Mutation-negative Breast Cancer Research Articles

Implication and Influence of Multigene Panel Testing with Genetic Counseling in Korean Patients with BRCA1/2 Mutation-Negative Breast Cancer.

PurposeThe aim of the study was to evaluate the clinical implication of multigene panel testing of beyond BRCA genes in Korean patients with BRCA1/2 mutation-negative breast cancer.Materials and MethodsBetween 2016 and 2019, a total of 700 BRCA1/2 mutation-negative breast cancer patients received comprehensive multigene panel testing and genetic counseling. Among them, 347 patients completed a questionnaire about cancer worry, genetic knowledge, and preference for the method of genetic tests during pre- and post-genetic test counseling. The frequency of pathogenic and likely pathogenic variants (PV/LPV) were analyzed.ResultsAt least one PV/LPV of 26 genes was found in 76 out of 700 patients (10.9 %). The rate for PV/LPV was 3.4% for high-risk genes (17 PALB2, 6 TP53, and 1 PTEN). PV/LPVs of clinical actionable genes for breast cancer management, high-risk genes and other moderate-risk genes such as ATM, BARD1, BRIP, CHEK2, NF1, and RAD51D, were observed in 7.4%. Patients who completed the questionnaire showed decreased concerns about the risk of additional cancer development (average score, 4.21 to 3.94; p < 0.001), influence on mood (3.27 to 3.13; p < 0.001), influence on daily functioning (3.03 to 2.94; p=0.006); and increased knowledge about hereditary cancer syndrome (66.9 to 68.8; p=0.025) in post-test genetic counseling. High cancer worry scales (CWSs) were associated with age ≤ 40 years and the identification of PV/LPV. Low CWSs were related to the satisfaction of the counselee.ConclusionComprehensive multigene panel test with genetic counseling is clinically applicable. It should be based on interpretable genetic information, consideration of potential psychological consequences, and proper preventive strategies.

Exome Sequencing in a Family with Luminal-Type Breast Cancer Underpinned by Variation in the Methylation Pathway.

Panel-based next generation sequencing (NGS) is currently preferred over whole exome sequencing (WES) for diagnosis of familial breast cancer, due to interpretation challenges caused by variants of uncertain clinical significance (VUS). There is also no consensus on the selection criteria for WES. In this study, a pathology-supported genetic testing (PSGT) approach was used to select two BRCA1/2 mutation-negative breast cancer patients from the same family for WES. Homozygosity for the MTHFR 677 C>T mutation detected during this PSGT pre-screen step was considered insufficient to cause bilateral breast cancer in the index case and her daughter diagnosed with early-onset breast cancer (<30 years). Extended genetic testing using WES identified the RAD50 R385C missense mutation in both cases. This rare variant with a minor allele frequency (MAF) of <0.001 was classified as a VUS after exclusion in an affected cousin and extended genotyping in 164 unrelated breast cancer patients and 160 controls. Detection of functional polymorphisms (MAF > 5%) in the folate pathway in all three affected family members is consistent with inheritance of the luminal-type breast cancer in the family. PSGT assisted with the decision to pursue extended genetic testing and facilitated clinical interpretation of WES aimed at reduction of recurrence risk.

Whole-exome sequencing and targeted gene sequencing provide insights into the role of PALB2 as a male breast cancer susceptibility gene.

Male breast cancer (MBC) is a rare disease whose etiology appears to be largely associated with genetic factors. BRCA1 and BRCA2 mutations account for about 10% of all MBC cases. Thus, a fraction of MBC cases are expected to be due to genetic factors not yet identified. To further explain the genetic susceptibility for MBC, whole-exome sequencing (WES) and targeted gene sequencing were applied to high-risk, BRCA1/2 mutation-negative MBC cases. Germ-line DNA of 1 male and 2 female BRCA1/2 mutation-negative breast cancer (BC) cases from a pedigree showing a first-degree family history of MBC was analyzed with WES. Targeted gene sequencing for the validation of WES results was performed for 48 high-risk, BRCA1/2 mutation-negative MBC cases from an Italian multicenter study of MBC. A case-control series of 433 BRCA1/2 mutation-negative MBC and female breast cancer (FBC) cases and 849 male and female controls was included in the study. WES in the family identified the partner and localizer of BRCA2 (PALB2) c.419delA truncating mutation carried by the proband, her father, and her paternal uncle (all affected with BC) and the N-acetyltransferase 1 (NAT1) c.97C>T nonsense mutation carried by the proband's maternal aunt. Targeted PALB2 sequencing detected the c.1984A>T nonsense mutation in 1 of the 48 BRCA1/2 mutation-negative MBC cases. NAT1 c.97C>T was not found in the case-control series. These results add strength to the evidence showing that PALB2 is involved in BC risk for both sexes and indicate that consideration should be given to clinical testing of PALB2 for BRCA1/2 mutation-negative families with multiple MBC and FBC cases. Cancer 2017;123:210-218. © 2016 American Cancer Society.

Relationship of clinicopathological features and chemotherapeutic outcomes in women with BRCA1 and BRCA2 mutation-negative familial breast cancer

To explore the relationship of clinicopathological features and response to neoadjuvant chemotherapy in women with BRCA1 and BRCA2 mutation-negative familial breast cancer. A total of 6 200 women with breast cancer were treated at our hospital from October 2003 to December 2012. All subjects underwent genetic testing for BRCA1 and BRCA2 genes. Patients with BRCA1 and BRCA2 mutations were excluded. This cohort of 5 842 patients with BRCA1 and BRCA2 mutation-negative breast cancer was classified as two groups: familial breast cancer patients (n=480) and sporadic breast cancer patients (n=5 362). The clinicalpathological data and response to neoadjuvant chemotherapy of the 480 patients with BRCA1 and BRCA2 mutation-negative familial breast cancer and the 5 362 patients with BRCA1 and BRCA2 mutation-negative sporadic breast cancer were compared retrospectively. Then the influencing factors of response to neoadjuvant chemotherapy were analyzed. Among the BRCA1 and BRCA2 mutation-negative breast cancer patients, 4.4% of the patients were diagnosed before 30 years of age in the familial breast cancer group, significantly higher than that of 2.6% in the sporadic breast cancer group(P=0.020). 5.0% of the patients in the familial breast cancer group had bilateral breast cancer, significantly higher than that of 2.7% in the sporadic breast cancer group (P=0.004). Compared with BRCA1 and BRCA2 mutation-negative sporadic breast cancer patients, the relative risk of early-onset breast cancer (≤ 30 years) and bilateral breast cancer were 1.73 and 1.91, respectively, significantly higher than that in the BRCA1 and BRCA2 mutation-negative familial breast cancer cases (P=0.020 and P=0.004). 2 964 patients in this cohort of 5 842 case sreceived neoadjuvant chemotherapy.The pathologic complete response (pCR) rate was significantly higher in the BRCA1 and BRCA2 mutation-negative familial breast cancer group than in the BRCA1 and BRCA2 mutation-negative sporadic breast cancer group (21.7% vs. 14.0%, P=0.001). Independent factors associated with pCR in BRCA1 and BRCA2 mutation-negative breast cancer patients were tumor size less than 2 cm (P=0.012), histologic grade Ⅲ (P<0.001), triple-negative breast cancers (P<0.001), and BRCA1 and BRCA2 mutation-negative familial breast cancer(P=0.001). Compared with BRCA1 and BRCA2 mutation-negative sporadic breast cancer, BRCA1 and BRCA2 mutation-negative familial breast cancer is more likely diagnosed before the age of 30 years and has a higher risk to develop bilateral breast cancer. BRCA1 and BRCA2 mutation-negative familial breast cancers are more likely to respond to neoadjuvant chemotherapy than BRCA1 and BRCA2 mutation-negative sporadic breast cancer.

Rare De Novo Germline Copy-Number Variation in Testicular Cancer

Although heritable factors are an important determinant of risk of early-onset cancer, the majority of these malignancies appear to occur sporadically without identifiable risk factors. Germline de novo copy-number variations (CNVs) have been observed in sporadic neurocognitive and cardiovascular disorders. We explored this mechanism in 382 genomes of 116 early-onset cancer case-parent trios and unaffected siblings. Unique de novo germline CNVs were not observed in 107 breast or colon cancer trios or controls but were indeed found in 7% of 43 testicular germ cell tumor trios; this percentage exceeds background CNV rates and suggests a rare de novo genetic paradigm for susceptibility to some human malignancies.

High Prevalence of Preinvasive Lesions Adjacent to BRCA1/2-Associated Breast Cancers

Mutations in BRCA1 and BRCA2 increase a woman's lifetime risk of developing breast cancer by 43% to 84%. It was originally postulated that BRCA1/2-associated breast cancers develop more rapidly than sporadic cancers and may lack preinvasive lesions. More recent studies have found preinvasive lesions in prophylactic mastectomy specimens from mutation carriers; however, there is little information on the presence of preinvasive lesions in tissue adjacent to breast cancers. Our aim is to investigate the role of preinvasive lesions in BRCA-associated breast carcinogenesis. We retrospectively compared BRCA1/2-associated breast cancers and sporadic breast cancers for the prevalence of preinvasive lesions [ductal carcinoma in situ (DCIS), lobular carcinoma in situ, and atypical lobular hyperplasia] in tissue adjacent to invasive breast cancers. Pathology was reviewed for 73 BRCA1/2-associated tumors from patients with breast cancer. We selected 146 patients with mutation-negative breast cancer as age-matched controls. Among the BRCA1/2-associated breast cancers, 59% had at least one associated preinvasive lesion compared with 75% of controls. Preinvasive lesions were more prevalent in BRCA2 mutation carriers than in BRCA1 mutation carriers (70% versus 52%, respectively). The most common preinvasive lesion in both groups was DCIS; 56% of BRCA1/2-associated breast cancers and 71% of the sporadic breast cancers had adjacent intraductal disease, respectively. Preinvasive lesions, most notably DCIS, are common in BRCA1/2-associated breast cancers. These findings suggest that BRCA1/2-associated breast cancers progress through the same intermediate steps as sporadic breast cancers, and that DCIS should be considered as a part of the BRCA1/2 tumor spectrum.

Basal cytokeratins in breast tumours among BRCA1, BRCA2and mutation-negative breast cancer families

IntroductionFinding new immunohistochemical markers that are specific to hereditary breast cancer could help us to select candidates for BRCA1/BRCA2 mutation testing and to understand the biological pathways of tumour development.MethodsUsing breast cancer tumour microarrays, immunohistochemical expression of cytokeratin (CK)-5/6, CK-14 and CK-17 was evaluated in breast tumours from BRCA1 families (n = 46), BRCA2 families (n = 40), non-BRCA1/BRCA2 families (n = 358) and familial breast cancer patients with one first-degree relative affected by breast or ovarian cancer (n = 270), as well as from patients with sporadic breast cancer (n = 364). Staining for CK-5/6, CK-14 and CK-17 was compared between these groups and correlated with other clinical and histological factors.ResultsCK-5/6, CK-14 and CK-17 were detected mostly among oestrogen receptor (ER)-negative, progesterone receptor (PR)-negative and high-grade tumours. We found the highest percentages of samples positive for these CKs among ER-negative/HER2-negative tumours. In univariate analysis, CK-14 was significantly associated with tumours from BRCA1 (39%; P < 0.0005), BRCA2 (27%; P = 0.011), and non-BRCA1/BRCA2 (21%; P < 0.005) families, as compared with sporadic tumours (10%). However, in multivariate analysis, CKs were not found to be independently associated with BRCA1 or BRCA2 mutation status, and the most effective predictors of BRCA1 mutations were age at onset, HER2 status, and either ER or PR status.ConclusionAlthough our study confirms that basal CKs can help to identify BRCA1 mutation carriers, this effect was weaker than previously suggested and CKs did not independently predict BRCA1 mutation either from sporadic or familial breast cancer cases. The most effective, independent predictors of BRCA1 mutations were age at onset, HER2 status, and either ER or PR status, as compared with sporadic or non-BRCA1/BRCA2 cancers.

BCoR-L1 variation and breast cancer

IntroductionBRCA1 is involved in numerous essential processes in the cell, and the effects of BRCA1 dysfunction in breast cancer carcinogenesis are well described. Many of the breast cancer susceptibility genes such as BRCA2, p53, ATM, CHEK2, and BRIP1 encode proteins that interact with BRCA1. BCL6 corepressor-like 1 (BCoR-L1) is a newly described BRCA1-interacting protein that displays high homology to several proteins known to be involved in the fundamental processes of DNA damage repair and transcription regulation. BCoR-L1 has been shown to play a role in transcription corepression, and expression of the X-linked BCoR-L1 gene has been reported to be dysregulated in breast cancer subjects. BCoR-L1 is located on the X chromosome and is subject to X inactivation.MethodsWe performed mutation analysis of 38 BRCA1/2 mutation-negative breast cancer families with male breast cancer, prostate cancer, and/or haplotype sharing around BCoR-L1 to determine whether there is a role for BCoR-L1 as a high-risk breast cancer predisposition gene. In addition, we conducted quantitative real-time PCR (qRT-PCR) on lymphoblastoid cell lines (LCLs) from the index cases from these families and a number of cancer cell lines to assess the role of BCoR-L1 dysregulation in cancer and cancer families.ResultsVery little variation was detected in the coding region, and qRT-PCR analysis revealed that BCoR-L1 expression is highly variable in cancer-free subjects, high-risk breast cancer patients, and cancer cell lines. We also report the investigation of a new expression control, DIDO1 (death inducer-obliterator 1), that is superior to GAPDH (glyceraldehyde-3-phosphate dehydrogenase) and UBC (ubiquitin C) for analysis of expression in LCLs.ConclusionOur results suggest that BCoR-L1 expression does not play a large role in predisposition to familial breast cancer.

Risk factors for breast cancer characterized by the estrogen receptor alpha A908G (K303R) mutation.

IntroductionEstrogen is important in the development of breast cancer, and its biological effects are mediated primarily through the two estrogen receptors alpha and beta. A point mutation in the estrogen receptor alpha gene, ESR1, referred to as A908G or K303R, was originally identified in breast hyperplasias and was reported to be hypersensitive to estrogen. We recently detected this mutation at a low frequency of 6% in invasive breast tumors of the Carolina Breast Cancer Study (CBCS).MethodsIn this report, we evaluated risk factors for invasive breast cancer classified according to the presence or absence of the ESR1 A908G mutation in the CBCS, a population-based case-control study of breast cancer among younger and older white and African-American women in North Carolina. Of the 653 breast tumors evaluated, 37 were ESR1 A908G mutation-positive and 616 were mutation-negative.ResultsESR1 A908G mutation-positive breast cancer was significantly associated with a first-degree family history of breast cancer (odds ratio [OR] = 2.69, 95% confidence interval [CI] = 1.15 to 6.28), whereas mutation-negative breast cancer was not. Comparison of the two case subgroups supported this finding (OR = 2.65, 95% CI = 1.15 to 6.09). There was also the suggestion that longer duration of oral contraceptive (OC) use (OR = 3.73, 95% CI = 1.16 to 12.03; Ptrend = 0.02 for use of more than 10 years) and recent use of OCs (OR = 3.63, 95% CI = 0.80 to 16.45; Ptrend = 0.10 for use within 10 years) were associated with ESR1 A908G mutation-positive breast cancer; however, ORs for comparison of the two case subgroups were not statistically significant. Hormone replacement therapy use was inversely correlated with mutation-negative breast cancer, but the effect on mutation-positive cancer was unclear due to the small number of postmenopausal cases whose tumors carried the mutation. Mutation-negative breast cancer was associated with several reproductive factors, including younger age at menarche (OR = 1.46, 95% CI = 1.09 to 1.94) and greater total estimated years of ovarian function (OR = 1.82, 95% CI = 1.21 to 2.74).ConclusionThese preliminary results suggest that OCs may interact with the ESR1 A908G mutant receptor to drive the development of some breast tumors.

Nordic collaborative study of the BARD1 Cys557Ser allele in 3956 patients with cancer: enrichment in familial BRCA1/BRCA2 mutation-negative breast cancer but not in other malignancies

Background: BARD1 was originally identified as a BRCA1-interacting protein but has also been described in tumour-suppressive functions independent of BRCA1. Several studies have indicated that the BARD1 gene is a...

Relationship of patients' age to histopathological features of breast tumours in BRCA1 and BRCA2 and mutation-negative breast cancer families.

IntroductionOur aim was to evaluate the relationship of patients' age to histopathological features of hereditary breast tumours in a series of breast cancer families not selected for age at diagnosis. In sporadic breast cancer, tumours from premenopausal patients have been shown to differ from those of postmenopausal patients, but this phenomenon has been little studied among familial patients.MethodsRepresentative areas of all available breast cancer tissue specimens (n = 262) from 25 BRCA1, 20 BRCA2, and 74 non-BRCA1/2 breast cancer families were punched into a tissue microarray. Immunohistochemical staining of oestrogen receptor, progesterone receptor, ERBB2, and p53 as well as the histology and grade of tumours in these three groups of families were studied in different age groups and compared with each other.ResultsWe found that only breast cancers from young (<50 years) BRCA1+ patients represent features documented as being typical of BRCA1-associated cancers, such as high tumour grade, negativity for oestrogen and progesterone receptors, and overexpression of p53. Among the BRCA2 families, the opposite was found, with a significantly higher frequency of tumours negative for oestrogen and progesterone receptors among the older patients than among the other groups, but no distinctive tumour characteristics among the younger BRCA2 patients.ConclusionTumours of BRCA1 and BRCA2 carriers aged 50 years or more differed significantly from those of younger carriers. This difference may reflect different biological behaviour and pathways of tumour development among the older and the younger BRCA1 and BRCA2 patients, with impact also on prognosis and survival.

Histopathological features of breast tumours in BRCA1, BRCA2 and mutation-negative breast cancer families.

IntroductionHistopathological features of BRCA1 and BRCA2 tumours have previously been characterised and compared with unselected breast tumours; however, familial non-BRCA1/2 tumours are less well known. The aim of this study was to characterise familial non-BRCA1/2 tumours and to evaluate routine immunohistochemical and pathological markers that could help us to further distinguish families carrying BRCA1/2 mutations from other breast cancer families.MethodsBreast cancer tissue specimens (n = 262) from 25 BRCA1, 20 BRCA2 and 74 non-BRCA1/2 families were studied on a tumour tissue microarray. Immunohistochemical staining of oestrogen receptor (ER), progesterone receptor (PgR) and p53 as well as the histology and grade of these three groups were compared with each other and with the respective information on 862 unselected control patients from the archives of the Pathology Department of Helsinki University Central Hospital. Immunohistochemical staining of erbB2 was also performed among familial cases.ResultsBRCA1-associated cancers were diagnosed younger and were more ER-negative and PgR-negative, p53-positive and of higher grade than the other tumours. However, in multivariate analysis the independent factors compared with non-BRCA1/2 tumours were age, grade and PgR negativity. BRCA2 cases did not have such distinctive features compared with non-BRCA1/2 tumours or with unselected control tumours. Familial cases without BRCA1/2 mutations had tumours of lower grade than the other groups.ConclusionsBRCA1 families differed from mutation-negative families by age, grade and PgR status, whereas ER status was not an independent marker.