BRCA1/2 Mutations and Breast/Ovarian Cancer Risk: A New Insights Review

The function of circular RNAs in regulating Wnt/β-catenin signaling: An innovative therapeutic strategy for breast and gynecological cancers

Breast cancer (BC) and gynecological malignancies, including cervical, ovarian, and uterine cancers, are significant global health challenges due to their high prevalence, complex nature, and elevated mortality rates. Dysregulation of the Wnt/β-catenin signaling pathway is a common feature in gynecological malignancies, contributing to cancer cell growth, progression, migration, and metastasis. Recent studies have highlighted the pivotal role of non-coding RNAs (ncRNAs), particularly circular RNAs (circRNAs), in modulating the Wnt/β-catenin signaling pathway. Acting as sponges for microRNAs (miRNAs), circRNAs regulate key oncogenic and tumor-suppressive processes by influencing Wnt-related components. This research explores the role of circRNAs in breast and gynecological malignancies, focusing on their regulatory effects on the Wnt/β-catenin pathway. The findings reveal that circRNAs modulate critical cellular processes such as proliferation, apoptosis, autophagy, and metastasis, with potential implications for therapeutic interventions. Targeting circRNA-mediated dysregulation of Wnt signaling could offer novel strategies for improving diagnostic precision, treatment efficacy, and survival outcomes in breast and gynecological cancers.

Role of PARP Inhibitors: A New Hope for Breast Cancer Therapy

Tumors formed by the unchecked growth of breast cells are known as breast cancer. The second most frequent cancer in the world is breast cancer. It is the most common cancer among females. In 2022, 2,296,840 women were diagnosed with breast cancer. The therapy of breast cancer is evolving through the development of Poly (ADP-ribose) polymerase (PARP) inhibitors, which are offering people with specific genetic profiles new hope as research into the disease continues. It focuses on patients with BRCA1 and BRCA2 mutations. This review summarizes the most recent research on the mechanisms of action of PARP inhibitors and their implications for breast cancer therapy. We review how therapeutic applications are developing and highlight recent studies showing the effectiveness of these medicines whether used alone or in combination. Furthermore, the significance of customized therapy is highlighted in enhancing patient outcomes as we address the function of genetic testing in identifying candidates for PARP inhibition. Recommendations for future research areas to maximize the therapeutic potential of PARP inhibitors are also included, along with challenges and limits in their clinical usage. The objective of this review is to improve our comprehension of the complex interaction between breast cancer biology and PARP inhibition. This knowledge will help to guide screening approaches, improve clinical practice, and support preventive initiatives for people at risk.

Risk-benefits assessment of tamoxifen or raloxifene as chemoprevention for risk reduction of breast cancer among BRCA1 and BRCA2 carriers: a meta-analysis

BACKGROUND

Breast cancer is a major global health burden, with hereditary factors such as BRCA1/2 mutations significantly increasing the lifetime risk. This meta-analysis aimed to evaluate the outcomes of selective estrogen receptor modulators (SERMs), tamoxifen, and raloxifene as chemopreventive agents for breast cancer risk reduction in BRCA1/2 mutation carriers.

METHODS

A meta-analysis was conducted according to the PRISMA guidelines. PubMed, Cochrane Library, and MEDLINE databases were searched for relevant studies published between 2000 and 2024. Case-control studies and observational cohort studies examining the use of tamoxifen/raloxifene in BRCA1/2 carriers were included. Data on the incidence and risk ratios of breast cancer were also extracted. Quality was assessed using the Newcastle-Ottawa Scale (NOS). A random-effects meta-analysis was performed using Review Manager (version 5.4.0).

RESULTS

Nine studies (13,676 women) were included. Two studies had low risk, and the remaining seven studies had moderate risk, as assessed by the NOS checklist. Pooled analysis showed tamoxifen/raloxifene decreased breast cancer risk compared to controls (RR 0.80, 95% CI 0.72-0.88, p = 0.04). The risk ratio of breast cancer incidence among BRCA1/2 carriers was reduced after tamoxifen use (RR 1.82, 95% CI 1.48-2.23, p < 0.00001). Subgroup analysis revealed reduced breast cancer risk with SERM use in both BRCA1 (RR 1.51, 95% CI 1.48-1.51) and BRCA2 carriers (RR 1.48, 95% CI 1.40-1.58). The heterogeneity ranged from 51 to 85%, representing high significance and variation in true effect sizes underlying the different included studies. Whereas the heterogeneity among subgroups BRCA1 and BRCA2 was 98%, and the difference was 0%, showing no difference in response to SERM for risk reduction of breast cancer.

CONCLUSION

This meta-analysis provides evidence that tamoxifen and raloxifene significantly reduce the breast cancer risk in women with BRCA1/2 mutations. Chemoprevention efficacy was similar for both BRCA1 and BRCA2 carriers. Further research is needed to validate these findings and to optimize their use in high-risk populations.

Sequencing of high-frequency mutated genes in breast cancer (BRCA) and associated-functions analysis

OBJECTIVE

Mutations or aberrant expression of genes in an organism tend not to be completely random and this cumulative effect predisposes to the development of malignant tumours. This study aims to reveal the possible aberrant expression of high frequency mutated genes, and then to investigate their role in development, prognosis, signalling pathway function and drug resistance in breast cancer.

METHODS

The mutated genes in breast cancer (BRCA) clinical samples were identified and detected by high-throughput sequencing. High-frequency mutant genes were counted. Gene expression profiles and the relationship with prognosis were analysed throughout TCGA database. qRT-PCR was used to analyse the mRNA levels of the six high-frequency mutant genes in BRCA tissues and cell lines. IHC was used to analyse the protein levels of the six high-frequency mutant genes in BRCA tissues. The linear interaction, single-cell layer clustering status and the influence in immune cell infiltration degree among these six high-frequency mutant genes were analysed by bioinformatics analysis. The STITCH and cMAP datasets were used for high-frequency mutant gene interaction networks, association signalling pathway enrichment and drug-transcriptome analyses. The effects of trastuzumab on the proliferative capacity of breast cancer cells, as well as on the expression of six high-frequency mutated genes were determined by CCK8 assay.

RESULTS

The genes that were statistically found to have high-frequency mutations in the samples recruited in the present study by high-throughput sequencing analysis included TP53, PIK3CA, NF1, TBX3, BRCA1 and BRCA2. The expression profiles of these genes and the correlation with prognosis were further demonstrated using the TCGA database: the trend in this study was similar to that of BRCA in TCGA. The mRNA and protein expression of these genes showed that the expression of TP53, NF1, TBX3, BRCA1 and BRCA2 was higher in tumor samples than that in normal samples, with an opposite trend for PIK3CA, a similar trend was observed in BRCA cell lines. The protein expressions of TP53, NF1, TBX3, BRCA1 and BRCA2 displayed the same trend by IHC. Other correlation results include 1) the single cell layer clustering of these six genes resulted in significant clustering with few overlapping regions; 2) these six genes showed different degrees of influence on BRCA immune cell infiltration; 3) these six genes showed a significant correlation between each other; 4) the network of each gene had partially overlapping molecules; and 5) the PI3K pathway was a key association pathway in BRCA. Finally, the cell proliferation ability results confirmed the optimal concentration of trastuzumab and its effect on mRNA expression of these six genes.

Germline pathogenic variants among high hereditary risk patients with breast and ovarian cancer and unaffected subjects in Lebanese Arab women

BACKGROUND

The prevalence of germline pathogenic variants in high hereditary risk breast and/or ovarian cancer patients and unaffected subjects referred for testing is an unmet need in low and middle-income countries.

AIM

To determine the prevalence of germline pathogenic variants in high hereditary risk patients with breast and/or ovarian cancer and unaffected individuals.

METHODS

We retrospectively reviewed records of patients and unaffected subjects referred for germline pathogenic variant testing due to high hereditary risk between 2010-2020. Data was collected and analyzed on Excel sheet.

RESULTS

In total, 358 individuals were included, including 257 patients and 101 unaffected individuals with relatives with breast or ovarian cancer. The prevalence of breast cancer susceptibility gene (BRCA) 1/2 pathogenic variants was 8.63% (19/220) in patients with breast cancer, and 15.1% (5/33) in those with ovarian cancer. Among the 25 of 220 patients with breast cancer tested by next-generation sequencing, 3 patients had pathogenic variants other than BRCA1/2. The highest risk was observed in those aged 40 years with breast cancer and a positive family history, where the BRCA1/2 prevalence was 20.1% (9/43). Among the unaffected subjects, 31.1% (14/45) had the same BRCA1/2 pathogenic variants in their corresponding relatives. Among the subjects referred because of a positive family history of cancer without known hereditary factors, 5.35% (3/56) had pathogenic variants of BRCA1 and BRCA2. The c.131G>T nucleotide change was noted in one patient and two unrelated unaffected subjects with a BRCA1 pathogenic variant.

CONCLUSION

This study showed a 8.63% prevalence of pathogenic variants in patients with breast cancer and a 15.1% prevalence in patients with ovarian cancer. Among the relatives of patients with BRCA1/2 pathogenic variants, 31% tested positive for the same variant, while 5.3% of subjects who tested positive due to a family history of breast cancer had a BRCA pathogenic variant.