Revised NCCN guidelines recommend that women ≤60 years with triple-negative breast cancer (TNBC) be referred for consideration of genetic counseling. Small, homogeneous samples have limited evaluation of BRCA mutation prevalence among different ethnicities affected by TNBC subtype. We sought to determine whether the prevalence of BRCA mutations within a TNBC cohort differs by demographic factors.
We performed a retrospective review of patients with TNBC referred for genetic counseling at two academic Hereditary Cancer Clinics between 2000 and 2012. Demographic data were collected, including age at diagnosis and race/ethnicity. Race was categorized as African American (AA), Ashkenazi Jewish (AJ), Asian, Caucasian, Hispanic, or other. Primary outcome was BRCA mutation status, analyzed by race/ethnicity and age at diagnosis.
A total of 469 patients with TNBC who underwent testing for BRCA genetic mutations were identified, of which 450 patients had evaluable BRCA testing results; 139 (30.8 %) had confirmed BRCA1 (n = 106) or BRCA2 (n = 32) mutations. BRCA mutation prevalence differed by ethnicity and race: AA (20.4 %), AJ (50 %), Asian (28.5 %), Caucasian (33.3 %), and Hispanic (20 %). The prevalence of genetic mutations also differed by age at diagnosis: <40 years (43.8 %), 40-49 years (27.4 %), 50-59 years (25.3 %), 60-69 years (12.5 %), and >70 years (16.6 %).
The prevalence of genetic mutations among women with TNBC referred for genetic counseling is high and differs significantly by ethnicity/race and age. This data helps to refine mutation risk estimates among women with TNBC, allowing for more personalized genetic counseling potentially aiding in improved patient decision-making.
"which is strongly connected with the loss of function of BRCA1/2 genes (Greenup et al., 2013). The association of TNBC with BRCA1 and BRCA2 mutations allows early identification of patients who were affected by hereditary cancer syndromes and it has important treatment implications for patients and their families (Greenup et al., 2013). To date, studies about miRNA alterations in TNBC were commonly performed in cell lines and clinical samples which have not been tested for BRCA mutations, and these studies were focused on determination of aberrant miRNA expression in this disease (Radojicic et al., 2011; Howe et al., 2012; Cascione et al., 2013; D'Ippolito and Iorio, 2013). "
"Germline mutations in the BRCA1 and BRCA2 breast cancer susceptibility genes have been associated with up to 15% of TNBC, and TNBC accounts for 70% of breast tumors arising in BRCA1 mutation carriers and 16–23% of breast tumors in BRCA2 carriers (8). Because BRCA1 and BRCA2 tumor suppressor genes play a key role in the control of genomic stability through regulation of DNA repair and centrosome duplication (9–11), these findings explain the causal role of BRCA1 and BRCA2 mutations in the development of high CIN commonly observed in TNBC tumors. "
[Show abstract][Hide abstract] ABSTRACT: Inflammatory breast cancer (IBC) is an angioinvasive and most aggressive type of advanced breast cancer characterized by rapid proliferation, chemoresistance, early metastatic development and poor prognosis. IBC tumors display a triple-negative breast cancer (TNBC) phenotype characterized by centrosome amplification, high grade of chromosomal instability (CIN) and low levels of expression of estrogen receptor α (ERα), progesterone receptor (PR) and HER-2 tyrosine kinase receptor. Since the TNBC cells lack these receptors necessary to promote tumor growth, common treatments such as endocrine therapy and molecular targeting of HER-2 receptor are ineffective for this subtype of breast cancer. To date, not a single targeted therapy has been approved for non-inflammatory and inflammatory TNBC tumors and combination of conventional cytotoxic chemotherapeutic agents remains the standard therapy. IBC tumors generally display activation of epithelial to mesenchymal transition (EMT) that is functionally linked to a CD44+/CD24-/Low stem-like phenotype. Development of EMT and consequent activation of stemness programming is responsible for invasion, tumor self-renewal and drug resistance leading to breast cancer progression, distant metastases and poor prognosis. In this study, we employed the luminal ER+ MCF-7 and the IBC SUM149PT breast cancer cell lines to establish the extent to which high grade of CIN and chemoresistance were mechanistically linked to the enrichment of CD44+/CD24low/- CSCs. Here, we demonstrate that SUM149PT cells displayed higher CIN than MCF-7 cells characterized by higher percentage of structural and numerical chromosomal aberrations. Moreover, centrosome amplification, cyclin E overexpression and phosphorylation of retinoblastoma (Rb) were restricted to the stem-like CD44+/CD24-/Low subpopulation isolated from SUM149PT cells. Significantly, CD44+/CD24-/Low CSCs displayed resistance to conventional chemotherapy but higher sensitivity to SU9516, a specific cyclin-dependent kinase 2 (Cdk2) inhibitor, demonstrating that aberrant activation of cyclin E/Cdk2 oncogenic signaling is essential for the maintenance and expansion of CD44+/CD24-/Low CSC subpopulation in IBC. In conclusion, our findings propose a novel therapeutic approach to restore chemosensitivity and delay recurrence of IBC tumors based on the combination of conventional chemotherapy with small molecule inhibitors of the Cdk2 cell cycle kinase.
International Journal of Oncology 06/2014; 45(3). DOI:10.3892/ijo.2014.2523 · 3.03 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: While the 5-year survival rate of breast cancer is at an all-time high of 90%, this disease remains the second most common cause of cancer-related death, surpassed only by lung cancer in the US. The reasons for this discrepancy stem from cancer subtypes which become resistant to current therapies. These subtypes: "Triple negative" and ErbB2-overexpressing, are discussed in this review.
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