The association between XRCC3 rs1799794 polymorphism and cancer risk: a meta-analysis of 34 case-control studies

Genomic instability in ovarian cancer: Through the lens of single nucleotide polymorphisms

Ovarian cancer (OC) is the deadliest gynecological malignancy among all female reproductive cancers. It is characterized by high mortality rate and poor prognosis. Genomic instability caused by mutations, single nucleotide polymorphisms (SNPs), copy number variations (CNVs), microsatellite instability (MSI), and chromosomal instability (CIN) are associated with OC predisposition. SNPs, which are highly prevalent in the general population, show a greater relative risk contribution, particularly in sporadic cancers. Understanding OC etiology in terms of genetic basis can increase the use of molecular diagnostics and provide promising approaches for designing novel treatment modalities. This will help deliver personalized medicine to OC patients, which may soon be within reach. Given the pivotal impact of SNPs in cancers, the primary emphasis of this review is to shed light on their prevalence in key caretaker genes that closely monitor genomic integrity, viz., DNA damage response, repair, cell cycle checkpoints, telomerase maintenance, and apoptosis and their clinical implications in OC. We highlight the current challenges faced in different SNP-based studies. Various computational methods and bioinformatic tools employed to predict the functional impact of SNPs have also been comprehensively reviewed concerning OC research. Overall, this review identifies that variants in the DDR and HRR pathways are the most studied, implying their critical role in the disease. Conversely, variants in other pathways, such as NHEJ, MMR, cell cycle, apoptosis, telomere maintenance, and PARP genes, have been explored the least.

Potential Single Nucleotide Polymorphisms markers for radiation dermatitis in head and neck cancer patients: a meta-analysis

PURPOSE

To identify potential Single Nucleotide Polymorphisms (SNPs) of susceptibility for the development of acute radiation dermatitis in head and neck cancer patients, and also to verify the association between SNPs and the severity of RD.

METHODS

This systematic review was reported according to the PRISMA guideline. The proportion meta-analysis was performed to identify the prevalence of genetic markers by geographical region and radiation dermatitis severity. The meta-analysis was performed to verify the association between genetic markers and RD severity. The certainty of the evidence was assessed by GRADE.

RESULTS

Thirteen studies were included. The most prevalent SNPs were XRCC3 (rs861639) (36%), TGFβ1 (rs1800469) (35%), and RAD51 (rs1801321) (34%). There are prevalence studies in Europe and Asia, with a similar prevalence for all SNPs (29-40%). The prevalence was higher in patients who developed radiation dermatitis ≤2 for any subtype of genes (75-76%). No SNP showed a statistically significant association with very low certainty of evidence.

CONCLUSION

The most prevalent SNPs may be predictors of acute RD. The analysis of SNP before starting radiation therapy may be a promising method to predict the risk of developing radiation dermatitis and allow radiosensitive patients to have a customized treatment. This current review provides new research directions.

Association of FSHR gene polymorphisms with poor ovarian response in patients undergoing IVF: A systematic review and meta-analysis

BACKGROUND

The results of studies on the association between polymorphisms in the FSHR gene and the risk of POR undergoing IVF have been inconsistent with each other, so we conducted a meta-analysis of all the available studies to explore the association between polymorphisms in the FSHR gene and the risk of POR.

METHODS

Literature that met the inclusion criteria was collected by searching six electronic databases and basic data from included studies were extracted. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to assess the strength of association between follicle-stimulating hormone receptor (FSHR) gene polymorphism and poor ovarian response (POR) risk. Begg's and Egger's tests were used to determine whether there was publication bias, and sensitivity analysis and TSA analysis were used to verify the stability and reliability of the results.

RESULTS

We included 24 articles, 22 of which explored rs6166, including 2,206 cases and 3,897 controls. 6 articles explored rs6165, including 444 cases and 875 controls. Under additive, heterozygote, and dominant models, rs6166 was significantly associated with POR (S vs. N: OR = 1.29, 95 % CI = 1.05-1.59, P = 0.017; NS vs. NN: OR = 1.33, 95 % CI = 1.02-1.74, P = 0.038; NS + SS vs. NN: OR = 1.38, 95 % CI = 1.04-1.84, P = 0.025). In ethnicity-based subgroup analyses, the additive, homozygote, heterozygote, and dominant models increased Asian POR risk. Among the five genetic models, rs6165 was significantly associated with POR (T vs. C: OR = 1.64, 95 % CI = 1.25-2.16, P = 0.000; TT vs. CC: OR = 2.76, 95 % CI = 1.43-5.32, P = 0.003; CT vs. CC: OR = 1.58, 95 % CI = 1.19-2.10, P = 0.001; TT vs. CC + CT: OR = 2.32, 95 % CI = 1.67-3.23, P = 0.000; CT + TT vs. CC: OR = 1.80, 95 % CI = 1.22-2.65, P = 0.003). In ethnicity-based subgroup analyses, all five genetic models increased the risk of POR in Caucasians.

CONCLUSION

According to the current meta-analysis, the rs6166 S allele was significantly associated with an increased risk of POR, especially in Asian populations. The rs6165 T allele was significantly associated with an increased risk of POR, especially in Caucasian populations.

Molecular Epidemiology in Amerindians of the Brazilian Amazon Reveals New Genetic Variants in DNA Repair Genes

Native American populations from the Brazilian Amazon have a low genetic diversity and a different genetic profile when compared to people from other continents. Despite this, few studies have been conducted in this group, and there is no description of their genetic data in the various currently existent international databases. The characterization of the genomic profile of a population not only has an impact in studies of population genetics, but also helps to advance diagnostic and therapeutic response studies, leading to the optimization of clinical applicability. Genetic variations in DNA repair genes have been associated with the modulation of susceptibility to various pathologies, as well as in their prognosis and therapy. This is the first study to investigate DNA repair genes in Amerindians from the Brazilian Amazon region. We investigated 13 important DNA repair genes in the exome of 63 Native Americans, comparing our results with those found in 5 continental populations, whose data are available in the Genome Aggregation Database. Our results showed that 57 variants already described in literature were differentially distributed in the Amerindian populations in relation to the continental populations, 7 of which have significant clinical relevance. In addition, 9 new variants were described, suggesting that they are unique to these populations. Our study reinforces the understanding that the Amazonian Native American population presents a unique genetic profile, and our findings may collaborate with the creation of public policies that optimize the quality of life of these groups as well as the Brazilian population, which presents a high degree of interethnic mixing with Amerindian groups.

NBN, RAD51 and XRCC3 Polymorphisms as Potential Predictive Biomarkers of Adjuvant Radiotherapy Toxicity in Early HER2-Positive Breast Cancer

Simple Summary

Adjuvant radiotherapy for breast cancer patients significantly improves survival and causes side effects. It is known that the response to radiotherapy is individual, but we are not yet able to predict patients with high risk for acute or late radiotherapy adverse events. This study aimed to investigate the association between homologous recombination repair (HRR) polymorphisms and radiotherapy toxicity and thus contribute to the knowledge on potential predictive biomarkers of radiotherapy toxicity in early HER2-positive breast cancer. This study was among the first to evaluate the role of HRR genetic variability with cardiac toxicity. RAD51 polymorphisms were associated with cardiac adverse events, while XRCC3 polymorphisms were associated with skin adverse events. Our results suggest that polymorphisms in key HRR genes might be used as potential biomarkers of late treatment-related adverse events in early HER2-positive breast cancer treated with radiotherapy.

Abstract

Radiotherapy (RT) for breast cancer significantly impacts patient survival and causes adverse events. Double-strand breaks are the most harmful type of DNA damage associated with RT, which is repaired through homologous recombination (HRR). As genetic variability of DNA repair genes could affect response to RT, we aimed to evaluate the association of polymorphisms in HRR genes with tumor characteristics and the occurrence of RT adverse events in early HER2-positive breast cancer. Our study included 101 breast cancer patients treated with adjuvant RT and trastuzumab. All patients were genotyped for eight single nucleotide polymorphisms in NBN, RAD51 and XRCC3 using competitive allele-specific PCR. Carriers of XRCC3 rs1799794 GG genotype were less likely to have higher tumor differentiation grade (OR = 0.05, 95% CI = 0.01–0.44, p = 0.007). Carriers of RAD51 rs1801321 TT genotype were more likely to have higher NYHA class in univariable (OR = 10.0; 95% CI = 1.63–61.33; p = 0.013) and multivariable (OR = 9.27; 95% CI = 1.28–67.02; p = 0.027) analysis. Carriers of RAD51 rs12593359 GG genotype were less likely to have higher NYHA class in univariable (OR = 0.09; 95% CI = 0.01–0.79; p = 0.030) and multivariable (OR = 0.07; 95% CI = 0.01–0.81; p = 0.034) analysis. Carriers of XRCC3 rs1799794 GG genotypes experienced more skin adverse events based on LENT-SOMA scale in univariable (OR = 5.83; 95% CI = 1.22–28.00; p = 0.028) and multivariable (OR = 10.90; 95% CI = 1.61–73.72; p = 0.014) analysis. In conclusion, XRCC3 and RAD51 polymorphisms might contribute to RT adverse events in early HER2-positive breast cancer patients.

Association between XRCC3 rs861539 Polymorphism and the Risk of Ovarian Cancer: Meta-Analysis and Trial Sequential Analysis

Background

Current studies on the relationship between XRCC3 rs861539 polymorphism and ovarian cancer risk have been inconsistent. Therefore, we performed a meta-analysis to explore their association.

Methods

Six electronic databases (PubMed, Embase, Web of Science, Cochrane Library, China National Knowledge Infrastructure, and China Wanfang Database) were searched for relevant studies published before December 2021. Meta-analysis, subgroup analysis, sensitivity analysis, and publication bias analysis were performed using Stata software 16.0. Trial sequential analysis (TSA) was performed using TSA 0.9.5.10 Beta software.

Results

A total of 12 studies were included in 9 literatures, comprising 4,634 cases of ovarian cancer and 7,381 controls. After Bonferroni correction, the meta-analysis showed an association between XRCC3 rs861539 polymorphism and ovarian cancer risk in the heterozygote model and the dominant model (GA vs. GG: OR = 0.88, 95%CI = 0.81-0.96, P = 0.003; GG vs. GA+AA: OR = 0.89, 95%CI = 0.82-0.96, P = 0.004). In an ethnically stratified subgroup analysis, XRCC3 rs861539 was shown to reduce the risk of ovarian cancer in Caucasian in the heterozygote model and the dominant model (GA vs. GG: OR = 0.88, 95%CI = 0.81-0.96, P = 0.004; GG vs. GA+AA: OR = 0.88, 95%CI = 0.81-0.96, P = 0.004). In the control source and detection method stratified subgroup analysis, hospital-based studies and PCR-RFLP-based studies were found to increase ovarian cancer risk (GG vs. AA: OR = 1.30, 95%CI = 1.05-1.62, P = 0.016; GG vs. AA: OR = 1.31, 95%CI = 1.06-1.62, P = 0.013).

Conclusion

This meta-analysis showed a significant association between XRCC3 rs861539 polymorphism and ovarian cancer risk, especially in Caucasians. Large-scale multicenter case-control studies in more different regions will be needed in the future.