Polygenic risk scores and breast and epithelial ovarian cancer risks for carriers of BRCA1 and BRCA2 pathogenic variants

Purpose We assessed the associations between population-based polygenic risk scores (PRS) for breast (BC) or epithelial ovarian cancer (EOC) with cancer risks forBRCA1andBRCA2pathogenic variant carriers. Methods Retrospective cohort data on 18,935BRCA1and 12,339BRCA2female pathogenic variant carriers of European ancestry were available. Three versions of a 313 single-nucleotide polymorphism (SNP) BC PRS were evaluated based on whether they predict overall, estrogen receptor (ER)-negative, or ER-positive BC, and two PRS for overall or high-grade serous EOC. Associations were validated in a prospective cohort. Results The ER-negative PRS showed the strongest association with BC risk forBRCA1carriers (hazard ratio [HR] per standard deviation = 1.29 [95% CI 1.25-1.33],P = 3x10(-72)). ForBRCA2, the strongest association was with overall BC PRS (HR = 1.31 [95% CI 1.27-1.36],P = 7x10(-50)). HR estimates decreased significantly with age and there was evidence for differences in associations by predicted variant effects on protein expression. The HR estimates were smaller than general population estimates. The high-grade serous PRS yielded the strongest associations with EOC risk forBRCA1(HR = 1.32 [95% CI 1.25-1.40],P = 3x10(-22)) andBRCA2(HR = 1.44 [95% CI 1.30-1.60],P = 4x10(-12)) carriers. The associations in the prospective cohort were similar. Conclusion Population-based PRS are strongly associated with BC and EOC risks forBRCA1/2carriers and predict substantial absolute risk differences for women at PRS distribution extremes.Peer reviewe

Transcriptome-wide association study of breast cancer risk by estrogen-receptor status

Previous transcriptome-wide association studies (TWAS) have identified breast cancer risk genes by integrating data from expression quantitative loci and genome-wide association studies (GWAS), but analyses of breast cancer subtype-specific associations have been limited. In this study, we conducted a TWAS using gene expression data from GTEx and summary statistics from the hitherto largest GWAS meta-analysis conducted for breast cancer overall, and by estrogen receptor subtypes (ER+ and ER-). We further compared associations with ER+ and ER- subtypes, using a case-only TWAS approach. We also conducted multigene conditional analyses in regions with multiple TWAS associations. Two genes, STXBP4 and HIST2H2BA, were specifically associated with ER+ but not with ER- breast cancer. We further identified 30 TWAS-significant genes associated with overall breast cancer risk, including four that were not identified in previous studies. Conditional analyses identified single independent breast-cancer gene in three of six regions harboring multiple TWAS-significant genes. Our study provides new information on breast cancer genetics and biology, particularly about genomic differences between ER+ and ER- breast cancer.Peer reviewe

Mutational spectrum in a worldwide study of 29,700 families with BRCA1 or BRCA2 mutations.

The prevalence and spectrum of germline mutations in BRCA1 and BRCA2 have been reported in single populations, with the majority of reports focused on White in Europe and North America. The Consortium of Investigators of Modifiers of BRCA1/2 (CIMBA) has assembled data on 18,435 families with BRCA1 mutations and 11,351 families with BRCA2 mutations ascertained from 69 centers in 49 countries on six continents. This study comprehensively describes the characteristics of the 1,650 unique BRCA1 and 1,731 unique BRCA2 deleterious (disease-associated) mutations identified in the CIMBA database. We observed substantial variation in mutation type and frequency by geographical region and race/ethnicity. In addition to known founder mutations, mutations of relatively high frequency were identified in specific racial/ethnic or geographic groups that may reflect founder mutations and which could be used in targeted (panel) first pass genotyping for specific populations. Knowledge of the population-specific mutational spectrum in BRCA1 and BRCA2 could inform efficient strategies for genetic testing and may justify a more broad-based oncogenetic testing in some populations

Genome-wide association study identifies 32 novel breast cancer susceptibility loci from overall and subtype-specific analyses.

Breast cancer susceptibility variants frequently show heterogeneity in associations by tumor subtype1-3. To identify novel loci, we performed a genome-wide association study including 133,384 breast cancer cases and 113,789 controls, plus 18,908 BRCA1 mutation carriers (9,414 with breast cancer) of European ancestry, using both standard and novel methodologies that account for underlying tumor heterogeneity by estrogen receptor, progesterone receptor and human epidermal growth factor receptor 2 status and tumor grade. We identified 32 novel susceptibility loci (P < 5.0 × 10-8), 15 of which showed evidence for associations with at least one tumor feature (false discovery rate < 0.05). Five loci showed associations (P < 0.05) in opposite directions between luminal and non-luminal subtypes. In silico analyses showed that these five loci contained cell-specific enhancers that differed between normal luminal and basal mammary cells. The genetic correlations between five intrinsic-like subtypes ranged from 0.35 to 0.80. The proportion of genome-wide chip heritability explained by all known susceptibility loci was 54.2% for luminal A-like disease and 37.6% for triple-negative disease. The odds ratios of polygenic risk scores, which included 330 variants, for the highest 1% of quantiles compared with middle quantiles were 5.63 and 3.02 for luminal A-like and triple-negative disease, respectively. These findings provide an improved understanding of genetic predisposition to breast cancer subtypes and will inform the development of subtype-specific polygenic risk scores

DCIS Progression and the Tumor Microenvironment: Molecular Insights and Prognostic Challenges

Ductal carcinoma in situ (DCIS) is the most common form of non-invasive breast cancer and a recognized precursor to invasive ductal carcinoma (IDC). Although DCIS itself is confined to the milk duct and not immediately life-threatening, its potential for progression to invasive disease necessitates careful clinical management. The increased detection of DCIS due to advancements in imaging and widespread screening programs has raised critical questions regarding its classification, prognosis, and optimal treatment strategies. While most cases exhibit indolent behavior, others harbor molecular characteristics that drive malignant transformation. A key challenge lies in distinguishing low-risk DCIS, which may never progress, from aggressive cases requiring intervention. Tumor microenvironment dynamics, immune cell infiltration, and molecular alterations, including hormone receptor (HR) status, human epidermal growth factor 2 (HER2) expression, and genetic mutations, play crucial roles in determining disease trajectory. This review explores the biological and molecular mechanisms underlying DCIS progression, with an emphasis on myoepithelial cells, tumor-infiltrating lymphocytes, and microenvironmental factors. By integrating recent findings, this article aims to refine risk stratification approaches and guide future strategies for personalized DCIS management. Improved prognostic biomarkers and targeted therapeutic interventions could help optimize treatment decisions, balancing the need for effective cancer prevention while minimizing overtreatment in low-risk patients

Association of recurrent mutations in BRCA1, BRCA2, RAD51C, PALB2, and CHEK2 with the risk of borderline ovarian tumor

Abstract Background There are several genes associated with ovarian cancer risk. Molecular changes in borderline ovarian tumor (BOT) indicate linkage of this disease to type I ovarian tumors (low-grade ovarian carcinomas). This study determined the prevalence and association of mutations in BRCA1, BRCA2, PALB2, RAD51C, and CHEK2 with the risk of BOTs. Methods The study group consisted of 102 patients with histologically confirmed BOT and 1743 healthy controls. In addition, 167 cases with ovarian cancer G1 were analyzed. The analyses included genotyping of 21 founder and recurrent mutations localized in 5 genes (BRCA1, BRCA2, PALB2, RAD51C, and CHEK2). The risk for developing BOT and low-grade ovarian cancer, as well as the association of tested mutations with survival, was estimated. Results The CHEK2 missense mutation (c.470T&gt;C) was associated with 2-times increased risk of BOT (OR=2.05, p=0.03), at an earlier age at diagnosis and about 10% worse rate of a 10-year survival. Mutations in BRCA1 and PALB2 were associated with a high risk of ovarian cancer G1 (OR=8.53, p=0.005 and OR=7.03, p=0.03, respectively) and were related to worse all-cause survival for BRCA1 carriers (HR=4.73, 95%CI 1.45–15.43, p=0.01). Conclusions Results suggest that CHEK2 (c.470T&gt;C) may possibly play a role in the pathogenesis of BOT, but due to the low number of BOT patients, obtained results should be considered as preliminary. Larger more in-depth studies are required. </jats:sec

BRCA1 promoter hypermethylation is not associated with germline variants in Polish breast cancer patients

Abstract Background Methylation of BRCA1 has been associated with an increased risk of breast cancer and specific clinical characteristics of the disease. In the British population, the genetic alteration c.-107 A/T has been shown to cause allelic methylation, leading to familial breast and ovarian cancer. However, this variant has not been detected in Polish population. Nonetheless, other genetic variants may still be associated with BRCA1 methylation, highlighting the need for further research. Aim of study This study aimed to analyze BRCA1 promoter region to identify germline alterations associated with BRCA1 methylation in peripheral blood DNA. Additionally, the correlation between the detected variants and breast cancer incidence, as well as clinical characteristics, was assessed. Materials and methods One hundred breast cancer patients with BRCA1 methylation were analyzed using pyrosequencing to quantify methylation levels. Immunohistochemistry (IHC) was performed on formalin-fixed paraffin-embedded (FFPE) tumor tissue samples from these patients to assess BRCA1 expression. In 47 patients with the highest BRCA1 methylation and decreased BRCA1 expression, Sanger sequencing was performed encompassing 643 bp of BRCA1 promoter to identify potential variants associated with methylation and/or breast cancer. A variant was identified and genotyped in multiple patient groups, including 336 BRCA1 methylation-positive women, 1898 unselected breast cancer cases, 2234 healthy controls, and 309 BRCA1 pathogenic variant (PV) carriers. Statistical analyses were performed using Fisher’s exact test and Chi-square test in Stata/IC version 16.1. Results The study identified BRCA1 c.20 + 101 C/G (rs799905) in the promoter region of the gene. However, no significant association was found between rs799905 and BRCA1 methylation or breast cancer risk. Nevertheless, a borderline association was observed between rs799905 and the occurrence of triple-negative breast cancer (TNBC) (p = 0.048) as well as lymph node (LN) metastases (p = 0.046). Among BRCA1 PV carriers, the GG genotype was significantly more frequent, while the CC genotype was 10 times less common compared to non-carriers (p = 0.003). Conclusion Rs799905 variant is not associated with BRCA1 methylation breast cancer risk. However, it may be linked to the occurrence of TNBC and LN metastases. Additionally, rs799905 may be associated to some extent with BRCA1 PVs, though further research is needed to clarify the nature of this potential correlation

Iron levels, genes involved in iron metabolism and antioxidative processes and lung cancer incidence.

BackgroundLung cancer is the most common adult malignancy accounting for the largest proportion of cancer related deaths. Iron (Fe) is an essential trace element and is a component of several major metabolic pathways playing an important role in many physiological processes. In this study we evaluated the association between Fe concentration in serum, iron metabolism parameters and genetic variaton in 7 genes involved in iron metabolism and anti-oxidative processes with the incidence of lung cancer in Poland.Materials and methodsThe study included 200 lung cancer patients and 200 matched healthy control subjects. We analyzed serum iron concentration and iron metabolism parameters (TIBC, UIBC, serum ferritin and transferrin saturation), and genotyped seven variants in seven genes: HFE, TFR1, HAMP, TF, SOD2, CAT and GPX1.ResultsLung cancer patients compared to their matched controls had significantly higher mean serum iron level (p = 0.01), ferritin level (p = 0.007) and TIBC (p = 0.006). Analysis revealed that higher concentration of iron and ferritin (IVth quartile) compared to the lower concentration (Ist quartile) was associated with over 2-fold increased lung cancer incidence. We also found that higher transferrin saturation (p = 0.01) and lower TIBC (pConclusionsThe results of this case control study indicate that higher body iron represented by higher Fe and ferritin levels may be associated with lung cancer incidence. Rs10421768 in HAMP may be associated with about 3-times higher lung cancer risk. Higher Fe body content may be associated with better survival of lung cancer patients

Polymorphisms in MMP-1, MMP-2, MMP-7, MMP-13 and MT2A do not contribute to breast, lung and colon cancer risk in polish population

Abstract Background Matrix metalloproteinases (MMPs) and metallothioneins (MTs) are Zinc-related proteins which are involved in processes crucial for carcinogenesis such as angiogenesis, proliferation and apoptosis. Several single nucleotide polymorphisms (SNPs) in MMPs and MTs that affect genes expression have been associated with cancer risk, including breast, lung and colon. Methods The study group consisted of 648 unselected patients (299 with breast cancer, 199 with lung cancer, 150 with colon cancer) and 648 unaffected individuals. Five SNPs, rs1799750 in MMP-1, rs243865 in MMP-2, rs11568818 in MMP-7, rs2252070 in MMP-13 and rs28366003 in MT2A were genotyped and serum zinc (Zn) level was measured. The cancer risk was calculated using multivariable logistic regression with respect to Zn. Results None of the 5 tested polymorphisms showed a correlation with cancer risk in studied groups, although for MMP-2, MMP-7 and MT2A non-significant differences in genotypes frequencies among cases and controls were observed. Conclusions Analyses of polymorphisms, rs1799750 in MMP-1, rs243865 in MMP-2, rs11568818 in MMP-7, rs2252070 in MMP-13 and rs28366003 in MT2A in relation to serum Zn level did not show significant association with breast, lung and colon cancer risk among polish patients. Further studies are needed to verify this observation. </jats:sec

Recurrent Mutations in BRCA1, BRCA2, RAD51C, PALB2 and CHEK2 in Polish Patients with Ovarian Cancer

The aim of the study was to analyze the frequency and magnitude of association of 21 recurrent founder germline mutations in BRCA1, BRCA2, PALB2, RAD51C, and CHEK2 genes with ovarian cancer risk among unselected patients in Poland. We genotyped 21 recurrent germline mutations in BRCA1 (9 mutations), BRCA2 (4 mutations), RAD51C (3 mutations), PALB2 (2 mutations), and CHEK2 (3 mutations) among 2270 Polish ovarian cancer patients and 1743 healthy controls, and assessed the odds ratios (OR) for developing ovarian cancer for each gene. Mutations were detected in 369 out of 2095 (17.6%) unselected ovarian cancer cases and 117 out of 1743 (6.7%) unaffected controls. The ovarian cancer risk was associated with mutations in BRCA1 (OR = 40.79, 95% CI: 18.67–114.78; p = 0.29 × 10−15), in BRCA2 (OR = 25.98; 95% CI: 1.55–434.8; p = 0.001), in RAD51C (OR = 6.28; 95% CI 1.77–39.9; p = 0.02), and in PALB2 (OR 3.34; 95% CI: 1.06–14.68; p = 0.06). There was no association found for CHEK2. We found that pathogenic mutations in BRCA1, BRCA2, RAD51C or PALB2 are responsible for 12.5% of unselected cases of ovarian cancer. We recommend that all women with ovarian cancer in Poland and first-degree female relatives should be tested for this panel of 18 mutations.</jats:p