risks among their relatives were modeled via Cox regression.

RESULTS

Female relatives of index women who were protein-truncating variant carriers in any of the 8 risk genes had an increased breast cancer risk compared with those of noncarriers (hazard ratio [HR] = 1.85, 95% confidence interval [CI] = 1.52 to 2.27), with the strongest association found for protein-truncating variants in BRCA1 and 2. These relatives had a statistically higher risk of early onset than late-onset breast cancer (P = .001). Elevated breast cancer risk was also observed in female relatives of index women with higher polygenic risk score (HR per SD = 1.28, 95% CI = 1.23 to 1.32). The estimated lifetime risk was 22.3% for female relatives of protein-truncating variant carriers and 14.4% for those related to women in the top polygenic risk score quartile. Moreover, relatives of index women with protein-truncating variant presence (HR = 1.30, 95% CI = 1.06 to 1.59) or higher polygenic risk score (HR per SD = 1.04, 95% CI = 1.01 to 1.07) were also at higher risk of nonbreast hereditary breast and ovary cancer syndrome-related cancers.

CONCLUSIONS

Protein-truncating variants of risk genes and higher polygenic risk score in index women are associated with an increased risk of breast and other hereditary breast and ovary syndrome-related cancers among relatives.

Penetrance of Gastric Adenocarcinoma Susceptibility Genes: A Systematic Review

BACKGROUND

Gastric adenocarcinoma (GAC) is the fifth most common cancer in the world, and the presence of germline pathogenic variants has been linked with approximately 5% of gastric cancer diagnoses. Multiple GAC susceptibility genes have been identified, but information regarding the risk associated with pathogenic variants in these genes remains obscure. We conducted a systematic review of existing studies reporting the penetrance of GAC susceptibility genes.

METHODS

A structured search query was devised to identify GAC-related papers indexed in MEDLINE/PubMed. A semi-automated natural language processing algorithm was applied to identify penetrance papers for inclusion. Original studies reporting the penetrance of GAC were included and the full-text articles were independently reviewed. Summary statistics, effect estimates, and precision parameters from these studies were compiled into a table using a predetermined format to ensure consistency.

RESULTS

Forty-five studies were identified reporting the penetrance of GAC among patients harboring mutations in 13 different genes: APC, ATM, BRCA1, BRCA2, CDH1, CHEK2, MLH1, MSH2, MSH6, PMS2, MUTYH-Monoallelic, NBN, and STK11.

CONCLUSION

Our systematic review highlights the importance of testing for germline pathogenic variants in patients before the development of GAC. Management of patients who harbor a pathogenic mutation is multifactorial, and clinicians should consider cancer risk for each applicable gene-cancer association throughout the screening and management process. The scarcity of studies we found investigating the risk of GAC among patients with pathogenic variants in GAC susceptibility genes highlights the need for more investigations that focus on producing robust risk estimates for gene-cancer associations.

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.

Gastric Cancer Risk and Pathogenesis in BRCA1 and BRCA2 Carriers

Carriers of a pathogenic germline variant (PV) in BRCA1 or BRCA2 are at increased risk for a number of malignancies, including breast, ovarian, pancreatic, and prostate cancer. In this review, we discuss emerging evidence that BRCA2 PV carriers, and likely also BRCA1 PV carriers, are also at increased risk for gastric cancer (GC), highlighting that GC may be part of the BRCA1/2 cancer risk spectrum. While the pathogenesis of GC among BRCA1/2 PV carriers remains unclear, increasing evidence reveals that GCs are often enriched with mutations in homologous recombination-associated genes such as BRCA1/2, and that GC prognosis and response to certain therapies can depend on BRCA1/2 expression. Given the strength of data published to date, a risk management strategy for GC among BRCA1/2 PV carriers is needed, and herein we also propose a potential strategy for GC risk management in this population. Moving forward, further study is clearly warranted to define the mechanistic relationship between BRCA1/2 PVs and development of GC as well as to determine how GC risk management should be factored into the clinical care of BRCA1/2 carriers.

Surveillance Outcomes in Patients With a Family History of Colorectal Cancer in Both Parents

Background and Aims

A family history of colorectal cancer (CRC) in a first-degree relative is a well-established risk factor for CRC. When individuals have 2 parents with CRC, the impact on risk is uncertain, and there are no established guidelines for surveillance. We sought to define the surveillance practices and outcomes in individuals with a family history of CRC in both parents.

Methods

We identified probands with a family history of CRC in both parents from our Hereditary Gastrointestinal Cancer Database. Charts were retrospectively reviewed for colonoscopy surveillance patterns and incidence of adenomas and CRC.

Results

Sixty-six patients met the inclusion criteria. Forty-two patients (64%) had genetic testing, and no pathogenic germline mutations were identified. During a mean surveillance period of 144 ± 82.2 months and a mean surveillance interval of 33.4 ± 16.6 months, a total of 3.2 ± 8.9 adenomas were found per patient. These were small (median 6.5 mm), and 96% exhibited only low-grade dysplasia. Six patients (9%) were diagnosed with CRC at a mean age of 61.5 ± 11.3 years, corresponding to an incidence rate of 14 cases/10,000 person-years. Patients with CRC were older at first colonoscopy than those without cancer (59 vs 46 years, P = .03), and half of these cases were diagnosed at this first colonoscopy.

Conclusion

Among patients with a family history of CRC in both parents, cases of CRC were seen primarily in those who significantly delayed their first colonoscopy. Initiation of colonoscopy at age 40 should be recommended to individuals with CRC in both parents, consistent with recommendations for those with 1 first-degree relative with CRC.

Homologous Recombination Deficiency in Ovarian, Breast, Colorectal, Pancreatic, Non-Small Cell Lung and Prostate Cancers, and the Mechanisms of Resistance to PARP Inhibitors

Homologous recombination (HR) is a highly conserved DNA repair mechanism that protects cells from exogenous and endogenous DNA damage. Breast cancer 1 (BRCA1) and breast cancer 2 (BRCA2) play an important role in the HR repair pathway by interacting with other DNA repair proteins such as Fanconi anemia (FA) proteins, ATM, RAD51, PALB2, MRE11A, RAD50, and NBN. These pathways are frequently aberrant in cancer, leading to the accumulation of DNA damage and genomic instability known as homologous recombination deficiency (HRD). HRD can be caused by chromosomal and subchromosomal aberrations, as well as by epigenetic inactivation of tumor suppressor gene promoters. Deficiency in one or more HR genes increases the risk of many malignancies. Another conserved mechanism involved in the repair of DNA single-strand breaks (SSBs) is base excision repair, in which poly (ADP-ribose) polymerase (PARP) enzymes play an important role. PARP inhibitors (PARPIs) convert SSBs to more cytotoxic double-strand breaks, which are repaired in HR-proficient cells, but remain unrepaired in HRD. The blockade of both HR and base excision repair pathways is the basis of PARPI therapy. The use of PARPIs can be expanded to sporadic cancers displaying the “BRCAness” phenotype. Although PARPIs are effective in many cancers, their efficacy is limited by the development of resistance. In this review, we summarize the prevalence of HRD due to mutation, loss of heterozygosity, and promoter hypermethylation of 35 DNA repair genes in ovarian, breast, colorectal, pancreatic, non-small cell lung cancer, and prostate cancer. The underlying mechanisms and strategies to overcome PARPI resistance are also discussed.

BRCA mutations and gastrointestinal cancers: When to expect the unexpected?

BRCA1/2 pathogenic variants are widely known as major risk factors mainly for breast and ovarian cancer, while their role in gastrointestinal (GI) malignancies such as colorectal cancer (CRC), gastric cancer and oesophageal cancer (OeC) is still not well established. The main objective of this review is to summarise the available evidence on this matter. The studies included in the review were selected from PubMed/GoogleScholar/ScienceDirect databases to identify published articles where BRCA1/2 pathogenic variants were assessed either as a risk factor or a prognostic/predictive factor in these malignancies. Our review suggests that BRCA1/2 might have a role as a risk factor for colorectal, gastric and OeC, albeit with differences among these diseases: In particular BRCA1 seems to be much more frequently mutated in CRC whereas BRCA2 appears to be much more closely associated with gastric and OeC. Early-onset cancer seems to be also associated with BRCA1/2 mutations and a few studies suggest a positive prognostic role of these mutations. The assessment of a potentially predictive role of these mutations is hampered by the fact that most patients with these diseases have been treated with platinum compounds, where it is expected that a higher probability of response should be seen. A few clinical trials focused on poly (ADP-ribose) polymerase inhibitors use in GI cancers are currently ongoing.

A multidisciplinary approach remains the best strategy to improve and strengthen the management of ovarian cancer (Review)

Ovarian cancer represents one of the most aggressive female tumors worldwide. Over the decades, the therapeutic options for the treatment of ovarian cancer have been improved significantly through the advancement of surgical techniques as well as the availability of novel effective drugs able to extend the life expectancy of patients. However, due to its clinical, biological and molecular complexity, ovarian cancer is still considered one of the most difficult tumors to manage. In this context, several studies have highlighted how a multidisciplinary approach to this pathology improves the prognosis and survival of patients with ovarian cancer. On these bases, the aim of the present review is to present recent advantages in the diagnosis, staging and treatment of ovarian cancer highlighting the benefits of a patient‑centered care approach and on the importance of a multidisciplinary team for the management of ovarian cancer.

Gastric Cancer in BRCA1 Germline Mutation Carriers: Results of Endoscopic Screening and Molecular Analysis of Tumor Tissues

INTRODUCTION

There is some evidence suggesting a link between BRCA1/2 germline mutations and increased risk of gastric cancer.

METHODS

Endoscopic screening for stomach malignancies was performed in 120 BRCA1 mutation carriers in order to evaluate the probability of detecting the tumor disease.

RESULTS

No instances of gastric cancer were revealed at the first visit. The analysis of atrophic changes performed by OLGA (Operative Link for Gastritis Assessment) criteria revealed that OLGA stages I-IV alterations were observed in 26 of 41 (63%) subjects aged >50 years as compared to 29 of 79 (37%) in younger subjects (p = 0.007, χ2 test). One BRCA1 mutation carrier developed gastric cancer 4 years after the first visit for endoscopic examination. We performed next-generation sequencing analysis for this tumor and additional 4 archival gastric cancers obtained from BRCA1/2 mutation carriers. Somatic loss of the remaining BRCA1/2 allele was observed in 3 out of 5 tumors analyzed; all of these carcinomas, but none of the malignancies with the retained BRCA1/2 copy, showed chromosomal instability.

CONCLUSION

Taken together, these data justify further studies on the relationships between the BRCA1/2 and gastric cancer.

Are pathogenic BRCA1 mutations associated with parotid mucoepidermoid carcinoma? A case report

OBJECTIVES

To describe a patient with BRCA1 mutation, mucoepidermoid parotid, multiple breasts, and thyroid cancers.

CASE REPORT

A women was diagnosed at 33-years-age with a triple-negative breast cancer (right breast), at 43-years-age with a triple-negative breast cancer in left breast and at 53-years-age with a primary papillary-thyroid carcinoma. At 55-years-age, she was diagnosed with a primary mucoepidermoid carcinoma in right parotid, and concomitantly, her right nipple was affected by Paget's disease and a recurrent carcinoma in right breast (HR + /HER2 = 3 +). At 57-years-age, after the recurrence of a triple-negative breast cancer (left breast), a geneticist evaluated the patient's family history, including one stomach, one non-smoking-related lung, and two smoking-related laryngeal cancers. Genetic testing revealed a BRCA1 mutation (Chr17:41:251.867). The patient's daughter (a non-cancer patient) tested negative for the mutation. Both remain under medical supervision.

CONCLUSIONS

We suggest that BRCA1 mutations are associated with non-breast and non-ovarian cancers such as salivary gland cancer.

Cancer Surveillance in Healthy Carriers of Germline Pathogenic Variants in BRCA1/2: A Review of Secondary Prevention Guidelines

Germline pathogenic alterations in the breast cancer susceptibility genes 1 (BRCA1) and 2 (BRCA2) are the most prevalent causes of hereditary breast and ovarian cancer. The increasing trend in proportion of cancer patients undergoing genetic testing, followed by predictive testing in families of new index patients, results in a significant increase of healthy germline BRCA1/2 mutation carriers who are at increased risk for breast, ovarian, and other BRCA-related cancers. This review aims to give an overview of available screening guidelines for female and male carriers of pathogenic or likely pathogenic germline BRCA1/2 variants per cancer type, incorporating malignancies that are more or less recently well correlated with BRCA1/2. We selected guidelines from national/international organizations and/or professional associations that were published or updated between January 1, 2015, and February 1, 2020. In total, 12 guidelines were included. This review reveals several significant discordances between the different guidelines. Optimal surveillance strategies depend on accurate age-specific cancer risk estimates, which are not reliably available for all BRCA-related cancers. Up-to-date national or international consensus guidelines are of utmost importance to harmonize counseling and proposed surveillance strategies for BRCA1/2 carriers.

BRCA1 and BRCA2 Gene Mutations and Lung Cancer Sisk: A Meta-Analysis

Background and objective: BRCA1 and BRCA2 are associated with many cancer types in addition to hereditary breast and ovarian cancers. However, their relation to lung cancer remains to be explored. Materials and Methods: Observation studies were systematically reviewed to explore the association of BRCA1 or BRCA2 with lung cancer. PubMed, MEDLINE [EBSCOhost], and relevant articles published up to 7 January 2020 were searched. Odd ratio (OR), standardized morbidity rate (SMR), and cancer-specific standardized incidence ratios (SIRs) were pooled together as relative risk (RR) estimates (95% confidence interval [CI], 0.66-1.40). Results: Thirteen studies were included for analysis. Results showed that the RR of BRCA2 is 0.76 (95% CI, 0.48-1.19), the overall RR is 0.96 (95% CI, 0.66-1.40), and that of BRCA1 is 0.66 (95% CI, 0.41-1.05), indicating that it was not associated with lung cancer. Conclusion: With the limitation of the retrospective study design and severe heterogeneity, these results inform clinicians and relevant families that BRCA1 and BRCA2 mutation carriers have no increased risk of lung cancer.