Project description:PurposeTriple-negative breast cancer (TNBC) is a highly heterogeneous disease and has the worst outcome among all subtypes of breast cancers. Although PARP inhibitors represent a promising treatment in TNBC with BRCA1/BRCA2 mutations, there is great interest in identifying drug combinations that can extend the use of PARP inhibitors to a majority of TNBC patients with wild-type BRCA1/BRCA2 Here we explored whether mTOR inhibitors, through modulating homologous recombination (HR) repair, would provide therapeutic benefit in combination with PARP inhibitors in preclinical models of BRCA-proficient TNBC.Experimental designWe have studied the effects of mTOR inhibitors on HR repair following DNA double-strand breaks (DSB). We further demonstrated the in vitro and in vivo activities of combined treatment of mTOR inhibitors with PARP inhibitors in BRCA-proficient TNBC. Moreover, microarray analysis and rescue experiments were used to investigate the molecular mechanisms of action.ResultsWe found that mTOR inhibitors significantly suppressed HR repair in two BRCA-proficient TNBC cell lines. mTOR inhibitors and PARP inhibitors in combination exhibited strong synergism against these TNBC cell lines. In TNBC xenografts, we observed enhanced efficacy of everolimus in combination with talazoparib (BMN673) compared with either drug alone. We further identified through microarray analysis and by rescue assays that mTOR inhibitors suppressed HR repair and synergized with PARP inhibitors through regulating the expression of SUV39H1 in BRCA-proficient TNBCs.ConclusionsCollectively, these findings strongly suggest that combining mTOR inhibitors and PARP inhibitors would be an effective therapeutic approach to treat BRCA-proficient TNBC patients.
Project description:Triple negative tumors represent 15% of breast cancer and are characterized by the lack of estrogen receptors, progesterone receptor, and HER2 amplification or overexpression. Approximately 25% of patients diagnosed with triple negative breast cancer carry a germline BRCA1 or BRCA2 mutation. They have an aggressive biology, and chemotherapy has been the mainstay of treatment for a long time. Despite intensive therapies, prognosis is still poor, and many patients will eventually relapse or die due to cancer. Therefore, novel targeted agents that can increase the treatment options for this disease are urgently needed. Recently, a new class of molecules has emerged as a standard of care for patients with triple negative breast cancer and germline BRCA1 or BRCA2 mutation: poly (ADP-ribose) (PARP) inhibitors. In the first part of the review, we summarize and discuss evidence supporting the use of PARP inhibitors. Currently, two PARP inhibitors have been approved for triple negative metastatic breast cancer-olaparib and talazoparib-based on two phase III trials, which showed a progression-free survival benefit when compared to chemotherapy. Safety profile was manageable with supportive therapies and dose reductions/interruptions. In addition, other PARP inhibitors are currently under investigation, such as talazoparib, rucaparib, and veliparib. Subsequently, we will discuss the potential role of PARP inhibitors in the future. Clinical research areas are investigating PARP inhibitors in combination with other agents and are including patients without germline BRCA mutations: ongoing phase II/III studies are combining PARP inhibitors with immunotherapy, while phases I and II trials are combining PARP inhibitors with other targeted agents such as ATM and PIK3CA inhibitors. Moreover, several clinical trials are enrolling patients with somatic BRCA mutation or patients carrying mutations in genes, other than BRCA1/2, involved in the homologous recombination repair pathway (e.g., CHECK2, PALB2, RAD51, etc.).
Project description:BackgroundTriple negative breast cancers (TNBC) are associated with an aggressive clinical course, earlier recurrence and short survival. BRCA - mutated tumours represent up to 25% of all TNBC. BRCA status is being studied as a predictive biomarker of response to platinum agents. However, the predictive role of BRCA status is still uncertain in this setting. Since TNBC is a very heterogeneous group of diseases, it is important to identify subsets of TNBC patients that may benefit from platinum-based therapy. This study aims to establish if the presence of a germline BRCA mutation in women with TNBC improves the pathologic complete response (pCR) after neoadjuvant chemotherapy with platinum compounds.MethodsAn extensive literature search was performed in MEDLINE, EMBASE and LILACS databases, WHO (WHO International Clinical Trials Registry Platform) and the Cochrane Controlled Trials Register Database, for online trial registries and conference proceedings. The measurement of pCR was assessed by pathology review of breast specimen and lymph nodes.ResultsThe overall OR was computed using random effects models.Seven studies were included, comprising a total of 808 TNBC patients, among which 159 were BRCA mutated. Among mutated TNBC patients, 93 (93/159; 58.4%) achieved pCR, while 410 wildtype patients (410/808; 50.7%) showed pCR (OR 1.459 CI 95% [0.953-2.34] p = 0.082) although this result did not reach statistical significance.ConclusionsThis meta-analysis shows that the addition of platinum to chemotherapy regimens in the neoadjuvant setting increases pCR rate in BRCA - mutated as compared to wild-type TNBC patients. However, this trend did not achieve statistical significance.Trial registrationCRD42018092341.
Project description:PURPOSE:As triple-negative breast cancers are associated with earlier recurrences and poorer survival, optimal treatment of early-stage breast cancer is essential. Several retrospective studies in triple-negative breast cancer have reported conflicting results in overall survival in patients receiving neoadjuvant or adjuvant systemic therapy. This study aims to analyze outcomes of adjuvant versus neoadjuvant in patients with early-stage triple-negative breast cancer with and without BRCA germline mutations. METHODS:Patients with stage I or II triple-negative breast cancer who had BRCA testing were identified from a prospective cohort study of 4027 patients. Clinical, demographic, genetic test results, chemotherapy, recurrence, and survival data were analyzed. Overall survival and disease-free survival were estimated using the Kaplan-Meier method. RESULTS:319 patients with stage I and II triple-negative breast cancer who met eligibility criteria were included in the analysis. 187 received adjuvant chemotherapy (58.6%) and 132 received neoadjuvant chemotherapy (41.4%). 135 were BRCA positive (42.3%) and 184 were BRCA negative (57.7%). There was no significant association between overall survival or disease-free survival and treatment with neoadjuvant versus adjuvant in the overall cohort. Furthermore, there were no significant differences between patient subgroups (neoadjuvant BRCA positive, neoadjuvant BRCA negative, adjuvant BRCA positive, and adjuvant BRCA negative) with respect to either overall survival or disease-free survival. CONCLUSIONS:Neoadjuvant versus adjuvant with standard anthracycline- and taxane-containing regimens results in similar disease-free survival and overall survival among patients with stage I and II triple-negative breast cancer regardless of BRCA status. Further studies are needed to evaluate whether similar results are observed with newer agents.
Project description:PurposeTo determine whether specific somatic copy-number alterations detectable in circulating tumor DNA (ctDNA) from patients with metastatic triple-negative breast cancer (mTNBC) are associated with sensitivity to platinum chemotherapy.Materials and methodsIn this secondary analysis of a large cohort of patients with mTNBC whose ctDNA underwent ultralow-pass whole-genome sequencing, tumor fraction and somatic copy-number alterations were derived with the ichorCNA algorithm. Seventy-two patients were identified who had received a platinum-based chemotherapy regimen in the metastatic setting. Gene-level copy-number analyses were performed with GISTIC2.0. Cytobands were associated with progression-free survival (PFS) to platinum chemotherapy using Cox proportional hazards models. The Cancer Genome Atlas and Molecular Taxonomy of Breast Cancer International Consortium data sets were interrogated for frequency of significant cytobands in primary triple-negative breast cancer (pTNBC) tumors.ResultsAmong 71 evaluable patients, 17q21 and 17q22 amplifications were most strongly associated with improved PFS with platinum chemotherapy. There were no significant differences in clinicopathologic features or (neo)adjuvant chemotherapy among patients with 17q22 amplification. Patients with 17q22 amplification (n = 17) had longer median PFS with platinum (7.0 v 3.8 months; log-rank P = .015) than patients without 17q22 amplification (n = 54), an effect that remained significant in multivariable analyses (PFS hazard ratio 0.37; 95% CI, 0.16 to 0.84; P = .02). Among 39 patients who received the nonplatinum chemotherapy agent capecitabine, there was no association between 17q22 amplification and capecitabine PFS (log-rank P = .69). In The Cancer Genome Atlas and Molecular Taxonomy of Breast Cancer International Consortium, 17q22 amplification occurred in more than 20% of both pTNBC and mTNBC tumors, whereas 17q21 was more frequently amplified in mTNBC relative to pTNBC (16% v 8.1%, P = .015).ConclusionThe 17q22 amplicon, detected by ctDNA, is associated with improved PFS with platinum chemotherapy in patients with mTNBC and warrants further investigation.
Project description:This analysis was used to search for genes that were differentially expressed between cells treated with DMSO and those treated with the mTOR inhibitor everolimus.
Project description:Treatment of triple negative breast cancer (TNBC) has been a big challenge since it is defined. To date, platinum-based chemotherapy has played a significant role in the treatment of TNBC patients. However, some patients do not respond to platinum salts or gradually develop chemoresistance, resulting in little effect, or even some adverse effects. Here, we review numerous preclinical and clinical investigations to summarize possible mechanisms and potential predictive biomarkers of platinum in TNBC. The homologous recombination deficiency (HRD) resulting from the loss of BRCA function is the main rationale of platinum efficacy in TNBC. BRCA mutation and methylation have been demonstrated to be important potential biomarkers. Based on genome-wide effects, BRCA-like classifier can identify the functional loss of BRCA and work as the predictor. HRD score that is able to identify the "BRCAness" and predict the sensitivity of platinum is increasingly considered. Taken together, all findings suggest that HR deficiency profile encompassed by BRCA mutation and high HRD score could predict response to platinum, even to other DNA-damage inducing agents. p53 family members and molecular subtypes of TNBC are also important alternative considerations for predicting platinum response based on the preclinical trials. Currently, tumor infiltrating lymphocyte level and thrombocytopenia are emerging as predictive biomarkers.