Assessment of somatic k-RAS mutations as a mechanism associated with resistance to EGFR-targeted agents: a systematic review and meta-analysis of studies in advanced non-small-cell lung cancer and metastatic colorectal cancer

Prognostic value of circulating tumor DNA in patients with colon cancer: Systematic review

The application of circulating tumor DNA(ctDNA) represents a non-invasive method for tumor detection. Its prognostic significance in patients with colorectal cancer is controversial. We performed a systematic review of data from published studies to assess the prognostic values of ctDNA in patients with colorectal cancer. We searched Medline, Embase, Web of Science, the Cochrane Library, and Scopus databases to identify eligible studies reporting disease-free survival (DFS) and overall survival (OS) stratified by ctDNA prior to December 6, 2016. We evaluated the quality and design of these studies. A total of 22 studies were eligible for systematic review. Among them, 11 studies investigated the prognostic value of ctDNA on disease-free survival (DFS). Seven of 11 studies showed that ctDNA was an independent variable to estimate the probability of DFS by multivariate analyses. Thirteen studies assessed the relationship between ctDNA and overall survival (OS). Eight of 13 studies showed that ctDNA was an independent predictor of worse OS through the use of multivariate analyses. This analysis provides evidence that ctDNA may be a prognostic biomarker, negatively correlated with the survival of patients with colorectal cancer.

Molecular Biomarkers for the Evaluation of Colorectal Cancer: Guideline From the American Society for Clinical Pathology, College of American Pathologists, Association for Molecular Pathology, and the American Society of Clinical Oncology

Purpose Molecular testing of colorectal cancers (CRCs) to improve patient care and outcomes of targeted and conventional therapies has been the center of many recent studies, including clinical trials. Evidence-based recommendations for the molecular testing of CRC tissues to guide epidermal growth factor receptor (EGFR) -targeted therapies and conventional chemotherapy regimens are warranted in clinical practice. The purpose of this guideline is to develop evidence-based recommendations to help establish standard molecular biomarker testing for CRC through a systematic review of the literature. Methods The American Society for Clinical Pathology (ASCP), College of American Pathologists (CAP), Association for Molecular Pathology (AMP), and the American Society of Clinical Oncology (ASCO) convened an Expert Panel to develop an evidence-based guideline to help establish standard molecular biomarker testing, guide targeted therapies, and advance personalized care for patients with CRC. A comprehensive literature search that included over 4,000 articles was conducted to gather data to inform this guideline. Results Twenty-one guideline statements (eight recommendations, 10 expert consensus opinions and three no recommendations) were established. Recommendations Evidence supports mutational testing for genes in the EGFR signaling pathway, since they provide clinically actionable information as negative predictors of benefit to anti-EGFR monoclonal antibody therapies for targeted therapy of CRC. Mutations in several of the biomarkers have clear prognostic value. Laboratory approaches to operationalize molecular testing for predictive and prognostic molecular biomarkers involve selection of assays, type of specimens to be tested, timing of ordering of tests and turnaround time for testing results. Additional information is available at: www.asco.org/CRC-markers-guideline and www.asco.org/guidelineswiki.

DDX59 promotes DNA replication in lung adenocarcinoma

DEAD box proteins are multifunctional proteins involved in every aspect in RNA metabolism and have essential roles in many cellular activities. Despite their importance, many DEAD box proteins remain uncharacterized. In this report, we found DDX59 overexpressed in lung adenocarcinoma. DDX59 knockdown reduced cell proliferation, anchorage-independent cell growth, and caused reduction of tumor formation in immunocompromised mice. In multiple lung cancer cells, we found that DDX59 knockdown inhibits DNA synthesis; wild-type DDX59 but not helicase-defective mutant of DDX59 enhances DNA synthesis. DDX59 knockdown caused reduction of MCM protein levels, decreased the loading of MCM ring protein onto chromatin, and therefore inhibited DNA replication. Our study reveals for the first time that DDX59 has an important role in lung cancer development through promoting DNA replication.

Litchi seed extract inhibits epidermal growth factor receptor signaling and growth of Two Non-small cell lung carcinoma cells

BACKGROUND

Litchi seeds possess rich amounts of phenolics and have been shown to inhibit proliferation of several types of cancer cells. However, the suppression of EGFR signaling in non-small cell lung cancer (NSCLC) by litchi seed extract (LCSE) has not been fully understood.

METHODS

In this study, the effects of LCSE on EGFR signaling, cell proliferation, the cell cycle and apoptosis in A549 adenocarcinoma cells and NCI- H661 large-cell carcinoma cells were examined.

RESULTS

The results demonstrated that LCSE potently reduced the number of cancer cells and induced growth inhibition, cell-cycle arrest in the G1 or G2/M phase, and apoptotic death in the cellular experiment. Only low cytotoxicity effect was noted in normal lung MRC-5 cells. LCSE also suppressed cyclins and Bcl-2 and elevated Kip1/p27, Bax and caspase 8, 9 and 3 activities, which are closely associated with the downregulation of EGFR and its downstream Akt and Erk-1/-2 signaling.

CONCLUSION

The results implied that LCSE suppressed EGFR signaling and inhibited NSCLC cell growth. This study provided in vitro evidence that LCSE could serve as a potential agent for the adjuvant treatment of NSCLC.

siRNA-Encapsulated Hybrid Nanoparticles Target Mutant K-ras and Inhibit Metastatic Tumor Burden in a Mouse Model of Lung Cancer

There is an unmet need in the development of an effective therapy for mutant K-ras-expressing non-small-cell lung cancer (NSCLC). Although various small molecules have been evaluated, an effective therapy remains a dream. siRNAs have the potential to downregulate mutant K-ras both at the protein and mRNA levels. However, a safe and effective delivery of siRNAs to tumors remains a limitation to their translational application in the treatment of this highly debilitating disease. Here we developed a novel hybrid nanoparticle carrier for effective delivery of anti-mutant K-ras to NSCLC (AKSLHN). The ability of this treatment modality to regress lung tumors in mouse models was evaluated as a monotherapy or as a combination treatment with erlotinib. Further, the toxicity of this treatment modality to healthy tissues was evaluated, along with its ability to elicit immune/inflammatory reactions. The results suggest that this treatment modality is a promising prospect for the treatment of mutant K-ras-expressing NSCLC without any accompanying toxicity. However, further understanding of the cellular-level interaction between AHSLHN and erlotinib needs to be attained before this promising treatment modality can be brought to the bedside.

An XIST-related small RNA regulates KRAS G-quadruplex formation beyond X-inactivation

X-inactive-specific transcript (XIST), a long non-coding RNA, is essential for the initiation of X-chromosome inactivation. However, little is known about other roles of XIST in the physiological process in eukaryotic cells. In this study, the bioinformatics approaches revealed XIST could be processed into a small non-coding RNA XPi2. The XPi2 RNA was confirmed by a northern blot assay; its expression was gender-independent, suggesting the role of XPi2 was beyond X-chromosome inactivation. The pull-down assay combined with LC-MS-MS identified two XPi2-associated proteins, nucleolin and hnRNP A1, connected to the formation of G-quadruplex. Moreover, the microarray data showed the knockdown of XPi2 down-regulated the KRAS pathway. Consistently, we tested the expression of ten genes, including KRAS, which was correlated with a G-quadruplex formation and found the knockdown of XPi2 caused a dramatic decrease in the transcription level of KRAS among the ten genes. The results of CD/NMR assay also supported the interaction of XPi2 and the polypurine-polypyrimidine element of KRAS. Accordingly, XPi2 may stimulate the KRAS expression by attenuating G-quadruplex formation. Our present work sheds light on the novel role of small RNA XPi2 in modulating the G-quadruplex formation which may play some essential roles in the KRAS- associated carcinogenesis.

Molecular pathology in real time

With the development of sophisticated individualized therapeutic approaches, the role of pathology in classification of tumors is enormously increasing. The solely morphological characterization of neoplastic process is no more sufficient for qualified decision on optimal therapeutic approach. Thus, morphologic diagnosis must be supplemented by molecular analysis of the lesion with emphasis on the detection of status of certain markers used as predictive factors for targeted therapy. Both intrinsic and acquired types of intratumor heterogeneity have an impact at various moments of cancer diagnostics and therapy. The primary heterogeneity of neoplastic tissue represents a significant problem in patients, where only limited biopsy samples from the primary tumor are available for diagnosis, such as core needle biopsy specimens in breast cancer, transthoracic or endobronchial biopsies in lung cancer, or endoscopic biopsies in gastric cancer. Detection of predictive markers may be influenced by this heterogeneity, and the marker detection may be falsely negative or (less probably) falsely positive. In addition, as these markers are often detected in the tissue samples from primary tumor, the differences between molecular features of the primary lesion and its metastases may be responsible for failure of systemic therapy in patients with discordant phenotype between primary and metastatic disease. The fact of tumor heterogeneity must be taken into consideration already in establishing pathological diagnosis. One has to be aware that limited biopsy specimen must not always be fully representative of the entire tumor volume. To overcome these limitations, there does not exist one single simple solution. Examination of more tissue (preference of surgical resection specimens over biopsies, whenever possible), use of ultra-sensitive methods able to identify the minute subclones as a source of possible resistance to treatment, and detection of secondary molecular events from the circulating tumor cells or circulating cell-free DNA are potential solutions how to handle this issue.

KRAS Mutation as a Potential Prognostic Biomarker of Biliary Tract Cancers

BACKGROUND

The aim of this study was to identify the unique molecular characteristics of biliary tract cancer (BTC) for the development of novel molecular-targeted therapies.

MATERIALS AND METHODS

We performed mutational analysis of KRAS, BRAF, PIK3CA, and FBXW7 and immunohistochemical analysis of EGFR and TP53 in 63 Japanese patients with BTC and retrospectively evaluated the association between the molecular characteristics and clinicopathological features of BTC.

RESULTS

KRAS mutations were identified in 9 (14%) of the 63 BTC patients; no mutations were detected within the analyzed regions of BRAF, PIK3CA, and FBXW7. EGFR overexpression was observed in 5 (8%) of the 63 tumors, while TP53 overexpression was observed in 48% (30/63) of the patients. Overall survival of patients with KRAS mutation was significantly shorter than that of patients with the wild-type KRAS gene (P = 0.005). By multivariate analysis incorporating molecular and clinicopathological features, KRAS mutations and lymph node metastasis were identified to be independently associated with shorter overall survival (KRAS, P = 0.004; lymph node metastasis, P = 0.015).

CONCLUSIONS

Our data suggest that KRAS mutation is a poor prognosis predictive biomarker for the survival in BTC patients.

KRAS oncogene in lung cancer: focus on molecularly driven clinical trials

KRAS mutations are the most frequent molecular abnormalities found in one out of four nonsmall cell lung cancers (NSCLC). Their incidence increases in cases of adenocarcinoma, smokers and Caucasian patients. Their negative value in terms of prognosis and responsiveness to both standard chemotherapy and targeted therapies remains under debate. Many drugs have been developed specifically for KRAS-mutated NSCLC patients. Direct inhibition of RAS activation failed to show any clinical efficacy. Inhibition of downstream targets of the mitogen-activated protein kinase (MEK) pathway is a promising strategy: phase II combinations of MEK 1/2 kinase inhibitors with chemotherapy doubled patients' clinical outcomes. One phase III trial in such a setting is ongoing. Double inhibition of MEK and epidermal growth factor receptor proteins is currently being assessed in early-phase trials. The association with mammalian target of rapamycin pathway inhibition leads to non-manageable toxicity. Other strategies, such as inhibition of molecular heat-shock proteins 90 or focal adhesion kinase are currently assessed. Abemaciclib, a cyclin-dependent kinase 4/6 inhibitor, showed promising results in a phase I trial, with a 54% disease control rate. Results of an ongoing phase III trial are warranted. Immunotherapy might be the next relevant step in KRAS-mutated NSCLC management due to the high burden of associated mutations and neo-antigens.

Molecular spectrum of KRAS, NRAS, BRAF, PIK3CA, TP53, and APC somatic gene mutations in Arab patients with colorectal cancer: determination of frequency and distribution pattern

BACKGROUND

The frequency rates of mutations such as KRAS, NRAS, BRAF, and PIK3CA in colorectal cancer (CRC) differ among populations. The aim of this study was to assess mutation frequencies in the Arab population and determine their correlations with certain clinicopathological features.

METHODS

Arab patients from the Arab Gulf region and a population of age- and sex-matched Western patients with CRC whose tumors were evaluated with next-generation sequencing (NGS) were identified and retrospectively reviewed. The mutation rates of KRAS, NRAS, BRAF, PIK3CA, TP53, and APC were recorded, along with clinicopathological features. Other somatic mutation and their rates were also identified. Fisher's exact test was used to determine the association between mutation status and clinical features.

RESULTS

A total of 198 cases were identified; 99 Arab patients and 99 Western patients. Fifty-two point seven percent of Arab patients had stage IV disease at initial presentation, 74.2% had left-sided tumors. Eighty-nine point two percent had tubular adenocarcinoma and 10.8% had mucinous adenocarcinoma. The prevalence rates of KRAS, NRAS, BRAF, PIK3CA, TP53, APC, SMAD, FBXW7 mutations in Arab population were 44.4%, 4%, 4%, 13.1%, 52.5%, 27.3%, 2% and 3% respectively. Compared to 48.4%, 4%, 4%, 12.1%, 47.5%, 24.2%, 11.1% and 0% respectively in matched Western population. Associations between these mutations and patient clinicopathological features were not statistically significant.

CONCLUSIONS

This is the first study to report comprehensive hotspot mutations using NGS in Arab patients with CRC. The frequency of KRAS, NRAS, BRAF, TP53, APC and PIK3CA mutations were similar to reported frequencies in Western population except SMAD4 that had a lower frequency and higher frequency of FBXW7 mutation.

EGFR gene copy number predicts response to anti-EGFR treatment in RAS wild type and RAS/BRAF/PIK3CA wild type metastatic colorectal cancer

Anti-EGFR antibodies are used for the treatment of RAS wild type metastatic colorectal cancer. We previously showed that EGFR gene copy number (GCN) predicts response to anti-EGFR therapy in KRAS exon 2 wild type metastatic colorectal cancer. The aim of our study was to analyse the predictive role of EGFR GCN in RAS/BRAF/PIK3CA wild type metastatic colorectal cancer. The material included 102 patients with KRAS exon 2 wild type metastatic colorectal cancer treated with anti-EGFR ± cytotoxic therapy. Next generation sequencing was used for KRAS, NRAS, BRAF and PIK3CA gene mutation analyses. EGFR GCN was analysed by EGFR immunohistochemistry guided automated silver in situ hybridisation. Increased EGFR GCN (≥4.0) predicted a better response and prolonged progression free survival in anti-EGFR treated RAS/BRAF/PIK3CA wild type patients (Log-rank test, p = 0.0004). In contrast, survival of RAS/BRAF/PIK3CA wild type, EGFR GCN below 4.0 patients did not differ from patients with mutant RAS, BRAF or PIK3CA. Our study indicates that EGFR GCN predicts anti-EGFR treatment efficacy in patients with RAS/BRAF/PIK3CA wt metastatic CRC. Tumours with EGFR GCN below 4.0 appear to be as refractory to anti-EGFR treatment as tumours with mutation in any of the RAS/RAF/PIK3CA pathway genes.

Epidermal Growth Factor Receptor (EGFR) Pathway Biomarkers in the Randomized Phase III Trial of Erlotinib Versus Observation in Ovarian Cancer Patients with No Evidence of Disease Progression after First-Line Platinum-Based Chemotherapy

BACKGROUND

In this work, we aimed to identify molecular epidermal growth factor receptor (EGFR) tissue biomarkers in patients with ovarian cancer who were treated within the phase III randomized European Organisation for Research and Treatment of Cancer-Gynaecological Cancer Group (EORTC-GCG) 55041 study comparing erlotinib with observation in patients with no evidence of disease progression after first-line platinum-based chemotherapy.

METHODS

Somatic mutations in KRAS, BRAF, NRAS, PIK3CA, EGFR, and PTEN were determined in 318 (38 %) and expression of EGFR, pAkt, pMAPK, E-cadherin and Vimentin, and EGFR and HER2 gene copy numbers in 218 (26 %) of a total of 835 randomized patients. Biomarker data were correlated with progression-free survival (PFS) and overall survival (OS).

RESULTS

Only 28 mutations were observed among KRAS, BRAF, NRAS, PIK3CA, EGFR, and PTEN (in 7.5 % of patients), of which the most frequent were in KRAS and PIK3CA. EGFR mutations occurred in only three patients. When all mutations were pooled, patients with at least one mutation in KRAS, NRAS, BRAF, PIK3CA, or EGFR had longer PFS (33.1 versus 12.3 months; HR 0.57; 95 % CI 0.33 to 0.99; P = 0.042) compared to those with wild-type tumors. EGFR overexpression was detected in 93 of 218 patients (42.7 %), and 66 of 180 patients (36.7 %) had EGFR gene amplification or high levels of copy number gain. Fifty-eight of 128 patients had positive pMAPK expression (45.3 %), which was associated with inferior OS (38.9 versus 67.0 months; HR 1.81; 95 % CI 1.11 to 2.97; P = 0.016). Patients with positive EGFR fluorescence in situ hybridization (FISH) status had worse OS (46.1 months) than those with negative status (67.0 months; HR 1.56; 95 % CI 1.01 to 2.40; P = 0.044) and shorter PFS (9.6 versus 16.1 months; HR 1.57; 95 % CI 1.11 to 2.22; P = 0.010). None of the investigated biomarkers correlated with responsiveness to erlotinib.

CONCLUSIONS

In this phase III study, increased EGFR gene copy number was associated with worse OS and PFS in patients with ovarian cancer. It remains to be determined whether this association is purely prognostic or is also predictive.

How close are we to standardised extended RAS gene mutation testing? The UK NEQAS evaluation

AIMS

Since 2008, KRAS mutation status in exon 2 has been used to predict response to anti-EGFR therapies. Recent evidence has demonstrated that NRAS status is also predictive of response. Several retrospective 'extended RAS' analyses have been performed on clinical trial material. Despite this, are we really moving towards such extended screening practice in reality?

METHODS

Data were analysed from four consecutive UK National External Quality Assessment Service for Molecular Genetics Colorectal cancer External Quality Assessment schemes (during the period 2014-2016), with up to 110 laboratories (worldwide) participating in each scheme. Testing of four or five tumour samples is required per scheme. Laboratories provided information on which codons were routinely screened, and provided genotyping and interpretation results for each sample.

RESULTS

At least 85% of laboratories routinely tested KRAS codons 12, 13 and 61. Over the four schemes, an increasing number of laboratories routinely tested KRAS codons 59, 117 and 146. Furthermore, more laboratories were introducing next generation sequencing technologies. The pattern of 'extended testing' was reassuringly similar for NRAS, although fewer laboratories currently test for mutations in this gene. Alarmingly, still only 36.1% and 24.1% of participating laboratories met the ACP Molecular Pathology and Diagnostics Group and American Society of Clinical Oncology guidelines, respectively, for extended RAS testing in the latest assessment.

CONCLUSIONS

Despite recommendations in the UK and USA on extended RAS testing, there has clearly been, based on these results, a delay in implementation. Inadequate testing results in patients being subjected to harmful treatment regimens, which would not be the case, were routine practice altered, in line with evidence-based guidelines.

EGFR gene copy number as a predictive/biomarker for patients with non-small-cell lung cancer receiving tyrosine kinase inhibitor treatment: a systematic review and meta-analysis

Epidermal growth factor receptor (EGFR) gene copy number has been proposed as a candidate biomarker for predicting treatment response to EGFR tyrosine kinase inhibitors (EGFR-TKIs) in patients with advanced non-small-cell lung cancer (NSCLC). MEDLINE, PubMed, Cochrane, and Google Scholar databases were searched until October 21, 2015 using the following search terms: lung neoplasms/lung cancer/non-small cell lung cancer/NSCLC, EGFR, gene amplification, copy number, erlotinib, gefitinib, tyrosine-kinase inhibitor/TKI, predictor. 17 studies were included in the analysis with a total of 2047 patients. The overall analysis found that increased EGFR gene copy number was associated with higher overall response rate (ORR), overall survival (OS) and progression-free survival (PFS; p values ≤0.008) compared with patients without a high EGFR gene copy number. Subgroup analysis found that in a population of patients who were primarily Caucasian, a higher EGFR gene copy number was also associated with increased ORR, OS, and PFS (p values ≤0.018). The results were similar in a population of Asian patients, except that a higher EGFR gene copy number was not associated with improved OS (p=0.248). Sensitivity analysis indicated that no one study overly influenced the results and that the findings are robust. The result of the analysis found that EGFR gene copy number was associated with increased OS and PFS, supporting the idea that EGFR gene copy number is a biomarker for response to EGFR-TKI therapy in patients with advanced NSCLC.

Somatic mutation analysis of KRAS, BRAF, HER2 and PTEN in EGFR mutation-negative non-small cell lung carcinoma: determination of frequency, distribution pattern and identification of novel deletion in HER2 gene from Indian patients

Somatic mutations of KRAS, BRAF, HER2, PTEN genes are the most important molecular markers after the EGFR gene mutation. The current study evaluated the frequency and distribution pattern of KRAS, BRAF, HER2, PTEN mutation in Indian non-small cell lung carcinoma patients. The frequency of KRAS, BRAF, HER2, PTEN mutations was 6.4 % (14/204), 1.5 % (3/204), 1.5 % (3/204), 0 % (0/204), respectively. KRAS, BRAF, HER2 mutations were more prevalent in males than in females. KRAS and HER2 showed a trend of a higher frequency of mutation in the age group of <60 years, whereas BRAF mutations were more frequent in the age group of ≥60 years. Sequencing analysis of KRAS gene revealed c.34G>T (G12C) (n = 8), c.35G>A (G12D) (n = 3), c.35G>T (G12 V) (n = 1) and c.34G>T (G12C)/c.41T>C (V14A) (n = 2) mutations. Three different BRAF mutations (L584P: n = 1, V600E: n = 1, K601E: n = 1) were detected. Two cases harboured c.2324_2325ins12 (ATACGTGATGGC duplication) in HER2 gene, and one case was positive for NG_007503.2 (NM_001005862.2):c.2218-4del. It is less certain, but still quite possible that this mutation will affect splicing as the deletion of one C actually brings in one additional purine into the region. In conclusion, the present study demonstrates an instance of diverse nature of KRAS, BRAF, HER2 and PTEN gene in Indian patients and confirms that the frequency of these gene mutations varies globally. To the best of our knowledge, this is the first Indian study to evaluate KRAS, BRAF, HER2 and PTEN gene mutations.

Case report: Durable response to afatinib in a patient with lung cancer harboring two uncommon mutations of EGFR and a KRAS mutation

Comprehensive genomic profiling for non-small cell lung cancer (NSCLC) is likely to identify more patients with rare genetic alterations including uncommon epidermal growth factor receptor gene (EGFR) mutations. It remains unclear how such patients should be treated, however. We here report a case of NSCLC positive for two uncommon mutations of EGFR and a KRAS mutation, including its treatment with the second-generation EGFR tyrosine kinase inhibitor (TKI) afatinib. Tumor specimen obtained by a NSCLC patient with no smoking history was analyzed by next-generation sequencing. Comprehensive genomic profiling revealed that the patient harbored the EGFR mutations G719C and S768I as well as the E49K mutation of KRAS. Treatment with afatinib was clinically effective as confirmed by PET-CT scans of bone metastases and by a marked decrease in the serum concentration of carcinoembryonic antigen. Afatinib was the most effective among seven EGFR-TKIs tested in inhibiting the growth of Ba/F3 cells expressing EGFR(S768I), showing an efficacy similar to that apparent with cells expressing the common EGFR mutant L858R, whereas first- and third-generation EGFR-TKIs were markedly less effective against EGFR(S768I) than against EGFR(L858R). These data suggest that EGFR-TKIs differ in their activity toward cells expressing EGFR(S768I) in vitro. Consistently, afatinib was clinically effective for the treatment of NSCLC harboring G719C and S768I mutations of EGFR. Further studies are warranted to determine the most appropriate EGFR-TKI for treatment of NSCLC harboring uncommon EGFR mutations.

Concomitant Statin Use Has a Favorable Effect on Gemcitabine-Erlotinib Combination Chemotherapy for Advanced Pancreatic Cancer

PURPOSE

Erlotinib-gemcitabine combined chemotherapy is considered as the standard treatment for unresectable pancreatic cancer. This study aimed to determine the clinical factors associated with response to this treatment.

MATERIALS AND METHODS

This retrospective study included 180 patients with unresectable pancreatic cancer who received ≥2 cycles of gemcitabine-erlotinib combination therapy as first-line palliative chemotherapy between 2006 and 2014. "Long-term response" was defined as tumor stabilization after >6 chemotherapy cycles.

RESULTS

The median progression-free survival (PFS) and overall survival (OS) were 3.9 and 8.1 months, respectively. On univariate analysis, liver metastasis (p=0.023) was negatively correlated with long-term response. Locally advanced stage (p=0.017), a history of statin treatment (p=0.01), and carcinoembryonic antigen levels <4.5 (p=0.029) had a favorable effect on long-term response. On multivariate analysis, a history of statin treatment was the only independent favorable factor for long-term response (p=0.017). Prognostic factors for OS and PFS were significantly correlated with liver metastasis (p=0.031 and 0.013, respectively). A history of statin treatment was also significantly associated with OS after adjusting for all potential confounders (hazard ratio, 0.48; 95% confidence interval, 0.26-0.92; p=0.026).

CONCLUSION

These results suggest that statins have a favorable effect on "long-term response" to gemcitabine-erlotinib chemotherapy in unresectable pancreatic cancer patients. Statins may have a chemoadjuvant role in stabilizing long-term tumor growth.

KRAS mutations affect prognosis of non-small-cell lung cancer patients treated with first-line platinum containing chemotherapy

KRAS mutations seem to indicate a poor outcome in Non-Small-Cell Lung Cancer (NSCLC) but such evidence is still debated. The aim of this planned ancillary study within the TAILOR trial was to assess the prognostic value of KRAS mutations in advanced NSCLC patients treated with platinum-based first-line chemotherapy. Patients (N = 540), enrolled in the study in 52 Italian hospitals, were centrally genotyped twice in two independent laboratories for EGFR and KRAS mutational status.

Of these, 247 patients were eligible and included in the present study. The primary endpoint was overall survival (OS) according to KRAS mutational status in patients harboring EGFR wild-type.

Sixty (24.3%) out of 247 patients harbored KRAS mutations. Median OS was 14.3 months and 10.6 months in wild-type and mutated KRAS patients, respectively (unadjusted Hazard Ratio [HR]=1.41, 95%Confidence Interval [CI]: 1.03-1.94 P = 0.032; adjusted HR=1.39, 95%CI: 1.00-1.94 P = 0.050). This study, with all consecutive patients genotyped, indicates that the presence of KRAS mutations has a mild negative impact on OS in advanced NSCLC patient treated with a first-line platinum-containing regimen. Trial Registration: clinicaltrials.gov identifier NCT00637910

Rapid targeted somatic mutation analysis of solid tumors in routine clinical diagnostics

Tumor genotyping is an essential step in routine clinical practice and pathology laboratories face a major challenge in being able to provide rapid, sensitive and updated molecular tests.

We developed a novel mass spectrometry multiplexed genotyping platform named PentaPanel to concurrently assess single nucleotide polymorphisms in 56 hotspots of the 5 most clinically relevant cancer genes, KRAS, NRAS, BRAF, EGFR and PIK3CA for a total of 221 detectable mutations. To both evaluate and validate the PentaPanel performance,we investigated 1025 tumor specimens of 6 different cancer types (carcinomas of colon, lung, breast, pancreas, and biliary tract, and melanomas), systematically addressing sensitivity, specificity, and reproducibility of our platform. Sanger sequencing was also performed for all the study samples.

Our data showed that PentaPanel is a high throughput and robust tool, allowing genotyping for targeted therapy selection of 10 patients in the same run, with a practical turnaround time of 2 working days. Importantly, it was successfully used to interrogate different DNAs isolated from routinely processed specimens (formalin-fixed paraffin embedded, frozen, and cytological samples), covering all the requirements of clinical tests.

In conclusion, the PentaPanel platform can provide an immediate, accurate and cost effective multiplex approach for clinically relevant gene mutation analysis in many solid tumors and its utility across many diseases can be particularly relevant in multiple clinical trials, including the new basket trial approach, aiming to identify appropriate targeted drug combination strategies.

An analysis of the relationship between metastases and cachexia in lung cancer patients

Weight loss and hematogenous metastases are poor prognosis factors in lung cancer patients that can but do not necessarily co‐occur. We retrospectively investigated the clinical association between cachexia, tumor characteristics (such as metastatic burden and mutational status), and treatment in lung cancer patients. The medical records of 394 lung cancer patients from two institutions (Columbia University, USA and Tohoku University, Japan) were reviewed. Information collected included the presence of cachexia, histologic subtype, tumor stage, number of metastases, mutation status, treatment, and survival. Descriptive statistics were performed. Only stage IV patients exhibited >5% weight loss (0.8%, 2.2%, 3.6%, and 5.1%, for stages I to IV; P = 0.0001). Patients with metastases developed cachexia more often than patients without metastases independent of treatment (6.0% and 7.1% weight loss in patients with metastases vs. 2.5% and 2.0% in patients without metastases, before [P = 0.0001] and after [P < 0.0001] treatment, respectively). The change in number of metastatic sites over time correlated with increasing weight loss (5.2%, 10.6%, 13.4%, and 13.4%, for an increase of 0, 1, 2, and ≥3 metastatic sites, from initial diagnosis to the endpoint; P < 0.0001). Patients with cachexia had worse survival than patients without cachexia (hazard ratio, 2.94; 95% confidence interval, 2.08–4.16; P < 0.0001). Tumors with mutated KRAS were associated with an increased risk of weight loss (11.4% weight loss in patients with mutated KRAS vs. 6.0% in patients with wild‐type KRAS; P = 0.0011). Our findings suggest that the capabilities of lung cancer to metastasize and cause cachexia might be linked intrinsically and are independent of treatments administered. KRAS‐mutated tumors were more commonly associated with cachexia.

EGFR-GRB2 Protein Colocalization Is a Prognostic Factor Unrelated to Overall EGFR Expression or EGFR Mutation in Lung Adenocarcinoma

INTRODUCTION

EGFR is a therapeutic target in NSCLC for EGFR-mutant patients. Proximity ligation assay (PLA) is a method to detect functional signaling associated protein complexes. Growth factor receptor bound protein 2 (GRB2) is an adaptor protein that binds to the phosphorylated residues of active EGFR. Interaction of EGFR and GRB2 correlates with active EGFR signaling and leads to activation of the MAPK/ERK pathway.

METHODS

A PLA developed to detect EGFR-GRB2 interaction was measured by quantitative immunofluorescence using Automated Quantitative Analysis technology. EGFR pathway activation was assessed in patients with NSCLC with different mutation status along with overall EGFR expression. Additionally, the PLA to detect EGFR-GRB2 interaction was evaluated as a prognostic marker in two cohorts of patients with lung adenocarcinoma.

RESULTS

The PLA to detect EGFR-GRB2 interaction was unrelated to overall EGFR expression or mutation in a series of patients with NSCLC with known mutation status. EGFR-mutant (p = 0.04) and EGFR/KRAS wild-type tumors (p = 0.0049) had significantly higher EGFR pathway activation compared with KRAS-mutant cases, with no significant difference shown between mutation sites. In two series of patients with lung adenocarcinoma, the PLA to detect EGFR-GRB2 interaction was independently associated with longer survival (hazard ratio = 0.46, 95% confidence interval: 0.2-0.78, p = 0.0085 and hazard ratio = 0.48, 95% confidence interval: 0.2-0.85, p = 0.017). Total EGFR protein expression alone was not correlated with outcome.

CONCLUSIONS

EGFR colocalization with GRB2 as assessed by PLA is not correlated with EGFR expression levels or mutation status, defining a patient group that may show EGFR pathway activation, as illustrated by its prognostic value. Future studies may determine whether this group is more likely to respond to EGFR-targeted therapies.

Comparative Effectiveness of Biomarkers to Target Cancer Treatment: Modeling Implications for Survival and Costs

BACKGROUND

Biomarkers used at the time of diagnosis to tailor treatment decisions may diffuse into clinical practice before data become available on whether biomarker testing reduces cancer mortality. In the interim, quantitative estimates of the mortality impact of testing are needed to assess the value of these diagnostic biomarkers. These estimates are typically generated by customized models that are resource intensive to build and apply.

METHODS

We developed a user-friendly system of models for Cancer Translation of Comparative Effectiveness Research (CANTRANce) to model the mortality impact of cancer interventions. The Diagnostic Biomarker module of this system projects the mortality impact of testing for a diagnostic biomarker, given data on how testing affects treatment recommendations. Costs and quality-of-life outcomes may also be modeled. We applied the Diagnostic Biomarker module to 2 case studies to demonstrate its capabilities.

RESULTS

The user interface (http://www.fhcrc.org/cantrance) allows comparative effectiveness researchers to use the Diagnostic Biomarker module of CANTRANce. Our case studies indicate that the model produces estimates on par with those generated by customized models and is a strong tool for quickly generating novel projections.

LIMITATIONS

The simple structure that makes CANTRANce user-friendly also constrains the complexity with which cancer progression can be modeled. The quality of the results rests on the quality of the input data, which may pertain to small or dissimilar populations or suffer from informative censoring.

CONCLUSIONS

The Diagnostic Biomarker module of CANTRANce is a novel public resource that can provide timely insights into the expected mortality impact of testing for diagnostic biomarkers. The model projections should be useful for understanding the long-term potential of emerging diagnostic biomarkers.

k-RAS mutations in non-small cell lung cancer patients treated with TKIs among smokers and non-smokers: a meta-analysis

Aim of the study

Recent studies have suggested that k-RAS mutations are related to the response to epidermal growth factor receptor (EGFR) tyrosine-kinase inhibitions (TKIs) in advanced non-small cell lung cancer (NSCLC) treatment. The aim of this meta-analysis was to assess the relationship between smoking history and k-RAS mutations in NSCLC treated with TKIs.

Material and methods

We searched MEDLINE and Web of Science up to 15 March 2014. The pooled relative risk (RR) was estimated by using fixed effect model or random effect model, according to heterogeneity between studies. We also carried out power analyses.

Results

We identified 12 studies with 1193 patients, including 196 patients (16.4%) with k-RAS mutations. The pooled k-RAS mutations incidence was 22.8% (174/764) in patients with smoke expose vs. 5.4% (23/429) in those with no smoke exposure. The pooled RR was 2.991 (95% CI: 1.884–4.746; Z = 4.65, p = 0.000). No publication bias was found (Begg's test: z = 1.09, p = 0.274 and Egger's test: t = 1.38, p = 0.201). In subgroup analyses, the pooled RR was 3.336 (95% CI: 1.925–5.779; Z = 4.30, p = 0.000) in the Caucasian subgroup, while in the Asian subgroup the pooled RR was 2.093 (95% CI: 0.909–4.822; Z = 1.73, p = 0.083), but the sample size was underpowered (0.465).

Conclusions

The current meta-analysis found that smoking was related to increased incidence of k-RAS mutations in non-small cell lung cancer treated with TKIs. This may be further evidence that smoking will lead to a worse prognosis in NSCLC patients treated with TKIs.

Hybridization-Induced Aggregation Technology for Practical Clinical Testing: KRAS Mutation Detection in Lung and Colorectal Tumors

KRAS mutations have emerged as powerful predictors of response to targeted therapies in the treatment of lung and colorectal cancers; thus, prospective KRAS genotyping is essential for appropriate treatment stratification. Conventional mutation testing technologies are not ideal for routine clinical screening, as they often involve complex, time-consuming processes and/or costly instrumentation. In response, we recently introduced a unique analytical strategy for revealing KRAS mutations, based on the allele-specific hybridization-induced aggregation (HIA) of oligonucleotide probe-conjugated microbeads. Using simple, inexpensive instrumentation, this approach allows for the detection of any common KRAS mutation in <10 minutes after PCR. Here, we evaluate the clinical utility of the HIA method for mutation detection (HIAMD). In the analysis of 20 lung and colon tumor pathology specimens, we observed a 100% correlation between the KRAS mutation statuses determined by HIAMD and sequencing. In addition, we were able to detect KRAS mutations in a background of 75% wild-type DNA-a finding consistent with that reported for sequencing. With this, we show that HIAMD allows for the rapid and cost-effective detection of KRAS mutations, without compromising analytical performance. These results indicate the validity of HIAMD as a mutation-testing technology suitable for practical clinical testing. Further expansion of this platform may involve the detection of mutations in other key oncogenic pathways.

KRAS and TP53 mutations in bronchoscopy samples from former lung cancer patients

Mutations in the KRAS and TP53 genes have been found frequently in lung tumors and specimens from individuals at high risk for lung cancer and have been suggested as predictive markers for lung cancer. In order to assess the prognostic value of these two genes' mutations in lung cancer recurrence, we analyzed mutations in codon 12 of the KRAS gene and in hotspot codons of the TP53 gene in 176 bronchial biopsies obtained from 77 former lung cancer patients. Forty-seven patients (61.0%) showed mutations, including 35/77 (45.5%) in the KRAS gene and 25/77 (32.5%) in the TP53 gene, among them 13/77 (16.9%) had mutations in both genes. When grouped according to past or current smoking status, a higher proportion of current smokers showed mutations, in particular those in the TP53 gene (P = 0.07), compared with ex-smokers. These mutations were found in both abnormal lesions (8/20 or 40%) and histologically normal tissues (70/156 or 44.9%) (P = 0.812). They consisted primarily of G to A transition and G to T transversion in both the KRAS (41/56 or 73.2%) and TP53 (24/34 or 70.6%) genes, consistent with mutations found in lung tumors of smoking lung cancer patients. Overall, recurrence-free survival (RFS) among all subjects could be explained by age at diagnosis, tumor stage, tumor subtype, and smoking (P < 0.05, Cox proportional hazard). Therefore, KRAS and TP53 mutations were frequently detected in bronchial tissues of former lung cancer patients. However, the presence of mutation of bronchial biopsies was not significantly associated with a shorter RFS time. © 2016 Wiley Periodicals, Inc.

First-line treatment of advanced epidermal growth factor receptor (EGFR) mutation positive non-squamous non-small cell lung cancer

BACKGROUND

Epidermal growth factor receptor (EGFR) mutation positive (M+) non-small cell lung cancer (NSCLC) is emerging as an important subtype of lung cancer comprising 10% to 15% of non-squamous tumours. This subtype is more common in women than men and is less associated with smoking.

OBJECTIVES

To assess the clinical effectiveness of single -agent or combination EGFR therapies used in the first-line treatment of people with locally advanced or metastatic EGFR M+ NSCLC compared with other cytotoxic chemotherapy (CTX) agents used alone or in combination, or best supportive care (BSC). The primary outcome was overall survival. Secondary outcomes included progression-free survival, response rate, toxicity, and quality of life.

SEARCH METHODS

We conducted electronic searches of the the Cochrane Register of Controlled Trials (CENTRAL) (2015, Issue 6), MEDLINE (1946 to 1 June 2015), EMBASE (1980 to 1 June 2015), and ISI Web of Science (1899 to 1 June 2015). We also searched the conference abstracts of the American Society for Clinical Oncology and the European Society for Medical Oncology (1 June 2015); Evidence Review Group submissions to the National Institute for Health and Care Excellence; and the reference lists of retrieved articles.

SELECTION CRITERIA

Parallel randomised controlled trials comparing EGFR-targeted agents (alone or in combination with cytotoxic agents or BSC) with cytotoxic chemotherapy (single or doublet) or BSC in chemotherapy-naive patients with locally advanced or metastatic (stage IIIB or IV) EGFR M+ NSCLC unsuitable for treatment with curative intent.

DATA COLLECTION AND ANALYSIS

Two review authors independently identified articles, extracted data, and carried out the 'Risk of bias' assessment. We conducted meta-analyses using a fixed-effect model unless there was substantial heterogeneity, in which case we also performed a random-effects analysis as a sensitivity analysis.

MAIN RESULTS

Nineteen trials met the inclusion criteria. Seven of these exclusively recruited people with EGFR M+ NSCLC; the remainder recruited a mixed population and reported results for people with EGFR M+ NSCLC as subgroup analyses. The number of participants with EGFR M+ tumours totalled 2317, of whom 1700 were of Asian origin.Overall survival (OS) data showed inconsistent results between the included trials that compared EGFR-targeted treatments against cytotoxic chemotherapy or placebo.Erlotinib was the intervention treatment used in eight trials, gefitinib in seven trials, afatinib in two trials, and cetuximab in two trials. The findings of one trial (FASTACT 2) did report a statistically significant OS gain for participants treated with erlotinib plus cytotoxic chemotherapy when compared to cytotoxic chemotherapy alone, but this result was based on a small number of participants (n = 97). For progression-free survival (PFS), a pooled analysis of 3 trials (n = 378) demonstrated a statistically significant benefit for erlotinib compared with cytotoxic chemotherapy (hazard ratio (HR) 0.30; 95% confidence interval (CI) 0.24 to 0.38).In a pooled analysis with 491 participants administered gefitinib, 2 trials (IPASS and NEJSG) demonstrated a statistically significant PFS benefit of gefitinib compared with cytotoxic chemotherapy (HR 0.39; 95% CI 0.32 to 0.48).Afatinib (n = 709) showed a statistically significant PFS benefit when compared with chemotherapy in a pooled analysis of 2 trials (HR 0.42; 95% CI 0.34 to 0.53).Commonly reported grade 3/4 adverse events for afatinib, erlotinib, and gefitinib monotherapy were rash and diarrhoea. Myelosuppression was consistently worse in the chemotherapy arms, fatigue and anorexia were also associated with some chemotherapies.No statistically significant PFS or OS benefit for cetuximab plus cytotoxic chemotherapy (n = 81) compared to chemotherapy alone was reported in either of the two trials.Six trials reported on quality of life and symptom improvement using different methodologies. For each of erlotinib, gefitinib, and afatinib, 2 trials showed improvement in one or more indices for the tyrosine-kinase inhibitor (TKI) compared to chemotherapy.The quality of evidence was high for the comparisons of erlotinib and gefitinib with cytotoxic chemotherapy and for the comparison of afatinib with cytotoxic chemotherapy.

AUTHORS' CONCLUSIONS

Erlotinib, gefitinib, and afatinib are all active agents in EGFR M+ NSCLC patients, and demonstrate an increased tumour response rate and prolonged progression-free survival compared to cytotoxic chemotherapy. We also found a beneficial effect of the TKI compared to cytotoxic chemotherapy. However, we found no increase in overall survival for the TKI when compared with standard chemotherapy. Cytotoxic chemotherapy is less effective in EGFR M+ NSCLC than erlotinib, gefitinib, or afatinib and is associated with greater toxicity. There were no data supporting the use of monoclonal antibody therapy.

Suppression of KRas-mutant cancer through the combined inhibition of KRAS with PLK1 and ROCK

No effective targeted therapies exist for cancers with somatic KRAS mutations. Here we develop a synthetic lethal chemical screen in isogenic KRAS-mutant and wild-type cells to identify clinical drug pairs. Our results show that dual inhibition of polo-like kinase 1 and RhoA/Rho kinase (ROCK) leads to the synergistic effects in KRAS-mutant cancers. Microarray analysis reveals that this combinatory inhibition significantly increases transcription and activity of cyclin-dependent kinase inhibitor p21(WAF1/CIP1), leading to specific G2/M phase blockade in KRAS-mutant cells. Overexpression of p21(WAF1/CIP1), either by cDNA transfection or clinical drugs, preferentially impairs the growth of KRAS-mutant cells, suggesting a druggable synthetic lethal interaction between KRAS and p21(WAF1/CIP1). Co-administration of BI-2536 and fasudil either in the LSL-KRAS(G12D) mouse model or in a patient tumour explant mouse model of KRAS-mutant lung cancer suppresses tumour growth and significantly prolongs mouse survival, suggesting a strong synergy in vivo and a potential avenue for therapeutic treatment of KRAS-mutant cancers.

The role of epithelial to mesenchymal transition in resistance to epidermal growth factor receptor tyrosine kinase inhibitors in non-small cell lung cancer

Inhibition of the epidermal growth factor receptor (EGFR) is an important strategy when treating non-small cell lung cancer (NSCLC) patients. However, intrinsic resistance or development of resistance during the course of treatment constitutes a major challenge. The knowledge on EGFR-directed tyrosine kinase inhibitors (TKIs) and their biological effect keeps increasing. Within the group of patients with EGFR mutations some benefit to a much higher degree than others, and for patients lacking EGFR mutations a subset experience an effect. Up to 70% of patients with EGFR mutations and 10-20% of patients without EGFR mutations initially respond to the EGFR-TKI erlotinib, but there is a severe absence of good prognostic markers. Despite initial effect, all patients acquire resistance to EGFR-TKIs. Multiple mechanisms have implications in resistance development, but much is still to be explored. Epithelial to mesenchymal transition (EMT) is a transcriptionally regulated phenotypic shift rendering cells more invasive and migratory. Within the EMT process lays a need for external or internal stimuli to give rise to changes in central signaling pathways. Expression of mesenchymal markers correlates to a bad prognosis and an inferior response to EGFR-TKIs in NSCLC due to the contribution to a resistant phenotype. A deeper understanding of the role of EMT in NSCLC and especially in EGFR-TKI resistance-development constitute one opportunity to improve the benefit of TKI treatment for the individual patient. Many scientific studies have linked the EMT process to EGFR-TKI resistance in NSCLC and our aim is to review the role of EMT in both intrinsic and acquired resistance to EGFR-TKIs.

Differentially Expressed miRNAs in Tumor, Adjacent, and Normal Tissues of Lung Adenocarcinoma

Lung cancer is the leading cause of cancer deaths. Non-small-cell lung cancer (NSCLC) is the major type of lung cancer. The aim of this study was to characterize the expression profiles of miRNAs in adenocarcinoma (AC), one major subtype of NSCLC. In this study, the miRNAs were detected in normal, adjacent, and tumor tissues by next-generation sequencing. Then the expression levels of differential miRNAs were quantified by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). In the results, 259, 401, and 389 miRNAs were detected in tumor, adjacent, and normal tissues of pooled AC samples, respectively. In addition, for the first time we have found that miR-21-5p and miR-196a-5p were gradually upregulated from normal to adjacent to tumor tissues; miR-218-5p was gradually downregulated with 2-fold or greater change in AC tissues. These 3 miRNAs were validated by qRT-PCR. Lastly, we predicted target genes of these 3 miRNAs and enriched the potential functions and regulatory pathways. The aberrant miR-21-5p, miR-196a-5p, and miR-218-5p may become biomarkers for diagnosis and prognosis of lung adenocarcinoma. This research may be useful for lung adenocarcinoma diagnosis and the study of pathology in lung cancer.

Successful personalized chemotherapy for metastatic gastric cancer based on quantitative BRCA1 mRNA expression level: A case report

Personalized chemotherapy is based on the specific genetic profile of individual patients and is replacing the traditional 'one size fits all' medicine. Breast cancer 1 (BRCA1) plays a central role in the chemotherapy-induced DNA damage response. It has been repeatedly demonstrated that BRCA1 mRNA levels were negatively associated with cisplatin sensitivity, but positively associated with docetaxel sensitivity in patients with gastric cancer in experimental and clinical studies. This feature leads to customized chemotherapy based on the BRCA1 mRNA expression level and results in a high efficacy of treatment. The present study describes the case of a 77-year-old patient with metastatic gastric cancer who was treated with personalized chemotherapy based on quantitative BRCA1 mRNA expression level. This study and the available literature data suggest that the expression level of BRCA1 mRNA is dynamic to BRCA1-based chemotherapy. More importantly, de novo assessment of BRCA1 status is a preferable option for ciscisplatin- or docetaxel-resistant patients, since the expression levels of BRCA1 mRNA in certain patients may alter significantly following treatment. Therefore, BRCA1 expression should be assessed for predicting differential chemosensitivity and tailoring chemotherapy in gastric cancer.

KRAS-Mutant Lung Cancers in the Era of Targeted Therapy

KRAS-mutant lung cancers account for approximately 25% of non-small cell lung carcinomas, thus representing an enormous burden of cancer worldwide. KRAS mutations are clear drivers of tumor growth and are characterized by a complex biology involving the interaction between mutant KRAS, various growth factor pathways, and tumor suppressor genes. While KRAS mutations are classically associated with a significant smoking history, they are also identified in a substantial proportion of never-smokers. These mutations are found largely in lung adenocarcinomas with solid growth patterns and tumor-infiltrating lymphocytes. A variety of tools are available for diagnosis including Sanger sequencing, multiplex mutational hotspot profiling, and next-generation sequencing. The prognostic and predictive roles of KRAS status remain controversial. It has become increasingly clear, however, that KRAS mutations drive primary resistance to EGFR tyrosine kinase inhibition. Until recently, mutant KRAS was not thought of as a clinically-targetable driver in lung cancers. With the expansion of our knowledge regarding the biology of KRAS-mutant lung cancers and the role of MEK and PI3K/mTOR inhibition, the face of targeted therapeutics for this genomic subset of patients is slowly beginning to change.

Expression of P40 and P63 in lung cancers using fine needle aspiration cases. Understanding clinical pitfalls and limitations

BACKGROUND

Fine-needle aspiration (FNA) biopsy of lung lesions is a highly accurate method for diagnosing and staging of lung cancers, particularly in patients with advanced cancer. Although, the majority of FNA cases of non-small cell lung carcinoma (NSCLC) can be subclassified by hematoxylin and eosin (H&E) sections, immunohistochemical (IHC) markers are usually necessary for difficult cases. Our previous study has shown that both P40 and P63 demonstrate differential sensitivity and specificity in the subclassification of squamous cell carcinoma (SqCC) using tumor tissue microarrays (TMA). In the present study, we further evaluated the utility of P40 and P63 and the potential pitfalls and limitations associated with the usefulness of these stains in FNA cases.

METHODS

By a computer search of pathology archives, 144 FNA biopsies with diagnoses of lung cancers and P40/P63 stains were identified, including 50 adenocarcinomas (ADCs), 56 SqCCs, 8 small cell lung carcinomas (SCLCs), and 12 cases of poorly differentiated carcinoma (PD CA). Ten benign FNA lung lesions and 8 other malignant neoplasms were also included as controls. Nuclear staining patterns of P40 and P63 were scored semi-quantitatively as 0 (negative), 1 (<10%, weak and focal), or 2 (>10%, strong and diffuse).

RESULTS

In lung SqCCs, P40 and P63 were positive in 77.3% and 89.5% cases, respectively. In ADCs, P40 was weakly and focally positive in 6.1% cases, and P63 was variably positive in 62.8% cases. In SCLCs, P40 and P63 were focally positive in 12.5% and 50% cases. In PD CAs, no P40 or P63 immunoreactivity was detected. In the group of other neoplasms (n=8) both P40 and P63 were positive in the case of metastatic non-seminomatous germ cell tumor (NSGCT) (n=1), and P63 was positive in the case of metastatic Merkel cell carcinoma (n=1). The sensitivity and specificity of P40 and P63 were 76.9%/93.3%, and 90.2%/50.7% in the lung SqCC.

CONCLUSIONS

P63 has a better sensitivity, and P40 has a better specificity for SqCC. A positive staining pattern with both markers was also found in certain non-SqCC cases. Recognizing limitations of these markers are particularly important in FNA cases.

The renewed battle against RAS-mutant cancers

The RAS genes encode for members of a large superfamily of guanosine-5'-triphosphate (GTP)-binding proteins that control diverse intracellular signaling pathways to promote cell proliferation. Somatic mutations in the RAS oncogenes are the most common activating lesions found in human cancers. These mutations invariably result in the gain-of-function of RAS by impairing GTP hydrolysis and are frequently associated with poor responses to standard cancer therapies. In this review, we summarize key findings of past and present landmark studies that have deepened our understanding of the RAS biology in the context of oncogenesis. We also discuss how emerging areas of research could further bolster a renewed global effort to target the largely undruggable oncogenic RAS and/or its activated downstream effector signaling cascades to achieve better treatment outcomes for RAS-mutant cancer patients.

Discordance of Mutation Statuses of Epidermal Growth Factor Receptor and K-ras between Primary Adenocarcinoma of Lung and Brain Metastasis

Mutations on epidermal growth factor receptor (EGFR) of adenocarcinomas of lung have been found to be associated with increased sensitivity to EGFR tyrosine kinase inhibitors and K-ras mutations may correlate with primary resistance. We aimed to explore the discordant mutation statuses of EGFR and K-ras between primary tumors and matched brain metastases in adenocarcinomas of lung. We used a sensitive Scorpion ARMS method to analyze EGFR mutation, and Sanger sequencing followed by allele-specific real-time polymerase chain reaction to analyze K-ras mutation. Forty-nine paired tissues with both primary adenocarcinoma of lung and matched brain metastasis were collected. Thirteen patients (26.5%) were discordant for the status of EGFR between primary and metastatic sites. K-ras gene could be checked in paired specimens from 33 patients, thirteen patients (39.6%) were discordant for the status of K-ras. In primary lung adenocarcinoma, there were 14 patients of mutant EGFR had mutant K-ras synchronously. This study revealed that the status of EGFR mutation in lung adenocarcinomas is relatively consistent between primary and metastatic sites compared to K-ras mutation. However, there are still a few cases of adenocarcinoma of lung showing discordance for the status of EGFR mutation. Repeated analysis of EGFR mutation is highly recommended if tissue from metastatic or recurrent site is available for the evaluation of target therapy.

Synergistic effects of sorafenib in combination with gemcitabine or pemetrexed in lung cancer cell lines with K-ras mutations

K-ras is currently accepted as the most frequently mutated oncogene in non-small cell lung cancer (NSCLC, including squamous carcinoma, adenocarcinoma, and large cell carcinoma). NSCLC patients with the K-ras mutation appear to be refractory to the majority of systemic therapies. In the present study, the in vitro antitumor effects and correlated molecular mechanisms of sorafenib combined with gemcitabine or pemetrexed were explored in the K-ras mutation-positive NSCLC A549 cell line. Sorafenib was seen to exhibit dose-dependent growth inhibition in the A549 cells, while sorafenib combined with pemetrexed demonstrated a greater synergism compared with sorafenib combined with gemcitabine. Sorafenib arrested the cell cycle at the G1 phase, while gemcitabine and pemetrexed caused arrest at the S phase. The molecular mechanism of this synergism was due to the downstream signalling pathways, which were efficiently suppressed by sorafenib, therefore increasing the incidence of the entry of the chemotherapeutic drugs into the apoptotic pathways. Moreover, sorafenib and pemetrexed demonstrated stronger synergism, demonstrating that inhibiting the Ras/Raf/Mek/Erk and Ras/PI3K/Akt pathways concurrently may achieve improved antitumor effects.

EGFR, KRAS and ROS1 variants coexist in a lung adenocarcinoma patient

The c-ros oncogene 1 (ROS1) fusion is almost mutually exclusive to epidermal growth factor receptor (EGFR), anaplastic lymphoma kinase (ALK) or Kirsten rat sarcoma viral oncogene homolog (KRAS) mutation in non-small cell lung cancer (NSCLC), and it is not seen in the literature for patients to exhibit three mutations. The present study reported a case of a 53-year-old male diagnosed with adenocarcinoma, exhibiting combined EGFR, KRAS mutations and ROS1 rearrangement. At the first line therapy, the patient was treated with crizotinib because of the KRAS mutation that is a known resistant factor of EGFR-TKI resistance, but no responsive. At the second line therapy, EGFR-TKI Icotinib revealed a good response until now. To the best of to our knowledge, this is the first case report of a patient with concurrent EGFR, KRAS mutations and ROS1 fusion. This patient had an excellent response to Icotinib but not crizotinib, suggesting that the EGFR mutation was the oncogenic driver but ROS1 fusion and KRAS mutation not.

Prognostic impact of KRAS mutation subtypes in 677 patients with metastatic lung adenocarcinomas

BACKGROUND

We previously demonstrated that patients with metastatic KRAS mutant lung cancers have a shorter survival compared with patients with KRAS wild-type cancers. Recent reports have suggested different clinical outcomes and distinct activated signaling pathways depending on KRAS mutation subtype. To better understand the impact of KRAS mutation subtype, we analyzed data from 677 patients with KRAS mutant metastatic lung cancer.

METHODS

We reviewed all patients with metastatic or recurrent lung cancers found to have KRAS mutations over a 6-year time period. We evaluated the associations among KRAS mutation type, clinical factors, and overall survival in univariate and multivariate analyses. Any significant findings were validated in an external multi-institution patient dataset.

RESULTS

Among 677 patients with KRAS mutant lung cancers (53 at codon 13, 624 at codon 12), there was no difference in overall survival for patients when comparing KRAS transition versus transversion mutations (p = 0.99), smoking status (p = 0.33), or when comparing specific amino acid substitutions (p = 0.20). In our dataset, patients with KRAS codon 13 mutant tumors (n = 53) had shorter overall survival compared with patients with codon 12 mutant tumors (n = 624) (1.1 versus 1.3 years, respectively; p = 0.009), and the findings were confirmed in a multivariate Cox model controlling for age, sex, and smoking status (hazard ratio: 1.52, 95% confidence interval: 1.11-2.08; p = 0.008). In an independent validation set of tumors from 682 patients with stage IV KRAS mutant lung cancers, there was no difference in survival between patients with KRAS codon 13 versus codon 12 mutations (1.0 versus 1.1 years, respectively; p = 0.41).

CONCLUSIONS

Among individuals with KRAS mutant metastatic lung cancers treated with conventional therapy, there are no apparent differences in outcome based on KRAS mutation subtype.

Metastasis-associated in colon cancer-1 promotes vasculogenic mimicry in gastric cancer by upregulating TWIST1/2

Vasculogenic mimicry (VM) is a blood supply modality that is strongly associated with the epithelial-mesenchymal transition (EMT), TWIST1 activation and tumor progression. We previously reported that metastasis-associated in colon cancer-1 (MACC1) induced the EMT and was associated with a poor prognosis of patients with gastric cancer (GC), but it remains unknown whether MACC1 promotes VM and regulates the TWIST signaling pathway in GC. In this study, we investigated MACC1 expression and VM by immunohistochemistry in 88 patients with stage IV GC, and also investigated the role of TWIST1 and TWIST2 in MACC1-induced VM by using nude mice with GC xenografts and GC cell lines. We found that the VM density was significantly increased in the tumors of patients who died of GC and was positively correlated with MACC1 immunoreactivity (p < 0.05). The 3-year survival rate was only 8.6% in patients whose tumors showed double positive staining for MACC1 and VM, whereas it was 41.7% in patients whose tumors were negative for both MACC1 and VM. Moreover, nuclear expression of MACC1, TWIST1, and TWIST2 was upregulated in GC tissues compared with matched adjacent non-tumorous tissues (p < 0.05). Overexpression of MACC1 increased TWIST1/2 expression and induced typical VM in the GC xenografts of nude mice and in GC cell lines. MACC1 enhanced TWIST1/2 promoter activity and facilitated VM, while silencing of TWIST1 or TWIST2 inhibited VM. Hepatocyte growth factor (HGF) increased the nuclear translocation of MACC1, TWIST1, and TWIST2, while a c-Met inhibitor reduced these effects. These findings indicate that MACC1 promotes VM in GC by regulating the HGF/c-Met-TWIST1/2 signaling pathway, which means that MACC1 and this pathway are potential new therapeutic targets for GC.

EGFR mutations in lung cancer: from tissue testing to liquid biopsy

ABSTRACT  The presence of EGFR mutations predicts the sensitivity to EGF receptor (EGFR)-tyrosine kinase inhibitors in a molecularly defined subset of non-small-cell lung carcinoma (NSCLC) patients. For this reason, EGFR testing of NSCLC is required to provide personalized treatment options and better outcomes for NSCLC patients. As surgery specimens are not available in the majority of NSCLC, other currently available DNA sources are small biopsies and cytological samples, providing however limited and low-quality material. In order to address this issue, the use of surrogate sources of DNA, such as blood, serum and plasma samples, which often contains circulating free tumor DNA or circulating tumor cells, is emerging as a new strategy for tumor genotyping.

The prevalence and prognostic significance of KRAS mutation subtypes in lung adenocarcinomas from Chinese populations

BACKGROUND

We performed this retrospective study to identify the prevalence of KRAS mutation in Chinese populations and make a comprehensive investigation of the clinicopathological features of KRAS mutation in these patients.

PATIENTS AND METHODS

Patients from 2007 to 2013 diagnosed with primary lung adeno-carcinoma who received a radical resection were examined for KRAS, EGFR, HER2, BRAF mutations, and ALK, RET, and ROS1 fusions. Clinicopathological features, including sex, age, tumor-lymph node-metastasis stage, tumor differentiation, smoking status, histological subtypes, and survival information were analyzed.

RESULT

KRAS mutation was detected in 113 of 1,368 patients. Nine different subtypes of KRAS mutation were identified in codon 12, codon 13, and codon 61. KRAS mutation was more frequently found in male patients and former/current smoker patients. Tumors with KRAS mutation had poorer differentiation. Invasive mucinous adenocarcinoma predominant and solid predominant subtypes were more frequent in KRAS mutant patients. No statistical significance was found in relapse-free survival or overall survival between patients with KRAS mutation and patients with other mutations.

CONCLUSION

In Chinese populations, we identified KRAS mutation in 8.3% (113/1,368) of the patients with lung adenocarcinoma. KRAS mutation defines a molecular subset of lung adenocarcinoma with unique clinicopathological features.

Inhibition of glycolytic enzyme hexokinase II (HK2) suppresses lung tumor growth

Background

The most common genetic changes identified in human NSCLC are Kras mutations (10–30 %) and p53 mutation or loss (50–70 %). Moreover, NSCLC with mutations in Kras and p53 poorly respond to current therapies, so we are trying to find a new target for the treatment strategies.

Methods

Flow cytometry, crystal violet staining and immunoblotting were used to assess cell cycle arrest, proliferation and apoptosis in lung cancer cell lines after 2-DG treatment and lentivirus infection by shRNA knock down. IHC and western blotting were carried for NSG xenograft model with 2-DG treatment and lentivirus infection by shRNA knock down.

Results

Knocking down Kras down-regulated the glycolytic enzyme hexokinase II (HK2) in KP2 (mouse lung cancer cell line with Kras mutation and p53 deletion) and H23 (human lung cancer cell line with Kras mutation and p53 mutation) cell lines. Genetic studies revealed that HK2 was required for the human and mouse lung cancer cell growth in vitro and in vivo. Our pharmacological studies confirmed that 2-DG, an inhibitor of HK2, inhibited human and mouse lung cancer cell growth through inducing cell apoptosis and autophagy.

Conclusions

HK2 is a promising treatment target for NSCLC with Kras activating and p53 function loss.

Systems Perturbation Analysis of a Large-Scale Signal Transduction Model Reveals Potentially Influential Candidates for Cancer Therapeutics

Dysregulation in signal transduction pathways can lead to a variety of complex disorders, including cancer. Computational approaches such as network analysis are important tools to understand system dynamics as well as to identify critical components that could be further explored as therapeutic targets. Here, we performed perturbation analysis of a large-scale signal transduction model in extracellular environments that stimulate cell death, growth, motility, and quiescence. Each of the model’s components was perturbed under both loss-of-function and gain-of-function mutations. Using 1,300 simulations under both types of perturbations across various extracellular conditions, we identified the most and least influential components based on the magnitude of their influence on the rest of the system. Based on the premise that the most influential components might serve as better drug targets, we characterized them for biological functions, housekeeping genes, essential genes, and druggable proteins. The most influential components under all environmental conditions were enriched with several biological processes. The inositol pathway was found as most influential under inactivating perturbations, whereas the kinase and small lung cancer pathways were identified as the most influential under activating perturbations. The most influential components were enriched with essential genes and druggable proteins. Moreover, known cancer drug targets were also classified in influential components based on the affected components in the network. Additionally, the systemic perturbation analysis of the model revealed a network motif of most influential components which affect each other. Furthermore, our analysis predicted novel combinations of cancer drug targets with various effects on other most influential components. We found that the combinatorial perturbation consisting of PI3K inactivation and overactivation of IP3R1 can lead to increased activity levels of apoptosis-related components and tumor-suppressor genes, suggesting that this combinatorial perturbation may lead to a better target for decreasing cell proliferation and inducing apoptosis. Finally, our approach shows a potential to identify and prioritize therapeutic targets through systemic perturbation analysis of large-scale computational models of signal transduction. Although some components of the presented computational results have been validated against independent gene expression data sets, more laboratory experiments are warranted to more comprehensively validate the presented results.

Epidermal Growth Factor Receptor, Excision-Repair Cross-Complementation Group 1 Protein, and Thymidylate Synthase Expression in Penile Cancer

OBJECTIVE

To describe the expression of tissue epidermal growth factor receptor (EGFR), excision-repair cross-complementation group 1 protein (ERCC1), and thymidylate synthase (TS) in patients with penile cancer and explore their association with stage and outcome.

METHODS

A total of 52 patients with penile squamous cell cancer who were treated at the University of Southern California from 1995 to 2010 were identified. Paraffin-embedded tissue underwent mRNA quantitation and immunohistochemistry for expression of EGFR, ERCC1, and TS. KRAS mutations were evaluated using polymerase chain reaction-based sequencing.

RESULTS

EGFR overexpression was common by mRNA (median, 5.09; range, 1.92-104.5) and immunohistochemistry. EGFR expression > 7 was associated with advanced stage and poor differentiation (P = .01 and .034 respectively) but not with survival in multivariate analysis. ERCC1 mRNA expression was a median of 0.65 (range, 0.21-1.87). TS expression was a median of 1.88 (range, 0.54-6.47). ERCC1 and TS expression were not associated with grade, stage, or survival. There were no KRAS mutations identified. A total of 17 men received chemotherapy; 8 (47%) had an objective response, including 1 with a pathologic complete response. There was a trend for lower expression of EGFR corresponding to a higher likelihood of response (response rate [RR]) to chemotherapy: 67% RR in EGFR mRNA < 7 versus 33% RR in EGFR > 7 (P = .31).

CONCLUSIONS

High expression of EGFR mRNA in squamous cell carcinoma of the penis is associated with advanced stage and poor differentiation, but not survival. In our small heterogeneous subset, molecular marker expression did not show a correlation with the likelihood of chemotherapy response. A prospective evaluation of the role of the EGFR pathway and its regulatory environment in penile cancer is warranted. Given the rarity of this cancer, collaborative prospective cohort evaluations and trials need to be encouraged.

Colorectal cancer: using blood samples and tumor tissue to detect K-ras mutations

We performed a meta-analysis to assess whether blood can be substituted for tumor tissue in K-ras mutation testing. PubMed, EMBASE, MEDLINE, and BIOSIS databases were searched. Twenty-three studies including 1261 patients were included. The pooled overall sensitivity, specificity, and concordance rate were 0.69 (95% CI: 0.59-0.78), 0.96 (95% CI: 0.93-0.97), and 0.86 (95% CI: 0.82-0.89), respectively. Subgroup analysis indicated that plasma (sensitivity: 0.74; mutation rate: 0.34) exhibited superior sensitivity compared with serum (sensitivity: 0.45; mutation rate: 0.24). We conclude that blood is a suitable substitute for tumor tissue in K-ras mutation testing. K-ras mutation positivity in blood can be used to identify patients who should not receive EGFR monoclonal antibody therapy, but the absence of blood positivity does not necessarily imply negativity.