Kirsten Rat Sarcoma Mutations Research Articles

Abstract 6623: Ala59 mutants of KRAS cooperate with Nf1 loss to enhance colon tumorigenesis

Abstract Understanding the role of KRAS allele heterogeneity in tumor development, and its influence on therapeutic efficacy, is critical for the improvement of cancer treatment. The Kirsten rat sarcoma (KRAS) gene is the most frequently mutated oncogene in colorectal cancer (CRC) and patients with CRC tumors positive for KRAS mutations have poorer outcomes and limited treatment options. Extensive work over the past four decades has shown that common oncogenic alleles of KRAS are associated with hyperactivation of the MAPK signaling pathway (i.e. RAF/MEK/ERK), and it is for this reason that patients with KRAS mutant tumors are excluded from targeted therapies against EGFR. Recently, we characterized two alleles of KRAS, KRASA59T and KRASA59E, that paradoxically promote KRAS activation but are impaired in their ability to promote BRAF dimerization (Johnson et al. Mol Cell. 2022. PMID: 35202574). Consistent with these biochemical functions, KRASA59T and KRASA59E are enriched in CRC tumors that already have genetic alterations in genes that regulate MAPK signaling (e.g. EGFR, BRAF, NRAS, NF1). Further, unlike other described oncogenic alleles of KRAS, clinical data suggest that these KRASA59T and KRASA59E may not confer intrinsic resistance to anti-EGFR therapies at all. While KRASA59T and KRASA59E may not promote BRAF dimers, here we show that KRASA59T and KRASA59E does promote dimerization between ARAF and CRAF, and using an unpublished conditional mouse mode of K-Ras (i.e. LSL-K-RasA59E) we tested (1) whether Ala59 alleles are oncogenic or (2) require cooperation with additional MAPK pathway activating mutations, and (3) whether Ala59 alleles can promote intrinsic resistance to EGFR inhibition. Here, we show that endogenous K-RasA59E can disturb colon homeostasis and decrease mouse survival in an autochthonous colon tumor model, demonstrating that A59E alone is an oncogenic allele of KRAS in the colon. Breeding of LSL-K-RasA59E mice with mice harboring a conditional knockout of Nf1 (i.e. Nf1fl/fl), a GTPase activating protein (GAP) that promotes activation of wildtype RAS, show that combined expression of K-RasA59E and wildtype RAS activation cooperatively perturb colon homeostasis and decrease mouse survival. Thus, while KRASA59E may not require a second genetic alteration to activate the MAPK signaling pathway, it can cooperate with these alterations to increase the severity of disease. Finally, using mouse colon derived organoids, we show that endogenous K-RasA59E neither promotes EGF independence of organoid growth nor confers on these organoids a resistance to EGFR inhibition. Thus, our data support a unique role for RAF dimer function in in KRAS mutant tumors of the colon in both development and sensitivity to drugs, as well as argue for the inclusion of KRASA59T and KRASA59E bearing CRC tumors in anti-EGFR therapies. Citation Format: Christian William Johnson, Elizabeth M. Terrell, Josh Cook, Bing Shui, Eve O'Donoghue, Shannon Hull, Moon Hee Yang, Shikha Sheth, Rona Yaeger, Scott Kopetz, Deborah K. Morrison, Kevin Haigis. Ala59 mutants of KRAS cooperate with Nf1 loss to enhance colon tumorigenesis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6623.

AMPLIFY-7P: Phase 1 and randomized phase 2 study of amphiphile immunotherapy ELI-002 7P as adjuvant treatment for subjects with G12D, G12R, G12V, G12C, G12A, G12S and G13D Kirsten rat sarcoma (KRAS)-mutated pancreatic ductal adenocarcinoma.

TPS720 Background: KRAS mutations occur in 25% of human tumors, frequently in pancreatic where over 85% relapse after locoregional treatment. ELI-002 7P is a lymph node targeted immunotherapy comprised of Amphiphile (Amph)-modified G12D, G12R, G12V, G12C, G12A, G12S and G13D mutant KRAS peptides together with an Amph-modified CpG oligonucleotide adjuvant. In the first in human AMPLIFY-201 study, a two peptide G12D/G12R formulation increased KRAS-specific T cells in 87% of patients, and T cell responses 13-fold or higher over baseline correlated with outcomes including reduction in risk of relapse or death. The AMPLIFY-7P study hypothesizes that adjuvant administration of ELI-002 7P will be safe and will delay relapse compared to observation in patients with KRAS mutated pancreatic cancers who have completed curative intent locoregional treatment. Methods: This open-label, phase 1 and randomized phase 2 study is evaluating ELI-002 7P in patients with KRAS mutated pancreatic adenocarcinoma following standard of care chemotherapy and surgery. In phase 2, patients are randomized 2:1 to ELI-002 7P versus observation with crossover of the observation arm permitted at the time of confirmed radiographic relapse via iRECIST. Eligible patients must be within 6 months of completion of locoregional treatment for up-front resectable pathologically confirmed pancreatic cancer (Stage I-III) with radiographic NED (no evidence of disease). Phase 2 patients are included regardless of biomarker evidence of recurrent disease, however, those who have not recovered absolute lymphocytes to the normal range following cytotoxic therapy are excluded. The primary phase 2 objective is to compare the efficacy of ELI-002 7P versus observation, with primary endpoint disease-free survival per investigator. Secondary objectives compare biomarker response (reduction or clearance of ctDNA or if ctDNA was not detectable, serum tumor antigen CA19-9) in the subset with positive baseline values, OS, safety, and iRECIST response rate in the crossover subset. Exploratory endpoints include immunogenicity, the association of immunogenicity with high resolution HLA typing, and evaluation of tumor-infiltrating T cells and the tumor microenvironment in the event biopsy tissue is available. An Independent Data Monitoring Committee reviewed phase 1 data and recommended opening phase 2. Subsequent patients will receive up to 10 doses of Amph-peptides 7P 700 mcg each (4.9 mg total), together with Amph-CpG-7909 (10.0 mg) administered over a five-month treatment period. In Phase 2, approximately 135 patients will be enrolled in the United States. An interim analysis is planned using group sequential design for control of overall alpha 0.10. Clinical trial information: NCT05726864 .

Biomarker expression and survival in patients with non-small cell lung cancer receiving adjuvant chemotherapy in Denmark.

Programmed cell death ligand-1 (PD-L1) expression may help identify patients with non-small cell lung cancer (NSCLC) who would benefit from immunotherapy. We assessed PD-L1 expression, and epidermal growth factor receptor (EGFR) and V-Ki-Ras2 Kirsten rat sarcoma (KRAS) mutations in NSCLC patients receiving adjuvant chemotherapy. Data for stage IB/II/IIIA NSCLC patients (diagnosed: 2001-2012) were retrieved from Danish population-based registries. Tumor tissue samples were tested for PD-L1 expression using VENTANA PD-L1 (SP263) Assay in tumor cells (TC) at ≥25% cutoff and immune cells (IC) at ≥1% and ≥25% cutoffs. KRAS and EGFR mutations were tested using PCR-based assays. Follow-up began 120 days after diagnosis until death/emigration/January 1, 2015, whichever came first. Using Cox proportional hazard regression, hazard ratios (HRs) were computed for overall survival (OS) for each biomarker, adjusting for age, sex, histology, comorbidities, and tissue specimen age. Among 391 patients identified, 40.4% had stage IIIA disease, 49.9% stage II, and 8.7% stage IB. PD-L1-TC was observed in 38% of patients, EGFR mutations in 4%, and KRAS mutations in 29%. KRAS mutations were more frequent among patients with PD-L1 TC≥25% versus TC<25% (37% versus 24%). OS was not associated with PD-L1 TC≥25% versus TC<25% (stage II: adjusted HR = 1.15 [95% confidence interval: 0.66-2.01]; stage IIIA: 0.72 [0.44-1.19]). No significant association was observed with OS and PD-L1-IC ≥1% and ≥25%. EGFR and KRAS mutations were not associated with a prognostic impact. A prognostic impact for NSCLC patients receiving adjuvant chemotherapy was not associated with PD-L1 expression, or with EGFR and KRAS mutations.

Predicting Multi-Gene Mutation Based on Lung Cancer CT Images and Mut-SeResNet

Epidermal growth factor receptor (EGFR) and Kirsten rat sarcoma (KRAS) are the most common driver genes in non-small cell lung cancer patients. However, frequent gene mutation testing raises a potential risk of cancer metastasis. In our paper, a Mut-SeResNet model based on the ResNet network that incorporated a residual block and attention mechanism was proposed to solve the performance degradation problem caused by a deepening of the network. We introduced a residual structure and extracted small differences between different levels to enhance the feature learning ability. The squeeze and excitation attention mechanism was adapted to fully extract the dependence between different channels of the feature image, and it calibrated the channel feature information. We used the dataset of 363 patients that were collected from collaborating hospitals to train our Mut-SeResNet model. The prediction accuracy for EGFR and KRAS mutations was 89.7% and 88.3%, respectively, with a loss accuracy of 6.4% and 9.2%, respectively. The results showed that the model provided a non-invasive and easy-to-use method to improve the accuracy and stability of clinical diagnosis.

Relationship between PET/CT images and KRAS gene mutations in colorectal cancer in Vietnamese patients.

We conducted this study to determine the relationship among standardized uptake value (SUV), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) indexes of Flourine-18 fluorodeoxyglucose positron emission tomography/computed tomography18 (FDG-PET/CT) imaging and Kirsten rat sarcoma (KRAS) gene mutations in colorectal cancer (CRC). This cross-sectional study was conducted in Bach Mai Hospital from 2020 to 2022. It included newly diagnosed CRC patients who underwent PET/CT examination prior to primary tumor resection. The maximum SUV (SUVmax - SUVmean), MTV, and TLG were considered. All pathologically confirmed CRC patients were accepted with further KRAS mutation status analysis. We enrolled 63 newly diagnosed CRC patients who underwent PET/CT examination prior to primary tumor resection. Among them, 31 (49.2%) patients had KRAS gene mutation. Patients with KRAS mutation status showed significantly different and higher SUVmax (p-value = 0.025), SUVmax t/b (p-value = 0.013), SUVmax t-b (p-value = 0.014), MTV (p-value = 0.023), and TLG (p-value = 0.011) than patients with WT KRAS. Other characteristics, including age, gender, tumor location, SUVb, SUVmean, SUVmax of lymph nodes, and SUVmax of liver metastasis, were insignificantly different between the two groups of patients with KRAS mutation status. Receiver operating curve analysis showed that the area under the curve was 0.672 for SUVmax (p-value = 0.019), SUVt/b (p-value = 0.045), and SUVt-b (p-value = 0.020). We observed a relationship, considering the quantitative parameters (SUVmax, SUVmax, SUVmax t-b, MTV, and TLG), between 18FDG-PET/CT images and the KRAS gene mutation in CRC by analyzing 63 patients prior to treatment.

The impact of RAS mutation on the treatment strategy of colorectal cancer.

Kirsten rat sarcoma (KRAS) is the most frequently mutated oncogene in colorectal cancer, being present in 30% of patients with localized disease and in almost half of the patients that develop metastatic disease. While the development of chemotherapy doublets and targeted therapy have improved survival in recent years, KRAS mutation still has a controversial role regarding its prognostic and predictive value both in the adjuvant and in the metastatic setting. The impact of KRAS mutation on treatment strategy remains to be better defined. The development of new KRAS inhibitors promising new treatment options is on the horizon.

Current status and quality of radiomic studies for predicting KRAS mutations in colorectal cancer patients: A systematic review and meta‑analysis

PurposeThe purpose of this study was to evaluate the methodological quality of radiomics-based studies for noninvasive, preoperative prediction of Kirsten rat sarcoma (KRAS) mutations in patients with colorectal cancer; furthermore, we systematically evaluate the diagnostic accuracy of predicting models. MethodsWe systematically searched PubMed, Embase, Cochrane Library and Web of Science databases up to 20 April 2022 for eligible studies. The methodological quality of included studies was assessed using the Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) and Radiomics Quality Score (RQS) tools. A meta-analysis of studies on the prediction of KRAS status in colorectal cancer patients was performed. ResultTwenty-nine studies were identified in the systematic review, including three studies on the prediction of KRAS status in colorectal cancer liver metastases. All studies had an average RQS score of 9.55 (26.5% of the total score), ranging from 3 to 17. Most studies demonstrated a low or unclear risk of bias in the domains of QUADAS-2. Nineteen studies were included in the meta-analysis, mostly imaged with magnetic resonance imaging (MRI), followed by computed tomography (CT), positron emission tomography-CT (PET/CT). With pooled sensitivity, specificity and area under the curve (AUC) of the training cohorts were 0.80(95% confidence interval(CI), 0.75–0.84), 0.80(95% CI, 0.74–0.85) and 0.87(95% CI, 0.84–0.90),respectively. The pooled sensitivity, specificity, and AUC for the validation cohorts (13 studies) were 0.78(95% CI, 0.71–0.84), 0.84(95% CI, 0.74–0.90), and 0.86(95% CI, 0.83–0.89), respectively. ConclusionRadiomics is a potential noninvasive technology that has a moderate preoperative diagnosis and prediction effect on KRAS mutations. However, it has not been implemented as a clinical decision-making tool. Future researchers should pay more attention to the methodological quality of the study and further externally validate the model using multicenter datasets.

KRAS mutation predict response and outcome in advanced non-small cell lung carcinoma without driver alterations receiving PD-1 blockade immunotherapy combined with platinum-based chemotherapy: a retrospective cohort study from China.

The selection of patients for immunotherapy remains challenging given the lack of highly specific and highly sensitive biomarkers. Kirsten rat sarcoma (KRAS) mutation is the most frequent molecular alteration found in advanced non-small cell lung carcinoma (NSCLC). We explored whether KRAS mutation status predicted the effects of first-line immune checkpoint inhibitor (ICI) treatment and platinum-based chemotherapy in Chinese patients with advanced NSCLC. Clinical data were extracted from medical records of patients with advanced NSCLC at the First Affiliated Hospital of Guangzhou Medical University in China between January 2019 and March 2020. Overall survival (OS) and progression-free survival (PFS) rates were compared via log-rank tests, and independent prognostic factors were identified via Cox regression. Patients with advanced NSCLC without driver alterations who were treated with ICI and platinum-based chemotherapy (N=80) were identified, including 28.7% with KRAS mutations and 71.3% with non-KRAS mutations. Tumor programmed death-ligand 1 (PD-L1) expression was analyzed using a 1% cutoff, and 32.5% of patients were negative and 67.5% were positive. The median tumor mutational burden (TMB) was 7.29 mutations per megabase (muts/Mb) (range, 0.08-44.8 muts/Mb), with 32.5% of cases <5 muts/Mb and 67.5% ≥5 muts/Mb. The median PFS and OS for the entire cohort were 9.8 (95% CI: 9.1-10.5) and 17.6 (95% CI: 14.4-20.8) months, respectively. The 6-month PFS rate was 67.5% and the 1-year OS rate was 72.5%. Thirty-five patients survived until the last follow-up. TheOS and PFS of patients with KRAS mutations were significantly higher than those in the non-KRAS mutant group (P<0.05). The Cox multivariate analyses showed that brain metastasis [hazard ratio (HR) =0.232, 95% CI: 0.102-0.530; P=0.001], TMB (HR =5.675, 95% CI: 1.948-16.535; P=0.001), KRAS mutation (HR =2.552, 95% CI: 1.141-5.708; P=0.023) were independent predictors of OS in patients treated with ICIs and platinum-based chemotherapy. Liver metastasis (HR =0.344, 95% CI: 0.191-0.619; P<0.001) and KRAS/tumor protein p53 (TP53) co-mutation (HR =0.220, 95% CI: 0.067-0.725; P=0.013) were the prognostic factor for PFS of qualified patients. This work provides evidence that KRAS mutation in advanced NSCLC may be served as a potential predictive biomarker for immunotherapeutic efficacy.

EP08.02-101 Real-world Data from KRAS-mutant Advanced NSCLC: the ATLAS Multicenter Cohort Study

Kirsten rat sarcoma (KRAS) mutations are the most common oncogenic driver in non-squamous Non-Small Cell Lung Cancer (NSCLC), occurring in approximately 25-30% of cases. Despite recent advent of novel selective KRAS inhibitors, the majority of KRAS-mutant patients still receive either immunotherapy alone or in combination with chemotherapy as upfront treatment in the routine practice. This study investigated real-world clinical features and survival outcomes of patients with advanced NSCLC harboring KRAS mutation who received standard first-line therapies in Italy.

Therapeutic Outcomes and Clinical Features of Advanced Non–Small Cell Lung Cancer Carrying KRAS Mutations: A Multicenter Real-life Retrospective Study

IntroductionTargeting Kirsten Rat Sarcoma (KRAS) has been deemed impossible for long time, but new drugs have recently demonstrated promising results. Evidence on the outcome of KRAS-mutant advanced-NSCLC treated with new standard regimens are still scarce. Thus, we aimed at assessing the incidence and clinical impact of KRAS mutations in a real-life population of advanced-NSCLC, exploring the prognostic significance of distinct alterations. Materials and MethodsThe present multicenter retrospective study, conducted by 5 Italian Centers from January 2018 to February 2020, involved 297 advanced KRAS mutant NSCLC. Complete clinico-pathological data were evaluated. ResultsOut of 297 patients, 130 carried KRAS_G12C mutation, while 167 presented with mutations other than G12C. Within KRAS_non-G12C group, 73%, 16.8% and 8.9% harboured G12X, codon 13 and Q61H alterations, respectively. No significant differences in survival outcome and treatment response were documented according to KRAS_G12C versus non-G12C, nor KRAS_G12C versus G12X versus other mutations. On univariate analysis ECOG PS, number and sites of metastatic lesions and PD-L1 status significantly impacted on survival. A clear trend towards worse prognosis was apparent in chemotherapy-treated patients, while immunotherapy-based regimens were associated to prolonged survival. Investigating the outcome of PD-L1 ≥ 50% population, we did not detect any significant difference between KRAS_G12C and non-G12C subsets. ConclusionHere, we report on real-life data from a large retrospective cohort of advanced NSCLC harbouring KRAS alterations, with particular attention to G12C mutation. Our study offers useful clues on survival outcome, therapeutic response and clinico-pathological correlations in KRAS-mutant setting, especially in the upcoming era of KRAS G12C targeting therapy.

Characteristics and immune checkpoint inhibitor effects on non-smoking non-small cell lung cancer with KRAS mutation: A single center cohort (STROBE-compliant).

Kirsten rat sarcoma (KRAS) mutation (KRASm) is associated with poor prognosis in non-small cell lung cancer (NSCLC) patients. We have aimed to survey NSCLC patients harboring KRASm in Taiwan, where never-smoking lung adenocarcinoma predominates, and analyze the immune checkpoint inhibitor effect on NSCLC harboring KRASm.NSCLC patients with KRASm were enrolled and tested on programmed death-ligand 1 (PD-L1) expression using available tissue. We analyzed their clinical features, PD-L1 status, responses to ICIs, and overall survival (OS).We studied 93 patients with a median age 66.0 years, 23.7% of whom were women, and 22.6% were never-smokers. The results showed that G12C (36.6%) was the most common KRASm. In 47 patients with available tissue for PD-L1 testing, PD-L1 expression was positive in 66.0% of patients, while PD-L1 ≥50% was higher in ever-smokers (P = .038). Among 23 patients receiving ICI treatment, those with PD-L1 ≥50% experience a 45.5% response rate to ICI. There were benefits from ICI treatment on OS compared with no ICI treatment (median OS 35.6 vs 9.8 months, P = .002) for all of our patients, and for patients with PD-L1 ≥50% (median OS not-reached vs 8.4 months, P = .008). There were no differences in survival across different KRAS subtypes (P = .666).Never-smokers composed more than one-fifth of KRASm in NSCLC in Taiwan. A high PD-L1 expression was related to smoking history and responded well to ICI. ICI treatment improved the OS in NSCLC patients with KRASm, particularly those with PD-L1 ≥50%.

Integrative Analysis of Pharmacokinetic and Metabolomic Profiles for Predicting Metabolic Phenotype and Drug Exposure Caused by Sotorasib in Rats.

Sotorasib is a novel targeted inhibitor of Kirsten rat sarcoma (KRAS) (G12C) that has shown exciting tumor-suppressing effects not only for single targeted agents but also for combination with immune checkpoint inhibitors. However, no integrative analysis of the pharmacokinetics (PK) and pharmacometabolomics (PM) of sotorasib has been reported to date. In the present study, a sensitive and robust high-performance liquid chromatography–tandem mass spectrometry (HPLC-MS/MS) method was firstly developed and fully validated for the quantitation of sotorasib in rat plasma. After one-step protein precipitation, sotorasib and an internal standard (carbamazepine) were separated on a Waters XBrige C18 column (50 mm × 2.1 mm, 3.5 μm) and analyzed in electrospray ionization positive ion (ESI+) mode. The optimized method was fully validated according to guidance and was successfully applied for the PK study of sotorasib at a dose of 10 mg/kg. In addition, a longitudinal and transversal PM was employed and correlated with PK using partial least squares model and Pearson’s analysis. With multivariate statistical analysis, the selected six (AUC model) and nine (C max model) metabolites completely distinguished the high- and low-exposure groups after sotorasib treatment, which indicates that these potential biomarkers can predict drug exposure or toxicity. The results of this study will not only shed light on how sotorasib disturbs the metabolic profiles and the relationship between PK and PM but also offer meaningful references for precision therapy in patients with the KRAS (G12C) mutation.

Kirsten rat sarcoma (KRAS) oncogene mutation predicts magnitude of response and outcomes in hepatic arterial infusion pump therapy of unresectable colorectal liver metastases.

The Kirsten rat sarcoma (KRAS) mutation predicts negative outcomes following resection of colorectal liver metastases (CRLM) and adjuvant hepatic arterial infusion (HAI) pump chemotherapy. Less is known on the effects of KRAS mutation on tumor response in patients with unresectable CRLM undergoing HAI chemotherapy with floxuridine. This is a retrospective cohort study investigating the effects of KRAS mutation on tumor response in patients with unresectable CRLM treated with HAI chemotherapy. Primary endpoint was objective response rate (ORR), secondary endpoints included overall tumor response and conversion to resectability. Twenty-five patients with unresectable liver metastases from colorectal cancer were treated with HAI chemotherapy between 2017-2019. Median number of liver lesions was 12 (range, 1-59) and almost all (n=24) had prior chemotherapy before starting HAI therapy. Median number of cycles administered via HAI pump was 6 (range, 3-12). Overall decrease in liver tumor burden was 63.5% (median; range, -257-100%) with an ORR of 20/25 (80%) and 10 (40%) patients converting to resectable status. Eleven (44%) patients had KRAS positive tumors. When compared to wild-type, KRAS positive tumors had less overall percent decrease (58% vs. 70%; P=0.04) and ORR (7/11 vs. 13/13; P=0.03). Fewer patients with KRAS positive tumors converted to resectable status during HAI therapy (2/11 vs. 8/13; P=0.05). At a median follow-up of 14.6 months (range, 4.0-36.6 months), overall survival is 45% among KRAS-positive and 77% for wild type patients. KRAS mutational status in patients with unresectable liver metastases from colorectal cancer predicts worse response to HAI chemotherapy compared to wild type.

Kirsten rat sarcoma mutation in South Indians with non-small lung cancer: A cause for concern?

Kirsten rat sarcoma mutation in South Indians with non-small lung cancer: A cause for concern?

Correlation between Programmed Death Ligand-1(PD-L1) Expression and Driver Gene Mutations in Non-Small Cell Lung Carcinoma- Adenocarcinoma Phenotype.

Background:Targeted therapy in adenocarcinoma is recommended. The use of immune check point inhibitors for the treatment of Non-small cell lung carcinoma (NSCLC) is used as both first-line and the second-line treatment strategy. The current study was undertaken to assess the frequency of programmed cell death ligand-1 (PD-L1) expression with anaplastic lymphoma kinase (ALK), proto-oncogene 1, receptor tyrosine kinase (ROS), epidermal growth factor receptor (EGFR), Kirsten rat sarcoma (KRAS), and v-Raf murine sarcoma viral oncogene homolog B (BRAF)V600E driver gene mutations in NSCLC adenocarcinoma phenotype. It assesses the frequencies of all markers in the cases where both treatment strategies can be implemented. Expression of the all markers was further compared with demographic, clinical parameters, and overall survival rate. Materials and Methods:The formalin-fixed paraffin-embedded (FFPE) tissue blocks were used in immunohistochemistry (IHC) staining and real-time polymerase chain reaction (RT-PCR) for determining the driver genes and PD-L1 expression in the 100 NSCLC-Adenocarcinoma cases. Results:PD-L1 positivity was observed in 26.36% (n=29/110) cases in adenocarcinoma. No significant differences in PD-L1 expression were observed among patients harboring ALK, ROS1, EGFR, KRAS, and BRAF mutations EGFR mutations had significant association with smoking status. (p= 0.008), Thyroid transcription factor 1 (TTF1) (p=0.0005) and Napsin (p=0.002) expression. ALK gene re-arrangement was significantly related to age (p= 0.001), gender (p= 0.009) and smoking status (p= 0.043). The single versus multiple driver mutations were significantly correlated with smoking status (p=0.005). In the survival rate analysis, EGFR (p=0.058), KRAS (p=0.021), and PD-L1 (p=0.039) were significantly high with the positive versus negative group. Conclusions:The current study is a novel attempt to document the co-expression of multiple driver mutations in the NSCLC-adenocarcinoma phenotype. PD-L1 immunopositivity in NSCLC-adenocarcinoma was higher with EGFR mutation as compared to those of KRAS, ALK, ROS, and BRAF driver genes.

Current Advances and Trends in KRAS Targeted Therapies for Colorectal Cancer.

Kirsten Rat Sarcoma (KRAS) gene somatic point mutations is one of the most prominently mutated proto-oncogenes known to date, and accounts for approximately 60% of all colorectal cancer cases. One of the most exciting drug development areas against colorectal cancer is the targeting of undruggable kinases and kinase-substrate molecules, although whether and how they can be integrated with other therapies remains a question. Current clinical trial data have provided supporting evidence on the use of combination treatment involving MEK inhibitors and either one of the PI3K inhibitors for patients with metastatic colorectal cancer to avoid the development of resistance and provide effective therapeutic outcome rather than using a single agent alone. Many clinical trials are also ongoing to evaluate different combinations of these pathway inhibitors in combination with immunotherapy for patients with colorectal cancer whose current palliative treatment options are limited. Nevertheless, continued assessment of these targeted cancer therapies will eventually allow patients with colorectal cancer to be treated using a personalized medicine approach. In this review, the most recent scientific approaches and clinical trials targeting KRAS mutations directly or indirectly for the management of colorectal cancer are discussed.

The Renaissance of KRAS Targeting in Advanced Non-Small-Cell Lung Cancer: New Opportunities Following Old Failures.

Non-small cell lung cancer (NSCLC) represents the perfect paradigm of ‘precision medicine’ due to its complex intratumoral heterogeneity. It is truly characterized by a range of molecular alterations that can deeply influence the natural history of this disease. Several molecular alterations have been found over time, paving the road to biomarker-driven therapy and radically changing the prognosis of ‘oncogene addicted’ NSCLC patients. Kirsten rat sarcoma (KRAS) mutations are present in up to 30% of NSCLC (especially in adenocarcinoma histotype) and have been identified decades ago. Since its discovery, its molecular characteristics and its marked affinity to a specific substrate have led to define KRAS as an undruggable alteration. Despite that, many attempts have been made to develop drugs capable of targeting KRAS signaling but, until a few years ago, these efforts have been unsuccessful. Comprehensive genomic profiling and wide-spectrum analysis of genetic alterations have only recently allowed to identify different types of KRAS mutations. This tricky step has finally opened new frontiers in the treatment approach of KRAS-mutant patients and might hopefully increase their prognosis and quality of life. In this review, we aim to highlight the most interesting aspects of (epi)genetic KRAS features, hoping to light the way to the state of art of targeting KRAS in NSCLC.

Kirsten rat sarcoma inhibitors in clinical development against nonsmall cell lung cancer.

The unique structure made Kirsten rat sarcoma (KRAS) 'undruggable' for quite an extended period. The functional mechanism of this small protein is well illustrated. However, there is no precision medicine for nonsmall cell lung cancer (NSCLC) patients burden with KRAS mutation. The attempts made by scientists to make challenge history against KRAS mutation and their druggable targets are worth elucidating. The appearance of orphan drug AMG510 in the market specifically targeting KRASG12C is a tremendous breakthrough. Several KRAS inhibitors are under development now. More studies focus on combo treatment of KRAS inhibition and immune checkpoint inhibitors (ICIs). Recent preclinical and clinical investigations have been reported that NSCLC patients with KRAS mutation can benefit from ICIs. The current review elucidates the development of KRAS inhibitors from basic research to clinical precision medicines. We retrospectively analyze the development of KRAS mutation targeting drugs and discuss the investigations for future development of KRAS inhibitors.

Targeting KRAS in pancreatic cancer: new drugs on the horizon.

Kirsten Rat Sarcoma (KRAS) is a master oncogene involved in cellular proliferation and survival and is the most commonly mutated oncogene in all cancers. Activating KRAS mutations are present in over 90% of pancreatic ductal adenocarcinoma (PDAC) cases and are implicated in tumor initiation and progression. Although KRAS is a critical oncogene, and therefore an important therapeutic target, its therapeutic inhibition has been very challenging, and only recently specific mutant KRAS inhibitors have been discovered. In this review, we discuss the activation of KRAS signaling and the role of mutant KRAS in PDAC development. KRAS has long been considered undruggable, and many drug discovery efforts which focused on indirect targeting have been unsuccessful. We discuss the various efforts for therapeutic targeting of KRAS. Further, we explore the reasons behind these obstacles, novel successful approaches to target mutant KRAS including G12C mutation as well as the mechanisms of resistance.

Multi-channel multi-task deep learning for predicting EGFR and KRAS mutations of non-small cell lung cancer on CT images.

Predicting the mutation statuses of 2 essential pathogenic genes [epidermal growth factor receptor (EGFR) and Kirsten rat sarcoma (KRAS)] in non-small cell lung cancer (NSCLC) based on CT is valuable for targeted therapy because it is a non-invasive and less costly method. Although deep learning technology has realized substantial computer vision achievements, CT imaging being used to predict gene mutations remains challenging due to small dataset limitations. We propose a multi-channel and multi-task deep learning (MMDL) model for the simultaneous prediction of EGFR and KRAS mutation statuses based on CT images. First, we decomposed each 3D lung nodule into 9 views. Then, we used the pre-trained inception-attention-resnet model for each view to learn the features of the nodules. By combining 9 inception-attention-resnet models to predict the types of gene mutations in lung nodules, the models were adaptively weighted, and the proposed MMDL model could be trained end-to-end. The MMDL model utilized multiple channels to characterize the nodule more comprehensively and integrate patient personal information into our learning process. We trained the proposed MMDL model using a dataset of 363 patients collected by our partner hospital and conducted a multi-center validation on 162 patients in The Cancer Imaging Archive (TCIA) public dataset. The accuracies for the prediction of EGFR and KRAS mutations were, respectively, 79.43% and 72.25% in the training dataset and 75.06% and 69.64% in the validation dataset. The experimental results demonstrated that the proposed MMDL model outperformed the latest methods in predicting EGFR and KRAS mutations in NSCLC.