BRAF V600E mutations: a series of case reports in patients with non-small cell lung cancer

Clinical and genetic characteristics of early-stage multiple primary and independent primary lung adenocarcinoma patients

AIMS

The difference between multiple primary lung cancers (MPLC) and intrapulmonary metastasis (IM) in patients with lung cancer is vital but controversial. Moreover, the genetic and clinical significance difference between MPLC and independent primary lung cancers (IPLC) patients is unknown.

METHODS

This study retrospectively researched clinical and genetic data of MPLC and IPLC patients from January 2019 to May 2021 at the affiliated hospital of Qingdao University, China. Ninety-four tissue samples from 41 early-stage patients with MPLC, and 94 tissue samples from 94 early-stage patients with IPLC were performed to targeted sequencing.

RESULTS

A total of 36 patients (88%) showed inconsistent driver mutations, and five MPLC patients (12%) shared single identical EGFR/BRAF/TP53 hotspot mutations in the early stage. In MPLC patients, high-frequency mutations included EGFR (63%), TP53 (12%), BRAF (12%), KRAS (10%), ERBB2 (4%), PIK3CA (3%), and MET (3%). In IPLC patients, high-frequency mutations included EGFR (55%), TP53(26%), KRAS (13%), MAP2K1 (5%), PIK3CA (4%), ERBB2 (4%), NF1 (4%), RET (3%), and BRAF (2%). The higher BRAF and fewer TP53 mutations may be related to the lower malignancy in MPLC patients.

CONCLUSIONS

The accuracy of pathological diagnosis in patients with early-stage MPLC does not need comprehensive molecular evaluation to supplement histology for differentiating early-stage MPLC and IM. Meanwhile, the molecular difference between MPLC and IPLC may be helpful to study the mechanism of MPLC pathogenesis.

Natural Disease History, Outcomes, and Co-mutations in a Series of Patients With BRAF-Mutated Non-small-cell Lung Cancer

BACKGROUND

BRAF mutations occur in 1% to 4% of non-small-cell lung cancer (NSCLC) cases. Previous retrospective studies have reported similar outcomes for BRAF-mutated NSCLC as compared with wild-type tumors without a known driver mutation or tumors harboring other mutations. However, select cases of prolonged survival have also been described, and thus, the natural history of BRAF-mutated NSCLC remains an area of ongoing study. The aim of this series was to describe the natural history, clinical outcomes, and occurrence of co-mutations in patients with BRAF-mutated NSCLC.

PATIENTS AND METHODS

Patients with BRAF-mutated NSCLC seen at Stanford University Medical Center from January 1, 2006 through July 31, 2015 were reviewed. The Kaplan-Meier method was used to calculate median overall survival, and the generalized Wilcoxon test was used to compare median survivals across subgroups of patients.

RESULTS

Within a cohort of 18 patients with BRAF-mutated NSCLC, V600E mutations were most common (72%; 13/18). Clinicopathologic features were similar between patients with V600E versus non-V600E mutations, although there was a trend toward more patients with non-V600E mutations being heavy smokers (80% vs. 31%; P = .12). Co-occurring mutations in TP53 were identified most commonly (28%; 5/18). The median overall survival for the entire cohort was 40.1 months, and the median survival from the onset of metastases (n = 16) was 28.1 months. Survival rates at 2 and 5 years from the onset of metastases were 56% and 13%, respectively.

CONCLUSION

The clinical behavior of BRAF-mutated NSCLC is variable, but favorable outcomes can be seen in a subset of patients.

Emerging targets in advanced non-small-cell lung cancer

New therapeutic options in non-small-cell lung cancer have been available through a great in-depth and genomic research, improving preclinical disease patterns and identifying the specific toxicity of target therapy. The multidisciplinary approach, increasingly practiced among clinicians, researchers, pharmaceutical companies and ethics committees has allowed the emergence of a new generation of translational clinical trials and the adoption of new technologies (e.g., point-of-care sequencing), then speeding up the development and trade of these new drugs. Consequently, there is a long list of therapeutic candidates that need to be efficiently evaluated early in the context of Phase I clinical trials. In this review, we discuss some of the key developments and novelties in the main histological groups.

Targeted drugs for systemic therapy of lung cancer with brain metastases

Brain metastases are very common in lung cancer patients. The condition of these patients is complicated and difficult to treat, and adverse reactions following treatment can affect the nervous system, which severely reduces quality of life. Lung cancers are categorized as small cell lung cancers and non-small cell lung cancers. Patients with brain metastasis of small cell lung cancers are generally treated with brain radiotherapy and systemic chemotherapy, but stage III/IV patients with brain metastasis of non-small cell lung cancers are generally not responsive to radiotherapy or chemotherapy. With the recent development of targeted drugs, tumor molecular profile detection allows the selection of appropriate targeted drugs for adjuvant pharmacological treatment of brain metastasis in lung cancer patients. In recent years, immune checkpoint inhibitors have emerged and have been approved by the Food and Drug Administration (FDA) for the treatment of certain cancers, but their efficacy in lung cancer patients with brain metastases still needs to be confirmed. This paper focuses on highlighting drugs for targeted therapy of brain metastasis in lung cancer patients and their molecular targets and mechanisms of drug resistance.

Targeting BRAF-Mutant Non-Small Cell Lung Cancer: From Molecular Profiling to Rationally Designed Therapy

Non-small cell lung cancer (NSCLC) remains the leading cause of cancer-related deaths globally. However, the identification of oncogenic driver alterations involved in the initiation and maintenance of NSCLC, such as epidermal growth factor receptor mutations and anaplastic lymphoma kinase translocation, has led to the development of novel therapies that directly target mutant proteins and associated signaling pathways, resulting in improved clinical outcomes. As sequencing techniques have improved, the molecular heterogeneity of NSCLC has become apparent, leading to the identification of a number of potentially actionable oncogenic driver mutations. Of these, one of the most promising therapeutic targets is B-Raf proto-oncogene, serine/threonine kinase (BRAF). Mutations in BRAF, observed in 2%-4% of NSCLCs, typically lead to constitutive activation of the protein and, as a consequence, lead to activation of the mitogen-activated protein kinase signaling pathway. Direct inhibition of mutant BRAF and/or the downstream mitogen-activated protein kinase kinase (MEK) has led to prolonged survival in patients with BRAF-mutant metastatic melanoma. This comprehensive review will discuss the clinical characteristics and prognostic implications of BRAF-mutant NSCLC, the clinical development of BRAF and MEK inhibitors from melanoma to NSCLC, and practical considerations for clinicians involving BRAF mutation screening and the choice of targeted therapy.

IMPLICATIONS FOR PRACTICE

Personalized medicine has begun to provide substantial benefit to patients with oncogene-driven non-small cell lung cancer (NSCLC). However, treatment options for patients with oncogenic driver mutations lacking targeted treatment strategies remain limited. Direct inhibition of mutant B-Raf proto-oncogene, serine/threonine kinase (BRAF) and/or downstream mitogen-activated protein kinase kinase (MEK) has the potential to change the course of the disease for patients with BRAF-mutant NSCLC, as it has in BRAF-mutant melanoma. Optimization of screening strategies for rare mutations and the choice of appropriate agents on an individual basis will be key to providing timely and successful intervention.

New strategies for targeting drug combinations to overcome mutation-driven drug resistance

Targeted therapies are suggested as an effective alternative for patients with cancer that harbor mutations, but treatment outcomes are frequently limited by primary or acquired drug resistance. The present review describes potential mechanisms of primary or acquired drug resistances to provide a resource for considering how to be overcome. We focus on strategies of targeted drug combinations to minimize the development of drug resistance within the context how resistance develops. Strategies benefit from the combined use of "omics" technologies, i.e., high-throughput functional genomics data, pharmacogenomics, or genome-wide CRISPR-Cas9 screening, to analyze and design targeted drug combinations for mutation-driven drug resistance. We also introduce new insights towards pathway-centric combined therapies as an alternative to overcome the heterogeneity and benefit patient prognoses.

Efficacy of sorafenib in BRAF-mutated non-small-cell lung cancer (NSCLC) and no response in synchronous BRAF wild type-hepatocellular carcinoma: a case report

BACKGROUND

Sorafenib is a multi-targeted kinase inhibitor with a demonstrated activity in renal cell carcinoma (RCC) and hepatocellular carcinoma (HCC), and it is currently used for the treatment of these pathologies. Ongoing clinical trials are studying its activity in other malignancies, such as non-small-cell lung cancer (NSCLC). However, no biological marker is known to define either the sensitivity or resistance to the drug.

CASE PRESENTATION

Here we report a case of a patient with two synchronous tumors, HCC and NSCLC, with metastases in the contralateral lung and bone. The patient was treated with gemcitabine as first line, with a resulting progressive disease after two months, and then with sorafenib at standard dosage in the second line setting. After 6 months of treatment CT scan showed a partial response in the primary lesion of the lung, complete response of the metastasis in the contralateral lung, and stability of HCC. The patient had progression in the lung, liver and bone after 13 months of therapy. A molecular characterization of NSCLC and HCC lesions was performed, revealing a BRAF exon 11 mutation (G469V) only in NSCLC. We hypothesize that the response observed in NSCLC lesions could be due to the presence of BRAF mutation, and that this alteration could be responsible in determining sorafenib sensitivity.

CONCLUSIONS

Results observed in this case encourage further research on the activity of sorafenib in both HCC and NSCLC, based on the presence of BRAF mutation. This could lead to a selection of HCC patients to be treated with this drug, and could help identify a novel treatment strategy for BRAF-mutated NSCLC patients.

Management of advanced non-small cell lung cancers with known mutations or rearrangements: latest evidence and treatment approaches

Precision oncology is now the evidence-based standard of care for the management of many advanced non-small cell lung cancers (NSCLCs). Expert consensus has defined minimum requirements for routine testing and identification of epidermal growth factor (EGFR) mutations (15% of tumors harbor EGFR exon 19 deletions or exon 21 L858R substitutions) and anaplastic lymphoma kinase (ALK) rearrangements (5% of tumors) in advanced lung adenocarcinomas (ACs). Application of palliative targeted therapies with oral tyrosine kinase inhibitors (TKIs) in advanced/metastatic lung ACs harboring abnormalities in EGFR (gefitinib, erlotinib, afatinib) and ALK/ROS1/MET (crizotinib) has consistently led to more favorable outcomes compared with traditional cytotoxic agents. In addition, mutations leading to resistance to first-line EGFR and ALK TKIs can now be successfully inhibited by soon to be approved third-generation EGFR TKIs (osimertinib, rociletinib) and second-generation ALK TKIs (ceritinib, alectinib). Notably, increasing feasibility, accessibility, and application of molecular profiling technologies has permitted dynamic growth in the identification of actionable driver oncogenes. Emerging genomic aberrations for which TKIs have shown impressive results in clinical trials and expansion of drug labels for approved agents are awaited include ROS1 rearrangements (1-2% of tumors, drug: crizotinib) and BRAF-V600E mutations (1-3% of tumors, drugs: vemurafenib, dafrafenib + trametinib). Evolving genomic events in which TKI responses have been reported in smaller series include MET exon 14 skipping mutations (2-4% of tumors, drug: crizotinib); high-level MET amplification (1-2% of tumors, drug: crizotinib); RET rearrangements (1% of tumors, drug: cabozantinib); and ERBB2 mutations (2-3% of tumors, drug: afatinib), among others. Unfortunately, the most common genomic event in NSCLC, KRAS mutations (25-30% of tumors), is not targetable with approved or in development small molecule inhibitors. Here, we review currently approved, emerging, and evolving systemic precision therapies matched with their driver oncogenes for the management of advanced NSCLC.