An overview of the research progress of BRCA gene mutations in breast cancer

Advancements in targeting tumor suppressor genes (p53 and BRCA 1/2) in breast cancer therapy

Globally, among numerous cancer subtypes, breast cancer (BC) is one of the most prevalent forms of cancer affecting the female population. A female's family history significantly increases her risk of developing breast cancer. BC is caused by aberrant breast cells that proliferate and develop into tumors. It is estimated that 5-10% of breast carcinomas are inherited and involve genetic mutations that ensure the survival and prognosis of breast cancer cells. The most common genetic variations are responsible for hereditary breast cancer but are not limited to p53, BRCA1, and BRCA2. BRCA1 and BRCA2 are involved in genomic recombination, cell cycle monitoring, programmed cell death, and transcriptional regulation. When BRCA1 and 2 genetic variations are present in breast carcinoma, p53 irregularities become more prevalent. Both BRCA1/2 and p53 genes are involved in cell cycle monitoring. The present article discusses the current status of breast cancer research, spotlighting the tumor suppressor genes (BRCA1/2 and p53) along with structural activity relationship studies, FDA-approved drugs, and several therapy modalities for treating BC. Breast cancer drugs, accessible today in the market, have different side effects including anemia, pneumonitis, nausea, lethargy, and vomiting. Thus, the development of novel p53 and BRCA1/2 inhibitors with minimal possible side effects is crucial. We have covered compounds that have been examined subsequently (2020 onwards) in this overview which may be utilized as lead compounds. Further, we have covered mechanistic pathways to showcase the critical druggable targets and clinical and post-clinical drugs targeting them for their utility in BC.

Role of the Wnt signaling pathway in the complex microenvironment of breast cancer and prospects for therapeutic potential (Review)

The focus on breast cancer treatment has shifted from the cytotoxic effects of single drugs on tumor cells to multidimensional multi‑pathway synergistic intervention strategies targeting the tumor microenvironment (TME). The activation of the Wnt signaling pathway in the TME of breast cancer cells serves a key regulatory role in tissue homeostasis and is a key driver of the carcinogenic process. Modulating the crosstalk between the Wnt pathway and TME of breast cancer is key for understanding the biological behavior of breast cancer and advancing the development of novel antitumor drugs. The present review aimed to summarize the complex mechanisms of the Wnt signaling pathway in the breast cancer TME, interactions between the Wnt signaling pathway and components of the breast cancer TME and breast cancer‑associated genes, as well as the interactions between the Wnt signaling pathway and other signaling cascades at the molecular level. Furthermore, the present review aimed to highlight the unique advantages of the Wnt signaling pathway in the macro‑regulation of the TME and the current therapeutic strategies targeting the Wnt signaling pathway, their potential clinical value and future research directions in breast cancer treatment.

Prevalence of BRCA1 and BRCA2 mutations in ovarian cancer patients from Yunnan Province in southwest China

Carriers with germline breast cancer 1/2 gene mutations ( BRCA m) are likely to develop ovarian cancer (OC). Therefore, identifying these mutations may enable individualized therapy for OC and preventive measures to reduce OC risk in BRCA m carrier families. Thus, we investigated the prevalence of BRCA m in OC patients from Yunnan Province in Southwest China. In total, 674 unselected OC patients were enrolled and tested for BRCA m via next-generation sequencing. Data on clinicopathological characteristics and personal/family history of cancer were collected. The prevalence rates of pathogenic/likely pathogenic BRCA m were 26.6% overall, 20.8% among BRCA1 m carriers, 5.5% among BRCA2 m carriers, and 0.3% among carriers of both BRCA1 m and BRCA2 m. The most common pathogenic mutation in the BRCA1 gene was c.5114T>C ( n  = 9). The number of BRCA m carriers was significantly greater among patients with serous cancer, a personal tumor history, a family history of hereditary breast and ovarian cancer (HBOC)-related tumors, and bilateral tumors. The most common pathogenic mutation in this cohort was c.5114T>C ( n  = 9) in BRCA1 . The prevalence and spectrum of BRCA m in OC patients from Yunnan Province are different from those in other groups. BRCA status testing is advised for all OC patients, particularly those with a family history of HBOC.

BRCA1/2 mutations and outcomes among Middle Eastern patients with early-onset breast cancer in Oman

BACKGROUND

High prevalence of early-onset breast cancer (EOBC) has been reported in Middle Eastern populations. For example, in Oman more than 50% of patients with breast cancer (BC) are under age 45 at diagnosis. Causes for this high incidence are unknown. Germline BRCA gene mutations have been associated with EOBC, however, prevalence of these mutations and how they relate to EOBC in Oman has not been assessed.

PATIENTS AND METHODS

Clinical data were collected for patients with BC treated at Royal Hospital, Oman between 2010 and 2022. Germline BRCA1/2 gene mutations were identified using sequencing and MLPA. Correlation and Kaplan-Meier survival analyses were performed to test relationships among clinico-pathological features, gene mutations, and outcomes.

RESULTS

Total of 1336 Middle Eastern patients with BC were included; 611 were aged <45 at diagnosis (45.7%). No significant correlation was found between BRCA1/2 mutation status and EOBC (P = .229), and the majority of EOBC cases had no family history of BC. EOBC tumors did, however, differ in clinicopathological features; EOBCs were significantly larger (P < .0001), of higher grade (P < .0001), and included more HER2-enriched, and triple negative subtypes (P = .018) compared with later onset cases. Accordingly, survival analyses revealed that EOBC had significantly worse disease-free survival (P = .002). BRCA gene variants showed a distinct range of mutations including, in BRCA2, 3 previously unreported mutations and 4 potential founder recurrent mutations.

CONCLUSION

Our findings showed that germline BRCA1/2 mutations were not over-represented in EOBC cases in Oman, and therefore are unlikely to be responsible for high EOBC rates.

Differential methylation of circulating free DNA assessed through cfMeDiP as a new tool for breast cancer diagnosis and detection of BRCA1/2 mutation

BACKGROUND

Recent studies have highlighted the importance of the cell-free DNA (cfDNA) methylation profile in detecting breast cancer (BC) and its different subtypes. We investigated whether plasma cfDNA methylation, using cell-free Methylated DNA Immunoprecipitation and High-Throughput Sequencing (cfMeDIP-seq), may be informative in characterizing breast cancer in patients with BRCA1/2 germline mutations for early cancer detection and response to therapy.

METHODS

We enrolled 23 BC patients with germline mutation of BRCA1 and BRCA2 genes, 19 healthy controls without BRCA1/2 mutation, and two healthy individuals who carried BRCA1/2 mutations. Blood samples were collected for all study subjects at the diagnosis, and plasma was isolated by centrifugation. Cell-free DNA was extracted from 1 mL of plasma, and cfMeDIP-seq was performed for each sample. Shallow whole genome sequencing was performed on the immuno-precipitated samples. Then, the differentially methylated 300-bp regions (DMRs) between 25 BRCA germline mutation carriers and 19 non-carriers were identified. DMRs were compared with tumor-specific regions from public datasets to perform an unbiased analysis. Finally, two statistical classifiers were trained based on the GLMnet and random forest model to evaluate if the identified DMRs could discriminate BRCA-positive from healthy samples.

RESULTS

We identified 7,095 hypermethylated and 212 hypomethylated regions in 25 BRCA germline mutation carriers compared to 19 controls. These regions discriminate tumors from healthy samples with high accuracy and sensitivity. We show that the circulating tumor DNA of BRCA1/2 mutant breast cancers is characterized by the hypomethylation of genes involved in DNA repair and cell cycle. We uncovered the TFs associated with these DRMs and identified that proteins of the Erythroblast Transformation Specific (ETS) family are particularly active in the hypermethylated regions. Finally, we assessed that these regions could discriminate between BRCA positives from healthy samples with an AUC of 0.95, a sensitivity of 88%, and a specificity of 94.74%.

CONCLUSIONS

Our study emphasizes the importance of tumor cell-derived DNA methylation in BC, reporting a different methylation profile between patients carrying mutations in BRCA1, BRCA2, and wild-type controls. Our minimally invasive approach could allow early cancer diagnosis, assessment of minimal residual disease, and monitoring of response to therapy.

Cost-effectiveness of talazoparib for patients with germline BRCA1/2 mutated HER2-negative advanced breast cancer in China and the US

Breast cancer is one of the tumors with the highest prevalence rate among women in the world, and its BRCA1/2 gene is a common mutation site. Talazoparib, as a targeted PARP inhibitor, can effectively control the occurrence and development of breast cancer with BRCA1/2 gene mutation, and play a therapeutic role. Based on the findings from the Phase III EMBRACE trial (NCT01945775 clinical trial), our analysis reveals that the talazoparib group demonstrated a significant extension in progression-free survival, along with improved response markers and patient-reported outcomes when compared to conventional therapies. This study aims to assess the cost-effectiveness of talazoparib for treating advanced breast cancer with germline BRCA1/2 mutations and HER2 negativity, considering the perspectives of health services in China and the United States. The results obtained will serve as a valuable reference for promoting rational drug utilization and enhancing medical resource efficiency. To evaluate the cost-effectiveness of Talazoparib more scientifically and provide clinicians with chemotherapy options, this paper developed a Markov model based on the EMBRACA clinical trial (clinical Trails.gov No., NCT01945775) to simulate the survival events of breast cancer patients in the Talazoparib group and the standard treatment group. The state transition probability and clinical data of breast cancer patients during treatment were extracted from the phase III EMBRACA clinical trial. The cost data generated during the treatment process comes from local hospital pricing, other references, and expert consultation. This article uses US dollars to calculate the treatment cost and incremental cost-effectiveness ratio. Health outcomes are expressed in Quality Adjusted Life Years (QALYs). In addition, Outcomes were measured in quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratio, which robustness was evaluated by deterministic and probabilistic sensitivity analyses. This article establishes a Markov model for single-item sensitivity analysis. The results show that the economic benefits of using Talazoparib as a new treatment strategy in both China and the United States are higher than other drugs, and it is cost-effective. Compared to the control group, the incremental cost incurred by the Talazoparib treatment group in China was $2484.48/QALY, with an incremental QALY of 1.5. However, Talazoparib in the United States holds a dominant position, saving costs of $10,223.43 and increasing QALYs by 1.5. The clinical treatment effect of Talazoparib group in BRCA1/2 mutant advanced breast cancer patients is better than that of the standard treatment group, and the progression free survival period is significantly prolonged. From the perspective of medical and health services in China and the United States, the Talazoparib group is more economical than the standard treatment group in treating patients with BRCA1/2 mutant advanced breast cancer.

Omission of adjuvant radiotherapy in low-risk elderly males with breast cancer

PURPOSE

Randomized clinical trials demonstrate that lumpectomy + hormone therapy (HT) without radiation therapy (RT) yields equivalent survival and acceptable local-regional outcomes in elderly women with early-stage, node-negative, hormone-receptor positive (HR +) breast cancer. Whether these data apply to men with the same inclusion criteria remains unknown.

METHODS

The National Cancer Database was queried for male patients ≥ 65 years with pathologic T1-2N0 (≤ 3 cm) HR + breast cancer treated with breast-conserving surgery with negative margins from 2004 to 2019. Adjuvant treatment was classified as HT alone, RT alone, or HT + RT. Male patients were matched with female patients for OS comparison. Survival analysis was performed using Cox regression and Kaplan - Meier method. Inverse probability of treatment weighting (IPTW) was applied to adjust for confounding.

RESULTS

A total of 523 patients met the inclusion criteria, with 24.4% receiving HT, 16.3% receiving RT, and 59.2% receiving HT + RT. The median follow-up was 6.9 years (IQR: 5.0-9.4 years). IPTW-adjusted 5-yr OS rates in the HT, RT, and HT + RT cohorts were 84.0% (95% CI 77.1-91.5%), 81.1% (95% CI 71.1-92.5%), and 93.0% (95% CI 90.0-96.2%), respectively. On IPTW-adjusted MVA, relative to HT, receipt of HT + RT was associated with improvements in OS (HR: 0.641; p = 0.042). RT alone was not associated with improved OS (HR: 1.264; p = 0.420).

CONCLUSION

Among men ≥ 65 years old with T1-2N0 HR + breast cancer, RT alone did not confer an OS benefit over HT alone. Combination of RT + HT demonstrated significant improvements in OS. De-escalation of treatment through omission of either RT or HT at this point should be done with caution.

Green synthesis of chitosan/silver nanocomposite using kaempferol for triple negative breast cancer therapy and antibacterial activity

The synthesis of polymer-encapsulated metal nanoparticles is a growing field of area due to their long-term uses in the development of new technologies. The present study describes the synthesis of chitosan/silver nanocomposite using kaempferol for anticancer and bactericidal activity. The formation of Kf-CS/Ag nanocomposite was confirmed by the development of a brown color and UV-absorbance around 438 nm. The IR study was utilized to determine the existence of Kf and CS in the synthesized nanocomposite. TEM analysis demonstrated that the synthesized nanocomposite have a predominantly uniform spherical shape and size ranges 7-10 nm. EDX spectrum showed the existence of Ag, C, and N elements in the nanocomposite material. Further, Kf-CS/Ag nanocomposite exhibited potential in vitro inhibitory property against triple-negative breast cancer (TNBC) cells and their IC50 values was found to be 53 μg/mL. Moreover, fluorescent assays such as DAPI and AO/EtBr confirmed the apoptosis induction ability of Kf-CS/Ag nanocomposite in MDA-MB-231 cells. The synthesized Kf-CS/Ag nanocomposite showed significant and dose-depended antibacterial property against S. aureus and P. aeruginosa. Thus, the obtained findings demonstrated that the synthesized nanocomposite can be potentially used to improve human health as biocidal nanocomposite in biomedical sectors.

Advances in Early Breast Cancer Risk Profiling: From Histopathology to Molecular Technologies

Early breast cancer (BC) is the definition applied to breast-confined tumors with or without limited involvement of locoregional lymph nodes. While risk stratification is essential for guiding clinical decisions, it can be a complex endeavor in these patients due to the absence of comprehensive guidelines. Histopathological analysis and biomarker assessment play a pivotal role in defining patient outcomes. Traditional histological criteria such as tumor size, lymph node involvement, histological type and grade, lymphovascular invasion, and immune cell infiltration are significant prognostic indicators. In addition to the hormone receptor, HER2, and-in specific scenarios-BRCA1/2 testing, molecular subtyping through gene expression profiling provides valuable insights to tailor clinical decision-making. The emergence of "omics" technologies, applicable to both tissue and liquid biopsy samples, has broadened our arsenal for evaluating the risk of early BC. However, a pressing need remains for standardized methodologies and integrated pathological models that encompass multiple analytical dimensions. In this study, we provide a detailed examination of the existing strategies for early BC risk stratification, intending to serve as a practical guide for histopathologists and molecular pathologists.