The effectiveness of afatinib and osimertinib in a Chinese patient with advanced lung adenocarcinoma harboring a rare triple EGFR mutation (R670W/H835L/L833V): a case report and literature review

The effectiveness of sequential afatinib and furmonertinib in an advanced lung adenocarcinoma with rare compound EGFR mutation (L833V/H835L)

Uncommon atypical mutations account for 10-15% of all epidermal growth factor receptor (EGFR) activating mutations in nonsmall-cell lung cancer (NSCLC). Tumors harboring rare EGFR mutations show highly heterogeneous responses to EGFR tyrosine kinase inhibitors (TKIs). There is insufficient clinical evidence for uncommon types of EGFR mutations, especially those with compound EGFR mutations. In addition, for those with uncommon compound EGFR mutations, few studies have focused on acquired resistance mechanisms and subsequent treatment strategies after disease progression on EGFR-TKIs. Here, a 66-year-old smoking male was diagnosed with lung adenocarcinoma accompanied by pleural metastasis. A rare L833V/H835L compound mutation in exon 21 of EGFR was detected in tumor biopsy by next-generation sequencing. Afatinib was used as first-line therapy and showed favorable efficacy. The patient continued afatinib treatment for a duration of 24 months. A new T790M mutation was detected with a rebiopsy after progression on afatinib. Then the patient received cryoablation therapy and a third-generation EGFR-TKI, furmonertinib. Our case suggests that a comprehensive screening for EGFR mutations should be conducted before and during treatment in clinical practice, and afatinib and furmonertinib could be first- and second-line treatment options in NSCLC patients harboring EGFR L833V/H835L mutations.

Osimertinib treatment response in a patient with lung adenocarcinoma harboring two rare EGFR mutations: A case report

Epidermal growth factor receptor (EGFR) mutations have emerged as the most well-studied oncogenic alterations in advanced non-small cell lung cancer. The presence of single common or rare EGFR mutations and extra complex EGFR mutations correlates with the response sensitivity to EGFR tyrosine kinase inhibitors. Therefore, given the lack of evidence for the emergence of rare EGFR mutation types, the pathogenic mechanisms of uncommon EGFR mutations and the optimal treatment strategies remain to be explored further. The present study describes the case of a patient diagnosed with lung adenocarcinoma (LUAD) carrying two rare EGFR exon 18 indel/G719C and exon 19 L747S mutations, in which persistent lesion shrinkage was exhibited within 16 months of osimertinib treatment. Given the paucity of clinical trials for the treatment of LUAD harboring complex EGER mutations, the present detailed case description may provide clinicians with effective clinical experience in treating patients.

Liquid biopsy for the management of NSCLC patients under osimertinib treatment

Therapeutic management of NSCLC patients is quite challenging as they are mainly diagnosed at a late stage of disease, and they present a high heterogeneous molecular profile. Osimertinib changed the paradigm shift in treatment of EGFR mutant NSCLC patients achieving significantly better clinical outcomes. To date, osimertinib is successfully administered not only as first- or second-line treatment, but also as adjuvant treatment while its efficacy is currently investigated during neoadjuvant treatment or in stage III, unresectable EGFR mutant NSCLC patients. However, resistance to osimertinib may occur due to clonal evolution, under the pressure of the targeted therapy. The utilization of liquid biopsy as a minimally invasive tool provides insight into molecular heterogeneity of tumor clonal evolution and potent resistance mechanisms which may help to develop more suitable therapeutic approaches. Longitudinal monitoring of NSCLC patients through ctDNA or CTC analysis could reveal valuable information about clinical outcomes during osimertinib treatment. Therefore, several guidelines suggest that liquid biopsy in addition to tissue biopsy should be considered as a standard of care in the advanced NSCLC setting. This practice could significantly increase the number of NSCLC patients that will eventually benefit from targeted therapies, such as EGFR TKIs.

Non-small cell lung cancer: an update on emerging EGFR-targeted therapies

INTRODUCTION

Current research in EGFR-mutated NSCLC focuses on the management of drug resistance and uncommon mutations, as well as on the opportunity to extend targeted therapies' field of action to earlier stages of disease.

AREAS COVERED

We conducted a review analyzing literature from the PubMed database with the aim to describe the current state of art in the management of EGFR-mutated NSCLC, but also to explore new strategies under investigation. To this purpose, we collected recruiting phase II-III trials registered on Clinicaltrials.govand conducted on EGFR-mutated NSCLC both in early and advanced stage.

EXPERT OPINION

With this review, we want to provide an exhaustive overview of current and new potential treatments in EGFR-mutated NSCLC, with emphasis on the most promising newly investigated strategies, such as association therapies in the first-line setting involving EGFR-TKIs and chemotherapy (FLAURA2) or drugs targeting different driver pathways (MARIPOSA). We also aimed at unearthing challenges to achieve in this field, specifically the need to fully exploit already available compounds while developing new ones, the management of new emerging toxicities and the necessity to improve our biological understanding of the disease to design trials with a solid scientific rationale and to allow treatment personalization such in case of uncommon mutations.

An epidermal growth factor receptor compound mutation of L858R with S768I in advanced non-small-cell lung cancer: a case report

BACKGROUND

In the current treatment landscape for non-small cell lung cancers, epidermal growth factor receptor-tyrosine kinase inhibitors have emerged as a well-established treatment option for patients with advanced or metastatic disease. This is particularly true for those with commonly occurring epidermal growth factor receptor mutations. However, the therapeutic efficacy of these agents for so-called rare epidermal growth factor receptor mutations, and in particular those characterized by a high degree of complexity, such as double mutations, remains a subject of clinical uncertainty.

CASE PRESENTATION

In this context, we present the case of a 64-year-old man of Moroccan descent, a lifelong non-smoker, diagnosed with metastatic non-small cell lung cancer characterized by a complex epidermal growth factor receptor mutation encompassing L858R and S768I. The patient subsequently underwent afatinib-based treatment, showing notable clinical results. These included a remarkable overall survival of 51 months, with a median progression-free survival of more than 39 months.

CONCLUSIONS

This case report is a compelling testimony to the evolving therapeutic landscape of non-small cell lung cancers, providing valuable insight into the potential therapeutic efficacy of epidermal growth factor receptor-tyrosine kinase inhibitors in the realm of rare and complex epidermal growth factor receptor mutations.

Clinical Response to Osimertinib in a Non-Small-Cell Lung Cancer Patient With EGFR L833V/H835L Mutations: A Case Report

Lung cancer, a leading cause of cancer mortality, often involves epidermal growth factor receptor (EGFR) mutations, common in 17% of Caucasian and 40% of Asian non-small-cell lung cancer (NSCLC) patients. While the exon 19 deletion and L858R mutation are prevalent, rare variants like L833V/H835L are less understood. This case reports a 75-year-old female with NSCLC harboring L833V/H835L mutations. Initial imaging showed a right upper lobe mass and nodularity in the left upper lobe. Biopsy confirmed adenocarcinoma, and genomic analysis identified EGFR L833V/H835L mutations. Based on these findings, the patient was treated with osimertinib 160 mg daily, reduced to 80 mg due to side effects. After 3 months, positron emission tomography (PET) scans revealed significant tumor reduction, and brain metastasis remained stable. This case demonstrates the efficacy of osimertinib for rare EGFR mutations, aligning with literature suggesting its potential for managing such variants. Although large-scale trials are impractical due to the rarity of these mutations, this report adds valuable evidence supporting osimertinib's use, highlighting the need for comprehensive genomic profiling in NSCLC.

[A Rare Case of Lung Adenocarcinoma with EGFR L833V/H835L Co-mutation and Literature Review]

Epidermal growth factor receptor (EGFR) mutations are the most common driver genes in the development of non-small cell lung cancer (NSCLC), of which mutations in exons 18-21 are frequent, especially the loss of exon 19 and exon 21 L858R mutation are the most frequent. Other rare gene mutations are rare. Simultaneous occurrence of two or more rare EGFR mutations are extremely rare in lung cancer, and the incidence of EGFR L833V/H835L rare gene compound mutations is very low, and there is little clinical data and evidence of relevant treatment methods. Some EGFR-tyrosine kinase inhibitors (EGFR-TKIs) are effective in treating lung cancer patients with rare gene mutations. In this article, we reported a case of NSCLC patient with a rare gene compound mutation EGFR L833V/H835L, who responded to Afatinib in combination with Anilotinib treatment well after 5 months of treatment, and computed tomography (CT) showed shrinkage of lung lesions. Meanwhile, we also compiled previously reported NSCLC patients with EGFR L833V/H835L rare gene compound mutation and summarized the characteristics of this group of patients and the effect of applying different kinds of EGFR-TKIs treatment.
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Complete response to first-line osimertinib monotherapy in a complex epidermal growth factor receptor mutant ( L833V / H835L ) lung adenocarcinoma patient: a case report

Although uncommon epidermal growth factor receptor (EGFR) mutations account for 10-15% EGFR mutant non-small cell lung cancer (NSCLC) patients, clinical evidence for uncommon EGFR mutations, such as complex mutations remain limited. In this study, we reported a NSCLC patient harboring complex EGFR L833V / H835L mutation in exon 21, who had a complete response to first-line osimertinib monotherapy. The patient admitted to our hospital for space-occupying lesions of right lower lung during an annual health checkup, and was diagnosed as stage IIIA lung adenocarcinoma. Targeted next-generation sequencing (NGS) on tumor samples showed a complex EGFR mutation: L833V / H835L in exon 21. Therefore, she was treated with osimertinib monotherapy and complete remission achieved soon. During follow-up period, no metastasis was found and serum carcinoembryonic antigen returned to normal. In addition, NGS monitoring of mutations in circulating tumor DNA maintained negative. The patient remain benefitted for osimertinib monotherapy over 22 months with no disease progression. Our case firstly provided clinical evidences of first-line osimertinib therapy in lung cancer patients with rare L833V / H835L EGFR mutation.

Successful treatment of lung adenocarcinoma complicated with a rare compound EGFR mutation L833V/H835L using aumolertinib: a case report and literature review

Background: The deletion of exon 19 and the Leu858Arg mutation of exon 21 are the most frequently observed mutations in the epidermal growth factor receptor (EGFR) gene, and patients with these mutations have shown significant benefits from EGFR-tyrosine kinase inhibitors (TKIs). However, there exists a small subgroup of patients with uncommon/rare mutations of EGFR, including compound mutations, which display a high degree of heterogeneity in terms of clinical features and variable sensitivities to EGFR-TKIs. The understanding of these uncommon mutations and their response to targeted therapy is still unclear and requires further investigation. Case presentation: We presented a case of a never-smoking patient with lung adenocarcinoma and brain metastasis. Initially, she received chemotherapy plus immune checkpoint inhibitor as first-line therapy as no EGFR mutations were detected by amplification-refractory mutation system-polymerase chain reaction. However, disease progressed rapidly. Subsequently, next-generation sequencing was carried out and revealed a rare compound mutation, L833V/H835L, in exon 21 of EGFR. As a result, she was switched to second-line therapy with the third-generation TKI aumolertinib, which demonstrated good efficacy. The patient was evaluated for a remarkable progression-free survival of 18 months and an overall survival of 29 months. Conclusion: The present study supports that aumolertinib might be a good treatment option for advanced NSCLC patients with EGFR L833V/H835L mutation, particularly in patients with brain metastasis. Furthermore, conducting a comprehensive screening for gene mutations is crucial in effectively identifying potential oncogenic driver mutations and guiding mutation-targeted therapy decisions in clinical practice.

Afatinib for the Treatment of NSCLC with Uncommon EGFR Mutations: A Narrative Review

Afatinib, the world's first irreversible ErbB family (containing four different cancer cell epidermal growth factor receptors, including EGFR, HER2, ErbB3, and ErbB4) inhibitor, is a second-generation oral epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI). It can be used as a first-line treatment for locally advanced or metastatic non-small-cell lung cancer (NSCLC) with an EGFR-sensitive mutation or for patients with locally advanced or metastatic squamous lung cancer whose disease progresses during or after platinum-containing chemotherapy. Currently, with the use of third-generation EGFR-TKIs, afatinib is no longer clinically indicated as the first choice for patients with NSCLC who have EGFR-sensitive mutations. However, afatinib showed a considerable inhibitory effect in NSCLC patients with uncommon EGFR mutations (G719X, S768I, and L861Q) according to a combined post hoc analysis of the LUX-Lung2/3/6 trials. With the development of genetic testing technology, the detection rate of uncommon EGFR mutations is increasing. The aim of this paper is to describe in detail the sensitivity of rare EGFR mutations to afatinib and to provide information and a reference for those suffering from advanced NSCLC who have uncommon EGFR mutations.

EGFR p.V774M/p.L833V compound mutations in lung adenocarcinoma responded well to almonertinib: a case report

Background

There are about 10-15% of uncommon EGFR mutations found in NSCLC patients, and their sensitivity to EGFR TKIs still lack sufficient clinical evidence, especially for rare compound mutations. Almonertinib is the third generation of EGFR-TKI that has demonstrated excellent efficacy in classical mutations, however, effects in rare mutations have also been rarely reported.

Case presentation

In this case report, we present a patient with advanced lung adenocarcinoma with a rare EGFR p.V774M/p.L833V compound mutations, who achieved long-lasting and stable disease control after first-line Almonertinib targeted therapy. This case report could provide more information for therapeutic strategy selecting of NSCLC patients harboring rare EGFR mutations.

Conclusion

We report for the first time the long-lasting and stable disease control with Almonertinib for EGFR p.V774M/p.L833V compound mutations treatment, hoping to provide more clinical case references for the treatment of rare compound mutations.

Effective treatment with icotinib in advanced lung adenocarcinoma harboring rare EGFR mutation G719A/L833V: A case report

RATIONALE

Mutations in epidermal growth factor receptor (EGFR) play critical roles in the pathogenesis of non-small cell lung cancer (NSCLC), and they are highly associated with sensitivity to tyrosine kinase inhibitors. Targeted therapies are approved for patients with "classical" mutations and a small number of other mutations. However, patients with rare, even double EGFR mutations have different responses to EGFR tyrosine kinase inhibitor, which brings uncertainty to clinical practice.

PATIENT CONCERNS

A 74-year-old woman, never-smoker, was presented with chest pain. Chest computed tomography scan showed a big lesion in the right upper lobe with mediastinal lymph nodes metastases. Fine-needle biopsy and pathology suggested lung adenocarcinoma. A rare G719A/L833V double mutation of EGFR was detected in both tissue and plasma samples by next-generation sequencing.Interventions and outcomes:Icotinib was used as first-line therapy and showed good efficacy. Partial response was achieved, and the progression-free survival was 8 months.

LESSONS

This is the first report of the icotinib treatment achieving long-lasting and stable disease control in an NSCLC patient with EGFR G719A/L833V mutation. Icotinib could be a first-line treatment option in NSCLC patients harboring EGFR G719A/L833V mutation.

Tyrosine Kinase Inhibitor Activity in Patients with NSCLC Harboring Uncommon EGFR Mutations: A Retrospective International Cohort Study (UpSwinG)

BACKGROUND

Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR TKIs) are standard of care for patients with EGFR mutation-positive non-small-cell lung cancer (NSCLC) with common mutations (Del19 or L858R); however, 7%-23% of NSCLC tumors harbor uncommon EGFR mutations. These mutations are highly heterogeneous, and developments in detection techniques are helping to identify mutations with little or no clinical data.

PATIENTS AND METHODS

In this retrospective, global, multi-center study (NCT04179890), existing health records were identified for consecutive EGFR TKI-naïve patients with uncommon EGFR mutations (T790M, ex20ins, major uncommon [G719X, L861Q, or S768I], or "other" mutations; compound mutations) treated with erlotinib, gefitinib, afatinib, or osimertinib in first or second line. Endpoints included time-to-treatment failure (TTF), objective response rate (ORR), and overall survival (OS).

RESULTS

Overall, 246 patients (median age: 69.5 years; Asian: 84%) were included from 9 countries. Most patients (92%) received an EGFR TKI as first-line therapy; 54%, 43% and 3% received afatinib, first-generation TKIs, and osimertinib, respectively. Median TTF and OS with EGFR TKIs were 9.9 and 24.4 months; ORR was 43%. In patients treated with first-line chemotherapy (n = 20), median TTF and ORR were 6.6 months and 41%. Outcomes were most favorable in patients with major uncommon or compound mutations. Overall, TTF was 11.3 months with afatinib and 8.8 months with first-generation EGFR TKIs across mutation categories. In most mutation categories, median OS was >2 years.

CONCLUSION

In a real-world setting, EGFR TKIs were the preferred treatment option in patients with uncommon EGFR mutations; strongest outcomes were seen in patients with major uncommon and compound mutations.

Afatinib treatment response in advanced lung adenocarcinomas harboring uncommon mutations

BACKGROUND

Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) have improved the prognosis of mutant lung cancer; however, the clinical application value of TKIs for nonclassical EGFR mutation is unclear, especially for patients with rare uncommon mutations.

METHODS

A retrospective study based on electronic medical records was conducted to collect data on the effectiveness of afatinib in patients with stage IIIB/IV lung adenocarcinoma (LUAD) bearing uncommon mutations between January 2017 and January 2021.

RESULTS

Forty-two patients with uncommon mutations treated with afatinib were enrolled. The objective response rate (ORR) was 50.0% (10 of 20 patients). The median time to treatment failure (TTF) was 11.7 months (95% confidence interval = 8.5-18.3 months). Of the 42 patients, the median TTF was 15.0, 11.7, and 16.6 months in patients with Gly719Xaa (G719X), Ser768Ile (S768I), and Leu861Gln (L861Q) mutations, respectively. In patients with the rare uncommon mutation, the median TTF was 10.0 months, and the ORR was 50.0%. Afatinib demonstrated clinical activity across a set type of specific rare uncommon mutations, including EGFR L747P, A767_V769dup, and L833V/H835L, with a case having a TTF of more than 1 year. Molecular profiling reports of 16 afatinib-resistant biopsy samples were available, and the secondary T790M mutation was detected in one patient with L833V/H835L mutation and one harboring S768I/L858R mutation.

CONCLUSIONS

Our findings suggested that afatinib is effective in patients with uncommon mutations. Mechanisms of afatinib resistance vary and need further investigation.

Successful treatment of triple EGFR mutation T785A/L861Q/H297_E298 with afatinib

Patients with non‐small cell lung cancer (NSCLC) and uncommon epidermal growth factor receptor (EGFR) mutation are characterized by high heterogeneity, and globally considered to have a worse prognosis than patients with the two common mutations; exon 19 deletion, and exon 21 L858R. Nevertheless, some uncommon mutations do confer sensitivity to tyrosine kinase inhibitors (TKIs) which is comparable with common mutations. In particular, some compound EGFR mutations seem to be characterized by a favorable prognosis. Unfortunately, the rarity of complex EGFR mutations results in difficult clinical decision‐making. Herein, to the best of our knowledge, we report the first case of an NSCLC patient with an EGFR triple mutation containing T785A/L861Q/H297_E298 who was successfully treated with afatinib.

Targeting rare and non-canonical driver variants in NSCLC - An uncharted clinical field

OBJECTIVES

Implementation of tyrosine kinase inhibitors (TKI) and other targeted therapies was a main advance in thoracic oncology with survival gains ranging from several months to years for non-small-cell lung cancer (NSCLC) patients. High-throughput comprehensive molecular profiling is of key importance to identify patients that can potentially benefit from these novel treatments.

MATERIAL AND METHODS

Next-generation sequencing (NGS) was performed on 4500 consecutive formalin-fixed, paraffin-embedded specimens of advanced NSCLC (n = 4172 patients) after automated extraction of DNA and RNA for parallel detection of mutations and gene fusions, respectively.

RESULTS AND CONCLUSION

Besides the 24.9 % (n = 1040) of cases eligible for approved targeted therapies based on the presence of canonical alterations in EGFR exons 18-21, BRAF, ROS1, ALK, NTRK, and RET, an additional n = 1260 patients (30.2 %) displayed rare or non-canonical mutations in EGFR (n = 748), BRAF (n = 135), ERBB2 (n = 30), KIT (n = 32), PIK3CA (n = 221), and CTNNB1 (n = 94), for which targeted therapies could also be potentially effective. A systematic literature search in conjunction with in silico evaluation identified n = 232 (5.5 %) patients, for which a trial of targeted treatment would be warranted according to available evidence (NCT level 1, i.e. published data showing efficacy in the same tumor entity). In conclusion, a sizeable fraction of NSCLC patients harbors rare or non-canonical alterations that may be associated with clinical benefit from currently available targeted drugs. Systematic identification and individualized management of these cases can expand applicability of precision oncology in NSCLC and extend clinical gain from established molecular targets. These results can also inform clinical trials.

Recent Advances on the Role of EGFR Tyrosine Kinase Inhibitors in the Management of NSCLC With Uncommon, Non Exon 20 Insertions, EGFR Mutations

The first-line treatment of choice for patients with EGFR mutation-positive NSCLC is an EGFR tyrosine kinase inhibitor (TKI), of which five as follows are predominantly available in practice: gefitinib, erlotinib, afatinib, dacomitinib, and osimertinib. Most prospective clinical trial data with these agents are limited to patients with the common activating and sensitizing EGFR mutations as follows: exon 19 deletions and exon 21 L858R point mutations. However, 10% to 20% of patients with NSCLC harbor uncommon EGFR mutations that have variable sensitivity to different EGFR TKIs. Owing to their molecular structures, afatinib, dacomitinib, and osimertinib have broader inhibitory profiles than the first-generation agents, gefitinib and erlotinib. Nevertheless, the paucity of prospective clinical data, the wide heterogeneity of uncommon mutations, and the existence of compound mutations in up to 25% of the cases complicate treatment decisions in this patient subgroup. Here, we collate the latest preclinical and clinical data regarding the activity of different TKIs against major uncommon EGFR mutations including compound mutations, but excluding exon 20 insertions which are generally insensitive to TKIs. On the basis of these data, we offer suggestions regarding treatment strategies for uncommon EGFR mutations. Moving forward, it will be important to include uncommon EGFR mutations in the first-line molecular analysis of all patients with adenocarcinoma of the lung, as this will help optimize patient outcomes according to their precise genotype.

Great Efficacy of Afatinib in a Patient with Lung Adenocarcinoma Harboring EGFR L833V/H835L Mutations: A Case Report

Uncommon mutations account for 10-15% of epidermal growth factor receptor (EGFR) mutations in patients with non-small-cell lung cancer (NSCLC). Most of them are proved to be sensitive or resistant to EGFR-tyrosine kinase inhibitors (TKIs). However, there is insufficient evidence for other less common types of EGFR mutations, such as complex mutations. Here, we present a 65-year-old never-smoking male who was diagnosed with stage IV lung adenocarcinoma. A rare L833V/H835L complex mutation in exon 21 of EGFR was detected in plasma and pleural effusion by next generation sequencing (NGS). Afatinib was used as first-line therapy and showed very good efficacy. To date, the patient is still benefited from afatinib treatment for a total of 10 months, with no signs of disease progression. Our case suggests that a comprehensive screening for EGFR mutations should be conducted before treatment in clinical practice, and afatinib could be a first-line treatment option in NSCLC patients harboring H833V/H835L mutations.

Long-term Survival With Afatinib in a Patient With Lung Adenocarcinoma Harboring Double Uncommon EGFR L861Q and G719X Mutations

BACKGROUND

In the majority of non-small cell lung cancer (NSCLC) patients with uncommon EGFR mutations, first generation epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) are ineffective. The second-generation TKI, afatinib, is considered effective in patients with uncommon mutations, however, long-term survivors have been rare.

CASE REPORT

We report herein a patient with lung adenocarcinoma harboring double uncommon EGFR L861Q and G719X mutations, who is free of disease 32 months after initiation of afatinib therapy. To our best knowledge, this patient has the longest response among other patients with double uncommon mutations.

CONCLUSION

Patients with this type of NSCLC may obtain long-term survival with afatinib.

Four generations of EGFR TKIs associated with different pathogenic mutations in non-small cell lung carcinoma

Non-small cell lung carcinoma (NSCLC) is a malignant tumour with poor prognosis and high mortality. Platinum-based dual-agent chemotherapy is the main therapeutic regimen for this disease. In recent years, because of the introduction of molecular targeted therapy, various targeted therapeutic agents against epidermal growth factor receptor (EGFR) have been rapidly developed, which has become a research hotspot for NSCLC treatment. Here, we review the latest studies describing the features and types of EGFR pathogenic mutations, currently established EGFR-tyrosine kinase inhibitors from the first to fourth generation, including their action mechanisms, acquired resistance, and clinical applications, and potential challenges and perspectives that current researchers should address.

Current Approaches in NSCLC Targeting K-RAS and EGFR

The research and treatment of non-small cell lung cancer (NSCLC) have achieved some important advances in recent years. Nonetheless, the overall survival rates for NSCLC remain low, indicating the importance to effectively develop new therapies and improve current approaches. The understanding of the function of different biomarkers involved in NSCLC progression, survival and response to therapy are important for the development of early detection tools and treatment options. Epidermal growth factor receptor (EGFR) and Kirsten rat sarcoma viral oncogene homolog (K-RAS) are two of the main significant biomarkers for the management of NSCLC. Mutations in these genes were associated with development and response to therapies. For example, the use of small molecule tyrosine kinase (TK) inhibitors and immunotherapy has led to benefits in some, but not all patients with altered EGFR. In contrast, there is still no effective approved drug to act upon patients harbouring K-RAS mutations. In addition, K-RAS mutations have been associated with lack of activity of TK inhibitors. However, promising approaches aimed to inhibit mutant K-RAS are currently under study. Therefore, this review will discuss these approaches and also EGFR therapies, and hopefully, it will draw attention to the need of continued research in the field in order to improve the outcomes in NSCLC patients.

Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors in non-small cell lung cancer harboring uncommon EGFR mutations: Focus on afatinib

The development of first-, second-, and third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) has revolutionized the treatment of patients with non-small cell lung cancer (NSCLC) harboring mutations in the EGFR. However, limited data are available regarding the activity of available EGFR TKIs against uncommon EGFR mutations. This is an important question because improvements in screening techniques are facilitating the identification of patients with uncommon mutations for whom optimal treatment has not yet been clarified. This uncertainty reflects the fact that most prospective clinical trials of EGFR TKIs have been restricted to patients with tumor harboring common (Del19 or L858R) mutations. In this article, we discuss the nature of EGFR mutation heterogeneity in NSCLC and review recent preclinical and clinical data that have assessed the sensitivity of different mutations to different EGFR TKIs. Recent preclinical data indicate that second-generation ErbB family blockers, such as afatinib, have a broad activity profile across uncommon EGFR mutations. Emerging evidence indicates that the preclinical data for afatinib are reflected in the clinic. Subanalysis of clinical trials, and real-world data, demonstrate that EGFRs with defined, but uncommon mutations such as G719X, S768I, and L861Q are sensitive to afatinib, which is now approved for tumors harboring these mutations. A recent clinical trial has demonstrated that EGFRs harboring some of these less common mutations also appear to be sensitive to the third-generation EGFR TKI, osimertinib. Treatment options for tumors with other uncommon mutations, notably exon 20 insertion, remain an area of unmet need, although osimertinib has shown preclinical activity in this setting, and early clinical activity has been seen with the dual EGFR/HER2 TKIs, poziotinib and TAK-788. Further data are required to help drive appropriate treatment decisions in patients whose tumors harbor these uncommon EGFR mutations. To see an abstract video summarising the content of the paper, please visit http://usscicomms.com/oncology/masood/seminars-in-oncology/.

The Value of Liquid Biopsies for Guiding Therapy Decisions in Non-small Cell Lung Cancer

Targeted therapies have allowed for an individualized treatment approach in non-small-cell lung cancer (NSCLC). The initial therapeutic decisions and success of targeted therapy depend on genetic identification of personal tumor profiles. Tissue biopsy is the gold standard for molecular analysis, but non-invasive or minimally invasive liquid biopsy methods are also now used in clinical practice, allowing for later monitoring and optimization of the cancer treatment. The inclusion of liquid biopsy in the management of NSCLC provides strong evidence on early treatment response, which becomes a basis for determining disease progression and the need for changes in treatment. Liquid biopsies can drive the decision making for treatment strategies to achieve better patient outcomes. Cell-free DNA and circulating tumor cells obtained from the blood are promising markers for determining patient status. They may improve cancer treatments, allow for better treatment control, enable early interventions, and change decision making from reactive actions toward more predictive early interventions. This review aimed to present current knowledge on and the usefulness of liquid biopsy studies in NSCLC from the perspective of how it has allowed individualized treatments according to gene profiling and how the method may alter the treatment decisions in the future.