Molecular profiling of non-small cell lung cancer

The impact of sarcopenia on the efficacy of PD-1 inhibitors in non-small cell lung cancer and potential strategies to overcome resistance

Recent studies have revealed that sarcopenia can adversely affect the efficacy of PD-1 inhibitors in the treatment of non-small cell lung cancer (NSCLC). PD-1 inhibitors are immune checkpoint inhibitors widely used in the treatment of various cancers. However, NSCLC patients may have poorer outcomes when receiving PD-1 inhibitor treatment, and sarcopenia may affect the efficacy of PD-1 inhibitors through immune and metabolic mechanisms. In this article, we summarize the reported negative impact of sarcopenia on the effectiveness of PD-1 inhibitors in the treatment of NSCLC in recent years. Based on existing research results, we analyze the possible mechanisms by which sarcopenia affects the efficacy of PD-1 inhibitors and discuss possible strategies to address this issue. This could help to understand the impact of sarcopenia on the treatment of PD-1 inhibitors and provide more accurate expectations of treatment outcomes for clinicians and patients. Additionally, we present tailored intervention strategies for sarcopenic patients undergoing PD-1 inhibitor therapy, aiming to optimize treatment efficacy and enhance patient quality of life. Nevertheless, further research is warranted to elucidate the mechanisms through which sarcopenia impacts PD-1 inhibitors and to identify more efficacious intervention approaches for improving the effectiveness of PD-1 inhibitor treatment in sarcopenic patients.

KRAS G12C Mutant Non-Small Cell Lung Cancer Linked to Female Sex and High Risk of CNS Metastasis: Population-based Demographics and Survival Data From the National Swedish Lung Cancer Registry

BACKGROUND

Real-world data on demographics related to KRAS mutation subtypes are crucial as targeted drugs against the p.G12C variant have been approved.

METHOD

We identified 6183 NSCLC patients with reported NGS-based KRAS status in the Swedish national lung cancer registry between 2016 and 2019. Following exclusion of other targetable drivers, three cohorts were studied: KRAS-G12C (n = 848), KRAS-other (n = 1161), and driver negative KRAS-wild-type (wt) (n = 3349).

RESULTS

The prevalence of KRAS mutations and the p.G12C variant respectively was 38%/16% in adenocarcinoma, 28%/13% in NSCLC-NOS and 6%/2% in squamous cell carcinoma. Women were enriched in the KRAS-G12C (65%) and KRAS-other (59%) cohorts versus KRAS-wt (48%). A high proportion of KRAS-G12C patients in stage IV (28%) presented with CNS metastasis (vs. KRAS-other [19%] and KRAS-wt [18%]). No difference in survival between the mutation cohorts was seen in stage I-IIIA. In stage IV, median overall survival (mOS) from date of diagnosis was shorter for KRAS-G12C and KRAS-other (5.8 months/5.2 months) vs. KRAS wt (6.4 months). Women had better outcome in the stage IV cohorts, except in KRAS-G12C subgroup where mOS was similar between men and women. Notably, CNS metastasis did not impact survival in stage IV KRAS-G12C, but was associated with poorer survival, as expected, in KRAS-other and KRAS-wt.

CONCLUSION

The KRAS p.G12C variant is a prevalent targetable driver in Sweden and significantly associated with female sex and presence of CNS metastasis. We show novel survival effects linked to KRAS p.G12C mutations in these subgroups with implications for clinical practice.

Cost Savings of Expedited Care with Upfront Next-Generation Sequencing Testing versus Single-Gene Testing among Patients with Metastatic Non-Small Cell Lung Cancer Based on Current Canadian Practices

This study assessed the total costs of testing, including the estimated costs of delaying care, associated with next-generation sequencing (NGS) versus single-gene testing strategies among patients with newly diagnosed metastatic non-small cell lung cancer (mNSCLC) from a Canadian public payer perspective. A decision tree model considered testing for genomic alterations using tissue biopsy NGS or single-gene strategies following Canadian guideline recommendations. Inputs included prevalence of mNSCLC, the proportion that tested positive for each genomic alteration, rebiopsy rates, time to test results, testing/medical costs, and costs of delaying care based on literature, public data, and expert opinion. Among 1,000,000 hypothetical publicly insured adult Canadians (382 with mNSCLC), the proportion of patients that tested positive for a genomic alteration with an approved targeted therapy was 38.0% for NGS and 26.1% for single-gene strategies. The estimated mean time to appropriate targeted therapy initiation was 5.1 weeks for NGS and 9.2 weeks for single-gene strategies. Based on literature, each week of delayed care cost CAD 406, translating to total mean per-patient costs of CAD 3480 for NGS and CAD 5632 for single-gene strategies. NGS testing with mNSCLC in current Canadian practice resulted in more patients with an identified mutation, shorter time to appropriate targeted therapy initiation, and lower total testing costs compared to single-gene strategies.

The solvent chosen for the manufacturing of electrospun polycaprolactone scaffolds influences cell behavior of lung cancer cells

The development of a trustworthy in vitro lung cancer model is essential to better understand the illness, find novel biomarkers, and establish new treatments. Polycaprolactone (PCL) electrospun nanofibers are a cost-effective and ECM-like approach for 3D cell culture. However, the solvent used to prepare the polymer solution has a significant impact on the fiber morphology and, consequently, on the cell behavior. Hence, the present study evaluated the effect of the solvent employed in the manufacturing on the physical properties of 15%-PCL electrospun scaffolds and consequently, on cell behavior of NCI-H1975 lung adenocarcinoma cells. Five solvents mixtures (acetic acid, acetic acid-formic acid (3:1, v/v), acetone, chloroform-ethanol (7:3, v/v), and chloroform-dichloromethane (7:3, v/v)) were tested. The highest cell viability ([Formula: see text] = 33.4%) was found for cells cultured on chloroform-ethanol (7:3) PCL scaffolds. Chloroform-dichloromethane (7:3) PCL scaffolds exhibited a roughness that enhanced the quality of electrospun filament, in terms of cell viability. Our findings highlighted the influence of the solvent on fiber morphology and protein adsorption capacity of nanofilaments. Consequently, these features directly affected cell attachment, morphology, and viability.

Prevalence, Treatment Patterns, and Outcomes of Individuals with EGFR Positive Metastatic Non-Small Cell Lung Cancer in a Canadian Real-World Setting: A Comparison of Exon 19 Deletion, L858R, and Exon 20 Insertion EGFR Mutation Carriers

Real-world evidence surrounding EGFR positive NSCLC patients in Canada is limited. Administrative databases in Alberta, Canada were used to evaluate EGFR testing and mutation prevalence in de novo metastatic NSCLC, as well as the characteristics, treatment patterns, and outcomes of individuals with Exon 19, L858R and Exon20ins mutations. Between 2013-2019, 2974 individuals underwent EGFR testing, of which 451 (15.2%) were EGFR positive. Among EGFR positive individuals, 221 (49.0%) had an Exon 19 mutation, 159 (35.3%) had an L858R mutation, and 18 (4%) had an Exon20ins mutation. The proportion of individuals who initiated 1L systemic therapy was 89.1% for Exon19, 85.5% for L858R, and 72.2% for Exon20ins carriers. The primary front-line systemic therapy was gefitinib or afatinib monotherapy for individuals with Exon 19 (93.4%) and L858R (94.1%) mutations versus platinum combination therapy for individuals with Exon20ins mutations (61.5%). The Exon20ins cohort had worse median overall survival from initiation of 1L systemic therapy (10.5 months [95% CI: 8.0-not estimable]) than the Exon19 (20.6 months [95% CI: 18.4-24.9]), and L858R cohorts (19.1 months [95% CI: 14.5-23.1]). These findings highlight that Exon20ins mutations represent a rare subset of NSCLC in which treatment options are limited and survival outcomes are worse relative to individuals with more common types of EGFR mutations.

Consensus Recommendations to Optimize Testing for New Targetable Alterations in Non-Small Cell Lung Cancer

Non-small cell lung cancer (NSCLC) has historically been associated with a poor prognosis and low 5-year survival, but the use of targeted therapies in NSCLC has improved patient outcomes over the past 10 years. The pace of development of new targeted therapies is accelerating, with the associated need for molecular testing of new targetable alterations. As the complexity of biomarker testing in NSCLC increases, there is a need for guidance on how to manage the fluid standard-of-care in NSCLC, identify pragmatic molecular testing requirements, and optimize result reporting. An expert multidisciplinary working group with representation from medical oncology, pathology, and clinical genetics convened via virtual meetings to create consensus recommendations for testing of new targetable alterations in NSCLC. The importance of accurate and timely testing of all targetable alterations to optimize disease management using targeted therapies was emphasized by the working group. Therefore, the panel of experts recommends that all targetable alterations be tested reflexively at NSCLC diagnosis as part of a comprehensive panel, using methods that can detect all relevant targetable alterations. In addition, comprehensive biomarker testing should be performed at the request of the treating clinician upon development of resistance to targeted therapy. The expert multidisciplinary working group also made recommendations for reporting to improve clarity and ease of interpretation of results by treating clinicians and to accommodate the rapid evolution in clinical actionability of these alterations. Molecular testing of all targetable alterations in NSCLC is the key for treatment decision-making and access to new therapies. These consensus recommendations are intended as a guide to further optimize molecular testing of new targetable alterations.

Genomic landscape of non-small-cell lung cancer with methylthioadenosine phosphorylase (MTAP) deficiency

INTRODUCTION

New treatment strategies for advanced non-small-cell lung carcinoma (NSCLC) include synthetic lethality targets focused on protein arginine methyl transferases such as PRMT5 that exploit the impact of genomic loss of methylthioadenosine phosphorylase (MTAP).

METHODS

Twenty nine thousand three hundred seventy nine advanced NSCLC cases underwent hybrid-capture based comprehensive genomic profiling between June 1, 2018 and May 31, 2020. PD-L1 expression was determined by immunohistochemistry (Dako 22C3 PharmDx assay).

RESULTS

13.4% (3928/29,379) NSCLC cases exhibited MTAP loss distributed in adenocarcinoma (59%), squamous cell carcinoma (22%), NSCLC not otherwise specified (16%), and 1% each for large-cell neuroendocrine, sarcomatoid, and adenosquamous carcinoma. Statistically significant differences in mitogenic driver alterations included more KRAS G12C mutations in MTAP-intact versus MTAP-lost (12% vs. 10%, p = 0.0003) and fewer EGFR short variant mutations in MTAP-intact versus MTAP-lost NSCLC (10% vs. 13%, p < 0.0001). Statistically significant differences in currently untargetable genomic alterations included higher frequencies of TP53 (70% vs. 63%, p < 0.0001) and RB1 inactivation (10% vs. 2%, p < 0.0001) in MTAP-intact compared to MTAP-lost NSCLC. SMARCA4 inactivation (7% vs. 10%, p < 0.0001) was less frequent in MTAP-intact versus MTAP-lost NSCLC. Alterations in ERBB2, MET, ALK, ROS1, and NTRK1 did not significantly differ between the two groups. Predictors of immunotherapy efficacy were higher in MTAP-intact versus MTAP-lost NSCLC including tumor mutational burden (9.4 vs. 8.6 mut/Mb, p = 0.001) and low (30% vs. 28%, p = 0.01) and high PD-L1 (32% vs. 30%, p = 0.01) expression. Alterations in biomarkers potentially predictive of immune checkpoint inhibitor resistance (STK11, KEAP1, and MDM2) were similar in the two groups.

CONCLUSIONS

MTAP loss occurs in 13% of NSCLC, supporting the development of targeted therapies to exploit PRMT5 hyper-dependence. MTAP loss is accompanied by small differences in targeted and immunotherapy options which may impact future combination strategies.

STK11 and KEAP1 mutations in non-small cell lung cancer patients: Descriptive analysis and prognostic value among Hispanics (STRIKE registry-CLICaP)

BACKGROUND

Mutations in STK11 (STK11^Mut) and, frequently co-occurring, KEAP1 mutations (KEAP1^Mut) are associated with poor survival in metastatic Non-small Cell Lung Cancer (mNSCLC) patients treated with immunotherapy. However, there are limited data regarding the prognostic or predictive significance of these genomic alterations among Hispanics.

METHODS

This retrospective study analyzed a cohort of Hispanic patients (N = 103) diagnosed with mNSCLC from the US and seven Latin American countries (LATAM) treated with immune checkpoint inhibitors (ICI) alone or in combination as first-line (Cohort A). All cases were treated in routine care between January 2016 and December 2021. The main objectives were to determine the association of mutations in STK11 or KEAP1 in these patients' tumors with overall (OS) and progression-free survival (PFS), presence of KRAS mutations, tumor mutational burden (TMB), and other relevant clinical variables. To compare outcomes with a STK11^Wt/KEAP1^Wt population, historical data from a cohort of Hispanic patients (N = 101) treated with first-line ICI was used, matching both groups by country of origin, gender, and Programed Death-ligand 1 (PD-L1) expression level (Cohort B).

RESULTS

Most tumors had mutations only in STK11 or KEAP1 (45.6%) without KRAS co-mutation or any other genomic alteration. Besides, 35%, 8.7%, 6.8%, and 3.9% were KRAS^Mut + STK11^Mut, KRAS^Mut + STK11^Mut + KEAP1^Mut, STK11^Mut + KEAP1^Mut, and KRAS^Mut + KEAP1^Mut, respectively. Based on KRAS status, STK11 alterations were associated with significantly lower PD-L1 expression among those with KRAS^Wt (p = 0.023), whereas KEAP1 mutations were predominantly associated with lower PD-L1 expression among KRAS^Mut cases (p = 0.047). Tumors with KRAS^Mut + KEAP1^Mut had significantly higher median TMB when compared to other tumors (p = 0.040). For Cohort A, median PFS was 4.9 months (95%CI 4.3-5.4), slightly longer in those with KEAP1^mut 6.1 months versus STK11^Mut 4.7 months (p = 0.38). In the same cohort, PD-L1 expression and TMB did not influence PFS. OS was significantly longer among patients with tumors with PD-L1 ≥ 50% (30.9 months), and different from those with PD-L1 1-49% (22.0 months), and PD-L1 < 1% (12.0 months) (p = 0.0001). When we compared the cohorts A and B, OS was significantly shorter for patients carrying STK1 [STK11^Mut 14.2 months versus STK11^Wt 27.0 months (p = 0.0001)] or KEAP1 [KEAP1^Mut 12.0 months versus KEAP1^Wt 24.4 months (p = 0.005)] mutations. PD-L1 expression significantly affected OS independently of the presence of mutations in STK11, KEAP1, or KRAS. TMB-H favored better OS.

CONCLUSIONS

This is the first large Hispanic cohort to study the impact of STK11 and KEAP1 mutations in NSCLC patient treated with ICI. Our data suggest that mutations in the above-mentioned genes are associated with PD-L1 expression levels and poor OS.

Untangling the KRAS mutated lung cancer subsets and its therapeutic implications

The Kirsten rat sarcoma virus transforming protein (KRAS) mutations (predominate in codons 12, 13, and 61) and genomically drive nearly one-third of lung carcinomas. These mutations have complex functions in tumorigenesis, and influence the tumor response to chemotherapy and tyrosine kinase inhibitors resulting in a poorer patient prognosis. Recent attempts using targeted therapies against KRAS alone have met with little success. The existence of specific subsets of lung cancer based on KRAS mutations and coexisting mutations are suggested. Their interactions need further elaboration before newer promising targeted therapies for KRAS mutant lung cancers can be used as earlier lines of therapy. We summarize the existing knowledge of KRAS mutations and their coexisting mutations that is relevant to lung cancer treatment, in this review. We elaborate on the prognostic impact of clinical and pathologic characteristics of lung cancer patients associated with KRAS mutations. We briefly review the currently available techniques for KRAS mutation detection on biopsy and cytology samples. Finally, we discuss the new therapeutic strategies for targeting KRAS-mutant non-small cell lung cancer (NSCLC). These may herald a new era in the treatment of KRAS^G12Cmutated NSCLC as well as be helpful to develop demographic subsets to predict targeted therapies and prognosis of lung cancer patients.

First-Line Pharmacotherapies and Survival among Patients Diagnosed with Non-Resectable NSCLC: A Real-Life Setting Study with Gender Prospective

Simple Summary

Women and men have a different biomolecular profile that could impact drug utilization and survival in non-small cell lung cancer (NSCLC) patients. The aim of the study was to describe first-line pharmacotherapy and overall survival in non-resectable (nr)NSCLC patients by gender. About 4400 incident cases of nrNSCLC were included. We reported a different use of target therapies on the basis of the known biomolecular profile between the two sexes. The survival improved in the last decade, and women and men also showed different survival if diagnosed with a squamous or non-squamous nrNSCLC.

Abstract

(1) Purpose: To describe first-line pharmacotherapy and overall survival in non-resectable non-small cell lung cancer (nrNSCLC) patients by gender. (2) Methods: Incident cases of nrNSCLC recorded between 2009 and 2019 (cohort entry) in the pathology registry of the regional administrative healthcare database of Tuscany were identified. Records of antineoplastic therapies delivered up to 4 months following cohort entry were classified as chemotherapy, target therapies, immunotherapies, and undefined monoclonal antibodies. First-line treatment and survival of patients receiving drug treatment was described. Analyses were stratified according to histology, gender, and cohort entry year. (3) Results: 4393 incident cases of nrNSCLC were included. Women with non-squamous-NSCLC received target-therapy more frequently than men (14.9% vs. 6.5%). Immunotherapy incidence of use varied between 3.8% (2017) and 9.1% (2019). The 2-year survival rate increased over time: for non-squamous-NSCLC, it was 22.3% (2009–2011) and 30.6% (2018–2019), while for squamous-NSCLC, it was 13.5% and 22.5%, respectively. After multivariate analysis, a low reduction in mortality risk in 2018–2019 vs. 2009–2011 was found (non-squamous: HR: 0.95 CI95%: 0.92–0.98; squamous: HR: 0.94 CI95%: 0.90–0.98). Among non-squamous NSCLC, median survival was longer in women than in men (389 vs. 276 days). (4) Conclusion: In light of sex-related biomolecular differences, among non-squamous NSCLC, women received target-therapy more frequently than men. Survival seemed to slightly improve over the study period for both histologies, despite a poor reduction in mortality risk was still observed.

Polycaprolactone Electrospun Scaffolds Produce an Enrichment of Lung Cancer Stem Cells in Sensitive and Resistant EGFRm Lung Adenocarcinoma

Simple Summary

The culture of lung cancer stem cells (LCSCs) is not possible using traditional flat polystyrene surfaces. The study of these tumor-initiating cells is fundamental due to their key role in the resistance to anticancer therapies, tumor recurrence, and metastasis. Hence, we evaluated the use of polycaprolactone electrospun (PCL-ES) scaffolds for culturing LCSC population in sensitive and resistant EGFR-mutated lung adenocarcinoma models. Our findings revealed that both cell models seeded on PCL-ES structures showed a higher drug resistance, enhanced levels of several genes and proteins related to epithelial-to-mesenchymal process, stemness, and surface markers, and the activation of the Hedgehog pathway. We also determined that the non-expression of CD133 was associated with a low degree of histological differentiation, disease progression, distant metastasis, and worse overall survival in EGFR-mutated non-small cell lung cancer patients. Therefore, we confirmed PCL-ES scaffolds as a suitable three-dimensional cell culture model for the study of LCSC niche.

Abstract

The establishment of a three-dimensional (3D) cell culture model for lung cancer stem cells (LCSCs) is needed because the study of these stem cells is unable to be done using flat surfaces. The study of LCSCs is fundamental due to their key role in drug resistance, tumor recurrence, and metastasis. Hence, the purpose of this work is the evaluation of polycaprolactone electrospun (PCL-ES) scaffolds for culturing LCSCs in sensitive and resistant EGFR-mutated (EGFRm) lung adenocarcinoma cell models. We performed a thermal, physical, and biological characterization of 10% and 15%-PCL-ES structures. Several genes and proteins associated with LCSC features were analyzed by RT-qPCR and Western blot. Vimentin and CD133 tumor expression were evaluated in samples from 36 patients with EGFRm non-small cell lung cancer through immunohistochemistry. Our findings revealed that PC9 and PC9-GR3 models cultured on PCL-ES scaffolds showed higher resistance to osimertinib, upregulation of ABCB1, Vimentin, Snail, Twist, Sox2, Oct-4, and CD166, downregulation of E-cadherin and CD133, and the activation of Hedgehog pathway. Additionally, we determined that the non-expression of CD133 was significantly associated with a low degree of histological differentiation, disease progression, and distant metastasis. To sum up, we confirmed PCL-ES scaffolds as a suitable 3D cell culture model for the study of the LCSC niche.

Understanding Contemporary Molecular Biomarker Testing Rates and Trends for Metastatic NSCLC Among Community Oncologists

INTRODUCTION

Although guidelines recommend testing for actionable biomarkers for patients with advanced or metastatic non-small cell lung cancer (NSCLC), testing rates have varied. This study aimed to assess molecular testing patterns in a large network of US community-based oncology practices.

METHODS

This retrospective observational study examined adult patients with newly diagnosed stage IV NSCLC with ≥ 2 visits in The US Oncology Network from July 1, 2016 to September 30, 2019. Testing patterns were examined using electronic health record structured fields and chart review. Structured data were analyzed for the overall study population (cohort A), and structured and unstructured data were analyzed for a select cohort of 300 patients (cohort B).

RESULTS

In cohort A (n = 3337), programmed death ligand 1 (37%) was the most frequently tested biomarker documented in structured data, followed by epidermal growth factor receptor (36%), anaplastic lymphoma kinase (35%), ROS1 (20%), and BRAF (16%). According to unstructured data in cohort B (n = 300), epidermal growth factor receptor (80%) was the most frequently tested biomarker, followed by anaplastic lymphoma kinase (79%), programmed death ligand 1 (72%), ROS1 (71%), and BRAF (56%). The proportion of tests ordered prior to first-line (1L) treatment increased from 2016 to 2018 for all biomarkers, as did the proportion of test results available prior to 1L treatment. However, some of the test results became available after 1L or later lines of treatment were in progress.

CONCLUSION

Our study found increased testing rates over time and decreases in testing turnaround times. However, rates of testing for all biomarkers still need to improve, as does completion of testing prior to initiation of therapy.

A retrospective observational study of the natural history of advanced non-small-cell lung cancer in patients with KRAS p.G12C mutated or wild-type disease

INTRODUCTION

The KRAS p.G12C mutation, prevalent in non-small-cell lung cancer (NSCLC), has only recently become a viable target. Here we present results of the largest retrospective observational study analyzing KRAS p.G12C in patients with advanced NSCLC.

MATERIALS AND METHODS

Adults with advanced NSCLC (All Advanced NSCLC cohort) and subcohorts with different mutation profiles (KRAS p.G12C [G12C] and KRAS/EGFR/ALK wild type [Triple WT]) diagnosed January 2011 to March 2019 were selected from a US clinico-genomic database; treatment-related characteristics, molecular profiles, real-world overall (rwOS) and progression-free survival (rwPFS) were analyzed.

RESULTS

Demographics were similar across cohorts, with more smokers and nonsquamous cell carcinoma histology in the G12C cohort. KRAS p.G12C was nearly mutually exclusive (≤1.2 %) with known actionable driver mutations, but non-driver co-mutations were common (STK11, 21.5 %; KEAP1, 7.0 %; TP53, 48.0 %). Among G12C patients, 20 % had no documentation of receiving systemic therapy. Across treated G12C patients, 67 % received immune checkpoint inhibitors; first-line usage increased from 0% (2014) to 81 % (2019). Among G12C patients, median (95 % CI) rwOS was 12.0 (9.6-15.3), 9.5 (8.1-13.1), and 6.7 (5.9-10.7) months after first, second, and third line of therapy, respectively; median (95 % CI) rwPFS was 5.0 (4.4-5.8), 4.0 (2.8-5.3), and 3.1 (2.4-4.3) months. Outcomes for the G12C subcohort were similar to those for all patients (All Advanced NSCLC cohort). Mutations in STK11/KEAP1 were associated with poorer survival across all cohorts.

CONCLUSION

The poor outcomes associated with KRAS p.G12C mutated advanced NSCLC indicate an unmet need for more effective novel treatments.

Profiling non-small cell lung cancer reveals that PD-L1 is associated with wild type EGFR and vascular invasion, and immunohistochemistry quantification of PD-L1 correlates weakly with RT-qPCR

Most lung cancer patients are diagnosed at an advanced stage, limiting their treatment options with very low response rate. Lung cancer is the most common cause of cancer death worldwide. Therapies that target driver gene mutations (e.g. EGFR, ALK, ROS1) and checkpoint inhibitors such anti-PD-1 and PD-L1 immunotherapies are being used to treat lung cancer patients. Identification of correlations between driver mutations and PD-L1 expression will allow for the best management of patient treatment. 851 cases of non-small cell lung cancer cases were profiled for the presence of biomarkers EGFR, KRAS, BRAF, and PIK3CA mutations by SNaPshot/sizing genotyping. Immunohistochemistry was used to identify the protein expression of ALK and PD-L1. Total PD-L1 mRNA expression (from unsorted tumor samples) was quantified by RT-qPCR in a sub-group of the cohort to assess its correlation with PD-L1 protein level in tumor cells. Statistical analysis revealed correlations between the presence of the mutations, PD-L1 expression, and the pathological data. Specifically, increased PD-L1 expression was associated with wildtype EGFR and vascular invasion, and total PD-L1 mRNA levels correlated weakly with protein expression on tumor cells. These data provide insights into driver gene mutations and immune checkpoint status in relation to lung cancer subtypes and suggest that RT-qPCR is useful for assessing PD-L1 levels.