Patterns of DNA mutations and ALK rearrangement in resected node negative lung adenocarcinoma

Improved survival and intracranial tumor control of EGFR-mutated NSCLC patients with newly developed brain metastases following stereotactic radiosurgery and EGFR-TKI: a large retrospective cohort study and meta-analyses

PURPOSE

To examine the differential effects of SRS and TKI on EGFR-mutated NSCLC patients with brain metastases (BMs) and outcomes following continuation of the same TKI agent in case of new BMs.

METHODS

This study included 608 NSCLC patients (2,274 BMs) while meta-analyses included 1,651 NSCLC patients (> 3,944 BMs). Overall survival (OS) and intracranial progression free survival (iPFS) were estimated using Kaplan-Meier methods. Hazard ratios (95% CI) of prognostic factors were estimated using Cox regression models.

RESULTS

The median OS/iPFS (95% CI) (months) for patients with wildtype EGFR/ALK, EGFR mutations, and ALK rearrangements were 17.7 (12.9-23.6)/12.1 (9.8-15.6), 28.9 (23.8-33.3)/17.7 (14.8-21.2), and 118.0 (not reached)/71.7 (15.1-not reached), respectively. In EGFR-mutated patients, meta-analyses combining our data showed significantly improved OS and iPFS of patients who received SRS and TKI (OS:35.1 months, iPFS:20.0 months) when compared to those who have SRS alone (OS:20.8 months, iPFS:11.8 months) or TKI alone (OS:24.3 months, iPFS:13.8 months). Having SRS for newly diagnosed BMs while keeping the existing TKI agent yielded OS (30.0 vs. 32.1 months, p = 0.200) non-inferior to patients who started combined SRS and TKI therapy for their newly diagnosed NSCLC with BMs. Multivariable analyses showed that good performance score and TKI therapy were associated with improved outcomes.

CONCLUSIONS

Combined SRS and TKI resulted in favorable outcomes in EGFR-mutated NSCLC patients with newly diagnosed BMs. Continuation of the same TKI agent plus SRS in case of new brain metastases yielded good clinical outcomes and may be considered a standard-of-care treatment.

Updates in the molecular pathology of non-small cell lung cancer

An understanding of the molecular pathology of non-small cell lung cancer (NSCLC) is important for pathologists as molecular characterization is now required for treatment decisions in advanced stage disease. While assessment for EGFR mutations, ALK and ROS1 fusions, and in some countries BRAF mutations, is now standard practice, other oncogenic mutations are also emerging that may impact routine clinical practice including alterations involving KRAS, NTRK, RET, MET and HER2. In addition, molecular pathology alterations of NSCLC are associated with responses to immune checkpoint therapy and are being increasingly investigated. Finally, specific molecular pathological alterations define some rarer subtypes of NSCLC such as salivary gland tumours, NUT carcinoma and SMARCA4-deficient undifferentiated tumour, and an understanding of the molecular pathology is important for their accurate diagnosis. In this review, the molecular pathology of NSCLC is discussed with a focus on clinically relevant molecular alterations.

TNM stages inversely correlate with the age at diagnosis in ALK-positive lung cancer

BACKGROUND

To clearly reveal the correlations between age at diagnosis, tumor-nodes-metastasis (TNM) stages and frequency of ALK-positive lung cancer.

METHODS

We reviewed patients who presented with ALK rearrangements (n=411) or KRAS-mutations (n=122) between September 2010 and January 2018. The clinical characteristics and overall survival were analyzed for the two genotype cohorts and stratified by different age categories (<40, 40-49, 50-59, ≥60 years).

RESULTS

In the ALK-positive cohort, the younger group showed more frequent disease in the T3/4 stage (P=0.014), lymph node metastasis (P=0.011) and distant metastasis (P=0.015) than the older groups. Meanwhile, the mean age at diagnosis for the ALK-positive patients showed a significant inverse correlation with the clinical stages (stage I/II vs. III vs. IV, 54.7 vs. 52.0 vs. 49.7 years; P<0.001), as well as with the T, N, and M categories. However, KRAS-mutant patients did not exhibit similar relationships to those observed in ALK-positive patients. Importantly, for ALK-positive patients, the frequency of stage IIIb-IV disease was almost twice that of stage I-IIIa disease (6.1% vs. 3.4%, P<0.001); there was a similar incidence of the different disease stages in KRAS-mutant lung cancer (P=0.924). Lastly, in ALK-positive patients, the ≥60 years group was associated with a trend toward better survival than the other younger groups.

CONCLUSIONS

The TNM stages exhibited a significant inverse correlation with age at diagnosis for ALK-positive lung cancer patients. More unique therapeutic strategies should be required in these young patients.

Essential roles of mitochondrial and heme function in lung cancer bioenergetics and tumorigenesis

Contrary to Warburg’s hypothesis, mitochondrial oxidative phosphorylation (OXPHOS) contributes significantly to fueling cancer cells. Several recent studies have demonstrated that radiotherapy-resistant and chemotherapy-resistant cancer cells depend on OXPHOS for survival and progression. Several cancers exhibit an increased risk in association with heme intake. Mitochondria are widely known to carry out oxidative phosphorylation. In addition, mitochondria are also involved in heme synthesis. Heme serves as a prosthetic group for several proteins that constitute the complexes of mitochondrial electron transport chain. Therefore, heme plays a pivotal role in OXPHOS and oxygen consumption. Further, lung cancer cells exhibit heme accumulation and require heme for proliferation and invasion in vitro. Abnormalities in mitochondrial biogenesis and mutations are implicated in cancer. This review delves into mitochondrial OXPHOS and lesser explored area of heme metabolism in lung cancer.

RNAi-based therapeutics for lung cancer: biomarkers, microRNAs, and nanocarriers

INTRODUCTION

Despite the current advances in the discovery of the lung cancer biomarkers and, consequently, in the diagnosis, this pathology continues to be the primary cause of cancer-related death worldwide. In most cases, the illness is diagnosed in an advanced stage, which limits the current treatment options available and reduces the survival rate. Therefore, RNAi-based therapy arises as a promising option to treat lung cancer.

AREAS COVERED

This review provides an overview on the exploitation of lung cancer biology to develop RNAi-based therapeutics to be applied in the treatment of lung cancer. Furthermore, the review analyzes the main nanocarriers designed to deliver RNAi molecules and induce antitumoral effects in lung cancer, and provides updated information about current RNAi-based therapeutics for lung cancer in clinical trials.

EXPERT OPINION

RNAi-based therapy uses nanocarriers to perform a targeted and efficient delivery of therapeutic genes into lung cancer cells, by taking advantage of the known biomarkers in lung cancer. These therapeutic genes are key regulatory molecules of crucial cellular pathways involved in cell proliferation, migration, and apoptosis. Thereby, the characteristics and functionalization of the nanocarrier and the knowledge of lung cancer biology have direct influence in improving the therapeutic effect of this therapy.

An Update on Predictive Biomarkers for Treatment Selection in Non-Small Cell Lung Cancer

It is now widely established that management of lung cancer is much more complex and cannot be centered on the binary classification of small-cell versus non-small cell lung cancer (NSCLC). Lung cancer is now recognized as a highly heterogeneous disease that develops from genetic mutations and gene expression patterns, which initiate uncontrolled cellular growth, proliferation and progression, as well as immune evasion. Accurate biomarker assessment to determine the mutational status of driver mutations such as EGFR, ALK and ROS1, which can be targeted by specific tyrosine kinase inhibitors, is now essential for treatment decision making in advanced stage NSCLC and has shifted the treatment paradigm of NSCLC to more individualized therapy. Rapid advancements in immunotherapeutic approaches to NSCLC treatment have been paralleled by development of a range of potential predictive biomarkers that can enrich for patient response, including PD-L1 expression and tumor mutational burden. Here, we review the key biomarkers that help predict response to treatment options in NSCLC patients.

Recent advances in the management of non-small cell lung cancer

Lung cancer is the number one cause of cancer-related death in both men and women. However, over the last few years, we have witnessed improved outcomes that are largely attributable to early detection, increased efforts in tobacco control, improved surgical approaches, and the development of novel targeted therapies. Currently, there are several novel therapies in clinical practice, including those targeting actionable mutations and more recently immunotherapeutic agents. Immunotherapy represents the most significant step forward in eradicating this deadly disease. Given the ever-changing landscape of lung cancer management, here we present an overview of the most recent advances in the management of non-small cell lung cancer.

Screening for ROS1 gene rearrangements in non-small-cell lung cancers using immunohistochemistry with FISH confirmation is an effective method to identify this rare target

AIMS

To assess the prevalence of ROS1 rearrangements in a retrospective and prospective diagnostic Australian cohort and evaluate the effectiveness of immunohistochemical screening.

METHODS AND RESULTS

A retrospective cohort of 278 early stage lung adenocarcinomas and an additional 104 prospective non-small-cell lung cancer (NSCLC) cases referred for routine molecular testing were evaluated. ROS1 immunohistochemistry (IHC) was performed (D4D6 clone, Cell Signaling Technology) on all cases as well as fluorescence in-situ hybridization (FISH) using the ZytoVision and Abbott Molecular ROS1 FISH probes, with ≥15% of cells with split signals considered positive for rearrangement. Eighty-eight cases (32%) from the retrospective cohort showed staining by ROS1 IHC, and one case (0.4%) showed ROS1 rearrangement by FISH. Nineteen of the prospective diagnostic cases showed ROS1 IHC staining, 12 (12%) cases of which were confirmed as ROS1 rearranged by FISH. There were no ROS1 rearranged cases that showed no expression of ROS1 with IHC. The ROS1 rearranged cases in the prospective cohort were all EGFR wild-type and anaplastic lymphoma kinase (ALK) rearrangement-negative. The sensitivity of ROS1 IHC in the retrospective cohort was 100% and specificity was 76%.

CONCLUSIONS

ROS1 rearrangements are rare events in lung adenocarcinomas. Selection of cases for ROS1 FISH testing, by excluding EGFR/ALK-positive cases and use of IHC to screen for potentially positive cases, can be used to enrich for the likelihood of identifying a ROS1 rearranged lung cancer and prevent the need to undertake expensive and time-consuming FISH testing in all cases.

Effectiveness of tyrosine kinase inhibitors on uncommon E709X epidermal growth factor receptor mutations in non-small-cell lung cancer

BACKGROUND

Clinical features of epidermal growth factor receptor (EGFR) mutations: L858R, deletions in exon 19, T790M, insertions in exon 20, G719X, and L861X in non-small-cell lung cancer (NSCLC) are well-known. The clinical significance of other uncommon EGFR mutations, such as E709X, is not well understood. This study aimed to improve the understanding of E709X, and the clinical response to tyrosine kinase inhibitors (TKIs) of NSCLC patients with such an uncommon mutation.

METHODS

Specimens from 3,146 patients were tested for EGFR mutations. We surveyed the clinical data and the effectiveness of TKI treatment in NSCLC patients with EGFR mutations E709X.

RESULTS

Of the 3,146 patients, 1,689 (53.7%) had EGFR mutations. This included 726 patients with deletions in exon 19, 733 patients with L858R, and 230 (13.6%) patients with other EGFR mutations. In the 230 patients who had mutations other than single deletion in exon 19 or single L858R in exon 21, 25 (1.5%) patients had the uncommon E709X mutations. Twenty patients had complex E709X mutations and five had single E709X mutation: delE709-T710insD. Of these 25 patients, 18 received either gefitinib or erlotinib treatment. The response rate of TKIs treatment was 50.0%, and the median progression-free survival was 6.2 months. All 5 patients who had delE709-T710insD were non-responders to TKI treatments.

CONCLUSION

E709X EGFR mutations constituted a small part of the whole group of EGFR mutations. Most patients had complex mutations. The mutation delE709-T710insD was a single mutation and was not associated with good response to TKI treatment.

EGFR-Co-Mutated Advanced NSCLC and Response to EGFR Tyrosine Kinase Inhibitors

OBJECTIVES

The evolution of EGFR tyrosine kinase inhibitors (TKIs) has changed the landscape of disease for a subset of patients with NSCLC. Most patients with an EGFR mutation respond to these drugs; however, a proportion show limited or no tumor response. We explored the impact of co-mutation (double or multiple mutation), compared with a single mutation, of the EGFR gene on response to TKIs in a series of patients with metastatic NSCLC.

METHODS

We retrospectively analyzed the mutation profiles of nonsquamous NSCLC tested at Royal Prince Alfred Hospital between 2012 and 2015 by MassArray using the OncoCarta v1.0 panel. Patients with metastatic disease whose tumors had sensitizing EGFR mutation(s) were included. The primary end point was progression-free survival (PFS). We used the Kaplan-Meier method for PFS and overall survival; the log rank test was used to compare groups with and without co-mutation. Multivariable analysis was done for PFS; response rate was assessed using chi-square and logistic regression analysis.

RESULTS

A total of 62 patients were included, and of these, eight (12.9%) had a co-mutation. The median PFS and overall survival times were 11.5 and 26.3 months, respectively. Patients with EGFR co-mutation had a significantly shorter median PFS than those with a single mutation (5.7 months versus 12.3 months, p = 0.02). The response rate to TKIs was significantly worse in those with co-mutation compared with in those without co-mutation (38% versus 89%, p < 0.001).

CONCLUSIONS

Taking into account the small number of patients in this study, PFS in patients with EGFR co-mutation appeared significantly shorter, and response rate significantly lower, than in patients with a single mutation. Data from multipanel testing may identify subgroups of patients who are likely to respond poorly to standard treatment. Clarification of these subgroups may improve patient care.

Spectrum of EGFR gene mutations and ALK rearrangements in lung cancer patients in Turkey

The EGFR gene and ALK rearrangements are two genetic drivers of non-small cell lung cancer (NSCLC). The frequency of EGFR mutations and ALK rearrangement varies according to not only ethnicity but also gender, smoking status and the histological type of NSCLC. In the present study, we demonstrated the distribution of EGFR mutations in 132 NSCLC patients by using a pyrosequencing technique and the distribution of ALK rearrangements in 51 NSCLC patients by using fluorescent in situ hybridization technique in Turkey. Additionally, we compared the clinicopathological data of NSCLC patients with the mutation status of EGFR in their cancerous tissues. Both EGFR mutations and ALK rearrangements were identified in 19 (14.39 %) and 1 (1.96 %) patients, respectively. We found EGFR mutations in codon 861, 719 and 858 with the ratios of 10.52 % (2/19), 10.52 % (2/19) and 31.58 % (6/19), respectively, and deletion of exon 19 in 47.37 % (9/19) of the patients. We found the frequency of EGFR mutations to be significantly higher in female patients and nonsmokers (p = 0.043, p = 0.027, respectively). Consequently, we found EGFR mutations to be more frequent in female patients and nonsmokers. Future studies on larger patient groups would provide more accurate data to exhibit the relationship between EGFR mutations and ALK rearrangements and the clinicopathological status.

Salivary duct carcinoma: Clinicopathologic features, morphologic spectrum, and somatic mutations

BACKGROUND

Accurate diagnosis of salivary duct carcinoma requires a high index of suspicion and clinicopathologic correlation. Hallmark genetic changes that may provide novel therapeutic options are being explored.

METHODS

One hundred ninety salivary gland malignancies at Royal Prince Alfred Hospital (from 1989-2014) were reviewed. Human epidermal growth factor receptor 2 (HER2) and androgen receptor status were determined along with multigene profiling.

RESULTS

Twenty-three salivary duct carcinomas were identified, predominantly in men in their fifth to ninth decades of life. Facial nerve palsy (12%) and cervical lymph node metastases (82%) were present, and 96% received postoperative adjuvant therapy. Histologically, the tumors resembled high-grade invasive and in situ ductal carcinoma of the breast. Micropapillary, papillary, sarcomatoid, oncocytic, and mucinous variants were seen. The tumors showed androgen receptor (70%), HER2 amplification (30%), and HRAS, AKT1, PIK3CA, and NRAS mutations (22%; cumulative). The 5-year disease-free survival was 36%.

CONCLUSION

Salivary duct carcinoma demonstrates a wide histopathologic spectrum. Treatment strategies need to take androgen receptor, HER2 amplification, and PIK3CA mutation into account. © 2015 Wiley Periodicals, Inc. Head Neck 38: E1838-E1847, 2016.

L858R-positive lung adenocarcinoma with KRAS G12V, EGFR T790M and EGFR L858R mutations: A case report

Improvement in the current understanding of the molecular basis of lung cancer at multiple levels, including the genetic, epigenetic and protein levels, has the potential to impact the diagnosis, prognosis and treatment of lung cancer. The mutation status of the tyrosine kinase domain of epidermal growth factor receptor (EGFR) is known to be a predictor of the response to gefitinib in lung cancer. Furthermore, mutations in the EGFR and KRAS genes appear to be mutually exclusive. The present study reports a rare case of a patient harboring two EGFR mutations (L858R and T790M) and a KRAS mutation (G12V). The development of gefitinib resistance was detected in the subsequent treatment. The present study indicates that EGFR and KRAS mutational analysis should be recommended for all patients with non-small-cell lung carcinoma.

Diagnostic Mutation Profiling and Validation of Non-Small-Cell Lung Cancer Small Biopsy Samples using a High Throughput Platform

BACKGROUND

A single platform designed for the synchronous screening of multiple mutations can potentially enable molecular profiling in samples of limited tumor tissue. This approach is ideal for the assessment of advanced non-small-cell lung cancer (NSCLC) diagnostic specimens, which often comprise small biopsies. Therefore, we aimed in this study to validate the mass spectrometry-based Sequenom LungCarta panel and MassARRAY platform using DNA extracted from a single 5 μM formalin-fixed paraffin-embedded tissue section.

METHODS

Mutations, including those with an equivocal spectrum, detected in 90 cases of NSCLC (72 lung biopsies, 13 metastatic tissue biopsies, three resections, and two cytology samples) were validated by a combination of standard sequencing techniques, immunohistochemical staining for p53 protein, and next-generation sequencing with the TruSight Tumor panel.

RESULTS

Fifty-five mutations were diagnosed in 47 cases (52%) in the following genes: TP53 (22), KRAS (15), EGFR (5), MET (3), PIK3CA (3), STK11 (2), NRF-2 (2), EPHA5 (1), EPHA3 (1), and MAP2K1 (1). Of the 90 samples, one failed testing due to poor quality DNA. An additional 7 TP53 mutations were detected by next-generation sequencing, which facilitated the interpretation of p53 immunohistochemistry but required 5 × 10 μM tumor sections per sample tested.

CONCLUSIONS

The LungCarta panel is a sensitive method of screening for multiple alterations (214 mutations across 26 genes) and which optimizes the use of limited amounts of tumor DNA isolated from small specimens.

The suitability of small biopsy and cytology specimens for EGFR and other mutation testing in non-small cell lung cancer

BACKGROUND

Patients with advanced non-small cell lung cancer (NSCLC) benefit from treatment with epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) when their tumor harbors an activating EGFR mutation. As the majority of NSCLC patients present with advanced disease, cytology and small biopsy specimens are frequently the only tissue available for mutation testing, but can pose challenges due to low tumor content. We aim to better define the suitability of these specimens for mutation testing.

METHODS

NSCLC cases referred to our institution for mutation testing over a 15-month period were retrospectively reviewed. Specimens were tested for mutations including EGFR, KRAS, and BRAF, using a multiplex PCR assay (OncoCarta Panel v1.0) and analyzed on the Agena Bioscience MassARRAY platform.

RESULTS

A total of 146 specimens were tested, comprising 53 (36.3%) resection specimens (including 28 lung resection specimens), 55 (37.7%) small biopsy specimens and 38 (26%) cytology specimens. Of 142 cases with sufficient DNA for mutation testing, EGFR mutations were detected in 31 specimens (21.8%), KRAS mutations in 31 specimens (21.8%) and BRAF mutations in three specimens (2.1%). There was no significant difference in the EGFR mutation rate between lung resection (10 of 28 cases; 35.7%), small biopsy (9 of 53 cases; 17%), and cytology specimens (8 of 36 cases; 22.2%).

CONCLUSIONS

Our results support the utility of small biopsy and cytology specimens for mutation testing. Careful evaluation of the adequacy of small specimens is required to minimize the risk of false negative or positive results.

BRAF mutations in non-small cell lung cancer

BACKGROUND

BRAF is a proto-oncogene encoding a serine/threonine protein kinase which promotes cell proliferation and survival. BRAF mutations are commonly seen in melanoma and papillary thyroid carcinoma. We aimed to investigate the prevalence and clinicopathological features of BRAF mutations in non-small cell lung cancer (NSCLC) cases submitted for routine mutation testing at our institution.

METHODS

Mutation analysis for BRAF, EGFR and KRAS was performed using Sequenom MassARRAY platform with OncoCarta panel v1.0. Pathological features were reviewed and immunohistochemistry for BRAF V600E was also performed.

RESULTS

Seven out of 273 cases (2.6%) had BRAF mutations (three males and four females, median age 70 years, all smokers), with six adenocarcinomas and one NSCLC, not otherwise specified (NOS). All had wild-type EGFR and KRAS. The identified BRAF mutations were V600E (4/7, 58%), K601N, L597Q and G469V. BRAF V600E immunohistochemistry was positive in two cases with V600E and negative in one case with K601N (tissue available in three cases only). No significant difference in age or gender was found (BRAF mutant vs. wild-type).

CONCLUSIONS

BRAF mutations occur in a small proportion of NSCLC that lack other driver mutations. The clinicopathological profile differs from that of EGFR mutant tumours. The potential benefits of BRAF-inhibitors should be investigated.

Somatic DNA mutation analysis in targeted therapy of solid tumours

Cancer is a disease of the genome with diverse aetiologies including the accumulation of acquired mutations throughout the genome. There has been a flood of knowledge improving our understanding of the biology and molecular genetics of melanoma, lung and colorectal cancer since the genomics era started. Translation of this knowledge into a better understanding of cell proliferation, survival and apoptosis has produced a paradigm shift in medical oncology enabling gene-based cancer treatment (called personalised or precision medicine). Somatic mutation analysis is crucial for a genomics approach since it can identify driver mutations-the "Achilles' heel" of cancer, and support clinical decision-making through targeted therapy. Nevertheless, the applications of somatic DNA testing in cancer face many challenges such as obtaining comprehensive coverage of the cancer genome with limited DNA being available, and delivering an accurate report in a timely fashion without false-negative and false-positive results. Further advances in DNA technologies and bioinformatics will overcome these issues and maximise opportunities for targeted therapy. Somatic mutation analysis will then become an integral part of cancer management for all malignancies.

Concurrent oncogene mutation profile in Chinese patients with stage Ib lung adenocarcinoma

Molecular characteristics in lung cancer are associated with carcinogenesis, response to targeted therapies, and prognosis. With concurrent oncogene mutations being reported more often, the adjustment of treatment based on the driver gene mutations would improve therapy. We proposed to investigate the distribution of concurrent oncogene mutations in stage Ib lung adenocarcinoma in a Chinese population and find out the correlation between survival outcome and the most frequently mutated genes in EGFR and KRAS in Chinese population. Simultaneously, we tried to validate the Sequenom method by real time fluoresce qualification reverse transcription polymerase chain reaction (RT-PCR) in oncogene detection. One hundred fifty-six patients who underwent complete surgical resection in our hospital between 1999 and 2007 were retrospectively investigated. Using time-of-flight mass spectrometry, 238 mutation hotspots in 19 oncogenes were examined. Genetic mutations occurred in 86 of 156 patients (55.13%). EGFR was most frequently gene contained driver mutations, with a rate of 44.23%, followed by KRAS (8.33%), PIK3CA (3.84%), KIT (3.20%), BRAF (2.56%), AKT (1.28%), MET (0.64%), NRAS (0.64%), HRAS (0.64%), and ERBB2 (0.64%). No mutations were found in the RET, PDGFRA, FGFR1, FGFR3, FLT3, ABL, CDK, or JAK2 oncogenes. Thirteen patients (8.3%) were detected in multiple gene mutations. Six patients had PIK3CA mutations in addition to mutations in EGFR and KRAS. EGFR mutations can coexist with mutations in NRAS, KIT, ERBB2, and BRAF. Only one case was found to have a KRAS mutation coexisting with the EGFR T790M mutation. Otherwise, mutations in EGFR and KRAS seem to be mutually exclusive. There is no survival benefit in favor of EGFR/KRAS mutation. Several concomitant driver gene mutations were observed in our study. None of EFGR/KRAS mutation was demonstrated as a prognostic factor. Polygenic mutation testing by time-of-flight mass spectrometry was validated by RT-PCR, which can be an alternative option to test for multiple mutations and can be widely applied to clinical practice and help to guide treatment.

Alterations of insulin-like growth factor-1 receptor gene copy number and protein expression are common in non-small cell lung cancer

Aims

Insulin-like growth factor-1 receptor (IGF1R) is a tyrosine kinase membrane receptor involved in tumourigenesis that may be a potential therapeutic target. We aimed to investigate the incidence and prognostic significance of alterations in IGF1R copy number, and IGF1R protein expression in resected primary non-small cell lung cancer (NSCLC), and lymph node metastases.

Methods

IGF1R gene copy number status was evaluated by chromogenic silver in situ hybridisation and IGF1R protein expression was evaluated by immunohistochemistry in tissue microarray sections from a retrospective cohort of 309 surgically resected NSCLCs and results were compared with clinicopathological features, including EGFR and KRAS mutational status and patient survival.

Results

IGF1R gene copy number status was positive (high polysomy or amplification) in 29.2% of NSCLC, and 12.1% exhibited IGF1R gene amplification. High IGF1R expression was found in 28.3%. There was a modest correlation between IGF1R gene copy number and protein expression (r=0.2, p<0.05). Alterations of IGF1R gene copy number and protein expression in primary tumours were significantly associated with alterations in lymph node metastases (p<0.01). High IGF1R gene copy number and protein expression was significantly higher in squamous cell carcinomas (SCC) compared with other subtypes of NSCLC (p<0.05). There were no other associations between IGF1R status and other clinicopathological features including patient age, gender, smoking status, tumour size, stage, grade, EGFR or KRAS mutational status or overall survival.

Conclusions

High IGF1R gene copy number and protein overexpression are frequent in NSCLC, particularly in SCCs, but they are not prognostically relevant.

Science and mechanism of action of targeted therapies in cancer treatment

OBJECTIVES

To identify common signaling pathways that control cancer growth and discuss the mechanism of action of cancer targeted therapies.

DATA SOURCES

Medical and nursing literature, research articles, published clinical guidelines.

CONCLUSION

Understanding the signaling pathways and genetic mutations that control cancer cell growth elucidates an understanding of the mechanism of targeted therapies.

IMPLICATIONS FOR NURSING PRACTICE

To understand the mechanism of action of targeted therapies, oncology nurses must first be familiar with the most common signaling pathways. Adding to this foundation, the nurse can easily learn about the classes of targeted therapies and the strategies to minimize and manage common side effects.

Clinical validation of an ultra high-throughput spiral microfluidics for the detection and enrichment of viable circulating tumor cells

BACKGROUND

Circulating tumor cells (CTCs) are cancer cells that can be isolated via liquid biopsy from blood and can be phenotypically and genetically characterized to provide critical information for guiding cancer treatment. Current analysis of CTCs is hindered by the throughput, selectivity and specificity of devices or assays used in CTC detection and isolation.

METHODOLOGY/PRINCIPAL FINDINGS

Here, we enriched and characterized putative CTCs from blood samples of patients with both advanced stage metastatic breast and lung cancers using a novel multiplexed spiral microfluidic chip. This system detected putative CTCs under high sensitivity (100%, n = 56) (Breast cancer samples: 12-1275 CTCs/ml; Lung cancer samples: 10-1535 CTCs/ml) rapidly from clinically relevant blood volumes (7.5 ml under 5 min). Blood samples were completely separated into plasma, CTCs and PBMCs components and each fraction were characterized with immunophenotyping (Pan-cytokeratin/CD45, CD44/CD24, EpCAM), fluorescence in-situ hybridization (FISH) (EML4-ALK) or targeted somatic mutation analysis. We used an ultra-sensitive mass spectrometry based system to highlight the presence of an EGFR-activating mutation in both isolated CTCs and plasma cell-free DNA (cf-DNA), and demonstrate concordance with the original tumor-biopsy samples.

CONCLUSIONS/SIGNIFICANCE

We have clinically validated our multiplexed microfluidic chip for the ultra high-throughput, low-cost and label-free enrichment of CTCs. Retrieved cells were unlabeled and viable, enabling potential propagation and real-time downstream analysis using next generation sequencing (NGS) or proteomic analysis.

Genomic medicine and targeted therapy for solid tumors

A marked paradigm shift in cancer therapy has occurred over the past 20 years. Systemic treatment has evolved from nonspecific cytotoxic chemotherapy to targeting cancer-associated pathways, profoundly changing treatment approaches in the metastatic and adjuvant settings. This review will highlight some of the major clinical advances in targeted cancer therapy in select epithelial malignancies made possible by the understanding of the molecular mechanisms driving tumor growth through genomic methods.

Molecular biology of lung cancer

Lung cancers are characterised by abundant genetic diversity with relatively few recurrent mutations occurring at high frequency. However, the genetic alterations often affect a common group of oncogenic signalling pathways. There have been vast improvements in our understanding of the molecular biology that underpins lung cancer in recent years and this has led to a revolution in the diagnosis and treatment of lung adenocarcinomas (ADC) based on the genotype of an individual's tumour. New technologies are identifying key and potentially targetable genetic aberrations not only in adenocarcinoma but also in squamous cell carcinoma (SCC) of the lung. Lung cancer mutations have been identified in v-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog (KRAS), epidermal growth factor receptor (EGFR), BRAF and the parallel phosphatidylinositol 3-kinase (PI3K) pathway oncogenes and more recently in MEK and HER2 while structural rearrangements in ALK, ROS1 and possibly rearranged during transfection (RET) provide new therapeutic targets. Amplification is another mechanism of activation of oncogenes such as MET in adenocarcinoma, fibroblastgrowth factor receptor 1 (FGFR1) and discoidin domain receptor 2 (DDR2) in SCC. Intriguingly, many of these genetic alternations are associated with smoking status and with particular racial and gender differences, which may provide insight into the mechanisms of carcinogenesis and role of host factors in lung cancer development and progression. The role of tumour suppressor genes is increasingly recognised with aberrations reported in TP53, PTEN, RB1, LKB11 and p16/CDKN2A. Identification of biologically significant genetic alterations in lung cancer that lead to activation of oncogenes and inactivation of tumour suppressor genes has the potential to provide further therapeutic opportunities. It is hoped that these discoveries may make a major contribution to improving outcome for patients with this poor prognosis disease.

Immunohistochemistry as a screening tool for ALK rearrangement in NSCLC: evaluation of five different ALK antibody clones and ALK FISH

AIMS

ALK FISH analysis is used as the reference standard to demonstrate ALK rearrangements, which qualify patients with pulmonary adenocarcinomas for therapy with ALK inhibitors. The aim of this study was to find screening ALK antibody clones with the best positive and best negative percentage agreement with ALK FISH.

METHODS AND RESULTS

Three hundred and three pulmonary adenocarcinomas were evaluated with ALK FISH and stained with five ALK antibody clones (5A4; D5F3; ALK1; ALK01; SP8) with standardized detection systems. D5F3 was additionally assessed using the OptiView enhanced detection and amplification system. ALK FISH found 14 cases (4.6%) that harboured ALK rearrangements. These stained at all intensities for D5F3 and 5A4. To identify rearranged cases among stained cases, we subsequently analysed all immunohistochemically positive cases with ALK FISH.

CONCLUSIONS

D5F3 with OptiView exclusively stained rearranged cases with strong intensity, without a single false-positive or false-negative case. The number of subsequent ALK FISH analyses required would have decreased from 303 to 14 cases (-95.4%), reducing significantly the time, work and costs without any loss of diagnostic quality and accuracy.

Intertumor heterogeneity of non-small-cell lung carcinomas revealed by multiplexed mutation profiling and integrative genomics

Non-small-cell lung cancer (NSCLC) is a heterogeneous disease, with a burden of genomic alterations exceeding most other tumors. The goal of our study was to evaluate the frequencies of co-occurring mutations and copy-number aberrations (CNAs) within the same tumor and to evaluate their potential clinical impact. Mass-spectrometry based mutation profiling using a customized lung cancer panel evaluating 214 mutations across 26 key NSCLC genes was performed on 230 nonsquamous NSCLC and integrated with genome-wide CNAs and clinical variables. Among the 138 cases having at least one mutation, one-third (41, 29.7%) showed two or more mutations, either in the same gene (double mutation) or in different genes (co-mutations). In epidermal growth factor receptor (EGFR) mutant cancers, there was a double mutation in 18% and co-mutations in the following genes: TP53 (10%), PIK3CA (8%), STK11 (6%) and MET (4%). Significant relationships were detected between EGFR mutation and 1p, 7p copy gains (harboring the EGFR gene) as well as 13q copy loss. KRAS mutation was significantly related with 1q gain and 3q loss. For Stage I, tumors harboring at least one mutation or PIK3CA mutation were significantly correlated with poor prognosis (p-value = 0.02). When combining CNAs and mutational status, patients having both KRAS mutation and the highest related CNA (3q22.3 copy loss) showed a significant poorer prognosis (p-value = 0.03). Our study highlights the clinical relevance of studying tumor complexity by integrative genomic analysis and the need for developing assays that broadly screen for both "actionable" mutations and copy-number alterations to improve precision of stratified treatment approaches.

Testing for ALK rearrangement in lung adenocarcinoma: a multicenter comparison of immunohistochemistry and fluorescent in situ hybridization

Rearrangements of anaplastic lymphoma kinase (ALK) gene in non-small cell lung cancer (NSCLC) define a molecular subgroup of tumors characterized clinically by sensitivity to ALK tyrosine kinase inhibitors such as crizotinib. Although ALK rearrangements may be detected by reverse transcriptase-PCR, immunohistochemistry or fluorescence in situ hybridization (FISH), the optimal clinical strategy for identifying ALK rearrangements in clinical samples remains to be determined. We evaluated immunohistochemistry using three different antibodies (ALK1, 5A4 and D5F3 clones) to detect ALK rearrangements and compared those with FISH. We report the frequency and clinicopathologic features of lung cancers harboring ALK translocations in 594 resected NSCLCs (470 adenocarcinomas; 83 squamous carcinomas, 26 large cell carcinomas and 15 other histological subtypes) using a tissue microarray approach. We identified an ALK gene rearrangement in 7/594 cases (1%) by FISH and all anti-ALK antibodies correctly identified the seven ALK-positive cases (100% sensitivity), although the intensity of staining was weak in some cases. These data indicate that the use of antibodies with high sensitivity and avidity to ALK may provide an effective pre-screening technique to complement the more expensive and labor-intensive approach of ALK FISH testing.

Cribriform and fused glands are patterns of high-grade pulmonary adenocarcinoma

The 2011 International Association for the Study of Lung Cancer, American Thoracic Society, and European Respiratory Society classification of pulmonary adenocarcinoma recognizes the prognostic significance of different histologic patterns but does not address the issue of tumor grade. We previously developed an objective and prognostic grading system for pulmonary adenocarcinomas that is based on associating patterns with their metastatic potential. The best prognostic stratification was achieved by summing the grades of the 2 most predominant patterns (histologic score). Here, we extend this work by evaluating the prognostic importance of variant patterns of adenocarcinoma, which are not recognized by the new International Association for the Study of Lung Cancer/American Thoracic Society/European Respiratory Society classification. Pathologic specimens from 249 resected stage I adenocarcinomas were reviewed. The proportions of standard and nonstandard patterns (cribriform and fused glands) were recorded for each case. The associations between the presence of standard and nonstandard patterns, tumor histologic score, and disease-free survival were evaluated. Cribriform and fused gland patterns were observed in 15% and 29% of tumors, respectively. These nonstandard patterns each composed 10% to 100% of the entire tumors but were the predominant pattern in only 5% and 7% of tumors, respectively. The presence of complex glandular patterns was associated with solid pattern (P < .001) and high histologic score (P < .0001). Disease-free survival for tumors with predominant complex glandular patterns was similar to that for high-grade tumors (P = .932) and was significantly worse than that for low- and intermediate-grade tumors (P = .0025). Complex glandular patterns have a significant prognostic value and should be considered patterns of high-grade adenocarcinoma.

Fibroblast growth factor receptor 1 (FGFR1) copy number is an independent prognostic factor in non-small cell lung cancer

Fibroblast growth factor receptor 1 (FGFR1) is an oncogene that can potentially be targeted by tyrosine kinase inhibitors. We aimed to investigate the prevalence and prognostic significance of alterations in FGFR1 copy number in non-small cell lung cancer (NSCLC). FGFR1 status was evaluated by chromogenic silver in situ hybridisation (ISH) in tissue microarray sections from a retrospective cohort of 304 surgically resected NSCLCs and results were correlated with the clinicopathological features and overall survival. High FGFR1 gene copy number (amplification or high-level polysomy) was significantly more frequent in squamous cell carcinomas (SCC) (24.8%) and large cell carcinomas (LCC) (25%) compared to adenocarcinomas (11.3%) (p = 0.01 and p = 0.03 respectively). Among NSCLC there was no significant correlation between FGFR1-positive status and other clinicopathological features including age, gender, smoking history, tumour size, lymph node status, stage, grade, vascular, lymphatic or perineural invasion. FGFR1-positive patients showed a tendency to longer overall survival in univariate analysis (p = 0.14). Multivariate survival analysis using Cox regression model confirmed FGFR1-positive patients had a significant reduction in the risk of death compared to FGFR1-negative patients (HR 0.6; p = 0.02). High FGFR1 gene copy number is a common finding in SCC and LCC and is an independent favourable prognostic factor.

EGFR mutant-specific immunohistochemistry has high specificity and sensitivity for detecting targeted activating EGFR mutations in lung adenocarcinoma

AIM

We assessed the diagnostic accuracy of epidermal growth factor receptor (EGFR) mutant-specific antibodies for detecting two common activating EGFR mutations.

METHODS

Immunohistochemical expression of mutation-specific antibodies against EGFR exon 19 deletion E746-A750 ((c.2235_2249del15 or c.2236_2250del15, p. Glu746_Ala750del) and exon 21 L858R point mutation (c.2573T>G, p.Leu858Arg) were assessed in a cohort of 204 resected early stage node negative lung adenocarcinomas, and protein expression was compared with DNA analysis results from mass spectrometry analysis.

RESULTS

Of seven cases with L858R point mutation, six were positive by immunohistochemistry (IHC). There were three false positive cases using L858R IHC (sensitivity 85.7%, specificity 98.5%, positive predictive value 66.7%, negative predictive value 99.5%). All seven E746-A750 exon 19 deletions identified by mutation analysis were positive by IHC. Four additional cases were positive for exon 19 IHC but negative by mutation analysis. The sensitivity of exon 19 IHC for E746-A750 was 100%, specificity 98.0%, positive predictive value 63.6% and negative predictive value 100%.

CONCLUSIONS

Mutant-specific EGFR IHC has good specificity and sensitivity for identifying targeted activating EGFR mutations. Although inferior to molecular genetic analysis of the EGFR gene, IHC is highly specific and sensitive for the targeted EGFR mutations. The antibodies are likely to be of clinical value in cases where limited tumour material is available, or in situations where molecular genetic analysis is not readily available.