Breast Cancer Adjuvant Radiotherapy in BRCA1/2, TP53, ATM Genes Mutations: Are There Solved Issues?
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ABSTRACT:
SUBMITTER: Lazzari G
PROVIDER: S-EPMC8126701 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:Certain rare, familial mutations in the ATM, BRCA1, BRCA2, CHEK2 or TP53 genes increase susceptibility to breast cancer but it has not, until now, been clear whether common polymorphic variants in the same genes also increase risk.We have attempted a comprehensive, single nucleotide polymorphism (SNP)- and haplotype-tagging association study on each of these five genes in up to 4,474 breast cancer cases from the British, East Anglian SEARCH study and 4,560 controls from the EPIC-Norfolk study, using a two-stage study design. Nine tag SNPs were genotyped in ATM, together with five in BRCA1, sixteen in BRCA2, ten in CHEK2 and five in TP53, with the aim of tagging all other known, common variants. SNPs generating the common amino acid substitutions were specifically forced into the tagging set for each gene.No significant breast cancer associations were detected with any individual or combination of tag SNPs.It is unlikely that there are any other common variants in these genes conferring measurably increased risks of breast cancer in our study population.
| S-EPMC1868915 | biostudies-literature
Project description:The role of the DNA double-strand-break (DSB) checkpoint/repair genes, ATM, BRCA1 and TP53, in sporadic breast cancer requires clarification, since ATM and BRCA1 mutations are rare in sporadic tumours. In an attempt to explain this phenomenon, we postulated that (i) in addition to genetic deletion, abnormal expression of DSB checkpoint/repair proteins might abolish the function of these genes and (ii) there might be a combined effect of individual defective genes during breast cancer pathogenesis. Using a largely homogenous group of 74 specimens of early-onset (< or =35 years of age) infiltrating ductal carcinomas, we examined associations between pathological grade and genetic deletion and/or abnormal protein expression of ATM, BRCA1 and TP53. The results showed that high-grade tumours displayed a high frequency of loss of heterozygosity (LOH) at, and/or abnormal expression of, ATM, BRCA1 and TP53. Multigenetic analysis showed abnormalities in BRCA1 to be independently associated with high-grade tumours. ATM and TP53 appeared to play an assistant role, abnormalities in these genes significantly increasing the possibility of poor differentiation in tumours with abnormalities in BRCA1. Furthermore, a higher number of abnormalities (LOH or abnormal expression) in these three genes correlated with poor tumour differentiation. Thus, this study suggests that combined changes in several DSB checkpoint/repair genes belonging to a common functional pathway are associated with breast cancer pathogenesis.
| S-EPMC2409464 | biostudies-other
Project description:Uterine serous carcinoma (USC) is not recognized as part of any defined hereditary cancer syndrome, and its association with hereditary breast and ovarian carcinoma and Lynch syndrome are uncertain.Using targeted capture and massively parallel genomic sequencing, 151 subjects with USC were assessed for germline mutations in 30 tumor suppressor genes, including BRCA1 (breast cancer 1, early onset), BRCA2, the DNA mismatch repair genes (MLH1 [mutL homolog 1], MSH2 [mutS homolog 2], MSH6, PMS2 [postmeiotic segregation increased 2]), TP53 (tumor protein p53), and 10 other genes in the Fanconi anemia-BRCA pathway. Ten cases with < 10% serous histology were also assessed.Seven subjects (4.6%) carried germline loss-of-function mutations: 3 subjects (2.0%) with mutations in BRCA1, 2 subjects (1.3%) with mutations in TP53, and 2 subjects (1.3%) with mutations in CHEK2 (checkpoint kinase 2). One subject with < 10% serous histology had an MSH6 mutation. Subjects with MSH6 and TP53 mutations had neither personal nor family histories suggestive of Lynch or Li-Fraumeni syndromes. Of the 22 women with USC and a personal history of breast carcinoma, the frequency of BRCA1 mutations was 9%, compared to 0.9% in 119 women with no such history.Approximately 5% of women with USC have germline mutations in 3 different tumor suppressor genes: BRCA1, CHEK2, and TP53. Mutations in DNA mismatch repair genes that cause Lynch syndrome are rare in USC. The germline BRCA1 mutation rate in USC subjects of 2% is higher than expected in a nonfounder population, suggesting that USC is associated with hereditary breast and ovarian carcinoma in a small proportion of cases. Women with USC and breast cancer should be offered genetic testing for BRCA1 and BRCA2 mutations.
| S-EPMC3966566 | biostudies-literature
Project description:PurposePreclinical data indicate that response to radiotherapy (RT) depends on DNA damage repair. In this study, we investigated the role of mutations in genes related to DNA damage repair in treatment outcome after RT.Materials and methodsPatients with solid tumor who participated in next generation sequencing panel screening using biopsied tumor tissue between October 2013 and February 2019 were reviewed and 97 patients that received RT were included in this study. Best response to RT and the cumulative local recurrence rate (LRR) were compared according to absence or presence of missense, nonsense, and frameshift mutations in ATM and/or BRCA1/2.ResultsOf the 97 patients, five patients harbored mutation only in ATM, 22 in only BRCA1/2, and six in both ATM and BRCA1/2 (ATMmtBRCAmt). Propensity score matching was performed to select the control group without mutations (ATMwtBRCAwt, n=33). In total, 90 RT-treated target lesions were evaluated in 66 patients. Highest objective response rate of 80% was observed in ATMmtBRCAmt lesions (p=0.007), which was mostly durable. Furthermore, the cumulative 1-year LRR was the lowest in ATMmtBRCAmt lesions and the highest in ATMwtBRCAwt lesions (0% vs. 47.9%, p=0.008). RT-associated toxicities were observed in 10 treatments with no significant difference among the subgroups (p=0.680).ConclusionTumors with ATM and BRCA1/2 mutations exhibited superior tumor response and local control after RT compared to tumors without these mutations. The results are hypothesis generating and suggest the need for integrating the tumor mutation profile of DNA repair genes during treatment planning.
| S-EPMC8756123 | biostudies-literature
Project description:INTRODUCTION: Germline TP53 mutations cause an increased risk to early-onset breast cancer in Li-Fraumeni syndrome (LFS) families and the majority of carriers identified through breast cancer cohorts have LFS or Li-Fraumeni-like (LFL) features. However, in Asia and in many low resource settings, it is challenging to obtain accurate family history and we, therefore, sought to determine whether the presence of early-onset breast cancer is an appropriate selection criteria for germline TP53 testing. METHODS: A total of 100 patients with early-onset breast cancer (? 35 years) treated at University Malaya Medical Centre between 2003 and 2009, were analyzed for germline mutations in BRCA1, BRCA2 and TP53 by full DNA sequencing. Of the mutations identified, we examined their likely pathogenicity on the basis of prevalence in a case-control cohort, co-segregation analyses and loss of heterozygosity (LOH) in tumor tissues. RESULTS: We identified 11 BRCA1 (11%) and 6 BRCA2 (6%) germline carriers among early-onset breast cancer patients. Of the 83 BRCA-negative patients, we identified four exonic variants and three intronic variants in TP53. Of these, two exonic variants are clinically relevant (E346X and p. G334_R335dup6) and two novel missense mutations (A138V and E285K) are likely to be clinically relevant, on the basis of co-segregation and loss of heterozygosity (LOH). Notably, E285K was found in two unrelated individuals and haplotype analyses suggest a founder effect. Two of the three intronic variants are likely benign based on their prevalence in a control population. Clinically relevant TP53 germline mutations were identified in three of the four patients (75%) with a family history of at least two LFS-linked cancers (breast, bone or soft tissue sarcoma, brain tumors or adrenocortical cancer); 1 of the 17 patients (6%) with a family history of breast cancer only, and 1 of the 62 patients (< 2%) with no family history of breast or LFS-linked cancers. CONCLUSIONS: Our study reports germline BRCA1, BRCA2 and TP53 mutations are found in early-onset breast cancer patients at 11%, 6% and 5% respectively, suggesting that TP53 mutation screening should be considered for these patients. However, we find that even in low resource Asian settings where family history is poorly reported, germline TP53 mutations are found predominantly among breast cancer patients with a family history of LFS-linked cancers.
| S-EPMC3446401 | biostudies-literature
Project description:To estimate the proportion of breast cancer families due to BRCA1 or BRCA2, we performed mutation screening of the entire coding regions of both genes supplemented with linkage analysis of 31 families, 8 containing male breast cancers and 23 site-specific female breast cancer. A combination of protein-truncation test and SSCP or heteroduplex analyses was used for mutation screening complemented, where possible, by the analysis of expression level of BRCA1 and BRCA2 alleles. Six of the eight families with male breast cancer revealed frameshift mutations, two in BRCA1 and four in BRCA2. Although most families with female site-specific breast cancers were thought to be due to mutations in either BRCA1 or BRCA2, we identified only eight mutations in our series of 23 site-specific female breast cancer families (34%), four in BRCA1 and four in BRCA2. According to the posterior probabilities calculated for mutation-negative families, based on linkage data and mutation screening results, we would expect 8-10 site-specific female breast cancer families of our series to be due to neither BRCA1 nor BRCA2. Thus, our results suggest the existence of at least one more major breast cancer-susceptibility gene.
| S-EPMC1712515 | biostudies-other
Project description:Familial breast cancer is estimated to account for 15-20% of all cases of breast cancer. Surveillance for familial breast cancer is well-established world-wide. However, this service does not exist in Jordan, due to the scarcity of information with regard to the genetic profiling of these patients, and therefore lack of recommendations for policy-makers. As such, patients with very strong family history of breast or ovarian cancers are not screened routinely; leading to preventable delay in diagnosis. Whole coding sequencing for BCRA1/BCRA2 using next-generation sequencing (NGS)/Ion PGM System was performed. Sanger sequencing were then used to confirm the pathogenic variants detected by NGS. In this study, 192 breast cancer patients (and 8 ovarian cancer cases) were included. The prevalence of recurrent pathogenic mutations was 14.5%, while the prevalence of newly detected mutations was 3.5%. Two novel pathogenic mutations were identified in BRCA2 genes. The common mutations in the Ashkenazi population used for screening may not apply in the Jordanian population, as previously reported mutations were not prevalent, and other new mutations were identified. These data will aid to establish a specific screening test for BRCA 1/BRCA2 in the Jordanian population.
| S-EPMC7568559 | biostudies-literature
Project description:PurposeIn some patients who receive adjuvant radiotherapy (RT) for the left breast, the stomach is located inside the RT field. This study investigates the incidence of gastric complications following adjuvant RT for breast cancer using data of the Health Insurance Review and Assessment Service in South Korea.MethodsWe identified 37,966 women who underwent surgery and received adjuvant RT for breast cancer. The cumulative incidence rate of gastric hemorrhage and gastric cancer was calculated and compared for left and right breast cancers.ResultsAmong 37,966 patients, 19,531 (51.4%) and 18,435 (48.6%) had right and left breast cancers, respectively. After a median follow-up duration of 6.3 years, the cumulative incidence of gastric cancer and gastric hemorrhage did not differ between right and left breast cancers (p = 0.414 and p = 0.166, respectively). The multivariable analysis revealed that old age was the only factor associated with the development of gastric cancer (p < 0.001) and gastric hemorrhage (p < 0.001). The incidence of gastric cancer and hemorrhage did not differ between patients who received adjuvant RT for right and left breast cancers.ConclusionIrradiation-related chronic complications of the stomach in patients with breast cancer are minimal. A study with a longer follow-up duration might be needed to assess the risk of gastric cancer.
| S-EPMC6769383 | biostudies-literature
Project description:IntroductionMutations affecting p53 or its upstream activator Chk2 are associated with resistance to DNA-damaging chemotherapy in breast cancer. ATM (Ataxia Telangiectasia Mutated protein) is the key activator of p53 and Chk2 in response to genotoxic stress. Here, we sought to evaluate ATM's potential role in resistance to chemotherapy.MethodsWe sequenced ATM and assessed gene expression levels in pre-treatment biopsies from 71 locally advanced breast cancers treated in the neoadjuvant setting with doxorubicin monotherapy or mitomycin combined with 5-fluorouracil. Findings were confirmed in a separate patient cohort treated with epirubicin monotherapy. Each tumor was previously analyzed for CHEK2 and TP53 mutation status.ResultsWhile ATM mutations were not associated with chemo-resistance, low ATM expression levels predicted chemo-resistance among patients with tumors wild-type for TP53 and CHEK2 (P = 0.028). Analyzing the ATM-chk2-p53 cascade, low ATM levels (defined as the lower 5 to 50% percentiles) or mutations inactivating TP53 or CHEK2 robustly predicted anthracycline resistance (P-values varying between 0.001 and 0.027 depending on the percentile used to define "low" ATM levels). These results were confirmed in an independent cohort of 109 patients treated with epirubicin monotherapy. In contrast, ATM-levels were not suppressed in resistant tumors harboring TP53 or CHEK2 mutations (P > 0.5).ConclusionsOur data indicate loss of function of the ATM-Chk2-p53 cascade to be strongly associated with resistance to anthracycline/mitomycin-containing chemotherapy in breast cancer.
| S-EPMC3446381 | biostudies-literature
Project description:BACKGROUND: Basal-like breast cancers (BLBC) are aggressive breast cancers for which, so far, no targeted therapy is available because they typically lack expression of hormone receptors and HER2. Phenotypic features of BLBCs, such as clinical presentation and early age of onset, resemble those of breast tumors from BRCA1-mutation carriers. The genomic instability of BRCA1-mutated tumors can be effectively targeted with DNA-damaging agents and poly-(ADP-ribose) polymerase 1 (PARP1) inhibitors. Molecular similarities between BLBCs and BRCA1-mutated tumors may therefore provide predictive markers for therapeutic response of BLBCs. METHODS: There are several known molecular features characteristic for BRCA1-mutated breast tumors: 1) increased numbers of genomic aberrations, 2) a distinct pattern of genomic aberrations, 3) a high frequency of TP53 mutations and 4) a high incidence of complex, protein-truncating TP53 mutations. We compared the frequency of TP53 mutations and the pattern and amount of genomic aberrations between BRCA1-mutated breast tumors, BLBCs and luminal breast tumors by TP53 gene sequencing and array-based comparative genomics hybridization (aCGH) analysis. RESULTS: We found that the high incidence of protein truncating TP53 mutations and the pattern and amount of genomic aberrations specific for BRCA1-mutated breast tumors are also characteristic for BLBCs and different from luminal breast tumors. CONCLUSIONS: Complex, protein truncating TP53 mutations in BRCA1-mutated tumors may be a direct consequence of genomic instability caused by BRCA1 loss, therefore, the presence of these types of TP53 mutations in sporadic BLBCs might be a hallmark of BRCAness and a potential biomarker for sensitivity to PARP inhibition. Also, our data suggest that a small subset of genomic regions may be used to identify BRCA1-like BLBCs. BLBCs share molecular features that were previously found to be specific for BRCA1-mutated breast tumors. These features might be useful for the identification of tumors with increased sensitivity to (high-dose or dose-dense) alkylating agents and PARP inhibitors.
| S-EPMC3002929 | biostudies-literature