Characterization With KRAS Mutant Is a Critical Determinant in Immunotherapy and Other Multiple Therapies for Non-Small Cell Lung Cancer

A novel subtype based on driver methylation-transcription in lung adenocarcinoma

AIMS

To identify driver methylation genes and a novel subtype of lung adenocarcinoma (LUAD) by multi-omics and elucidate its molecular features and clinical significance.

METHODS

We collected LUAD patients from public databases, and identified driver methylation genes (DMGs) by MethSig and MethylMix algrothms. And novel driver methylation multi-omics subtypes were identified by similarity network fusion (SNF). Furthermore, the prognosis, tumor microenvironment (TME), molecular features and therapy efficiency among subtypes were comprehensively evaluated.

RESULTS

147 overlapped driver methylation were identified and validated. By integrating the mRNA expression and methylation of DMGs using SNF, four distinct patterns, termed as S1-S4, were characterized by differences in prognosis, biological features, and TME. The S2 subtype showed unfavorable prognosis. By comparing the characteristics of the DMGs subtypes with the traditional subtypes, S3 was concentrated in proximal-inflammatory (PI) subtype, and S4 was consisted of terminal respiratory unit (TRU) subtype and PI subtype. By analyzing TME and epithelial mesenchymal transition (EMT) features, increased immune infiltration and higher expression of immune checkpoint genes were found in S3 and S4. While S4 showed higher EMT score and expression of EMT associated genes, indicating S4 may not be as immunosensitive as the S3. Additionally, S3 had lower TIDE and higher IPS score, indicating its increased sensitivity to immunotherapy.

CONCLUSION

The driver methylation-related subtypes of LUAD demonstrate prognostic predictive ability that could help inform treatment response and provide complementary information to the existing subtypes.

Prognostic value of KRAS G12V mutation in lung adenocarcinoma stratified by stages and radiological features

OBJECTIVE

KRAS G12V is one of the most common KRAS mutation variants in lung adenocarcinoma (LUAD), and yet its prognostic value is still unrevealed. In this study, we investigated the clinicopathologic characteristics and prognostic value of the KRAS G12V mutation in LUAD.

METHODS

Data of 3829 patients who underwent LUAD resection between 2008 and 2020 were collected. Mutations were classified as wild-type, G12V, or non-G12V. The clinicopathologic characteristics, postoperative outcomes, and recurrence pattern were analyzed among groups.

RESULTS

In total, 3554 patients were wild-type and 275 patients harbored a KRAS mutation: 60 patients with G12V (22.2%) and 215 patients with non-G12V (77.8%). The KRAS G12V mutation was more frequent in male patients, older patients (≥60 years), former/current smokers, those patients with radiologic solid nodules, and those with highly invasive histologic subtypes. Tumors carrying KRAS G12V mutation exhibited elevated programmed death-ligand 1 expression in comparison with wild-type tumors. KRAS G12V was more prevalent in older patients and had less lymphovascular invasion compared with other mutation types. FGF3, RET, and KDR co-mutations occurred more frequently in the KRAS G12V group. Multivariate analysis demonstrated that the KRAS G12V mutation was an independent prognostic factor in stage Ⅰ tumors, whereas the KRAS non-G12V mutation was not. KRAS G12V was associated with early recurrence and locoregional recurrence.

CONCLUSIONS

The KRAS G12V mutation was associated with aggressive clinical-pathologic phenotype and early recurrence. To note, this mutation exhibited a significantly worse prognosis in patients with part-solid and stage Ⅰ lung adenocarcinoma. Meanwhile, the prognostic significance of KRAS G12C and G12V variants was comparable.

Response of PRIMPOL-Knockout Human Lung Adenocarcinoma A549 Cells to Genotoxic Stress

Human DNA primase/polymerase PrimPol synthesizes DNA primers de novo after replication fork stalling at the sites of DNA damage, thus contributing to the DNA damage tolerance. The role of PrimPol in response to the different types of DNA damage is poorly understood. We knocked out the PRIMPOL gene in the lung carcinoma A549 cell line and characterized the response of the obtained cells to the DNA damage caused by hydrogen peroxide, methyl methanesulfonate (MMS), cisplatin, bleomycin, and ionizing radiation. The PRIMPOL knockout reduced the number of proliferating cells and cells in the G2 phase after treatment with MMS and caused a more pronounced delay of the S phase in the cisplatin-treated cells. Ionizing radiation at a dose of 10 Gy significantly increased the content of apoptotic cells among the PRIMPOL-deficient cells, while the proportion of cells undergoing necroptosis increased in both parental and knockout cells at any radiation dose. The viability of PRIMPOL-deficient cells upon the hydrogen peroxide-induced oxidative stress increased compared to the control cells, as determined by the methyl tetrazolium (MTT) assay. The obtained data indicate the involvement of PRIMPOL in the modulation of adaptive cell response to various types of genotoxic stress.

Genomic profiling of NGS-based ctDNA from Chinese non-small cell lung cancer patients

PURPOSE

Cell-free circulating tumor DNA (ctDNA) in plasma enables rapid and repeat testing of actionable mutations. Next-generation sequencing (NGS) is an attractive platform for multiplex sequencing capabilities compared to traditional methods such as PCR. The purpose of this study is to evaluate the value of the NGS-based ctDNA assay and to identify the genomic alteration profile of ctDNA in real-world Chinese non-small cell lung (NSCLC) patients.

METHODS

In total, 294 Chinese patients with pathological diagnosis of Phase III-IV NSCLC were enrolled. 3-4 mL peripheral blood was collected and NGS-based analysis was carried out using a 20-gene panel. The analytical sensitivity and specificity of ctDNA NGS-based assay was validated using droplet digital PCR (ddPCR).

RESULTS

We have tested 570 sites from 286 samples using ddPCR, which included 108 positive sites and 462 negative sites from NGS results, and the concordance rate was 99.8% (418/419) for single-nucleotide variants (SNVs) and 96.7% (146/151) for insertions and deletions (InDels). The most frequent genes were TP53 (32%), EGFR (31.97%), KRAS (6.46%), PIK3CA (4.76%), and MET (4.08%). Exon 19 deletion (19del) was the most common alteration in EGFR and G12C was the most common alteration in KRAS. Furthermore, the detection rate of TP53 was higher in the male and patients with squamous cell carcinoma. We also found the prevalence of TP53 in L858R was higher than in 19del (61.29% vs. 40%; p = 0.1115).

CONCLUSION

The results indicate that the results of NGS-based ctDNA assay are highly consistent with ddPCR. In Chinese NSCLC patients, TP53 mutation was more frequently associated with male and squamous cell carcinoma. The prevalence of concomitant mutations in L858R may be different from that in 19del.

Cancer immune evasion through KRAS and PD-L1 and potential therapeutic interventions

Oncogenic driver mutations have implications that extend beyond cancer cells themselves. Aberrant tumour cell signalling has various effects on the tumour microenvironment and anti-tumour immunity, with important consequences for therapy response and resistance. We provide an overview of how mutant RAS, one of the most prevalent oncogenic drivers in cancer, can instigate immune evasion programs at the tumour cell level and through remodelling interactions with the innate and adaptive immune cell compartments. Finally, we describe how immune evasion networks focused on RAS, and the immune checkpoint molecule PD-L1 can be disrupted through therapeutic intervention, and discuss potential strategies for combinatorial treatment. Video abstract.

Predictive potential of angiopoietin-2 in a mCRC subpopulation treated with vanucizumab in the McCAVE trial

Introduction

Angiopoetin-2 (Ang-2) is a key mediator of tumour angiogenesis. When upregulated it is associated with tumour progression and poor prognosis. Anti-vascular endothelial growth factor (VEGF) therapy has been widely used in the treatment of metastatic colorectal cancer (mCRC). The potential benefit of combined inhibition of Ang-2 and VEGF-A in previously untreated patients with mCRC was evaluated in the phase II McCAVE study (NCT02141295), assessing vanucizumab versus bevacizumab (VEGF-A inhibitor), both in combination with mFOLFOX-6 (modified folinic acid [leucovorin], fluorouracil and oxaliplatin) chemotherapy. To date, there are no known predictors of outcome of anti-angiogenic treatment in patients with mCRC. In this exploratory analysis, we investigate potential predictive biomarkers in baseline samples from McCAVE participants.

Methods

Tumour tissue samples underwent immunohistochemistry staining for different biomarkers, including Ang-2. Biomarker densities were scored on the tissue images using dedicated machine learning algorithms. Ang-2 levels were additionally assessed in plasma. Patients were stratified by KRAS mutation status determined using next generation sequencing. Median progression-free survival (PFS) for each treatment group by biomarker and KRAS mutation was estimated using Kaplan-Meier plots. PFS hazard ratios (and 95% confidence intervals) were compared using Cox regression.

Results

Overall low tissue baseline levels of Ang-2 were associated with longer PFS, especially in patients with wild-type KRAS status. In addition, our analysis identified a new subgroup of patients with KRAS wild-type mCRC and high levels of Ang-2 in whom vanucizumab/mFOLFOX-6 prolonged PFS significantly (log-rank p=0.01) by ~5.5 months versus bevacizumab/mFOLFOX-6. Similar findings were seen in plasma samples.

Discussion

This analysis demonstrates that additional Ang-2 inhibition provided by vanucizumab shows a greater effect than single VEGF-A inhibition in this subpopulation. These data suggest that Ang-2 may be both a prognostic biomarker in mCRC and a predictive biomarker for vanucizumab in KRAS wild-type mCRC. Thus, this evidence can potentially support the establishment of more tailored treatment approaches for patients with mCRC.

RAS: Circuitry and therapeutic targeting

Cancer has affected the lives of millions worldwide and is truly regarded as a devastating disease process. Despite advanced understanding of the genomic underpinning of cancer development and progression, therapeutic challenges are still persistent. Among all the human cancers, around 33% are attributed to mutations in RAS oncogene, a crucial component of the signaling pathways. With time, our understanding of RAS circuitry has improved and now the fact that it activates several downstream effectors, depending on the type and grades of cancer has been established. The circuitry is controlled via post-transcriptional mechanisms and frequent distortions in these mechanisms lead to important metabolic as well as immunological states that favor cancer cells' growth, survival, plasticity and metastasis. Therefore, understanding RAS circuitry can help researchers/clinicians to develop novel and potent therapeutics that, in turn, can save the lives of patients suffering from RAS-mutant cancers. There are many challenges presented by resistance and the potential strategies with a particular focus on novel combinations for overcoming these, that could move beyond transitory responses in the direction of treatment. Here in this review, we will look at how understanding the circuitry of RAS can be put to use in making strategies for developing therapeutics against RAS- driven malignancies.

Efficacy of Immunotherapy in Second-Line Treatment of KRAS-Mutated Patients with Non-Small-Cell Lung Cancer-Data from Daily Practice

Background The implementation of next-generation sequencing (NGS) into daily practice allows for the identification of a greater number of molecular abnormalities. We aimed to confirm the benefits of immunotherapy in the group of patients with KRAS aberrations treated within clinical practice. Methods This study was a retrospective analysis of the patients (pts) treated in routine practice within the National Drug Programme in Poland. The NGS was performed using a FusionPlex Comprehensive Thyroid and Lung (CTL) kit (ArcherDx) and sequenced using a MiniSeq (Illumina). The analyses were performed with the R language environment, version 4.1.3. Results A total of 96 pts with chemotherapy-pre-treated advanced NSCLC (CS III−IV) were qualified for nivolumab or atezolizumab treatment following a molecular diagnosis by the NGS and the exclusion of EGFR and ALK gene abnormalities. A mutation in the KRAS gene was found in 26 patients (27%); among them, the variant p.Gly12Cyc (G12C) was the most common (42%). The median PFS and OS for the overall population were 2 months (95% CI: 1.8−2.75) and 10 months (95% CI: 6.9−16.2), respectively. No differences were observed in terms of the mPFS between the KRAS-mutated and KRAS wild-type (WT) patients. A trend toward a longer OS was observed in the group of patients with the KRAS mutation, but the difference was not statistically significant (p = 0.43). In the multivariate analysis, the presence of mutations in the KRAS gene had no prognostic significance, while the occurence of grade 3 toxicity and the neutrophil-to-lymphocyte ratio (NLR) > 3.5 were found as statistically significant factors. Conclusions Immunotherapy in the second-line treatment of advanced NSCLC allows for a benefit regardless of the KRAS gene mutation status. The treatment sequence, including molecularly targeted drugs such as sotorasib and adagrasib, is still discussed. The NGS is a valuable method to identify a variety of molecular abnormalities in patients with NSCLC in daily practice.

KRAS G12 isoforms exert influence over up-front treatments: A retrospective, multicenter, Italian analysis of the impact of first-line immune checkpoint inhibitors in an NSCLC real-life population

BACKGROUND

KRAS is commonly mutated in non-small cell lung cancer (NSCLC); however, the prognostic and predictive impact of each G12 substitution has not been fully elucidated. The approval of specific G12C inhibitors has modified the idea of KRAS "undruggability", and although the first-line standard consists of immune checkpoint inhibitors (ICIs) with or without chemotherapy, as suggested at ASCO 2022, the outcome in KRAS-mutated population is still controversial.

METHODS

We retrospectively described the clinical and pathological characteristics of a homogeneous G12 mutated cohort of 219 patients treated in four Italian oncologic units. We evaluated the outcome (PFS at 18 months and OS at 30 months) of those who underwent standard first-line treatment according to PD-L1 status, focusing on differences across single mutations.

RESULTS

In the study population, 47.9% of patients harbor the KRAS G12C mutation; 20.5%, G12V; 17.4%, G12D; and 8.2%, G12A. Smoking was a common behavior of patients harboring transversions and transition mutations. PD-L1 expression does not show particular distribution in the case series, although we recorded a prevalence of PD-L1 <1% in G12V (51.4%) compared to G12A (26.7%). ICIs alone was the clinician's choice in 32.7% of patients, and the chemo-immune combination in 17.3% of patients. We described the independent prognostic role of young age (p = 0.007), female gender (p = 0.016), and an ICI-based regimen (p = 0.034) regardless of mutations. Overall, our data confirm the worst prognostic value of G12V mutation apart from treatment choice unlike the other major mutations (C, D, and A) that showed a favorable trend in PFS.

CONCLUSIONS

KRAS G12 mutations are confirmed to have different characteristics, and the outcome is influenced by ICI first-line regimen. This study provides valuable information for further analysis in the future.

Lung Adenocarcinoma Tumor Origin: A Guide for Personalized Medicine

Simple Summary

Lung cancer is the leading cause of cancer-related death worldwide, with an average 5-year survival rate of approximately 15%. Among the multiple histological type of lung cancer, adenocarcinoma is the most common. Adenocarcinoma is characterized by a high degree of heterogeneity at many levels, including histological, cellular, and molecular. Understanding the cell of origin of adenocarcinoma, and the molecular changes during tumor progression, will allow better therapeutic strategies.

Abstract

Lung adenocarcinoma, the major form of lung cancer, is the deadliest cancer worldwide, due to its late diagnosis and its high heterogeneity. Indeed, lung adenocarcinoma exhibits pronounced inter- and intra-tumor heterogeneity cofounding precision medicine. Tumor heterogeneity is a clinical challenge driving tumor progression and drug resistance. Several key pieces of evidence demonstrated that lung adenocarcinoma results from the transformation of progenitor cells that accumulate genetic abnormalities. Thus, a better understanding of the cell of origin of lung adenocarcinoma represents an opportunity to unveil new therapeutic alternatives and stratify patient tumors. While the lung is remarkably quiescent during homeostasis, it presents an extensive ability to respond to injury and regenerate lost or damaged cells. As the lung is constantly exposed to potential insult, its regenerative potential is assured by several stem and progenitor cells. These can be induced to proliferate in response to injury as well as differentiate into multiple cell types. A better understanding of how genetic alterations and perturbed microenvironments impact progenitor-mediated tumorigenesis and treatment response is of the utmost importance to develop new therapeutic opportunities.