Identification and Functional Characterization of EGFR V769M, a Novel Germline Variant Associated With Multiple Lung Adenocarcinomas

Lung cancer in patients who have never smoked - an emerging disease

Lung cancer is the most common cause of cancer-related deaths globally. Although smoking-related lung cancers continue to account for the majority of diagnoses, smoking rates have been decreasing for several decades. Lung cancer in individuals who have never smoked (LCINS) is estimated to be the fifth most common cause of cancer-related deaths worldwide in 2023, preferentially occurring in women and Asian populations. As smoking rates continue to decline, understanding the aetiology and features of this disease, which necessitate unique diagnostic and treatment paradigms, will be imperative. New data have provided important insights into the molecular and genomic characteristics of LCINS, which are distinct from those of smoking-associated lung cancers and directly affect treatment decisions and outcomes. Herein, we review the emerging data regarding the aetiology and features of LCINS, particularly the genetic and environmental underpinnings of this disease as well as their implications for treatment. In addition, we outline the unique diagnostic and therapeutic paradigms of LCINS and discuss future directions in identifying individuals at high risk of this disease for potential screening efforts.

Identification of the Unique Clinical and Genetic Features of Chinese Lung Cancer Patients With EGFR Germline Mutations in a Large-Scale Retrospective Study

BACKGROUND

Epidemiological surveys have suggested that lung cancer has inherited susceptibility and shows familial aggregation. However, the distribution and prevalence of epidermal growth factor receptor (EGFR) germline variants and their roles in lung cancer genetic predisposition in Chinese population remain to be elucidated.

METHODS

In this study, EGFR germline and somatic variants were retrospectively reviewed from the next-generation sequencing results of 31,906 patients with lung cancer. Clinical information was also collected for patients with confirmed EGFR germline mutations.

RESULTS

A total of 22 germline EGFR variants were identified in 64 patients with lung cancer, accounting for 0.2% of the total cases studied. Five patients were diagnosed as multiple primary carcinomas. Family history was documented in 31.3% (20/64) of patients, 55% of which were diagnosed as lung cancer. G863D was the most frequent EGFR germline mutation, followed by P848L, D1014N, and K757R. Somatic EGFR-sensitive mutations were identified in 51.6% of patients with germline EGFR mutations. The proportion of L858R mutation, exon 19 deletion, and rare sensitive mutation was 50%, 17.6%, and 32.4%, respectively. D1014N and T790M mutations were common in young patients. The family members of patients with P848L, R776H, V769M, and V774M mutations were more commonly diagnosed with cancers. A total of 19 patients were confirmed to have received EGFR tyrosine kinase inhibitors (TKIs), but the response to EGFR-TKIs differed among patients with different EGFR mutations.

CONCLUSION

Chinese patients with lung cancer harbored unique and dispersive EGFR germline mutations and showed unique clinical and genetic characteristics, with varied response patterns to EGFR-TKI treatment.

A Nationwide Study on the Impact of Routine Testing for EGFR Mutations in Advanced NSCLC Reveals Distinct Survival Patterns Based on EGFR Mutation Subclasses

EGFR mutation analysis in non-small-cell lung cancer (NSCLC) patients is currently standard-of-care. We determined the uptake of EGFR testing, test results and survival of EGFR-mutant NSCLC patients in the Netherlands, with the overall objective to characterize the landscape of clinically actionable EGFR mutations and determine the role and clinical relevance of uncommon and composite EGFR mutations. Non-squamous NSCLC patients diagnosed in 2013, 2015 and 2017 were identified in the Netherlands Cancer Registry (NCR) and matched to the Dutch Pathology Registry (PALGA). Overall, 10,254 patients were included. Between 2013-2017, the uptake of EGFR testing gradually increased from 72.7% to 80.9% (p < 0.001). Multi-gene testing via next-generation sequencing (increased from 7.8% to 78.7% (p < 0.001), but did not affect the number of detected EGFR mutations (n = 925; 11.7%; 95% confidence interval (CI), 11.0-12.4) nor the distribution of variants. For patients treated with first-line EGFR inhibitors (n = 651), exon 19 deletions were associated with longer OS than L858R (HR 1.58; 95% CI, 1.30-1.92; p < 0.001) or uncommon, actionable variants (HR 2.13; 95% CI, 1.60-2.84; p < 0.001). Interestingly, OS for patients with L858R was similar to those with uncommon, actionable variants (HR 1.31; 95% CI, 0.98-1.75; p = 0.069). Our analysis indicates that grouping exon 19 deletions and L858R into one class of 'common' EGFR mutations in a clinical trial may mask the true activity of an EGFR inhibitor towards specific mutations.

Profiling Oncogenic Germline Mutations in Unselected Chinese Lung Cancer Patients

Introduction

Emerging evidence has suggested that inherited factors are also involved in lung cancer development. However, most studies focused on well-elucidated cancer predisposition genes, the majority of which are tumor suppressor genes. The profile of germline mutations in oncogenic driver genes remains unrevealed, which might also provide potential clinical implications for lung cancer management.

Methods

Sequencing data from 36,813 unselected lung cancer patients who underwent somatic mutation profiling were retrospectively reviewed. All recruited patients had matched white blood cell samples sequenced in parallel using a capture-based panel including eight key lung cancer driver genes (epidermal growth factor receptor (EGFR), anaplastic lymphoma kinase (ALK), MET proto-oncogene, receptor tyrosine kinase (MET), Kirsten rat sarcoma viral oncogene homolog (KRAS), Erb-B2 receptor tyrosine kinase 2(ERBB2), ROS proto-oncogene 1, receptor tyrosine kinase (ROS1), ret proto-oncogene (RET), and B-Raf proto-oncogene, serine/threonine kinase (BRAF)). Likely pathogenic/pathogenic (LP/P) variants were called according to the classification criteria of the American College of Medical Genetics and Genomics. Variants of uncertain significance (VUS) located in the kinase domains of driver genes and occurring recurrently (n ≥3) were also included for further analyses.

Results

Seven different LP/P variants in EGFR, MET, or RET were identified in 0.03% of lung cancer patients (n = 14) and 25 different VUS in the kinase domains of seven driver genes (except KRAS) were found with a prevalence of 0.3% (n = 117).Collectively, germline mutations were most frequently seen in ROS1 (n = 31, 0.084%), followed by MET (n = 23, 0.062%), EGFR (n = 22, 0.06%), ALK (n = 22, 0.06%) and RET (n = 17, 0.046%). LP/P variants and VUS fell the most commonly in EGFR (n = 10, 72%) and ROS1 (n = 31, 26%), respectively. Of the 10 patients with EGFR LP/P germline mutation, 70% also acquired somatic EGFR driver mutation exon21 p.L858R or exon19 deletion at baseline; while the three patients with pathogenic germline RET mutation displayed distinct baseline somatic profiles of rare EGFR mutation or KRAS exon2 p.G12C. We discovered 11 germline mutations that also occurred somatically, including four LP/P variants and seven VUS.

Conclusion

We present the first study to systemically characterize the germline mutation in oncogenic driver genes in a large cohort of unselected patients with lung cancers.

Mutational landscape of multiple primary lung cancers and its correlation with non-intrinsic risk factors

Multiple primary lung cancers (MPLCs) harbour various genetic profiles among the tumours, even from individuals with same non-intrinsic risk factors. Paired mutational analyses were performed to obtain a census of mutational events in MPLC and assess their relationship with non-intrinsic risk factors. Thirty-eight surgical specimens from 17 patients diagnosed as MPLC were used. Extracted DNAs were sequenced for somatic mutations in 409 cancer-associated genes from a comprehensive cancer panel. We statistically analysed the correlation between each driver mutation frequency and non-intrinsic risk factors using Fisher's exact test, and whether genetic mutations occurred concomitantly or randomly in MPLC using an exact test. Comprehensive genetic analyses suggested different mutation profiles in tumours within the same individuals, with some exceptions. EGFR, KRAS, TP53, or PARP1 mutations were concomitantly detected in some MPLC cases. EGFR mutations were significantly more frequent in never or light smokers and females. Concomitant EGFR or KRAS mutations in MPLCs were significantly more frequent than expected by chance (P = .0023 and .0049, respectively) suggesting a more prominent role of non-intrinsic risk factors in EGFR and KRAS mutations than other mutations, which occurred more randomly. Concomitant EGFR or KRAS mutations were particularly prominent in never or light smokers and males.

Potential genetic modifiers for somatic EGFR mutation in lung cancer: a meta-analysis and literature review

BACKGROUND

Accumulating evidence indicates inherited risk in the aetiology of lung cancer, although smoking exposure is the major attributing factor. Family history is a simple substitute for inherited susceptibility. Previous studies have shown some possible yet conflicting links between family history of cancer and EGFR mutation in lung cancer. As EGFR-mutated lung cancer favours female, never-smoker, adenocarcinoma and Asians, it may be argued that there may be some underlying genetic modifiers responsible for the pathogenesis of EGFR mutation.

METHODS

We searched four databases for all original articles on family history of malignancy and EGFR mutation status in lung cancer published up to July 2018. We performed a meta-analysis by using a random-effects model and odds ratio estimates. Heterogeneity and sensitivity were also investigated. Then we conducted a second literature research to curate case reports of familial lung cancers who studied both germline cancer predisposing genes and their somatic EGFR mutation status; and explored the possible links between cancer predisposing genes and EGFR mutation.

RESULTS

Eleven studies have been included in the meta-analysis. There is a significantly higher likelihood of EGFR mutation in lung cancer patients with family history of cancer than their counterparts without family history, preferentially in Asians (OR = 1.35[1.06-1.71], P = 0.01), those diagnosed with adenocarcinomas ((OR = 1.47[1.14-1.89], P = 0.003) and those with lung cancer-affected relatives (first and second-degree: OR = 1.53[1.18-1.99], P = 0.001; first-degree: OR = 1.76[1.36-2.28, P < 0.0001]). Familial lung cancers more likely have concurrent EGFR mutations along with mutations in their germline cancer predisposition genes including EGFR T790 M, BRCA2 and TP53. Certain mechanisms may contribute to the combination preferences between inherited mutations and somatic ones.

CONCLUSIONS

Potential genetic modifiers may contribute to somatic EGFR mutation in lung cancer, although current data is limited. Further studies on this topic are needed, which may help to unveil lung carcinogenesis pathways. However, caution is warranted in data interpretation due to limited cases available for the current study.