RE: Immune checkpoint profiles in luminal B breast cancer (Alliance)

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Emerging PARP inhibitors for treating breast cancer

International audienceSome breast cancers harbor defects in DNA repair pathways, including BRCA1 and BRCA2 mutations, leading to a genomic instability. Compromised DNA-damage repair response is found in 11 to 42% of triple negative breast cancers, with a frequency varying according to family history and ethnicity. The oral PARP inhibitors are a promising strategy in breast cancer exploiting Homologous Deficient Recombination deficiency (HRD) by a synthetic lethal approach. Several PARP inhibitors have currently reached early phase trials with studies on going in the adjuvant, neoadjuvant and metastatic setting. Area covered: Here, we review completed and ongoing trials with PARP inhibitors as well as their mechanisms of activity and acquired resistance. Expert opinion: PARP inhibitors show promising results in breast cancer. However, several issues are raised including the identification of biomarkers to predict treatment response and strategies to counteract emerging resistance

Vinflunine for the treatment of breast cancer

International audienceIntroduction: Breast cancer is the most frequently diagnosed cancer and the highest cause of cancer mortality in females worldwide. The development of drugs improving overall survival in late-stage metastatic breast cancer remains a challenge. Vinflunine is the most recently developed drug in the vinca alkaloid class. Its arrival has been eagerly awaited for treatment of solid tumors, and in particular, for metastatic breast cancer.Areas covered: The pharmacological features of vinflunine are described. Its clinical development as monotherapy or in combination in metastatic breast cancer is detailed. A literature search on the topic was conducted through PubMed, clinical trials and the proceedings of the main cancer congresses.Expert opinion: The overall results from phase III studies, and in particular those that combined vinflunine with capecitabine, have been less favorable. The combination's effectiveness was at best moderate compared with other drugs which also target metastatic breast cancer, and complicated by significant hematological and gastrointestinal adverse effects. Its use in advanced metastatic breast cancer cannot currently be recommended

Emerging PARP inhibitors for treating breast cancer

International audienceSome breast cancers harbor defects in DNA repair pathways, including BRCA1 and BRCA2 mutations, leading to a genomic instability. Compromised DNA-damage repair response is found in 11 to 42% of triple negative breast cancers, with a frequency varying according to family history and ethnicity. The oral PARP inhibitors are a promising strategy in breast cancer exploiting Homologous Deficient Recombination deficiency (HRD) by a synthetic lethal approach. Several PARP inhibitors have currently reached early phase trials with studies on going in the adjuvant, neoadjuvant and metastatic setting. Area covered: Here, we review completed and ongoing trials with PARP inhibitors as well as their mechanisms of activity and acquired resistance. Expert opinion: PARP inhibitors show promising results in breast cancer. However, several issues are raised including the identification of biomarkers to predict treatment response and strategies to counteract emerging resistance

Somatic mRNA Analysis of BRCA1 Splice Variants Provides a Direct Theranostic Impact on PARP Inhibitors

International audienceBACKGROUND:The identification of pretherapeutic somatic BRCA variants can have considerable clinical impact given that they affect response to the new poly (ADP-ribose) polymerase (PARP)-targeted therapy. One major issue with this type of testing is the identification of splicing variants of uncertain significance (VUS) on degraded somatic messenger RNA. It is therefore important to be able to quickly characterize these splice variants.OBJECTIVE:As part of PARP inhibitor targeted therapy, we have investigated a method for the direct confirmation of potential pathogenic somatic splice variants of BRCA1 found in fixed tumor samples. Previously these VUS have commonly only been tested by in silico analysis.METHODS:Five BRCA1 variants affecting splicing were characterized from formalin-fixed, paraffin-embedded (FFPE) ovarian carcinoma tissues by next-generation sequencing (NGS). Three patient samples had already been functionally characterized and were used as controls. Total somatic RNA from samples was extracted, reverse-transcribed, and amplified with several primer pairs encompassing the target exon. The polymerase chain reaction (PCR) products were analyzed by capillary gel electrophoresis to assess possible changes in size due to splicing alterations. Finally, we confirmed our results by cloning, followed by Sanger sequencing, and analyzed the expression of the aberrant forms.RESULTS:Our molecular approach made it possible to visualize the splicing outcomes of three variants (c.5194-2A>G, c.5434C>G, and c.547+1G>A) already identified and present in databases and/or identified with prediction tools (ClinVar, UMD, ARUP Utah database, and Human Splice Finder splices sites prediction) and to confirm their exon skipping consequences, their expression in tumors, and thus their pathogenicity. The c.4484+5G>A variant was not found in databases and was predicted to have no impact on splicing, but was found to display altered processing in tumor tissue. This variant also had a major detrimental impact on transcriptional expression.CONCLUSION:In a break from purely in silico approaches, we propose a simple and rapid pretherapeutic functional analysis of somatic BRCA1 variants potentially involved in splicing alterations. This approach will allow more ovarian cancer patients to benefit from new therapies targeting PARP

A pharmacokinetic evaluation of alpelisib for the treatment of HR+, HER2-negative, PIK3CA-mutated advanced or metastatic breast cancer

International audienceIntroduction: In most cases, metastatic breast cancer remains an incurable disease. A PIK3CA mutation is detected in 30-40% of all hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-) advanced breast cancers. PIK3CA activating mutations have been linked to endocrine resistance. PI3K inhibitors therefore offer promising new therapeutic options for this disease. Areas covered: This review discusses the pharmacologic properties, preclinical development, clinical efficacy, and safety profile of alpelisib, a PI3K inhibitor indicated in HR+/HER2 - PIK3CA-mutated advanced breast cancer, describing current therapeutic indication and open questions. Expert opinion: Following results of the SOLAR-1 trial, alpelisib became the first PI3K inhibitor approved by the U.S. Food and Drug Administration, in combination with fulvestrant, for postmenopausal women and men with HR+/HER2 - PIK3CA-mutated advanced breast cancer following progression on or after an endocrine-based regimen. This trial showed a substantial improvement in progression-free survival. However, given the side effects of alpelisib, the treatment decision should follow a thorough benefit-risk assessment. The BYLieve trial suggests alpelisib-fulvestrant benefit after progression on CDK 4/6 inhibitors. The identification of patients that are likely to benefit the most from PI3K inhibitors is still eagerly sought

Proteomics Approaches to Define Senescence Heterogeneity and Chemotherapy Response

International audienceIn primary cells, senescence induces a permanent proliferative arrest to prevent the propagation of malignant cells. However, the outcome of senescence is more complex in advanced cancer cells where senescent states are heterogeneous. Here, this heterogeneity is discussed and it is proposed that proteomic analysis should be used to identify specific signatures of cancer cells that use this pathway as an adaptive mechanism. Since senescent cells produce an inflammatory secretome, MRM approaches and quantification with internal standards might be particularly suited to follow the expression of the corresponding markers in body fluids. Used in combination with imaging medical technics, a better characterization of senescence heterogeneity should help to monitor the response to chemotherapy treatment

Abstract P4-06-11: High immune response identified as a good prognostic factor by proteomic SWATH-MS approach in 157 ER+/HER2- early breast cancer

International audienceBackground: Estrogen positive/HER2 negative (ER+/HER2-) early (e) breast carcinoma (BC) is an heterogeneous entity, on the prognostic and predictive plan. Several prognostic multigene tests have been developed to identify patients in whom chemotherapy could be safely avoided. Proteomic is a complementary approach as variations in mRNA expression only account for ≈40% of the tumor-encoded protein range and it is taking into account, as other OMICs the tumoral microenvironment Sequential Windowed Acquisition of All Theoretical fragment (SWATH-MS) proteomic approach let an accurate and reproducible label-free quantification of large proteome. To our knowledge, no study has been conducted in a large cohort of luminal BC by SWATH-MS. The aim of this study was to establish a proteomic cartography of ER+/HER2- eBC and identify prognostic biomarkers. Methods: Frozen primary tumors were collected from 157 ER+/HER2- eBC treated in the ICO cancer center between 2006 and 2009. Patients were included if they fulfilled the following criteria: 1) ductal carcinoma; 2) unilateral; 3) first occurrence; 4) have received adjuvant chemotherapy. Clinicopathologic characteristics as outcomes were collected. Each sample was analyzed using SWATH-MS acquisition method as previously described (Aebersold et al, 2012). Peak extraction of the SWATH data was performed using either the Spectronaut software (ver 8.0, Biognosys, Switzerland). Peptide identification results were filtered with a q-value of < 1%. We performed clustering analysis (fuzzy clustering method) based on the 15% of most variant proteins. Functional annotation of clusters based on GO biological process terms enrichment (GOEA) was performed by means of ToppGene and GORILLA web tools. Results: The median of follow-up was 8.34 years. Respectively 32, 4 and 7 patients presented a metastatic, locoregional and controlateral recurrence. 684 among 4555 proteins represented the 15% of most variants proteins.Two ER+/HER2- eBC clusters were identified (C1 [23%] and C2 [77%]) by means of fuzzy clustering and GOEA. Two significant clinicopathological differences were observed between the two subgroups: more unifocal tumors in C1 (P = 0.0415) and mostly a clear better outcome in term of Disease Free Survival (DFS), Distant DFS (DDFS) and Overall survival (OS) in patients belonging to C2 (cf table 1). Functional annotation found that C1 was characterized by mRNA processing and protein synthesis (GO:0006396: RNA processing; GO:0008380: RNA splicing; GO:0016071: mRNA metabolic process; GO:0022613: ribonucleoprotein complex biogenesis), and C2 by a high immune response (GO:0002757: immune response-activating signal transduction; GO:0050778: positive regulation of immune response; GO:0002253: activation of immune response; GO:0050776: regulation of immune response). Differential protein expression according to the C1-C2 clusters will be presented at the meeting. Conclusion: Proteomic cartography by SWATH-MS can clearly distinguish two ER+/HER2- eBC subgroups with clear different prognosis with a better outcome for C2 patients compared to C1 patients. High immune response observed in C2 could underlie this difference with results that must be confirmed on external cohort. Nevertheless this approach could be considered as a complementary approach, helpful for clinical decision for administration of adjuvant treatment