Comparison of EGFR and KRAS mutations in primary and unpaired metastatic lung adenocarcinoma with potential chemotherapy effect

Molecular features of NSCLC patients with liver metastasis

Background

Metastasis is the primary cause of lung cancer-related death. Primary cancer cells invade through the lymphatic or blood vessels to distant sites. Recently, it was proposed that lymphatic metastasis was more a hallmark of tumor aggressiveness or metastatic potential than a gateway to metastases. Therefore, the underlying molecular mechanism of metastasis is not entirely clear.

Objectives

This study aimed to explore the genetic mechanisms underlying liver metastases from lung cancer and to evaluate the efficacy of different therapies in these patients.

Design

We retrospectively analyzed the mutation spectrum of different biopsy samples including primary lung tumors, liver, lymph node metastasis, and circulating tumor DNA (ctDNA) from 1090 non-small-cell lung cancer (NSCLC) patients with liver metastasis between the years 2017 and 2022.

Methods

Demographic and disease characteristics were summarized using descriptive parameters. Time to treatment discontinuation was used to analyze the clinical outcome.

Results

More liquid biopsies were performed than tissue biopsies, especially in the treated advanced NSCLC patients. Liver metastasis before treatment was associated with poor response to immune checkpoint inhibitors and targeted therapy. Liver and lymph node metastasis had higher levels of single nucleotide variants and copy number variants than primary lung tumors. In paired lung and liver, lymph nodes, and simultaneous ctDNA, we found actionable mutations were always shared, while metastasis samples had multiple private mutations. Serial ctDNA analysis identifies potential resistant mutations and describes the evolution of tumor cells.

Conclusion

Liver and lymph node metastasis in NSCLC showed shared actionable mutations. Of note, the discrepancy of private mutations in liver and lymph node metastases indicated that liver metastases are mainly seeded by the primary tumor rather than the earlier colonized lymph node metastases.

Proteomic Analysis of the Air-Way Fluid in Lung Cancer. Detection of Periostin in Bronchoalveolar Lavage (BAL)

Background: Bronchoalveolar lavage (BAL) is a specific type of air-way fluid. It is a commonly used clinical specimen for the diagnosis of benign diseases and cancers of the lung. Although previous studies have identified several disease-associated proteins in the BAL, the potential utility of BAL in lung cancer is still not well-studied. Based upon the fact that the majority of secreted proteins are glycoproteins, we have profiled N-glycoproteins in BAL collected from lung cancers, and investigated the expression of glycoproteins such as the matrix N-glycoprotein, periostin, in lung cancers. Methods: BAL specimens (n = 16) were collected from lung cancer patients, and analyzed using mass spectrometry-based quantitative N-glycoproteomic technique. Additional BAL specimens (n = 39) were independently collected to further evaluate the expression of periostin by using an enzyme-linked immunosorbent assay (ELISA). Results: A total of 462 glycoproteins were identified in BAL samples using N-glycoproteomic technique, including 290 in lung adenocarcinoma (ADC, n = 5), 376 in squamous cell carcinoma (SQCC, n = 4), 309 in small cell lung carcinoma (SCLC, n = 4), and 316 in benign lung disease (n = 3). The expressions of several glycoproteins were elevated, including 8 in ADC, 12 in SQCC, and 17 in SCLC, compared to benign BALs. The expression of periostin was detected in all subtypes of lung cancers. To further investigate the expression of periostin, an ELISA assay was performed using additional independently collected BALs (n = 39) The normalized levels of periostin in benign disease, ADC, SQCC, and SCLC were 255 ± 104 (mean ± SE) and 4,002 ± 2,181, 3,496 ± 1,765, and 1,772 ± 1,119 ng/mg of total BAL proteins. Conclusion: Our findings demonstrate that proteomic analysis of BAL can be used for the study of cancer-associated extracellular proteins in air-way fluid from lung cancer patients.

Distinct Patterns of mRNA and lncRNA Expression Differences Between Lung Squamous Cell Carcinoma and Adenocarcinoma

This study aimed to assess mRNA and lncRNA expression differences between lung squamous cell carcinoma (LUSC) and lung adenocarcinoma (LUAD). Cancer tissues were obtained from three LUSC and three LUAD patients, followed by RNA-seq. Differentially expressed mRNAs (DE-mRNAs) and lncRNAs (DE-lncRNAs) were identified between LUSC and LUAD, after which functional enrichment analysis and protein-protein interaction (PPI) network construction was performed on DEGs. Coexpression analysis of lncRNA-gene and prediction of DEG-related miRNAs as well as function enrichment analysis, and construction of competing endogenous RNAs (ceRNA) regulatory network were then conducted. Moreover, survival analysis on differentially expressed RNAs was performed based on data downloaded from The Cancer Genome Atlas (TCGA) database. In this study, 518 DEGs and 117 DE-lncRNAs were identified between LUSC and LUAD. The DEGs were mainly associated with cell adhesion, PI3K-Akt signaling pathway, and focal adhesion. PPI network analysis indicated several genes with highest connectivity, such as CCND1. DE-lncRNAs that coexpressed with DEGs were also associated with tight junction and DE-lncRNAs that had more corepressed relationships with DEGs included GSEC, NKX2-1-AS1, LINC01415, and LINC00839. Moreover, the genes and lncRNAs with higher connectivity in the ceRNA network included NEAT1, SLC5A3, LINC00839, ETV1, CMTM4, and SNX30. Several genes were significantly related to the survival of patients with LUSC and LUAD, including ETV1, RTKN2, SNX30, PAK2, and CCND1. Genes and lncRNAs associated with cell junction have specific patterns in two major histological subtypes of NSCLC. GSEC, NKX2-1-AS1, NEAT1, CCND1, and ETV1 may be potential novel biomarkers for personalized treatment strategies of NSCLC.

Transthoracic fine-needle aspiration diagnosis of solid, subsolid, and partially calcified lung nodules: A retrospective study from a single academic center

Background:

The large-scale National Lung Cancer Screening Trial demonstrated an increased detection of early-stage lung cancers using low-dose computed tomography scan in the screening population. It also demonstrated a 20% reduction of lung cancer-related deaths in these patients.

Aims:

Although both solid and subsolid lung nodules are evaluated in studies, subsolid and partially calcified lung nodules are often overlooked.

Materials and Methods:

We reviewed transthoracic fine-needle aspiration (FNA) cases from lung nodule patients in our clinics and correlated cytological diagnoses with radiologic characteristics of lesions. A computer search of the pathology archive was performed over a period of 12 months for transthoracic FNAs, including both CT- and ultrasound-guided biopsies.

Results:

A total of 111 lung nodule cases were identified. Lesions were divided into three categories: solid, subsolid, and partially calcified nodules according to radiographic findings. Of 111 cases, the average sizes of the solid (84 cases), subsolid (22 cases), and calcified (5 cases) lesions were 1.952 ± 2.225, 1.333 ± 1.827, and 1.152 ± 1.984 cm, respectively. The cytological diagnoses of three groups were compared. A diagnosis of malignancy was made in 64.28% (54 cases) in solid, 22.72% (5 cases) in subsolid, and 20% (1 case) in partially calcified nodules. Among benign lesions, eight granulomatous inflammations were identified, including one case of solid, five cases of subsolid, and two cases of calcified nodules.

Conclusions:

Our study indicates that solid nodules have the highest risk of malignancy. Furthermore, the cytological evaluation of subsolid and partially calcified nodules is crucial for the accurate diagnosis and appropriate clinical management of lung nodule patients.

Expression of p16 and p53 in non-small-cell lung cancer: clinicopathological correlation and potential prognostic impact

Aim: p16 and p53 are frequently altered intracellular pathways in cancers. We investigated the aberrant expression of p16 and its relationship with p53 and HPV status in primary non-small-cell lung carcinoma. Patients & methods: Lung tumor tissue microarray (n = 163), immunohistochemical study of p16 and p53, and HPV in-situ hybridization were analyzed. Results: p16 and p53 were detected in 50.7 and 57.3% of adenocarcinoma (ADCs; n = 75), and 35.2 and 63.6% of squamous cell carcinoma (n = 88). HPV was detected in 16 and 10.2% of ADC and squamous cell carcinoma. In ADCs, p16 positive tumors demonstrated a favorable median overall survival time of 60.9 months, compared with p16 negative tumors of 46.9 months (p < 0.05). Furthermore, we did not find significant relationships between p16 expression and HPV status, nor with p53 expression. Conclusion: p16 play an unique role in lung cancer survival. The mechanism of p16 needs to be further studied.

Detection of RAS and RAS-associated alterations in primary lung adenocarcinomas. A correlation between molecular findings and tumor characteristics

Rat sarcoma (RAS) and RAS-associated pathways play important roles in the pathogenesis of lung cancers and in the development of targeted therapies. However, the clinical significance of RAS pathways is still not fully understood. We investigated the RAS-associated molecular aberrations in primary lung adenocarcinomas and correlated molecular findings with clinicopathological characteristics of tumors. A total of 220 surgically resected tumors were identified for which a lung cancer molecular panel (testing 7 genes by next-generation sequencing and 3 genes for rearrangement by fluorescence in situ hybridization) had been performed. The overall molecular alterations were detected in 143 cases (65.00%), including 58 cases (26.36%) of KRAS, 40 cases (18.18%) of EGFR, 24 cases (10.91%) of BRAF, 8 cases (3.64%) of PIK3CA, 7 cases (3.18%) of NRAS, 6 cases (2.73%) of ALK alterations. KRAS, BRAF, NRAS, and PIK3CA mutations were more commonly seen in smokers and occurred with much higher rates than previously published data. BRAF^V600E mutations were commonly seen in female smokers, whereas, BRAF^non-V600E mutations were seen in both male and female smokers with moderately to poorly differentiated tumors. PIK3CA mutations were predominantly occurred in p.E545K and p.E542K on exon 9 in moderately to poorly differentiated tumors.

EGFR Mutations and Resistance to Irreversible Pyrimidine-Based EGFR Inhibitors

PURPOSE

Mutant selective irreversible pyrimidine-based EGFR kinase inhibitors, including WZ4002, CO-1686, and AZD9291, are effective in preclinical models and in lung cancer patients harboring the EGFR T790M gefitinib/erlotinib resistance mutation. However, little is known about how cancers develop acquired resistance to this class of EGFR inhibitors. We sought to identify and study EGFR mutations that confer resistance to this class of agents.

EXPERIMENTAL DESIGN

We performed an N-ethyl-N-nitrosourea (ENU) mutagenesis screen in EGFR-mutant (sensitizing alone or with concurrent EGFR T790M) Ba/F3 cells and selected drug-resistant clones. We evaluated the sensitivity of EGFR inhibitors in models harboring drug-resistant EGFR mutations.

RESULTS

We identified 3 major drug resistance mutations. EGFR L718Q, L844V, and C797S cause resistance to both WZ4002 and CO-1686 while, in contrast, only EGFR C797S leads to AZD9291 resistance. Cells containing an EGFR-sensitizing mutation, Del 19 or L858R, in conjunction with L718Q, L844V, or C797S retain sensitivity to quinazoline-based EGFR inhibitors, gefitinib and afatinib. The C797S mutation, in the presence of Del 19 or L858R and T790M, causes resistance to all current EGFR inhibitors, but L858R/T790M/C797S remains partially sensitive to cetuximab which leads to disruption of EGFR dimerization.

CONCLUSIONS

Our findings provide insights into resistance mechanisms to irreversible pyrimidine-based EGFR inhibitors and identify specific genomic contexts in which sensitivity is retained to existing clinical EGFR inhibitors. These findings will guide the development of new strategies to inhibit EGFR.

Utility of five commonly used immunohistochemical markers TTF-1, Napsin A, CK7, CK5/6 and P63 in primary and metastatic adenocarcinoma and squamous cell carcinoma of the lung: a retrospective study of 246 fine needle aspiration cases

BACKGROUND

Fine needle aspiration (FNA) biopsy plays a critical role in the diagnosis and staging of lung primary and metastatic lung carcinoma. Accurate subclassification of adenocarcinoma (ADC) and/or squamous cell carcinoma (SqCC) is crucial for the targeted therapy. However, the distinction between ADC and SqCC may be difficult in small FNA specimens. Here, we have retrospectively evaluated the utility of TTF-1, Napsin A, CK7, P63 and CK5/6 immunohistochemical (IHC) markers in the distinguishing and subclassification of ADC and SqCC.

METHODS

A total of 246 FNA cases were identified by a computer search over a two-year period, including 102 primary NSCLC and 144 primary NSCLC which had metastasized to other sites. The immunostaining patterns of TTF-1, Napsin A, CK7, P63 and CK5/6 were correlated with the histological diagnosis of the tumor.

RESULTS

In 72 primary ADCs, TTF-1, Napsin A and CK7 showed a sensitivity and specificity of 84.5%/96.4%, 92.0%/100%, and 93.8%/50.0%. In 30 primary SqCCs, CK5/6 and P63 showed a sensitivity and specificity of 100%/77.8% and 91.7%/78.3%. In 131 metastatic ADCs, Napsin A showed the highest specificity (100%), versus TTF-1 (87.5%) and CK7 (25%) but decreased sensitivity (67.8% versus 86.9% and 100%); whereas in 13 metastatic SqCCs, CK5/6 and P63 showed a sensitivity/specificity of 100%/84.6% and 100%/68.4%. Bootstrap analysis showed that the combination of TTF-1/CK7, TTF-1/Napsin A and TTF-1/CK7/Napsin A had a sensitivity/specificity of 0.960/0.732, 0.858/0.934, 0.972/0.733 for primary lung ADCs and 0.992/0.642, 0.878/0.881, 0.993/0.618 for metastatic lung ADCs.

CONCLUSIONS

Our study demonstrated that IHC markers had variable sensitivity and specificity in the subclassification of primary and metastatic ADC and SqCC. Based on morphological findings, an algorithm with the combination use of markers aided in the subclassification of NSCLCs in difficult cases.

Lung Cytopathology (Bronchial and Aspiration Cytology)

This chapter is focused on the discussion and review of cytomorphological features of benign and malignant respiratory lesions. The respiratory system can be divided into upper and lower tract, thus, the variety of sampling and preparation methods are also reviewed, since the cytomorphology of the lesion may reveal differently depending on the sampling and preparation techniques. In addition, the critical information regarding molecular tests of lung carcinomas are also reviewed.

Expression of transcript factors SALL4 and OCT4 in a subset of non-small cell lung carcinomas (NSCLC)

BACKGROUND

SALL4 and OCT4 are transcription factors and play essential roles in stem cell development and oncogenesis. However, the expression of these transcription factors has not been well studied in lung cancers. In this study, we evaluated the expression of SALL4 and OCT4 in non-small cell lung carcinomas (NSCLC) by immunochemistry. NSCLC tissue microarrays (TMAs) were constructed with a total of 77 primary lung adenocarcinomas (ADCs) and 90 primary lung squamous cell carcinomas (SqCCs). A mouse monoclonal anti-human SALL4 (1:400 dilution) and a polyclonal anti-human OCT4 (1:200 dilution) antibodies were used. Nuclear staining of SALL4 and OCT4 was scored semi-quantitatively using a three tiered scale. The expressions of SALL4 and OCT4 were correlated with the tumor differentiation, pathological stage, and patients' clinical information.

RESULTS

In primary ADCs, the stronger expression of SALL4 and OCT4 was 7.8% and 9.1%, respectively. The stronger expression of SALL4 was inversely correlated with tumor differentiations. In primary SqCCs, the stronger expressions of SALL4 and OCT4 were 16.7% and 0%, respectively. The expression of SALL4 is correlated with the expression of OCT4, but inversely correlated with the tumor stage in SqCCs.

CONCLUSIONS

We found that both SALL4 and OCT4 were differentially expressed in a subset of primary ADC and SqCC. Our finding suggest that different stem cell markers may be expressed and/or play differential role in different subtypes of NSCLC. The potential role of SALL4 and OCT4 needs to be further investigated in NSCLC.

The clinical relevance of KRAS gene mutation in non-small-cell lung cancer

PURPOSE OF REVIEW

There are conflicting data on the potential prognostic and predictive role of mutant KRAS in non-small-cell lung cancer (NSCLC).

RECENT FINDINGS

KRAS is the most frequently mutated oncogene in lung adenocarcinoma patients of non-Asian ethnicity. Novel data also revealed that allelic variants of mutant KRAS are different concerning their biochemistry, which may influence their prognostic and predictive role in NSCLC. Though mutant KRAS is not the target of molecular therapy yet, a molecular diagnostic algorithm involving KRAS determination can define a subgroup of tumors where no further diagnostic test is necessary due to the exclusivity of this driver oncogene mutation. Recent data indicated that the prognostic role of mutant KRAS in lung adenocarcinomas in Asian patients is evident, while more research is neccessary in non-Asian populations. Studies also suggest the potential predictive role of mutant KRAS in the context of chemosensitivity of NSCLC which may depend on the individual drug types. Recent data on the negative predictive role of KRAS mutation on the efficacy of EGFR tyrosine kinase inhibitor (TKI) therapies confirm previous findings.

SUMMARY

Studies on the prognostic and predictive role of mutant KRAS in lung adenocarcinoma must be extended to the analysis of the potential role for allelic variants.

The utility of a novel triple marker (combination of TTF1, napsin A, and p40) in the subclassification of non-small cell lung cancer

In lung cancer, targeted therapies depend on accurate histological subclassification of the tumor. The majority of lung cancers can be subclassified based on hematoxylin and eosin staining; however, classification may be difficult in small biopsies. In this study, we investigated the utility of a newly developed triple marker (combination of TTF1/Napsin A/p40) and compared the sensitivity and specificity of this novel marker with individual markers in the subclassification of non-small cell lung carcinomas. Lung cancer tissue microarrays were constructed using surgical resection material from the Johns Hopkins Hospital. They included 77 adenocarcinomas (ADCs), 77 squamous cell carcinomas (SqCCs), and 46 cases of metastatic lung ADCs. Immunostaining patterns of all markers were scored semi-quantitatively and compared. In ADCs, the sensitivity and specificity of the triple marker were 93.5% and 77.5%, respectively. The sensitivity and specificity of TTF1 and Napsin A were 85.7% and 75.0%, and 89.6% and 90.0%. In SqCCs, the sensitivity and specificity of the triple marker were 88.3% and 92.5%, while the p40, p63 and CK5/6 showed 80.5% and 90.0%; 93.5% and 80.0%; and 89.6% and 80.0%. In addition, the sensitivity and specificity of the triple marker in metastatic ADCs showed 71.7% and 73.5%, respectively. Our triple marker (combination of TTF1/Napsin A/p40) showed a similar sensitivity and specificity for the subclassification of NSCLC when compared to individual markers. Our study not only demonstrates a useful combination of immunomarkers but also optimally conserves tissue for molecular marker testing.

Biological resonance for cancer metastasis, a new hypothesis based on comparisons between primary cancers and metastases

Many hypotheses have been proposed to try to explain cancer metastasis. However, they seem to be contradictory and have some limitations. Comparisons of primary tumors and matched metastases provide new insight into metastasis. The results show high concordances and minor differences at multiple scales from organic level to molecular level. The concordances reflect the commonality between primary cancer and metastasis, and also mean that metastatic cancer cells derived from primary cancer are quite conservative in distant sites. The differences reflect variation that cancer cells must acquire new traits to adapt to foreign milieu during the course of evolving into a new tumor in second organs. These comparisons also provided new information on understanding mechanism of vascular metastasis, organ-specific metastasis, and tumor dormancy. The collective results suggest a new hypothesis, biological resonance (bio-resonance) model. The hypothesis has two aspects. One is that primary cancer and matched metastasis have a common progenitor. The other is that both ancestors of primary cancer cells and metastatic cancer cells are under similar microenvironments and receive similar or same signals. When their interactions reach a status similar to primary cancer, metastasis will occur. Compared with previous hypotheses, the bio-resonance hypothesis seems to be more applicable for cancer metastasis to explain how, when and where metastasis occurs. Thus, it has important implications for individual prediction, prevention and treatment of cancer metastasis.