Ovarian Cancer: BRCA Genetics Reveals Targets for New Therapies (original) (raw)
Related papers
BRCAness: Finding the Achilles Heel in Ovarian Cancer
The Oncologist, 2012
Ovarian cancer is the leading cause of death among gynecological cancers. It exhibits great heterogeneity in tumor biology and treatment response. Germline mutations of DNA repair genes BRCA1/2 are the fundamental defects in hereditary ovarian cancer that expresses a distinct phenotype of high response rates to platinum agents, improved disease-free intervals and survival rates, and high-grade serous histology. The term “BRCAness” describes the phenotypic traits that some sporadic ovarian tumors share with tumors in BRCA1/2 germline mutation carriers and reflects similar causative molecular abnormalities. BRCA pathway studies and molecular profiling reveal BRCA-related defects in almost half of the cases of ovarian cancer. BRCA-like tumors are particularly sensitive to DNA-damaging agents (e.g., platinum agents) because of inadequate BRCA-mediated DNA repair mechanisms, such as nucleotide-excision repair and homologous recombination (HR). Additional inhibition of other DNA repair pa...
BRCA1/2 genetic background-based therapeutic tailoring of human ovarian cancer: hope or reality?
Journal of Ovarian Research, 2009
Ovarian epithelial tumors are an hallmark of hereditary cancer syndromes which are related to the germ-line inheritance of cancer predisposing mutations in BRCA1 and BRCA2 genes. Although these genes have been associated with multiple different physiologic functions, they share an important role in DNA repair mechanisms and therefore in the whole genomic integrity control. These findings have risen a variety of issues in terms of treatment and prevention of breast and ovarian tumors arising in this context. Enhanced sensitivity to platinum-based anticancer drugs has been related to BRCA1/2 functional loss. Retrospective studies disclosed differential chemosensitivity profiles of BRCA1/2-related as compared to "sporadic" ovarian cancer and led to the identification of a "BRCA-ness" phenotype of ovarian cancer, which includes inherited BRCA1/ 2 germ-line mutations, a serous high grade histology highly sensitive to platinum derivatives. Molecularly-based tailored treatments of human tumors are an emerging issue in the "era" of molecular targeted drugs and molecular profiling technologies. We will critically discuss if the genetic background of ovarian cancer can indeed represent a determinant issue for decision making in the treatment selection and how the provocative preclinical findings might be translated in the therapeutic scenario. The presently available preclinical and clinical evidence clearly indicates that genetic background has an emerging role in treatment individualization for ovarian cancer patients.
International Journal of Cancer, 2019
BRCA1-driven ovarian cancers (OC) are characterized by intratumoural heterogeneity: while the majority of malignant cells demonstrate somatic loss of the remaining BRCA1 allele, there are This article is protected by copyright. All rights reserved. persistent cells with preserved BRCA1 function. These BRCA1-proficient tumour cells rapidly repopulate tumour mass during neoadjuvant chemotherapy. OC relapses arising after treatment holidays are characterized by reappearance of somatic BRCA1 inactivation. This plasticity of BRCA1 status explains failures of systemic therapy to eradicate tumour clones and accounts for platinum sensitivity of recurrent BRCA1-driven OC.
2016
Ovarian cancer (OC) is the seventh most common cancer in women. Although women diagnosed with OC are usually treated frontline with platinum-based chemotherapy, most of them relapse once treatment is halted. Therefore, maintenance therapies have been developed to secure the response and delay further chemotherapy. There are two established maintenance therapies for women affected by platinum-sensitive recurrent OC: bevacizumab, a humanized monoclonal antibody targeting vascular endothelial growth factor, and olaparib, an inhibitor of poly (adenosine diphosphate [ADP]-ribose) polymerase (PARPi). Loss-of-function mutations in genes in the homologous recombination pathway, especially BRCA1 and BRCA2, predict higher rates of platinum sensitivity, better overall survival (OS), and better response to PARPi in women with OC. Among patients with platinum-sensitive recurrent OC, a BRCA mutation is the first genetically defined predictive marker for targeted therapy, since these patients are ...
JAMA, 2011
Context Attempts to determine the clinical significance of BRCA1/2 mutations in ovarian cancer have produced conflicting results. Objective To determine the relationships between BRCA1/2 deficiency (ie, mutation and promoter hypermethylation) and overall survival (OS), progression-free survival (PFS), chemotherapy response, and whole-exome mutation rate in ovarian cancer. Design, Setting, and Patients Observational study of multidimensional genomics and clinical data on 316 high-grade serous ovarian cancer cases that were made public between 2009 and 2010 via The Cancer Genome Atlas project. Main Outcome Measures OS and PFS rates (primary outcomes) and chemotherapy response (secondary outcome). Results BRCA2 mutations (29 cases) were associated with significantly better OS (adjusted hazard ratio [HR], 0.33; 95% CI, 0.16-0.69; P=.003 and 5-year OS, 61% for BRCA2-mutated vs 25% for BRCA wild-type cases) and PFS (adjusted HR, 0.40; 95% CI, 0.22-0.74; P=.004 and 3-year PFS, 44% for BRCA2-mutated vs 16% for BRCA wild-type cases), whereas neither BRCA1 mutations (37 cases) nor BRCA1 methylation (33 cases) was associated with prognosis. Moreover, BRCA2 mutations were associated with a significantly higher primary chemotherapy sensitivity rate (100% for BRCA2-mutated vs 82% [P=.02] and 80% [P=.05] for BRCA wild-type and BRCA1mutated cases, respectively) and longer platinum-free duration (median platinumfree duration, 18.0 months for BRCA2-mutated vs 11.7 [P=.02] and 12.5 [P=.04] months for BRCA wild-type and BRCA1-mutated cases, respectively). BRCA2mutated, but not BRCA1-mutated cases, exhibited a "mutator phenotype" by containing significantly more mutations than BRCA wild-type cases across the whole exome (median mutation number per sample, 84 for BRCA2-mutated vs 52 for BRCA wildtype cases, false discovery rate Ͻ0.1). Conclusion Among women with high-grade serous ovarian cancer, BRCA2 mutation, but not BRCA1 deficiency, was associated with improved survival, improved chemotherapy response, and genome instability compared with BRCA wild-type.
Journal of Ovarian Research, 2019
Epithelial ovarian cancer is the most lethal gynecologic malignancy. In most women, it is diagnosed at an advanced stage, which largely explains the poor prognosis of this malignancy. Germline mutations of the genes BRCA1 and BRCA2, which encode proteins essential for the repair of double-strand DNA breaks through homologous recombination, lead to increased cancer predisposition. BRCA mutations are present in approximately 14% of epithelial ovarian cancers. Somatic BRCA mutations have also been described. Current first-line treatment of highgrade epithelial ovarian cancer includes debulking surgery followed by combination chemotherapy, usually carboplatin and paclitaxel. Ovarian cancer is highly sensitive to chemotherapy, in particular to platinum drugs. Most patient will achieve remission with initial chemotherapy, but most will eventually experience disease recurrence. Targeted therapies, including the anti-angiogenic agent bevacizumab and oral poly (ADP-ribose) polymerase (PARP) inhibitors, have been recently approved for the treatment of ovarian cancer, based on the results from randomized clinical trials showing significant benefits in terms of progression-free survival, with acceptable tolerability and no detrimental effects on quality of life. Olaparib, the first PARP inhibitor to be granted approval, is currently indicated as maintenance monotherapy in ovarian cancer patients with relapsed disease and mutated BRCA who have achieved a complete or partial response to platinum-based chemotherapy. The analysis of BRCA mutational status has, therefore, also become crucial for therapeutic decisions. Such advances are making personalized treatment of ovarian cancer feasible. Here we briefly review treatments for platinum-sensitive, high-grade serous epithelial ovarian cancer that are currently available in Italy, with a focus on targeted therapies and the relevance of BRCA mutational analysis. Based on the evidence and on current guidelines, we propose strategies for the tailored treatment of patients with relapsed ovarian cancer that take into account BRCA mutational status and the treatment received in the first-line setting.
Cancer Research, 2009
Acquired platinum resistance is a serious problem in the treatment of ovarian carcinomas. However, the mechanism of the drug resistance has not been elucidated. Here, we show functional significance of restoration of BRCA2 protein by secondary BRCA2 mutations in acquired drug resistance of BRCA2-mutated ovarian carcinoma. Three ovarian cancer cell lines (PEO1, PEO4 and PEO6) were derived from a BRCA2 mutation (5193C>G (Y1655X)) carrier with ovarian carcinoma with acquired cisplatin resistance and a secondary BRCA2 mutation (5193C>T (Y1655Y)) that canceled the inherited mutation. PEO1 was BRCA2-deficient and sensitive to cisplatin and a poly(ADP-ribose) polymerase inhibitor, AG14361, while PEO4 was resistant. PEO4 and PEO6, derived from ascites at the time of relapse with cisplatin resistance, had the secondary mutation and were BRCA2proficient. In vitro cisplatin/AG14361 selection of PEO1 led to restoration of BRCA2 due to another secondary BRCA2 mutation. BRCA2 depletion sensitized BRCA2-restored PEO1 clones and PEO4 to cisplatin/AG14361. Thus, restoration of BRCA2 due to secondary BRCA2 mutation is involved in acquired drug resistance of BRCA2-mutated ovarian carcinoma.
The DNA repair proteins BRCA1 and ERCC1 as predictive markers in sporadic ovarian cancer
International Journal of Cancer, 2009
This study compares Breast Cancer 1 (BRCA1) and excision repair cross complementation group 1 (ERCC1) expression as predictive markers and evaluates the in vitro enhancement of platinum sensitivity using targeted agents in sporadic ovarian cancer (OC). A retrospective study was performed of advanced stage OC patients receiving platinum-based chemotherapy. BRCA1 and ERCC1 mRNA expression was determined from frozen tissue of 51 patients. Median overall survival (OS) was longer for patients with lower BRCA1 vs. higher BRCA1 (46 vs.33 months, p = 0.03). High BRCA1 was predictive of poorer OS specifically in patients with residual disease (RD) <2 cm (p = 0.03). There was a non-significant association for patients with lower ERCC1 and RD <2 cm in favor of improved OS and time to progression. Patients who expressed higher levels of both BRCA1 and ERCC1 mRNA had a shorter OS compared to patients with lower levels of either or both transcript (33 vs.46 months, p = 0.04). When Cox proportional modeling was used by representing BRCA1 and ERCC1 mRNA expression as a continuous variable, both emerge as potential predictors of survival. OC cell lines were exposed to chemotherapy in combination with DNA repair pathway inhibitors and cell viability was assessed. In vitro histone deacetylase (HDAC) inhibition increased the sensitivity of A2780s/cp cells to cisplatin and carboplatin but not to taxol, coincident with a significant decrease in BRCA1 and ERCC1 expression, suggesting that this compound directly targets DNA repair. In summary, this study shows that low BRCA1 and ERCC1 expression correlate with improved survival in advanced OC and HDAC inhibition induces synergistic cytotoxicity with platinum in vitro. © 2008 Wiley-Liss, Inc.