Project description:RAF family proteins are serine-threonine kinases that play a central role in the MAPK pathway which is involved in embryogenesis, cell differentiation, cell proliferation and death. Deregulation of this pathway is found in up to 30% of all human cancers and BRAF mutations can be identified in 1.5-3.5% of NSCLC patients. Following the positive results obtained through the combination of BRAF and MEK inhibitors in BRAF-mutant melanoma, the same combination was prospectively assessed in BRAF-mutant NSCLC. In cohort B of the BRF113928 trial, 57 pretreated NSCLC patients were treated with dabrafenib plus trametinib: an ORR of 68.4%, a disease control rate of 80.7%, a median PFS of 10.2 months and a median OS of 18.2 months were observed. Similar results were reported in the first-line setting (cohort C), with an ORR of 63.9%, a DCR of 75% and a median PFS and OS of 10.2 and 17.3 months, respectively. The combination was well tolerated: the main adverse events were pyrexia (64%), nausea (56%), diarrhoea (56%), fatigue (36%), oedema (36%) and vomiting (33%). These positive results led to the approval of the combination of dabrafenib and trametinib for the treatment of BRAF V600E metastatic NSCLC patients regardless of previous therapy. Ongoing research should better define the role of new generation RAF inhibitors for patients with acquired resistance, the activity of chemo-immunotherapy or the combination of TKIs with chemotherapy or with immunotherapy in patients with BRAF-mutated cancers.
Project description:The role of microRNAs in small-cell lung carcinoma (SCLC) is largely unknown. miR-34a is known as a p53 regulated tumor suppressor microRNA in many cancer types. However, its therapeutic implication has never been studied in SCLC, a cancer type with frequent dysfunction of p53. We investigated the expression of a panel of 7 microRNAs (miR-21, miR-29b, miR-34a/b/c, miR-155, and let-7a) in 31 SCLC tumors, 14 SCLC cell lines, and 26 NSCLC cell lines. We observed significantly lower miR-21, miR-29b, and miR-34a expression in SCLC cell lines than in NSCLC cell lines. The expression of the 7 microRNAs was unrelated to SCLC patients' clinical characteristics and was neither prognostic in term of overall survival or progression-free survival nor predictive of treatment response. Overexpression or downregulation of miR-34a did not influence SCLC cell viability. The expression of these 7 microRNAs also did not predict in vitro sensitivity to cisplatin or etoposide in SCLC cell lines. Overexpression or downregulation of miR-34a did not influence sensitivity to cisplatin or etoposide in SCLC cell lines. In contrast to downregulation of the miR-34a target genes cMET and Axl by overexpression of miR-34a in NSCLC cell lines, the intrinsic expression of cMET and Axl was low in SCLC cell lines and was not influenced by overexpression of miR-34a. Our results suggest that the expression of the 7 selected microRNAs are not prognostic in SCLC patients, and miR-34a is unrelated to the malignant behavior of SCLC cells and is unlikely to be a therapeutic target.
Project description:BackgroundBRAF mutations occur in 2-4% non-small cell lung cancer (NSCLC) patients and can be categorized into three functional classes based on signaling mechanism and kinase activity: RAS-independent kinase-activating V600 monomers (class 1), RAS-independent kinase-activating dimers (class 2) and RAS-dependent kinase-inactivating heterodimers (class 3). The association between functional classes and clinical features in Chinese NSCLC patients remains unexplored. Our multi-center study aimed to survey the BRAF mutation rate and analyze the associated clinical features in this population.MethodsCapture-based sequencing data of either plasma or tissue samples obtained from 8405 Chinese stage I-IV NSCLC patients were retrospectively analyzed.ResultsBRAF mutations were detected in 238 patients, revealing an overall mutation rate of 2.8%. Among them, 32%, 21% and 13% had BRAF mutant class 1, 2 and 3 respectively. The remaining 34% had other BRAF mutations. V600 (32%) and G469 (13%) were the two most predominant BRAF mutations. Patients with class 2 and 3 mutations were more likely to have concurrent KRAS mutations (P = 0.001). Collectively, BRAF mutations, including non-class 1-3 mutations, were more likely to occur in males (P < 0.01). However, females were more likely to harbor class 1 mutations (P < 0.02). We also compared the overall survival (OS) of first-line chemotherapy-treated advanced-stage patients and revealed comparable OS among the three groups.ConclusionOur study revealed a 2.8% BRAF mutation rate in Chinese NSCLC patients. Our data also showed a male predominance when all BRAF mutations were considered collectively, and a female predominance for class 1 mutations. Furthermore, BRAF V600E is less likely to have concurrent KRAS mutations comparing to the other two classes.
Project description:BackgroundResistance mechanisms to combination therapy with dabrafenib plus trametinib remain poorly understood in patients with BRAFV600E-mutant advanced non-small-cell lung cancer (NSCLC). We examined resistance to BRAF inhibition by single CTC sequencing in BRAFV600E-mutant NSCLC.MethodsCTCs and cfDNA were examined in seven BRAFV600E-mutant NSCLC patients at failure to treatment. Matched tumour tissue was available for four patients. Single CTCs were isolated by fluorescence-activated cell sorting following enrichment and immunofluorescence (Hoechst 33342/CD45/pan-cytokeratins) and sequenced for mutation and copy number-alteration (CNA) analyses.ResultsBRAFV600E was found in 4/4 tumour biopsies and 5/7 cfDNA samples. CTC mutations were mostly found in MAPK-independent pathways and only 1/26 CTCs were BRAFV600E mutated. CTC profiles encompassed the majority of matched tumour biopsy CNAs but 72.5% to 84.5% of CTC CNAs were exclusive to CTCs. Extensive diversity, involving MAPK, MAPK-related, cell cycle, DNA repair and immune response pathways, was observed in CTCs and missed by analyses on tumour biopsies and cfDNA. Driver alterations in clinically relevant genes were recurrent in CTCs.ConclusionsResistance was not driven by BRAFV600E-mutant CTCs. Extensive tumour genomic heterogeneity was found in CTCs compared to tumour biopsies and cfDNA at failure to BRAF inhibition, in BRAFV600E-mutant NSCLC, including relevant alterations that may represent potential treatment opportunities.
Project description:The management of non-small cell lung cancer (NSCLC) has changed significantly with the discovery of specific drug targets. These drugs have helped transform patient care and outcomes. BRAF mutated NSCLC is now recognised as a rare form of lung cancer. Data has begun to emerge supporting the use of BRAF/MEK inhibitors that target BRAFV600E mutations in the mitogen-activated protein kinase (MAPK) pathway. Multiple phase 2 studies have been performed assessing the effectiveness of single agent BRAF inhibition and combination BRAF/MEK inhibition in pretreated and untreated patient populations. Consistently overall response rate (ORR) and progression free survival (PFS) are improved with the addition of a MEK inhibitor. A 2-cohort phase 2 study demonstrated an ORR of 33% vs. 67% and PFS of 5.5 vs. 10.2 months in those treated with single agent dabrafenib vs. dabrafenib and trametinib respectively. A similar ORR of 63% and PFS of 10.9 months was seen in a separate phase 2 study in patients treated with Dabrafenib and Trametinib in the first line setting. Immunotherapy is beginning to show promise as an active therapy in BRAF mutated NSCLC in both V600E and non-V600E subtypes; however, this requires further study and clarification. BRAFV600E mutated NSCLC treated with chemotherapy have been widely reported to be associated with worse outcomes when compared to those without a mutation. With efficacy of combination BRAF/MEK established and early evidence of immune checkpoint inhibitor activity careful consideration should be given when choosing the most appropriate therapy in this select patient cohort.
Project description:PURPOSE:BRAF mutations are found in a subset of non-small cell lung cancers (NSCLC). We examined the clinical characteristics and treatment outcomes of patients with NSCLC harboring BRAF mutations. EXPERIMENTAL DESIGN:Using DNA sequencing, we successfully screened 883 patients with NSCLC for BRAF mutations between July 1, 2009 and July 16, 2012. Baseline characteristics and treatment outcomes were compared between patients with and without BRAF mutations. Wild-type controls consisted of patients with NSCLC without a somatic alteration in BRAF, KRAS, EGFR, and ALK. In vitro studies assessed the biologic properties of selected non-V600E BRAF mutations identified from patients with NSCLC. RESULTS:Of 883 tumors screened, 36 (4%) harbored BRAF mutations (V600E, 18; non-V600E, 18) and 257 were wild-type for BRAF, EGFR, KRAS, and ALK negative. Twenty-nine of 36 patients with BRAF mutations were smokers. There were no distinguishing clinical features between BRAF-mutant and wild-type patients. Patients with advanced NSCLC with BRAF mutations and wild-type tumors showed similar response rates and progression-free survival (PFS) to platinum-based combination chemotherapy and no difference in overall survival. Within the BRAF cohort, patients with V600E-mutated tumors had a shorter PFS to platinum-based chemotherapy compared with those with non-V600E mutations, although this did not reach statistical significance (4.1 vs. 8.9 months; P = 0.297). We identified five BRAF mutations not previously reported in NSCLC; two of five were associated with increased BRAF kinase activity. CONCLUSIONS:BRAF mutations occur in 4% of NSCLCs and half are non-V600E. Prospective trials are ongoing to validate BRAF as a therapeutic target in NSCLC.
Project description:BackgroundNon-small-cell lung cancer (NSCLC) is characterized by abnormalities of numerous signaling proteins that play pivotal roles in cancer development and progression. Many of these proteins have been reported to be correlated with clinical outcomes of NSCLC. However, none of them could provide adequate accuracy of prognosis prediction in clinical application.MethodsA total of 384 resected NSCLC specimens from two hospitals in Beijing (BJ) and Chongqing (CQ) were collected. Using immunohistochemistry (IHC) staining on stored formalin-fixed paraffin-embedded (FFPE) surgical samples, we examined the expression levels of 75 critical proteins on BJ samples. Random forest algorithm (RFA) and support vector machines (SVM) computation were applied to identify protein signatures on 2/3 randomly assigned BJ samples. The identified signatures were tested on the remaining BJ samples, and were further validated with CQ independent cohort.ResultsA 6-protein signature for adenocarcinoma (ADC) and a 5-protein signature for squamous cell carcinoma (SCC) were identified from training sets and tested in testing sets. In independent validation with CQ cohort, patients can also be divided into high- and low-risk groups with significantly different median overall survivals by Kaplan-Meier analysis, both in ADC (31 months vs. 87 months, HR 2.81; P < 0.001) and SCC patients (27 months vs. not reached, HR 9.97; P < 0.001). Cox regression analysis showed that both signatures are independent prognostic indicators and outperformed TNM staging (ADC: adjusted HR 3.07 vs. 2.43, SCC: adjusted HR 7.84 vs. 2.24). Particularly, we found that only the ADC patients in high-risk group significantly benefited from adjuvant chemotherapy (P = 0.018).ConclusionsBoth ADC and SCC protein signatures could effectively stratify the prognosis of NSCLC patients, and may support patient selection for adjuvant chemotherapy.
Project description:ObjectivesThis retrospective study investigated prognostic factors in advanced non-small cell lung cancer (NSCLC) with bone-only metastasis, and developed a graded prognostic assessment (GPA) model to estimate patient survival.MethodsThe primary endpoint was overall survival. We investigated the patients with advanced NSCLC with bone-only metastasis at the initial diagnosis and diagnosed between 2013 and 2019 in our hospital. A log-rank test and Cox proportional hazards model were used to examine factors. A GPA model was developed in the training set based on the factors that were determined significant according to their hazard ratios and verified by the validation set.ResultsWe finally included 220 patients for analysis. These patients were divided into two groups, 147 cases for the training cohort and 73 for the validation cohort. The following were significant independent prognostic factors, and were included in the GPA model: smoking; EGFR (epidermal growth factor receptor) sensitive/ALK (anaplastic lymphoma kinase) mutations; loss of weight; hypoalbuminemia; and primary site treated by surgery or radiotherapy. GPA score of nil was assigned to smoking, without sensitive mutations, loss of weight, hypoalbuminemia, and without local treatment of primary site; the corresponding superior alternatives were scored 1.5, 2.0, 1.5, 1.5, and 1.5, respectively. The median survival times of patients with GPA scores of nil to 3.0, 3.5 to 6.0, and 6.5 to 8.0 were 14.2, 29.5, and 56.6 months in the training set (P < 0.001) and 15.2, 31.2, and 54.0 months in the validation set (P < 0.001).ConclusionThe survival time of patients with NSCLC with bone-only metastasis was dramatically influenced by the presence of the determined prognostic factors. The GPA model developed in this study may be a useful clinical tool to estimate the life expectancy of these patients, and guide treatment.
Project description:IntroductionBRAF mutation involved 2-4% of lung adenocarcinoma. Differences in clinicopathologic features and patient outcome exist between V600E and non-V600E BRAF mutated NSCLC. Thus, we sought to assess the frequency and clinical relevance of BRAF mutations in a real-life population of advanced-NSCLC, investigating the potential prognostic significance of distinct genetic alterations.Materials and methodsThe present multicenter Italian retrospective study involved advanced BRAF mutant NSCLC. Complete clinicopathologic data were evaluated for BRAF V600E and non-V600E patients.ResultsA total of 44 BRAFmut NSCLC patients were included (V600E, n = 23; non-V600E, n = 21). No significant differences in survival outcome and treatment response were documented, according to V600E vs. non-V600E mutations, although a trend towards prolonged PFS was observed in the V600E subgroup (median PFS = 11.3 vs. 6.0 months in non-V600E). In the overall population, ECOG PS and age significantly impacted on OS, while bone lesions were associated with shorter PFS. Compared to immunotherapy, first-line chemotherapy was associated with longer OS in the overall population, and especially in the BRAF V600E subtype.ConclusionsHere, we report on real-life data from a retrospective cohort of advanced-NSCLC harboring BRAF alterations. Our study offers relevant clues on survival outcome, therapeutic response, and clinicopathologic correlations of BRAF-mutant NSCLC.