Comparison of KRAS and EGFR gene status between primary non-small cell lung cancer and local lymph node metastases: implications for clinical practice

Differentiating EGFR from ALK mutation status using radiomics signature based on MR sequences of brain metastasis

PURPOSE

More and more small brain metastases (BMs) in asymptomatic patients can be detected even prior to their primary lung cancer with the development of MRI. The aim of this study was to develop a predictive radiomics model to identify epidermal growth factor receptor (EGFR) and anaplastic lymphoma kinase (ALK) mutation status in BM and explore the optimal MR sequence for predication.

METHODS

This retrospective study included 186 patients with proven BM of lung cancer (training cohort: 70 patients with EGFR mutations and 65 patients with ALK rearrangements; testing cohort: 26 patients with EGFR mutations and 25 patients with ALK rearrangements). Radiomics features were separately extracted from contrast-enhanced T1-weighted imaging (T1-CE), T2 fluid-attenuated inversion recovery (T2-FLAIR) and T2WI sequences. The model for three MR sequences were constructed using a random forest classifier. ROC curves were used to validate the capability of the models in the training and testing cohorts.

RESULTS

The AUCs of the T2-FLAIR model were significantly higher than those of the T1-CE model in training cohort (0.991 versus 0.954) and testing cohort (0.950 versus 0.867) and much higher than those of the T2WI model in training cohort (0.991 versus 0.880) and testing cohort (0.950 versus 0.731). Besides, the F1 scores of the T1-CE model were slightly higher than the T2-FLAIR model and much higher than the T2WI model in two cohorts.

CONCLUSION

T2-FLAIR and T1-CE radiomics models that can be used as noninvasive tools for identifying EGFR and ALK mutation status are helpful to guide therapeutic strategies.

The current state of the art and future trends in RAS-targeted cancer therapies

Despite being the most frequently altered oncogenic protein in solid tumours, KRAS has historically been considered ‘undruggable’ owing to a lack of pharmacologically targetable pockets within the mutant isoforms. However, improvements in drug design have culminated in the development of inhibitors that are selective for mutant KRAS in its active or inactive state. Some of these inhibitors have proven efficacy in patients with KRAS^G12C-mutant cancers and have become practice changing. The excitement associated with these advances has been tempered by drug resistance, which limits the depth and/or duration of responses to these agents. Improvements in our understanding of RAS signalling in cancer cells and in the tumour microenvironment suggest the potential for several novel combination therapies, which are now being explored in clinical trials. Herein, we provide an overview of the RAS pathway and review the development and current status of therapeutic strategies for targeting oncogenic RAS, as well as their potential to improve outcomes in patients with RAS-mutant malignancies. We then discuss challenges presented by resistance mechanisms and strategies by which they could potentially be overcome.

The RAS oncogenes are among the most common drivers of tumour development and progression but have historically been considered undruggable. The development of direct KRAS inhibitors has changed this paradigm, although currently clinical use of these novel therapeutics is limited to a select subset of patients, and intrinsic or acquired resistance presents an inevitable challenge to cure. Herein, the authors provide an overview of the RAS pathway in cancer and review the ongoing efforts to develop effective therapeutic strategies for RAS-mutant cancers. They also discuss the current understanding of mechanisms of resistance to direct KRAS inhibitors and strategies by which they might be overcome.

Owing to intrinsic and extrinsic factors, KRAS and other RAS isoforms have until recently been impervious to targeting with small-molecule inhibitors.

Inhibitors of the KRAS^G12C variant constitute a potential breakthrough in the treatment of many cancer types, particularly non-small-cell lung cancer, for which such an agent has been approved by the FDA.

Several forms of resistance to KRAS inhibitors have been defined, including primary, adaptive and acquired resistance; these resistance mechanisms are being targeted in studies that combine KRAS inhibitors with inhibitors of horizontal or vertical signalling pathways.

Mutant KRAS has important effects on the tumour microenvironment, including the immunological milieu; these effects must be considered to fully understand resistance to KRAS inhibitors and when designing novel treatment strategies.

Iterative Upgrading of Small Molecular Tyrosine Kinase Inhibitors for EGFR Mutation in NSCLC: Necessity and Perspective

Molecular targeted therapy has been reported to have fewer adverse effects, and offer a more convenient route of administration, compared with conventional chemotherapy. With the development of sequencing technology, and research on the molecular biology of lung cancer, especially whole-genome information on non-small cell lung cancer (NSCLC), various therapeutic targets have been unveiled. Among the NSCLC-driving gene mutations, epidermal growth factor receptor (EGFR) mutations are the most common, and approximately 10% of Caucasian, and more than 50% of Asian, NSCLC patients have been found to have sensitive EGFR mutations. A variety of targeted therapeutic agents for EGFR mutations have been approved for clinical applications, or are undergoing clinical trials around the world. This review focuses on: the indications of approved small molecular kinase inhibitors for EGFR mutation-positive NSCLC; the mechanisms of drug resistance and the corresponding therapeutic strategies; the principles of reasonable and precision molecular structure; and the drug development discoveries of next-generation inhibitors for EGFR.

Sialic acid conjugate-modified liposomal platform modulates immunosuppressive tumor microenvironment in multiple ways for improved immune checkpoint blockade therapy

Immune checkpoint blockade (ICB) treatment is promising for the clinical therapy of numerous malignancies. However, most cancer patients rarely benefit from such single-agent immunotherapies because of the complexity of both the tumor and tumor microenvironment. A tumor-specific liposomal vehicle (DOX-SAL) modified with a sialic acid-cholesterol conjugate (SA-CH) and remotely loaded with doxorubicin (DOX) is herein reported for improving chemoimmunotherapy. The intravenous administration of DOX-SAL dramatically downregulates tumor-associated macrophage (TAM)-mediated immunosuppression, inhibits immunoregulatory functions, and promotes intratumoral infiltration of CD8⁺ T cells. Compared to conventional liposomes, DOX-SAL-mediated combination therapy with a PD-1-blocking monoclonal antibody (aPD-1 mAb) almost completely eliminates B16F10 tumors and efficiently inhibits 4T1 tumors. Moreover, cancer stem cells exhibit efficient tumor-initiating, tumor-propagating, and immunosuppressive tumor microenvironment-shaping capabilities. To further improve the treatment efficacy of an immunologically "cold" tumor, metformin (MET), which selectively eradicates breast cancer tumor stem cells, is co-encapsulated with DOX into liposomes to develop DOX/MET-SAL. The combination therapy with DOX/MET-SAL and aPD-1 mAb in a 4T1 orthotopic mouse model indicates their synergetic benefit on primary tumor inhibition, metastasis suppression, and survival rate improvement. Thus, the multifunctional liposomal platform has potential value for ICB combination immunotherapy.

Multiparametric MRI-Based Radiomics Approaches for Preoperative Prediction of EGFR Mutation Status in Spinal Bone Metastases in Patients with Lung Adenocarcinoma

BACKGROUND

Preoperative prediction of epidermal growth factor receptor (EGFR) mutation status in patients with spinal bone metastases (SBM) from primary lung adenocarcinoma is potentially important for treatment decisions.

PURPOSE

To develop and validate multiparametric magnetic resonance imaging (MRI)-based radiomics methods for preoperative prediction of EGFR mutation based on MRI of SBM.

STUDY TYPE

Retrospective.

POPULATION

A total of 97 preoperative patients with lumbar SBM from lung adenocarcinoma (77 in training set and 20 in validation set).

FIELD STRENGTH/SEQUENCE

T1-weighted, T2-weighted, and T2-weighted fat-suppressed fast spin echo sequences at 3.0 T.

ASSESSMENT

Radiomics handcrafted and deep learning-based features were extracted and selected from each MRI sequence. The abilities of the features to predict EGFR mutation status were analyzed and compared. A radiomics nomogram was constructed integrating the selected features.

STATISTICAL TESTS

The Mann-Whitney U test and χ² test were employed for evaluating associations between clinical characteristics and EGFR mutation status for continuous and discrete variables, respectively. Least absolute shrinkage and selection operator was used for selection of predictive features. Sensitivity (SEN), specificity (SPE), and area under the receiver operating characteristic curve (AUC) were used to evaluate the ability of radiomics models to predict the EGFR mutation. Calibration and decision curve analysis (DCA) were performed to assess and validate nomogram results.

RESULTS

The radiomics signature comprised five handcrafted and one deep learning-based features and achieved good performance for predicting EGFR mutation status, with AUCs of 0.891 (95% confidence interval [CI], 0.820-0.962, SEN = 0.913, SPE = 0.710) in the training group and 0.771 (95% CI, 0.551-0.991, SEN = 0.750, SPE = 0.875) in the validation group. DCA confirmed the potential clinical usefulness of the radiomics models.

DATA CONCLUSION

Multiparametric MRI-based radiomics is potentially clinical valuable for predicting EGFR mutation status in patients with SBM from lung adenocarcinoma.

LEVEL OF EVIDENCE

3 TECHNICAL EFFICACY: 2.

Pancoast-Tobias Syndrome: A Unique Presentation of Lung Cancer

A 65-year-old man with 50 pack-year smoking history presented to the emergency department for evaluation of upper back and right shoulder pain secondary to a fall. Physical examination was notable for anisocoria with a constricted left pupil (miosis), mild ptosis of the left eyelid, and bilateral shoulder pain, right more than left, with both passive and active movements. Chest computed tomography identified a soft tissue mass at the left lung apex with extension into the pleural surface, associated with destructive osseous changes of the right scapula, adjacent ribs, and thoracic vertebral bodies. Imaging of the brain revealed multiple masses suspicious of metastatic brain lesions. Biopsy of the right supraclavicular lymph node revealed lung tissue adenocarcinoma and negative Kirsten rat sarcoma viral oncogene homolog (K-Ras), epidermal growth factor receptor (EGFR), B-raf proto-oncogene (BRAF), C-ros oncogene 1 (ROS1), and anaplastic lymphoma kinase (ALK) rearrangement. Recognizing Pancoast syndrome in patients with significant smoking history, anisocoria, and shoulder pain is crucial for identifying the underlying etiology and expediting the treatment.

Detection of Low-Frequency KRAS Mutations in cfDNA From EGFR-Mutated NSCLC Patients After First-Line EGFR Tyrosine Kinase Inhibitors

Background

Molecular profiling of advanced EGFR mutated NSCLC has recently demonstrated the co-existence of multiple genetic alterations. Specifically, co-existing KRAS-mutations in EGFR NSCLCs have been described, despite their prevalence at progression and their role in the response to EGFR tyrosine kinase inhibitors (TKIs) remain marginally explored. Aim of our study was to investigate the prevalence of co-existing KRAS mutations at the time of progressive disease and explore their impact on clinical outcome.

Materials and Methods

We retrospectively analyzed by digital droplet PCR prevalence of KRAS co-mutations in 106 plasma samples of EGFR mutated NSCLC patients, in progressive disease after EGFR TKI treatment as first-line therapy.

Results

KRAS co-mutations (codon 12 and 13) were identified in 3 patients (2.8% of analyzed samples), with low allelic frequency (<0.2%), and had a negative impact on clinical outcome to first-line EGFR TKI.

Conclusion

Detection of KRAS mutations in cell-free DNA of EGFR mutant NSCLC patients at progression after first or second generation EGFR TKI is a rare event. Due to their low abundance, the negative impact of KRAS mutations on the response to EGFR TKI remains to be confirmed in larger studies.

Assessment of colon cancer molecular mechanism: a system biology approach

AIM

The current study aimed to assess and compare colon cancer dysregulated genes from the GEO and STRING databases.

BACKGROUND

Colorectal cancer is known as the third most common kind of cancer and the second most important reason for global cancer-related mortality rates. There have been many studies on the molecular mechanism of colon cancer.

METHODS

From the STRING database, 100 differentially expressed proteins related to colon cancers were retrieved and analyzed by network analysis. The central nodes of the network were assessed by gene ontology. The findings were compared with a GSE from GEO.

RESULTS

Based on data from the STRING database, TP53, EGFR, HRAS, MYC, AKT1, GAPDH, KRAS, ERBB2, PTEN, and VEGFA were identified as central genes. The central nodes were not included in the significant DEGs of the analyzed GSE.

CONCLUSION

A combination of different database sources in system biology investigations provides useful information about the studied diseases.

Clonality analysis of pulmonary tumors by genome-wide copy number profiling

Multiple tumors in patients are frequently diagnosed, either synchronous or metachronous. The distinction between a second primary and a metastasis is important for treatment. Chromosomal DNA copy number aberrations (CNA) patterns are highly unique to specific tumors. The aim of this study was to assess genome-wide CNA-patterns as method to identify clonally related tumors in a prospective cohort of patients with synchronous or metachronous tumors, with at least one intrapulmonary tumor. In total, 139 tumor pairs from 90 patients were examined: 35 synchronous and 104 metachronous pairs. Results of CNA were compared to histological type, clinicopathological methods (Martini-Melamed-classification (MM) and ACCP-2013-criteria), and, if available, EGFR- and KRAS-mutation analysis. CNA-results were clonal in 74 pairs (53%), non-clonal in 33 pairs (24%), and inconclusive in 32 pairs (23%). Histological similarity was found in 130 pairs (94%). Concordance between histology and conclusive CNA-results was 69% (74 of 107 pairs: 72 clonal and two non-clonal). In 31 of 103 pairs with similar histology, genetics revealed non-clonality. In two out of four pairs with non-matching histology, genetics revealed clonality. The subgroups of synchronous and metachronous pairs showed similar outcome for the comparison of histological versus CNA-results. MM-classification and ACCP-2013-criteria, applicable on 34 pairs, and CNA-results were concordant in 50% and 62% respectively. Concordance between mutation matching and conclusive CNA-results was 89% (8 of 9 pairs: six clonal and two non-clonal). Interestingly, in one patient both tumors had the same KRAS mutation, but the CNA result was non-clonal. In conclusion, although some concordance between histological comparison and CNA profiling is present, arguments exist to prefer extensive molecular testing to determine whether a second tumor is a metastasis or a second primary.

Clinical Validation of Discordant Trunk Driver Mutations in Paired Primary and Metastatic Lung Cancer Specimens

OBJECTIVES

To propose an operating procedure for validation of discordant trunk driver mutations.

METHODS

Concordance of trunk drivers was examined by next-generation sequencing in 15 patients with two to three metastatic lung cancers and 32 paired primary and metastatic lung cancers.

RESULTS

Tissue identity was confirmed by genotyping 17 single-nucleotide polymorphisms within the panel. All except three pairs showed concordant trunk drivers. Quality assessment conducted in three primary and metastatic pairs with discordant trunk drivers indicates metastasis from a synchronous or remote lung primary in two patients. Review of literature revealed high discordant rates of EGFR and KRAS mutations, especially when Sanger sequencing was applied to examine primary and lymph node metastatic tumors.

CONCLUSIONS

Trunk driver mutations are highly concordant in primary and metastatic tumors. Discordance of trunk drivers, once confirmed, may suggest a second primary cancer. Guidelines are recommended to establish standard operating procedures for validation of discordant trunk drivers.

Aberrant expression of vasculogenic mimicry, PRRX1, and CIP2A in clear cell renal cell carcinoma and its clinicopathological significance

Vasculogenic mimicry (VM) involves a tubular structure with a basement membrane that is similar to and communicates with vessels but functions independent of blood vessels to nourish tumor cells, promote tumor progression, invasion, and metastasis, with reduced 5-year survival rates. Tumor cell proliferation, invasion, and metastasis are promoted by the epithelial-mesenchymal transition (EMT). Paired-related homeobox 1 (PRRX1), a newly discovered EMT inducer, has been shown to correlate with metastasis and prognosis in diverse cancer types. Cancerous inhibitor of protein phosphatase 2A (CIP2A) was initially recognized as an oncoprotein. In this study, we aimed to investigate the expression and clinical significance of the EMT markers PRRX1, CIP2A and VM in clear cell renal cell carcinoma (CCRCC) and their respective associations with clinicopathological parameters and survival.Expression of PRRX1, CIP2A and VM in whole CCRCC tissues from 110 patients was analyzed by immunohistochemical and histochemical staining. Fisher's exact test or the chi square test was used to assess associations with positive or negative staining of these markers and clinicopathological characteristics.Positive expression of CIP2A and VM presence was significantly higher and that of PRRX1 was significantly lower in CCRCC tissues than in corresponding normal tissues. Furthermore, positive expression of CIP2A and VM was significantly associated with tumor grade, size, lymph node metastasis (LNM) stage, and tumor node metastasis (TNM) stage and inversely associated with overall survival time (OST). Moreover, levels of PRRX1 were negatively associated with tumor grade, size, LNM stage, and TNM stage. The PRRX1 subgroup had a significantly longer OST time than did the PRRX1 subgroup. In multivariate analysis, high VM and CIP2A, tumor grade, LNM stage, TNM stage, and low PRRX1 levels were identified as potential independent prognostic factors for OST in CCRCC patients.VM and expression of CIP2A and PRRX1 represent promising biomarkers for metastasis and prognosis and potential therapeutic targets in CCRCC.

Intratumor heterogeneity and tissue distribution of KRAS mutation in non-small cell lung cancer: implications for detection of mutated KRAS oncogene in exhaled breath condensate

Purpose

Mutated KRAS oncogene in exhaled breath condensate (EBC) can be a genetic marker of non-small cell lung cancer (NSCLC). However, a possibility of inhomogeneous distribution in cancer tissue and intratumor heterogeneity of KRAS mutation may decrease its significance. We investigated a status of KRAS point mutation and its sequence at codon 12 in 51 NSCLC patients after tumor resection. The comparison of KRAS mutation status between EBC–DNA and cancer tissue was performed in 19 cases.

Methods

Five cancer tissue samples from disparate tumor regions and one from normal lung were harvested at surgery. EBC was collected for DNA analysis the previous day. KRAS point mutations at codon 12 were detected using mutant-enriched PCR technique and pyrosequenced.

Results

Forty-six cancers revealed concordance of KRAS mutation status: 27 contained mutated KRAS and 19 had only wild KRAS. Five NSCLCs revealed inhomogeneous distribution of KRAS mutation. Two different mutations were found in 14 NSCLCs and the most frequent one was G12D and G12V (n = 8). No mutated KRAS was found in normal lung. The concordance ratios of KRAS sequence in codon 12 between EBC–DNA and cancer were 18/19 for NSCLC patients and 11/12 for KRAS mutation positive NSCLC.

Conclusions

Intratumor heterogeneity and inhomogeneous distribution of KRAS point mutation in codon 12 in cancer tissue can occur in NSCLCs. There was a high accordance between KRAS mutation status in EBC–DNA and cancer tissue in NSCLC patients what suggests usefulness of monitoring KRAS mutation in EBC–DNA as a biomarker of NSCLC.

Characterization of genetic alterations in brain metastases from non-small cell lung cancer

Brain metastasis (BM) is the primary contributor to mortality in non‐small cell lung cancer (NSCLC) patients. Although the findings of NSCLC genetic sequencing studies suggest the potential for personalizing therapeutic approaches, the genetic profiles and underlying mechanisms of BM progression remain poorly understood. Here, we investigated the genetic profiles of brain metastases from NSCLC in six patients with primary tumors and corresponding BM samples via whole exome sequencing and targeted panel sequencing. We have demonstrated considerable genetic heterogeneity between primary lung cancer and corresponding brain metastases specimens. High‐frequency mutations were found in NOTCH2,NOTCH2NL,FANCD2,EGFR, and TP53. Additionally, EGFR and TP53 consistently exhibited high frequencies of mutation between primary tumors and corresponding brain metastases. The implication is that most of the genetic alterations may be acquired or lost during malignant progression, and the stable EGFR and TP53 mutational status between paired primary tumors and metastatic sites confirms that most mutations detected on analysis of the primary tumor or metastases are sufficient for clinical decision‐making, and suggest there is no need to re‐biopsy recurrent tumors or metastases for most NSCLC patients.

Deciphering Clinicoradiologic Phenotype for Thymidylate Synthase Expression Status in Patients with Advanced Lung Adenocarcinoma Using a Radiomics Approach

We aimed to identify predictive clinicoradiologic characteristics of thymidylate synthase (TS) expression status in advanced non-squamous non-small cell lung cancer patients. We reviewed clinicoradiologic features of 169 patients stratified into TS-negative (n = 84) and TS-positive (n = 85) groups, including quantitative CT radiomic features of both primary lung and metastatic lesions from initial CT and PET. Clinical factors including age and smoking history were significantly associated with TS as well as radiomic features. The predictive performance for dichotomizing TS expression status was slightly higher when imaging features of primary lung lesions were added compared to the model based solely on the clinical features, but without statistical significance (10-fold cross-validated AUC = 0.619 and 0.581, respectively; P = 0.425). The predictive performance of clinicoradiologic parameters slightly increased with primary lung lesions only compared to the inclusion of metastatic lesions, but without statistical significance (10-fold cross-validated AUC = 0.619 and 0.554, respectively; P = 0.203). Overall survival was prolonged in the TS-negative group compared to the TS-positive group (P = 0.001). TS-negativity is a potential prognostic biomarker, and our study presents that although CT radiomic features have potential for predicting TS expression status, clinical significance is uncertain. The addition of radiomic features to clinical factors did not show significant improvement in predicting TS-negativity.

A case report of tongue metastasis from lung squamous cell carcinoma and literature review

RATIONALE

Tongue metastasis from lung cancer is extremely rare, and the prognosis of these patients is rather poor.

PATIENT CONCERS

A 56-year-old man was found a 4-cm cavity lesion in the left upper lobe, which was initially misdiagnosed as tuberculosis.

DIAGNOSES

A case of lung squamous cell carcinoma that metastasized to the base of a patient's tongue.

INTERVATIONS

We send the biopsy of the lung and the tongue lesions for gene sequencing.

OUTCOMES

He received systemic chemotherapy, but continued to have pain at the base of his tongue and died 7 months later.

LESSONS

From sequencing data, mutations in KRAS proto-oncogene, GTPase (KRAS), phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA), and tumor protein p53 (TP53) were found in the tumor biopsy of the patient. All of these were indicators of poor prognosis.

Sarcomatoid carcinoma of the lung: a rare histological subtype of non-small cell lung cancer with a poor prognosis even at earlier tumour stages

Objectives

Pulmonary sarcomatoid carcinoma (PSC) is a rare histological subtype of non-small cell lung cancer and comprises a diagnostically and therapeutically challenging group of tumours. We explored the clinicopathological features and prognostic factors of this tumour.

Methods

We conducted a retrospective study of all patients who were treated for PSC in the Department of Thoracic Surgery between May 2005 and December 2014. Primary outcomes of interest were patient survival and prognostic factors.

Results

A total of 58 patients were treated for sarcomatoid carcinoma within the described period and 46 patients underwent surgical resection with curative intent. The mean follow-up period was 30 months. Of the operated patients, 21.7% had pathological stage I disease, and 78.3% had more advanced disease. There were 25 carcinosarcomas, 10 pleomorphic carcinomas, 7 spindle cell carcinomas, 3 giant cell carcinomas and 1 pulmonary blastoma. Overall 5-year survival of the operated patients was 28.7%. A total of 28 patients experienced recurrence and died cancer-related. Our analysis revealed that tumour size, gender, histological entity, lymphatic vessel invasion (L1) and vascular invasion (V1) did not influence survival. There was a trend for decreased survival in older patients (>65 years).

Conclusions

Surgical treatment can achieve satisfactory results with low perioperative mortality, but the overall prognosis even with multimodality concepts and in earlier tumour stages is worse compared to other types of non-small cell lung cancer.

Loss of β-arrestin-2 and Activation of CXCR2 Correlate with Lymph Node Metastasis in Non-small Cell Lung Cancer

Background: Although β-arrestin-2 (β-arr2) and CXCR2 have been shown to affect various malignant tumors, their exact roles in lung cancer remain unclear. We investigated expression of β-arr2 and CXCR2 in patients with non-small cell lung cancer (NSCLC) and their correlation with lymph node metastasis and prognosis.

Methods: We reviewed medical records of 136 patients with NSCLC who underwent surgical resection, and assessed their specimens immunohistochemically for expression of β-arr2 and CXCR2 in primary tumors and metastatic lymph nodes (MLNs), respectively.

Results: High β-arr2 expression was seen in 63 specimens (46.3%), and was significantly associated with male patients (P=0.011), squamous cell carcinoma (P=0.003), and lymph node metastasis (P<0.001). High CXCR2 expression was seen in 62 specimens (45.6%), and was significantly correlated only with lymph node metastasis (P<0.001). Expression of β-arr2 was significantly lower at MLNs than at primary lesions (Z=-2.315; P=0.021; Wilcoxon signed-rank), whereas CXCR2 expression was significantly higher in MLNs than in primary lesions (Z=-3.712; P<0.001; Wilcoxon signed-rank). No relationship was seen between β-arr2 and CXCR2 expression in primary lesions (r=-0.065, P=0.548; Spearman rank coefficient), but they were inversely related in MLNs (r=-0.263, P=0.012). Kaplan-Meier survival curve was shown that low β-arr2 and high CXCR2 expressions was associated with poor survival (log-rank: χ²=5.926, P=0.015).

Conclusions: β-arr2 may promote lymph node metastasis in NSCLC by modulating CXCR2 activation.

Comparison of Epidermal Growth Factor Receptor Mutations between Metastatic Lymph Node Diagnosed by EBUS-TBNA and Primary Tumor in Non-Small Cell Lung Cancer

Introduction

Although the use of endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is increasing for epidermal growth factor receptor (EGFR) testing in lung cancer, the discordance rate in EGFR mutations between lymph node (LN) samples obtained by EBUS-TBNA and primary tumor (PT) is not well known. Thus, we compared the EGFR mutation status of LN samples obtained by EBUS-TBNA and PTs to estimate the efficacy of using EBUS-TBNA specimens for EGFR testing in advanced, non-squamous, non-small cell lung cancer (NSCLC).

Materials and Methods

Using data of patients from the EBUS-TBNA database (N = 1914) obtained between January 2009 and January 2013, we identified 100 treatment-naïve, advanced, non-squamous NSCLC patients (stage 3 and 4) with matched LN specimens obtained by EBUS-TBNA and PT specimens. Of these, 74 patients with paired specimens were feasible for EGFR mutation analysis, which we performed using a direct sequencing method.

Results

Of the 74 cases, at least one major [exon 19 deleted (19del) and L858R] or minor (T790M, exon 20 insertion, and other point mutations) EGFR mutation was detected in 31 cases (41.9%), which included PT (n = 31, 41.9%) and LN (n = 28, 37.8%) specimens. Major mutations were detected in 25 PT (33.8%, 19del = 13, L858R = 12) and 22 LN (29.8%, 19del = 11, L858R = 11) specimens. The discordance rate in major mutations between matched PT and LN specimens was 4.1% (3/74). Among minor mutations, T790M was detected in LN specimen only in 2 cases with L858R in PT and LN. The discordance rate major and minor EGFR mutations combined between matched PT and LN specimens was 12% (9/74).

Conclusions

We observed a high concordance rate of major EGFR mutations between matched LN specimens sampled by EBUS-TBNA and PTs, suggesting that LN samples obtained by EBUS-TBNA from advanced non-squamous NSCLC patients are effective for use in EGFR mutation testing.

Circulating tumour DNA profiling reveals heterogeneity of EGFR inhibitor resistance mechanisms in lung cancer patients

Circulating tumour DNA (ctDNA) analysis facilitates studies of tumour heterogeneity. Here we employ CAPP-Seq ctDNA analysis to study resistance mechanisms in 43 non-small cell lung cancer (NSCLC) patients treated with the third-generation epidermal growth factor receptor (EGFR) inhibitor rociletinib. We observe multiple resistance mechanisms in 46% of patients after treatment with first-line inhibitors, indicating frequent intra-patient heterogeneity. Rociletinib resistance recurrently involves MET, EGFR, PIK3CA, ERRB2, KRAS and RB1. We describe a novel EGFR L798I mutation and find that EGFR C797S, which arises in ∼33% of patients after osimertinib treatment, occurs in <3% after rociletinib. Increased MET copy number is the most frequent rociletinib resistance mechanism in this cohort and patients with multiple pre-existing mechanisms (T790M and MET) experience inferior responses. Similarly, rociletinib-resistant xenografts develop MET amplification that can be overcome with the MET inhibitor crizotinib. These results underscore the importance of tumour heterogeneity in NSCLC and the utility of ctDNA-based resistance mechanism assessment.

FGFR1 Amplification in Squamous Cell Carcinoma of the Lung with Correlation of Primary and Metastatic Tumor Status

BACKGROUND

The FGFR1 gene can be amplified in squamous cell carcinoma of the lung (SqCC). The aim of this study was to compare FGFR1 status with stage and matched primaries with metastases.

METHODS

Cases with FGFR1 fluorescence in situ hybridization (FISH) testing performed from 2000 to 2013 were evaluated for amplification status and clinicopathologic features.

RESULTS

Of the 336 cases tested by FGFR1 FISH, 52 (15%) were positive for amplification. Eight (13%) of 60 N0 cases and eight (17%) of 46 N1 or N2 cases were amplified, with no statistically significant difference. Of the 24 cases with matched primary and metastatic tumors, 22 (92%) were synchronous and one (4%) had discordant amplification.

CONCLUSIONS

Frequency of FGFR1 amplification is similar in SqCC with and without lymph node metastases, but status in metastatic sites may be discordant from the primary in a small subset of cases, which may affect the decision to perform testing of metastatic SqCCs.

Differences in driver genes between smoking-related and non-smoking-related lung cancer in the Chinese population

Recently, non-smoking-related lung cancer was classified as an independent disease entity because it is different from tobacco-associated lung cancer. Non-smoking-related lung cancer occurs more often in women than men, and the predominant histological type is adenocarcinoma (ADC) rather than squamous cell carcinoma. Most of the driver gene alterations that have been identified in ADC in never-smokers include epidermal growth factor receptor mutations, KRAS mutations, echinoderm microtubule-associated protein like 4/anaplastic lymphoma kinase fusion, and ROS1 fusion, among others. Meanwhile, significant progress has been made in the treatment of ADC. However, in comparison with ADC, no such available molecular targets exist for smoking-associated lung cancer, for which treatment strategies are limited. Next-generation sequencing has been widely applied to the discovery of more genetic profiles of lung cancers. This review summarizes the differences between smoking-related and non-smoking-related lung cancer as follows: different somatic mutation burdens, C:G→A:T transversions, common and novel driver genes, and treatment strategies. Overall, smoking-related lung cancer is more complicated than non-smoking-related lung cancer. Furthermore, we review the prevalence of driver genes in smoking-associated and non-smoking-associated lung cancers in the Chinese population.

The kinase inhibitor D11 induces caspase-mediated cell death in cancer cells resistant to chemotherapeutic treatment

Background

Multi-drug resistance and predisposition to metastasize are major clinical problems in cancer treatment. Malignant primary brain tumor and pancreatic cancer are two well-known examples of malignant tumors resistant to conventional therapies where aberrant EGFR-mediated and NF-κB signal transduction pathways are likely to play an important role. We have recently identified 1,3-Dichloro-6-[(E)-((4-methoxyphenyl)imino)methyl] diben-zo(b,d) furan-2,7-diol (D11) as a potent and selective inhibitor of CK2 a serine/threonine protein kinase that modulates the aforementioned signaling cascades.

Methods

Human cancer cell lines (glioblastoma and pancreatic adenocarcinoma) resistant to conventional chemotherapeutic agents were incubated with increasing concentrations of D11 for variable amounts of time. Cell viability, cell death and effects on major signal transduction pathways deregulated in cancer cells were analyzed by ELISA, FACS and Western blot-based assays, respectively. Moreover, effects on cell migration and in cell protein-protein association were investigated by wound-healing and in situ proximity ligation assays, respectively.

Results

We show here, that D11 treatment leads to i) significant caspase-mediated apoptotic cell death, ii) down-regulation of EGFR expression and iii) inhibition of NF-κB transcriptional activity. Furthermore, cell exposure to D11 results in impaired cell migration and correlates with reduced expression of the ion co-transporter and cell volume regulator Na⁺-K⁺-2Cl⁻ (NKCC1).

Conclusions

Data reported here underline the therapeutic potential of D11 with respect to certain types of cancer that carry aberrant intracellular signaling cascades and/or exhibit sustained cell migration and suggest a new therapeutic strategy against chemotherapy resistance.

Electronic supplementary material

The online version of this article (doi:10.1186/s13046-015-0234-6) contains supplementary material, which is available to authorized users.

Mutation status concordance between primary lesions and metastatic sites of advanced non-small-cell lung cancer and the impact of mutation testing methodologies: a literature review

Increased understanding of the genetic aetiology of advanced non-small-cell lung cancer (aNSCLC) has facilitated personalised therapies that target specific molecular aberrations associated with the disease. Biopsy samples for mutation testing may be taken from primary or metastatic sites, depending on which sample is most accessible, and upon differing diagnostic practices between territories. However, the mutation status concordance between primary tumours and corresponding metastases is the subject of debate. This review aims to ascertain whether molecular diagnostic testing of either the primary or metastatic tumours is equally suitable to determine patient eligibility for targeted therapies. A literature search was performed to identify articles reporting studies of mutations in matched primary and metastatic aNSCLC tumour samples. Clinical results of mutation status concordance between matched primary and metastatic tumour samples from patients with aNSCLC were collated. Articles included in this review (N =26) all reported mutation status data from matched primary and metastatic tumour samples obtained from adult patients with aNSCLC. Generally, substantial concordance was observed between primary and metastatic tumours in terms of EGFR, KRAS, BRAF, p16 and p53 mutations. However, some level of discordance was seen in most studies; mutation testing methodologies appeared to play a key role in this, along with underlying tumour heterogeneity. Substantial concordance in mutation status observed between primary and metastatic tumour sites suggests that diagnostic testing of either tumour type may be suitable to determine a patient's eligibility for personalised therapies. As with all diagnostic testing, highly sensitive and appropriately validated mutation analysis methodologies are desirable to ensure accuracy. Additional work is also required to define how much discordance is clinically significant given natural tumour heterogeneity. The ability of both primary and metastatic tumour sites to accurately reflect the tumour mutation status will allow more patients to receive therapies personalised to their disease.

Significance of EGFR signaling pathway genetic alterations in radically resected non-small cell lung cancers from a Polish cohort. One institutional study

PURPOSE

We evaluated the distribution and clinical impact of EGFR, KRAS and HER2 copy number gains and EGFR, KRAS and BRAF activating mutations in resected non-small cell lung cancers (NSCLCs) from 151 Polish patients.

MATERIALS AND METHODS

Quantitative PCR and DNA sequencing were used for copy number evaluation and mutational analysis, respectively.

RESULTS

An increased EGFR CN was found in 21.2% of the tumors, more commonly of the non-squamous histology (P=0.029), larger in size (P=0.004) and those obtained from women (P=0.040). HER2 copy gain was observed in 21.8% of the patients, more frequently with lymph node metastases (P=0.048) and stage IIIA disease (P=0.061). KRAS gain was found in 29.3% of the tumors, and was not associated with patients' clinicopathological features. No BRAF mutations were found. EGFR and KRAS mutation frequency and associations with clinicopathological characteristics did not differ significantly from those previously described for the NSCLC patients of Caucasian ethnicity. Strong associations existed between most of the analyzed alterations. In the multivariate model, EGFR mutations constituted an independent prognostic factor of the disease recurrence in adenocarcinoma patients (HR 7.20; 95%CI 1.31-39.48; P=0.023), while an increased EGFR copy number tended to indicate a shorter overall survival (HR 4.85; 95%CI 0.92-25.58; P=0.062).

CONCLUSIONS

EGFR pathway genes alterations are frequent in NSCLCs from Polish patients and have a prognostic potential for patients' clinical outcome after a curative tumor resection. Gene CN evaluation by quantitative PCR provides comparable results and enables assay standardization, yet the optimal scoring system needs to be developed.

Analysis of KRAS and BRAF genes mutation in the central nervous system metastases of non-small cell lung cancer

KRAS mutations are associated with tumor resistance to EGFR TKIs (erlotinib, gefitinib) and to monoclonal antibody against EGFR (cetuximab). Targeted treatment of mutated RAS patients is still considered as a challenge. Inhibitors of c-Met (onartuzumab or tiwantinib) and MEK (selumetinib—a dual inhibitor of MEK1 and MEK2) signaling pathways showed activity in patients with mutations in KRAS that can became an effective approach in carriers of such disorders. BRAF mutation is very rare in patients with NSCLC, and its presence is associated with sensitivity of tumor cells to BRAF inhibitors (vemurafenib, dabrafenib). In the present study, the frequency and type of KRAS and BRAF mutation were assessed in 145 FFPE tissue samples from CNS metastases of NSCLC. In 30 patients, material from the primary tumor was simultaneously available. Real-time PCR technique with allele-specific molecular probe (KRAS/BRAF Mutation Analysis Kit, Entrogen, USA) was used for molecular tests. KRAS mutations were detected in 21.4 % of CNS metastatic lesions and in 23.3 % of corresponding primary tumors. Five mutations were identified both in primary and in metastatic lesions, while one mutation only in primary tumor and one mutation only in the metastatic tumor. Most of mutations were observed in codon 12 of KRAS; however, an individual patient had diagnosed a rare G13D and Q61R substitutions. KRAS mutations were significantly more frequent in adenocarcinoma patients and smokers. Additional analysis indicated one patient with rare coexistence of KRAS and DDR2 mutations. BRAF mutation was not detected in the examined materials. KRAS frequency appears to be similar in primary and CNS.

Flexible lab-tailored cut-offs for suitability of formalin-fixed tumor samples for diagnostic mutational analyses

The selection of proper tissues from formalin-fixed and paraffin-embedded tumors before diagnostic molecular testing is responsibility of the pathologist and represents a crucial step to produce reliable test results. The international guidelines suggest two cut-offs, one for the percentage and one for the number of tumor cells, in order to enrich the tumor content before DNA extraction. The aim of the present work was two-fold: to evaluate to what extent a low percentage or absolute number of tumor cells can be qualified for somatic mutation testing; and to determine how assay sensitivities can guide pathologists towards a better definition of morphology-based adequacy cut-offs. We tested 1797 tumor specimens from melanomas, colorectal and lung adenocarcinomas. Respectively, their BRAF, K-RAS and EGFR genes were analyzed at specific exons by mutation-enriched PCR, pyrosequencing, direct sequencing and real-time PCR methods. We demonstrate that poorly cellular specimens do not modify the frequency distribution of either mutated or wild-type DNA samples nor that of specific mutations. This observation suggests that currently recommended cut-offs for adequacy of specimens to be processed for molecular assays seem to be too much stringent in a laboratory context that performs highly sensitive routine analytical methods. In conclusion, new cut-offs are needed based on test sensitivities and documented tumor heterogeneity.

Epidermal growth factor receptor mutation heterogeneity analysis of pulmonary sarcomatoid carcinoma successfully treated with erlotinib: A case report

Pulmonary sarcomatoid carcinoma (PSC) is a rare histological subtype of non-small cell lung cancer, and the available studies on the response to epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) is limited. In the present study, a 73-year-old female presented with a large mass in the lower right lung, which was diagnosed as a PSC on biopsy. An amplification-refractory mutation system (ARMS) test revealed that the patient possessed the wild-type EGFR gene, and the patient subsequently underwent radiotherapy (60 Gy) and four 21-day cycles of chemoradiotherapy (1,600 mg gemcitabine, days 1 and 8; 30 mg, cisplatin, days 1-3). Following radiotherapy and chemotherapy treatment, a CT scan revealed complete remission of the mass in the lower right lung, however, metastases were identified in the paraaortic lymph node, bilateral iliac fossa and the right gluteal region. Notably, an EGFR exon 21 L858R gene mutation was identified in the mass of the right gluteal metastasis. Therefore, treatment with erlotinib was initiated. The patient continued to experience progression-free survival for six months following the initiation of erlotinib therapy. However, multiple metastases were then identified, and all lesions possessed the wild-type EGFR gene, as identified by the ARMS test. The findings suggest that erlotinib is a viable therapeutic option for the treatment of PSC patients that possess an EGFR mutation. The spatio-temporal evolution of EGFR mutational heterogeneity in PSC may result in drug-resistance, which challenges EGFR-TKI therapy and EGFR gene mutation diagnosis.

LDA-SVM-based EGFR mutation model for NSCLC brain metastases: an observational study

Epidermal growth factor receptor (EGFR) activating mutations are a predictor of tyrosine kinase inhibitor effectiveness in the treatment of non-small-cell lung cancer (NSCLC). The objective of this study is to build a model for predicting the EGFR mutation status of brain metastasis in patients with NSCLC. Observation and model set-up. This study was conducted between January 2003 and December 2011 in 6 medical centers in Southwest China. The study included 31 NSCLC patients with brain metastases. Eligibility requirements were histological proof of NSCLC, as well as sufficient quantity of paraffin-embedded lung and brain metastases specimens for EGFR mutation detection. The linear discriminant analysis (LDA) method was used for analyzing the dimensional reduction of clinical features, and a support vector machine (SVM) algorithm was employed to generate an EGFR mutation model for NSCLC brain metastases. Training-testing-validation (3 : 1 : 1) processes were applied to find the best fit in 12 patients (validation test set) with NSCLC and brain metastases treated with a tyrosine kinase inhibitor and whole-brain radiotherapy. Primary and secondary outcome measures: EGFR mutation analysis in patients with NSCLC and brain metastases and the development of a LDA-SVM-based EGFR mutation model for NSCLC brain metastases patients. EGFR mutation discordance between the primary lung tumor and brain metastases was found in 5 patients. Using LDA, 13 clinical features were transformed into 9 characteristics, and 3 were selected as primary vectors. The EGFR mutation model constructed with SVM algorithms had an accuracy, sensitivity, and specificity for determining the mutation status of brain metastases of 0.879, 0.886, and 0.875, respectively. Furthermore, the replicability of our model was confirmed by testing 100 random combinations of input values. The LDA-SVM-based model developed in this study could predict the EGFR status of brain metastases in this small cohort of patients with NSCLC. Further studies with larger cohorts should be carried out to validate our findings in the clinical setting.

Microwave-assisted synthesis of new fluorinated coumarin–pyrimidine hybrids as potent anticancer agents, their DNA cleavage and X-ray crystal studies

Rapid and high yielding synthesis of new fluorinated coumarin–pyrimidine hybrids and their application as potent anticancer agents is described.

Meta-analysis of epidermal growth factor receptor and KRAS gene status between primary and corresponding metastatic tumours of non-small cell lung cancer

The epidermal growth factor receptor (EGFR) and KRAS gene status in paired primary non-small cell lung cancer (NSCLC) and metastatic tumours has been investigated by many studies, but remains controversial. We systematically reviewed studies in English of EGFR and KRAS gene status in primary and corresponding metastatic NSCLC up to 15 January 2014. Studies were selected rigorously from PubMed, EMBASE, as well as Cochrane Library databases. We carried out a meta-analysis to clarify EGFR mutations, EGFR amplification, positive rate of EGFR protein expression and KRAS mutations in primary and corresponding metastatic NSCLC. Our data suggested that the overall EGFR mutation rate, gene copy number, protein expression were not different between primary tumours and corresponding metastases, with the pooled odd ratios and 95% confidence interval 1.043 (0.686-1.586, P = 0.844), 0.604 (0.355-1.027, P = 0.063) and 1.447 (0.948-2.208, P = 0.087), respectively. The overall KRAS mutation rate of primary tumours was not different from that of matched metastases, with the odds ratio and 95% confidence interval being 1.224 (0.808-1.856, P = 0.340). The discordant rates of EGFR and KRAS mutations in paired primary and metastatic NSCLC were 14.5 and 16.7%, respectively. Among the discordant gene mutations in primary and metastatic lesions, the frequency of occurrence of mutation was not different from the frequency of loss of mutation for EGFR (P = 0.093) and KRAS gene (P = 0.227). These results indicate that EGFR and KRAS mutations are present frequently in metastases and occur before metastasis. Therefore, routine analysis of EGFR or KRAS gene status both in primary and metastatic tumours is not recommended.

Tumour tissue sampling for lung cancer management in the era of personalised therapy: what is good enough for molecular testing?

In the era of personalised cancer therapy, the demand for molecular profiling of the patient's tumour is steadily increasing. In advanced nonsmall cell lung cancer (NSCLC) patients, testing for epidermal growth factor receptor (EGFR) mutations and anaplastic lymphoma kinase (ALK) gene rearrangements has become an essential component of clinical practice to select patients who are most likely to benefit from EGFR and ALK tyrosine kinase inhibitors, respectively. Furthermore, obtaining tissue specimens from recurrent or metastatic tumours or from patients who develop resistance to initial effective therapies are essential for our understanding of the molecular basis of tumour progression and development of drug resistance. Therefore, the sampling of tumour tissue that is representative and is adequate in quantity and quality for pathological diagnosis and genomic profiling is crucial. In this review, we will discuss factors that should be considered in obtaining and processing biopsy specimens to enable routine molecular analysis in NSCLC patients.

The efficacy of EGFR gene mutation testing in various samples from non-small cell lung cancer patients: a multicenter retrospective study

Introduction

Testing for the epidermal growth factor receptor (EGFR) gene mutations requires considerable multidisciplinary experience of clinicians (for appropriate patient selection), pathologists (for selection of appropriate cytological or histological material) and geneticists (for performing and reporting reliable molecular tests). We present our experience on the efficacy of routine EGFR testing in various types of tumor samples and the frequency of EGFR mutations in a large series of Polish non-small cell lung cancer (NSCLC) patients.

Methods

Deletions in exon 19 and substitution L858R in exon 21 of EGFR gene were assessed using real-time PCR techniques in 1,138 small biopsies or cytological specimens and in 1,312 surgical samples.

Results

Out of 2,450 diagnostic samples (containing >10 % of tumor cells), the occurrence of EGFR gene mutations was 9 %; more frequently in women (13.9 %) and adenocarcinoma patients (10 %), particularly with accompanying expression of TTF1 (13.0 %). The frequency of EGFR gene mutations was similar in cytological and histological specimens, and in primary and metastatic lesions, and did not depend on the percentage of tumor cells and quality of isolated DNA. Cytological or small biopsy, compared to surgical specimens showed lower percentage of tumor cells, with no impact on the quality of real-time PCR assay.

Conclusion

Cytological and small biopsy samples with low (10–20 %) content of tumor cells and specimens from metastatic lesions are a sufficient source for EGFR mutation testing in NSCLC patients. The incidence of EGFR gene mutations in examined population was similar to those reported in other Caucasian populations.

Intratumoral distribution of EGFR mutations and copy number in metastatic lung cancer, what impact on the initial molecular diagnosis?

BACKGROUND

Activating epidermal growth factor receptor (EGFR) mutations characterize a subgroup of non-small-cell lung cancer that benefit from first line EGFR tyrosine kinase inhibitors (EGFR-TKI). However, the existence of polyclonal cell populations may hinder personalized-medicine strategies as patients' screening often depends upon a single tumor-biopsy sample. The purpose of this study is to clarify and to validate in clinical testing conditions the accuracy of EGFR genotyping using different tumor sites and various types of samples (transthoracic, surgical or endoscopic biopsies and cytology specimens).

METHODS

We conducted a retrospective review of 357 consecutive patients addressed for EGFR mutation screening in accordance with the directive of the European Medicines Agency (stage IV NSCLC). Fifty-seven samples were EGFR mutated and 40 had adequate tumor specimens for analysis on multiple spatially separated sites. Ten wild type samples were also analyzed. A total of 153 and 39 tumor fragments, from mutated and non-mutated cases respectively, were generated to analyze tumor heterogeneity or primary-metastatic discordances. After histological review of all fragments, EGFR genotyping was assessed using the routine diagnostic tools: fragment analysis for insertions and deletions and allele specific TaqMan probes for point mutations. EGFR copy number (CN) was evaluated by qPCR using TaqMan probes.

RESULTS

The identification of EGFR mutations was independent of localization within primary tumor, of specimen type and consistent between primary and metastases. At the opposite, for half of the samples, tumor loci showed different EGFR copy number that may affect mutation detection cut-off.

CONCLUSIONS

This is the largest series reporting multiple EGFR testing in Caucasians. It validates the accuracy of EGFR mutation screening from single tumor-biopsy samples before first line EGFR-TKI. The unpredictable variability in EGFR CN and therefore in EGFR wild type/mutant allelic ratio justifies the implementation of sensitive methods to identify patients with EGFR mutated tumors.

Prevalence of driver mutations in non-small-cell lung cancers in the People's Republic of China

Lung cancer is a leading cause of cancer-related mortality worldwide and in the People’s Republic of China. Recently, the pathological proportions of the various forms of lung cancer have changed. A shift to a preponderance of adenocarcinoma at the expense of squamous cell carcinoma is observable. Treatment decisions have historically been based on tumor histology, and evolution of our molecular understanding of cancer has led to development of targeted therapeutic agents. It is essential to further understand mutations that drive cancer development (driver mutations) in relevant genes and their effects on cancer cell proliferation and survival. The epidemiology of lung cancer in the People’s Republic of China has been extensively reviewed elsewhere. However, molecular epidemiological data from mainland China are scarce. Consequently, we herein review the prevalence of driver mutations in Chinese patients.

Quantification of EGFR mutations in primary and metastatic tumors in non-small cell lung cancer

BACKGROUND

EGFR mutation detection has been widely applied in the prediction of TKIs therapy in Non-Small Cell Lung Cancer (NSCLC). Metastatic tumors rather than primary tumors were usually assayed for those patients in advanced stages. Although the difference of EGFR mutation status in primary and metastatic tumors has been reported, the quantitative difference (ratio of mutated EGFR among total EGFR) in primary and metastatic tumors as well as in different sites of primary tumors was not clear.

METHODS

Genomic DNA in Formalin Fixed-Paraffin Embedded samples of primary and metastatic tumors of 50 NSCLC patients was extracted. Real-time fluorescent PCR was performed to quantify the EGFR mutation ratios.

RESULTS

The EGFR mutation ratios detected in different sites of primary tumors were highly concordant, whereas the EGFR mutation ratios in metastatic tumors were lower than those in primary tumors.

CONCLUSIONS

Randomly chosen sample may reliably represent the type and ratio of mutations of EGFR in primary tumors. EGFR mutation ratios in primary tumors and metastatic tumors are different. If metastatic tumors are used for the detection of EGFR mutation, the sensitivity of the detection assay must be considered.

Erlotinib in wild type epidermal growth factor receptor non-small cell lung cancer: A systematic review

BACKGROUND:

Targeting epidermal growth factor receptors (EGFR) is an innovative approach to managing non-small cell lung cancer (NSCLC) which harbors EGFR mutation. However, the efficacy of these agents like erlotinib in patients without the mutation is not known.

METHODS:

This systematic review included Phase III randomized clinical trials that compared single agent erlotinib to other management options in the setting of NSCLC with reported outcome data on patients with EGFR wild type (EGFRWT) tumors. Outcome data include overall survival (OS), progression free survival (PFS) and response rate (RR). Random effects meta-analysis was used to pool outcomes across studies.

RESULTS:

Three studies met the inclusion criteria. These studies included a total of 2044 patients with outcome data on 674 patients with EGFRWT tumors (33%). Meta-analysis revealed a statistically significant improvement in OS with erlotinib (hazard ratio of 0.780; 95% confidence interval: 0.654-0.930, P = 0.006). Data were not available to perform PFS or RR analysis. The quality of this evidence is considered to be moderate to high.

CONCLUSION:

Our study revealed a significant benefit of erlotinib in patient with EGFRWT tumors compared with other approaches. These findings add another therapeutic option to patients generally considered difficult to treat.

Rechallenge therapy and treatment holiday: different strategies in management of metastatic colorectal cancer

Fluoropyrimidines, oxaliplatin, irinotecan and biologic therapies (Bevacizumab, Panitumumab, and Cetuximab) represent the backbone of metastatic colorectal cancer (CRC) treatment. The improvement in survival for mCRC patient led to two main outstanding issues: 1) there is a significant number of patients progressing beyond the third or fourth line of treatment still suitable for further therapy when enrollment into clinical trial is not possible. In this situation, the role of any therapy rechallenge (either chemotherapy alone, chemotherapy and biologic therapy or biologic therapy alone) is still not clear, particularly in patients who had previously responded, and if treatment choice is based on traditional dogma of primary and secondary resistance, rechallenge does not seem to be justified. 2) Prolonged intensive treatment is burdened from the high risk of cumulative toxicity, worsening in quality of life and a not well defined possibility of early acquired resistance.Different hypothesis could justify the research of different strategy in treatment of mCRC:1) Epigenetic changes might drive resistance and treatment could induce these changes. Re-expression of silenced tumor suppressive genes might resensitize tumors to therapy. It is therefore possible that a drug holiday (intermittent treatment) could allow reversion to a previous epigenetic profile. Moreover an intermittent treatment could delay acquired resistance. 2) It is plausible that tumor grows as a polyclonal mass. If it responds but then becomes resistant to one or more treatments, retreatment might be successful if changing therapies allows to that clone of cells to re-emerge. On these basis, we focused this review on the actual evidences in management of mCRC patients in terms of chemotherapy or biological therapies rechallenge and intermittent treatment. Moreover, we will discuss the potential biological mechanisms of the observed results of early clinical trials.

The quest to overcome resistance to EGFR-targeted therapies in cancer

All patients with metastatic lung, colorectal, pancreatic or head and neck cancers who initially benefit from epidermal growth factor receptor (EGFR)-targeted therapies eventually develop resistance. An increasing understanding of the number and complexity of resistance mechanisms highlights the Herculean challenge of killing tumors that are resistant to EGFR inhibitors. Our growing knowledge of resistance pathways provides an opportunity to develop new mechanism-based inhibitors and combination therapies to prevent or overcome therapeutic resistance in tumors. We present a comprehensive review of resistance pathways to EGFR-targeted therapies in lung, colorectal and head and neck cancers and discuss therapeutic strategies that are designed to circumvent resistance.

EGFR activating mutations detected by different PCR techniques in Caucasian NSCLC patients with CNS metastases: short report

EGFR mutation testing has become an essential determination to decide treatment options for NSCLC. The mutation analysis is often conducted in samples with low percentage of tumour cells from primary tumour biopsies. There is very little evidence that samples from metastatic tissues are suitable for EGFR testing. We had evaluated the frequency of EGFR mutations with three highly sensitive PCR techniques in formalin-fixed, paraffin-embedded samples of 143 NSCLC patients with central nervous system (CNS) metastases. 32 corresponding primary tumours were also examined. We used PCR followed by DNA fragments length analysis (FLA), ASP–PCR and PNA–LNA PCR clamp techniques. We found 9 (6.29 %) EGFR gene mutations in CNS samples: 3 (2.1 %) in exon 19 and 6 (4.2 %) in exon 21. The full concordance between CNS metastases and primary tumour samples was observed. PCR followed by DNA–FLA and PNA–LNA PCR clamp were sensitive enough to detect exon 19 deletions. Two mutations in exon 21 were detected by ASP–PCR only, one L858R substitution was detected only by PNA–LNA PCR clamp. With respect to sensitivity, PCR followed by DNA–FLA achieved a level of detection of at least 10 % of mutated DNA for exon 19 deletion, as for ASP–PCR it was at least 5 % of mutated DNA for L858R substitution. Higher sensitivity of 1 % of mutated DNA was achieved by PNA–LNA PCR clamp technique for both mutations. The use of different methodological techniques authenticates the negative result of molecular tests.

The incidence of EGFR-activating mutations in bone metastases of lung adenocarcinoma

Poor prognosis of lung adenocarcinoma is associated with early occurrence of distant metastases. This type of non-small-cell lung carcinoma more frequently involves EGFR gene abnormalities, which determine the efficacy of EGFR tyrosine kinase inhibitor therapies (EGFR TKIs). It is probable that genetic abnormalities present in primary tumor will also be present in metastases. Unfortunately little is known about the incidence of these mutations in the metastases and about the effectiveness of molecularly targeted therapy in such patients. Formalin-fixed, paraffin-embedded tumor tissue was prepared from 431 samples of primary adenocarcinoma, 61 of adenocarcinoma central nervous system (CNS) metastases and 8 of adenocarcinoma bone metastases. The presence of exon 19 deletions was examined using the PCR technique and amplified PCR product fragment length analysis. The ASP-PCR technique was used to evaluate the L858R substitutions in exon 21, and the results were analyzed using ALF Express II sequencer. In the adenocarcinoma metastases to bone obtained from 8 patients, deletions in exon 19 of the EGFR gene were revealed in 3 smoking men and one non-smoking woman, while L858R substitution in exon 21 was found in one smoking woman and one man of unknown smoking status. The incidence of EGFR gene mutations in the bone metastases was 75%, in the primary adenocarcinoma--12.8%, and in the adenocarcinoma metastases to CNS--14.75%. Five patients with EGFR gene mutation revealed in bone metastases were treated with EGFR TKIs; the majority of them had a satisfactory response to therapy.

Molecular testing guideline for selection of lung cancer patients for EGFR and ALK tyrosine kinase inhibitors: guideline from the College of American Pathologists, International Association for the Study of Lung Cancer, and Association for Molecular Pathology

OBJECTIVE

To establish evidence-based recommendations for the molecular analysis of lung cancers that are required to guide EGFR- and ALK-directed therapies, addressing which patients and samples should be tested, and when and how testing should be performed.

PARTICIPANTS

Three cochairs without conflicts of interest were selected, one from each of the 3 sponsoring professional societies: College of American Pathologists, International Association for the Study of Lung Cancer, and Association for Molecular Pathology. Writing and advisory panels were constituted from additional experts from these societies.

EVIDENCE

Three unbiased literature searches of electronic databases were performed to capture published articles from January 2004 through February 2012, yielding 1533 articles whose abstracts were screened to identify 521 pertinent articles that were then reviewed in detail for their relevance to the recommendations. EVIDENCE was formally graded for each recommendation.

CONSENSUS PROCESS

Initial recommendations were formulated by the cochairs and panel members at a public meeting. Each guideline section was assigned to at least 2 panelists. Drafts were circulated to the writing panel (version 1), advisory panel (version 2), and the public (version 3) before submission (version 4).

CONCLUSIONS

The 37 guideline items address 14 subjects, including 15 recommendations (evidence grade A/B). The major recommendations are to use testing for EGFR mutations and ALK fusions to guide patient selection for therapy with an epidermal growth factor receptor (EGFR) or anaplastic lymphoma kinase (ALK) inhibitor, respectively, in all patients with advanced-stage adenocarcinoma, regardless of sex, race, smoking history, or other clinical risk factors, and to prioritize EGFR and ALK testing over other molecular predictive tests. As scientific discoveries and clinical practice outpace the completion of randomized clinical trials, evidence-based guidelines developed by expert practitioners are vital for communicating emerging clinical standards. Already, new treatments targeting genetic alterations in other, less common driver oncogenes are being evaluated in lung cancer, and testing for these may be addressed in future versions of these guidelines.

Molecular testing guideline for selection of lung cancer patients for EGFR and ALK tyrosine kinase inhibitors: guideline from the College of American Pathologists, International Association for the Study of Lung Cancer, and Association for Molecular Pathology

OBJECTIVE

To establish evidence-based recommendations for the molecular analysis of lung cancers that are that are required to guide EGFR- and ALK-directed therapies, addressing which patients and samples should be tested, and when and how testing should be performed.

PARTICIPANTS

Three cochairs without conflicts of interest were selected, one from each of the 3 sponsoring professional societies: College of American Pathologists, International Association for the Study of Lung Cancer, and Association for Molecular Pathology. Writing and advisory panels were constituted from additional experts from these societies.

EVIDENCE

Three unbiased literature searches of electronic databases were performed to capture articles published published from January 2004 through February 2012, yielding 1533 articles whose abstracts were screened to identify 521 pertinent articles that were then reviewed in detail for their relevance to the recommendations. Evidence was formally graded for each recommendation.

CONSENSUS PROCESS

Initial recommendations were formulated by the cochairs and panel members at a public meeting. Each guideline section was assigned to at least 2 panelists. Drafts were circulated to the writing panel (version 1), advisory panel (version 2), and the public (version 3) before submission (version 4).

CONCLUSIONS

The 37 guideline items address 14 subjects, including 15 recommendations (evidence grade A/B). The major recommendations are to use testing for EGFR mutations and ALK fusions to guide patient selection for therapy with an epidermal growth factor receptor (EGFR) or anaplastic lymphoma kinase (ALK) inhibitor, respectively, in all patients with advanced-stage adenocarcinoma, regardless of sex, race, smoking history, or other clinical risk factors, and to prioritize EGFR and ALK testing over other molecular predictive tests. As scientific discoveries and clinical practice outpace the completion of randomized clinical trials, evidence-based guidelines developed by expert practitioners are vital for communicating emerging clinical standards. Already, new treatments targeting genetic alterations in other, less common driver oncogenes are being evaluated in lung cancer, and testing for these may be addressed in future versions of these guidelines.

Molecular testing guideline for selection of lung cancer patients for EGFR and ALK tyrosine kinase inhibitors: guideline from the College of American Pathologists, International Association for the Study of Lung Cancer, and Association for Molecular Pathology

OBJECTIVE

To establish evidence-based recommendations for the molecular analysis of lung cancers that are required to guide EGFR- and ALK-directed therapies, addressing which patients and samples should be tested, and when and how testing should be performed.

PARTICIPANTS

Three cochairs without conflicts of interest were selected, one from each of the 3 sponsoring professional societies: College of American Pathologists, International Association for the Study of Lung Cancer, and Association for Molecular Pathology. Writing and advisory panels were constituted from additional experts from these societies.

EVIDENCE

Three unbiased literature searches of electronic databases were performed to capture articles published from January 2004 through February 2012, yielding 1533 articles whose abstracts were screened to identify 521 pertinent articles that were then reviewed in detail for their relevance to the recommendations. Evidence was formally graded for each recommendation.

CONSENSUS PROCESS

Initial recommendations were formulated by the cochairs and panel members at a public meeting. Each guideline section was assigned to at least 2 panelists. Drafts were circulated to the writing panel (version 1), advisory panel (version 2), and the public (version 3) before submission (version 4).

CONCLUSIONS

The 37 guideline items address 14 subjects, including 15 recommendations (evidence grade A/B). The major recommendations are to use testing for EGFR mutations and ALK fusions to guide patient selection for therapy with an epidermal growth factor receptor (EGFR) or anaplastic lymphoma kinase (ALK) inhibitor, respectively, in all patients with advanced-stage adenocarcinoma, regardless of sex, race, smoking history, or other clinical risk factors, and to prioritize EGFR and ALK testing over other molecular predictive tests. As scientific discoveries and clinical practice outpace the completion of randomized clinical trials, evidence-based guidelines developed by expert practitioners are vital for communicating emerging clinical standards. Already, new treatments targeting genetic alterations in other, less common driver oncogenes are being evaluated in lung cancer, and testing for these may be addressed in future versions of these guidelines.

New monoallelic combination of KRAS gene mutations in codons 12 and 13 in the lung adenocarcinoma

PURPOSE

In a retrospective analysis of the prevalence of KRAS mutations in patients with advanced non-small cell lung cancer (NSCLC), we detected a unique and not earlier described case of a double combination of mutations at codons 12 and 13 of the KRAS gene in a patient with lung adenocarcinoma.

MATERIAL/METHODS

To determine the molecular characteristics of the infrequent mutation and the mutational status of the KRAS gene in metastatic brain tumors in the same patient, we performed morphological and molecular tests.

RESULTS

Molecular analysis of the nature of the double mutation showed that the unique combination of variants is a monoallelic mutation. This type of changes has not yet been registered in the Catalogue of Somatic Mutations in Cancer database. Molecular assessment of the KRAS mutation status in the brain metastatic site in the same patient, showed no mutations in codons 12 and 13. Moreover, we did not find mutation at exon 19 and 21 of EGFR gene, both in primary tumor as well as in secondary metastatic foci in the brain.

CONCLUSIONS

The presented case shows an example of KRAS gene molecular mosaicism and heterogeneity of lung adenocarcinoma primary and metastatic tumors. Molecular heterogeneity of lung adenocarcinoma tumors can significantly affect eligibility of patients for targeted therapies.