The role of RAS oncogene in survival of patients with lung cancer: a systematic review of the literature with meta-analysis

NF1 mutations identify molecular and clinical subtypes of lung adenocarcinomas

The tumor suppressor gene neurofibromin 1 (NF1) is a major regulator of the RAS-MAPK pathway. NF1 mutations occur in lung cancer but were not extensively explored. We hypothesized that NF1-mutated tumors could define a specific population with a distinct clinical and molecular profile. We performed NF1 sequencing using next generation sequencing (NGS) in 154 lung adenocarcinoma surgical specimens with known KRAS, EGFR, TP53, BRAF, HER2, and PIK3CA status, to evaluate the molecular and clinical specificities of NF1-mutated lung cancers. Clinical data were retrospectively collected, and their associations with molecular profiles assessed. In this series, 24 tumors were NF1 mutated (17.5%) and 11 were NF1 deleted (8%). There was no mutation hotspot. NF1 mutations were rarely associated with other RAS-MAPK pathway mutations. Most of patients with NF1 alterations were males (74.3%) and smokers (74.3%). Overall survival and disease-free survival were statistically better in patients with NF1 alterations (N = 34) than in patients with KRAS mutations (N = 30) in univariate analysis. Our results confirm that NF1 is frequently mutated and represents a distinct molecular and clinical subtype of lung adenocarcinoma.

Is chemotherapy rechallenge feasible in advanced-stage non-small-cell lung cancer?

BACKGROUND

Despite recent progress, non-small cell lung cancer (NSCLC) first-line treatment remains a platinum-based doublet in most cases. No guidelines exist beyond third line. Chemotherapy rechallenge is an option, but little data is available in NSCLC. Our study aims to describe patients who underwent chemotherapy rechallenge while assessing its efficacy and safety.

METHODS

Consecutive patients with advanced-stage NSCLC receiving first-line treatment in Tenon hospital in 2011 were included, with a 5-year follow-up. Patients were analyzed according to chemotherapy rechallenge or not. Chemotherapy rechallenge was defined as re-initiation of a previously administered chemotherapy agent at any point in the treatment sequence, with at least one treatment regimen between first use and rechallenge.

RESULTS

Of 149 patients, 18 underwent chemotherapy rechallenge (12%). They were younger (56 vs. 61 years, P=0.04), mostly women (61% vs. 30%, P=0.02), with lepidic adenocarcinoma (23% vs. 3.5%, P=0.03), a better general state of health (100% performance status 0-1 vs. 74%, P=0.04), and fewer cardiovascular comorbidities (16% vs. 42%, P=0.04). They were more likely to have received a receptor tyrosine kinase inhibitor treatment (89% vs. 43%, P=0.0003). Progression-free survival was longer at first use than at rechallenge (median 9.2 vs. 2.7 months, P=0.002). No increased toxicity was observed at rechallenge compared to first use. Finally, a subsequent line of treatment was given after rechallenge in 61% of the patients.

CONCLUSION

Patients eligible for chemotherapy rechallenge were those with good prognostic factors. Chemotherapy rechallenge may provide a well-tolerated additional line of treatment, with decreased efficacy compared to its first application.

Molecular heterogeneity in lung cancer: from mechanisms of origin to clinical implications

Molecular heterogeneity is a frequent event in cancer responsible of several critical issues in diagnosis and treatment of oncologic patients. Lung tumours are characterized by high degree of molecular heterogeneity associated to different mechanisms of origin including genetic, epigenetic and non-genetic source. In this review, we provide an overview of recognized mechanisms underlying molecular heterogeneity in lung cancer, including epigenetic mechanisms, mutant allele specific imbalance, genomic instability, chromosomal aberrations, tumor mutational burden, somatic mutations. We focus on the role of spatial and temporal molecular heterogeneity involved in therapeutic implications in lung cancer patients.

Contribution of smoking habit to the prognosis of stage I KRAS-mutated non-small cell lung cancer

BACKGROUND

One of the known risk factors for non-small cell lung cancer (NSCLC) is somatic mutation in the Kirsten rat sarcoma (KRAS) gene. The relationship with smoking is well known.

METHODS

We retrospectively studied the data of 92 patients who underwent pulmonary resection January 2003 and June 2012 and were diagnosed as KRAS-mutated pathological stage I adenocarcinoma.

RESULTS

Among them, 33 patients who were non to light smoker (NLS) (smoking index, 0 to 400) were compared with 59 middle to heavy smoker (MHS) (> 400). The 5-year overall survival (OS) was significantly better in NLS (96.9%) than in MHS (80.0%); however, no significant difference was observed compared with wild-type KRAS (92.8%) (p= 0.66). The presence of p53 was significantly associated with smoking history (p< 0.01). The 5-year OS for NLS with p53-negative KRAS codon 12-mutated NSCLC (n= 28) was significantly better (96.3%) than that for MHS with both p53-positive and -negative KRAS mutation (p= 0.03 and p< 0.03, respectively).

CONCLUSIONS

A non to light smoking habit might contribute to an improvement in prognosis that is equivalent to that of wild-type KRAS, and p53 mutation did not affect survival in smokers harboring KRAS codon 12.

Characteristics and Outcomes of Patients With Metastatic KRAS-Mutant Lung Adenocarcinomas: The Lung Cancer Mutation Consortium Experience

INTRODUCTION

Mutations in the KRAS gene are the most common driver oncogenes present in lung adenocarcinomas. We analyzed the largest multi-institutional database available containing patients with metastatic KRAS-mutant lung adenocarcinomas.

METHODS

The Lung Cancer Mutation Consortium (LCMC) is a multi-institutional collaboration to study the genomic characteristics of lung adenocarcinomas, treat them with genomically directed therapeutic approaches, and assess their outcomes. Since its inception in 2009, the LCMC has enrolled more than 1900 patients and has performed pretreatment, multiplexed, molecular characterization along with collecting clinical data. We evaluated the characteristics of patients with KRAS mutation in the LCMC and the association with overall survival.

RESULTS

Data from 1655 patients with metastatic lung adenocarcinomas were analyzed. Four hundred fifty (27%) patients had a KRAS mutation, 58% were female, 93% were smokers, and there was a median age of 65 years. Main KRAS subtypes were: G12C 39%; and G12D and G12V at 18% each. Among patients with KRAS mutation, G12D had a higher proportion of never-smokers (22%, p < 0.001). Patients with KRAS-mutant tumors had a trend toward shorter median survival compared to all others in the series (1.96 versus 2.22; P = 0.08) and lower 2-year survival rate (49% [95% confidence interval: 44%-54%] and 55% [95% confidence interval: 52%-58%], respectively).

CONCLUSIONS

In the LCMC study, 27% of lung adenocarcinomas patients harbored a KRAS mutation and up to one-third of them had another oncogenic driver. Patients with both KRAS and STK11 mutations had a significantly inferior clinical outcome.

Prognostic value of KRAS/TP53/PIK3CA in non-small cell lung cancer

The present study explored the association between KRAS proto-oncogene GTPase (KRAS), phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit α (PIK3CA) and tumor protein p53 (TP53) mutations, and the clinical features and survival prognosis in 50 patients with non-small cell lung cancer (NSCLC). The most common concurrent single gene mutation was TP53, followed by KRAS and PIK3CA. Co-existing mutations were found in 17 patients. KRAS, PIK3CA and TP53 mutations were associated with carbohydrate antigen 19-9 expression, invasive growth, vacuolar signs and margin lobulation on chest CT. The incidence of distant metastasis (bone and adrenal) with KRAS and TP53 mutations was greater than that of local metastasis (pleura). Patients with the wild-type genes experienced longer progression-free survival (PFS) times than those with KRAS, TP53, KRAS/TP53 or PIK3CA/TP53 mutations. Patients with KRAS/TP53 or PIK3CA/TP53 mutations experienced shorter PFS times than those with a single KRAS or TP53 mutation. KRAS, PIK3CA and TP53 mutations were associated with distant metastases and a poor prognosis. Patients with NSCLC should receive routine KRAS, PIK3CA and TP53 gene sequencing to determine mutations for the analysis of clinical characteristics and prognosis.

K-ras Mutation Subtypes in NSCLC and Associated Co-occuring Mutations in Other Oncogenic Pathways

INTRODUCTION

Although KRAS mutations in NSCLC have been considered mutually exclusive driver mutations for a long time, there is now growing evidence that KRAS-mutated NSCLC represents a genetically heterogeneous subgroup. We sought to determine genetic heterogeneity with respect to cancer-related co-mutations and their correlation with different KRAS mutation subtypes.

METHODS

Diagnostic samples from 4507 patients with NSCLC were analyzed by next-generation sequencing by using a panel of 14 genes and, in a subset of patients, fluorescence in situ hybridization. Next-generation sequencing with an extended panel of 14 additional genes was performed in 101 patients. Molecular data were correlated with clinical data. Whole-exome sequencing was performed in two patients.

RESULTS

We identified 1078 patients with KRAS mutations, of whom 53.5% had at least one additional mutation. Different KRAS mutation subtypes showed different patterns of co-occurring mutations. Besides mutations in tumor protein p53 gene (TP53) (39.4%), serine/threonine kinase 11 gene (STK11) (19.8%), kelch like ECH associated protein 1 gene (KEAP1) (12.9%), and ATM serine/threonine kinase gene (ATM) (11.9%), as well as MNNG HOS Transforming gene (MET) amplifications (15.4%) and erb-b2 receptor tyrosine kinase 2 gene (ERBB2) amplifications (13.8%, exclusively in G12C), we found rare co-occurrence of targetable mutations in EGFR (1.2%) and BRAF (1.2%). Whole-exome sequencing of two patients with co-occurring phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha gene (PIK3CA) mutation revealed clonality of mutated KRAS in one patient and subclonality in the second, suggesting different evolutionary backgrounds.

CONCLUSION

KRAS-mutated NSCLC represents a genetically heterogeneous subgroup with a high frequency of co-occurring mutations in cancer-associated pathways, partly associated with distinct KRAS mutation subtypes. This diversity might have implications for understanding the variability of treatment outcome in KRAS-mutated NSCLC and for future trial design.

Effect of Coexisting KRAS and TP53 Mutations in Patients Treated With Chemotherapy for Non-small-cell Lung Cancer

BACKGROUND

KRAS and TP53 are common mutations in non-small-cell lung cancer (NSCLC). The Lung Adjuvant Cisplatin Evaluation Biological Program group found adjuvant chemotherapy to be deleterious in patients with coexisting KRAS/TP53 mutations.

PATIENTS AND METHODS

To validate these results, patients with NSCLC tested for KRAS and TP53 mutations and receiving chemotherapy for any stage NSCLC were selected. Mutation status was analyzed using next generation sequencing (Illumina) or multiplex recurrent mutation detection (MassARRAY, Agena Biosciences) assays, and was correlated with clinical and demographic data. Disease-free (DFS) or progression-free survival (PFS) was the main endpoint, and overall survival (OS) was the secondary endpoint.

RESULTS

Among 218 patients, 28 had coexisting KRAS/TP53 mutations, 77 TP53, 37 KRAS, 76 had neither KRAS nor TP53 mutation (WT/WT). There was no DFS/PFS difference for the KRAS/TP53 group versus all others among 99 patients who received adjuvant chemotherapy (hazard ratio [HR], 1.22; 95% confidence interval [CI], 0.61-2.44; P = .57), 27 stage III patients who received chemo-radiation (HR, 0.87; 95% CI, 0.32-2.38; P = .8), and 63 patients who received palliative chemotherapy (HR, 0.68; 95% CI, 0.31-1.48; P = .33). OS was longer in the WT/WT group compared with any other group (KRAS: HR, 1.87; 95% CI, 1.02-3.43; P = .043; TP53: HR, 2.17; 95% CI, 1.3-3.61; P = .0028; KRAS/TP53: HR, 2.06; 95% CI, 1.09-3.88; P = .026). No OS difference was seen for KRAS/TP53 compared with the other groups (HR, 1.26; 95% CI, 0.75-2.13; P = .38).

CONCLUSIONS

There was no significant difference in DFS/PFS between the 4 groups. However, OS was longer for patients with TP53 and KRAS wild-type NSCLC who received chemotherapy for any stage compared with patients with KRAS, TP53 mutation, or double mutant tumors.

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

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

RAS mutations in acute myeloid leukaemia patients: A review and meta-analysis

RAS oncogene mutations frequently occur in acute myeloid leukaemia (AML), but the prognostic significance of RAS mutations in AML is inconclusive. We searched the databases of PubMed, Web of Science, EMBASE, and Cochrane from 1990 to 2018. In this study, 24 eligible studies were included, and the meta-analysis was conducted with the Comprehensive Meta-Analysis Version 2 software program. The row hazard ratio (HR) was adjusted and re-evaluated when publication bias existed after detecting all the heterogeneities. A combined analysis showed that RAS mutations were not associated with a poor prognosis in general AML patients (HR: 0.96, 95% CI: 0.78-1.19, p = 0.70). To further verify the results, a subgroup analysis was conducted. Interestingly, in the analysis of age bracket, children with RAS mutations had an unfavourable survival (HR: 1.35, 95% CI: 1.05-1.75, p = 0.02) of AML, but the adults did not (HR: 0.87, 95% CI: 0.70-1.09, p = 0.21). Further analysis of the subgroup of children indicated that patients with NRAS mutations had an adverse prognosis (HR: 1.55, 95% CI: 1.13-2.12, p = 0.007), but not those with KRAS mutations (HR: 1.51, 95% CI: 0.34-6.73, p = 0.59). In conclusion, this study revealed that RAS mutations did not influence the over survival for adults with AML. However, NRAS mutations may be a key prognostic marker related with poor survival for children with AML.

Survival difference according to mutation status in a prospective cohort study of Australian patients with metastatic non-small-cell lung carcinoma

BACKGROUND

Non-small-cell lung cancer (NSCLC) is a heterogeneous disease comprising not only different histological subtypes but also different molecular subtypes.

AIM

To describe the frequency of oncogenic drivers in patients with metastatic NSCLC, the proportion of patients tested and survival difference according to mutation status in a single-institution study.

METHODS

Metastatic NSCLC patients enrolled in a prospective Thoracic Malignancies Cohort Study between July 2012 and August 2016 were selected. Patients underwent molecular testing for epidermal growth factor receptor (EGFR), anaplastic lymphoma kinase (ALK) gene rearrangements, Kirsten rat sarcoma (KRAS), B-Raf proto-oncogene (BRAF) mutations and ROS1 gene rearrangements. Survival was calculated using the Kaplan-Meier method for groups of interest, and comparisons were made using the log-rank test.

RESULTS

A total of 392 patients were included, 43% of whom were female with median age of 64 years (28-92). Of 296 patients tested, 172 patients (58%) were positive for an oncogenic driver: 81 patients (27%) were EGFR positive, 25 patients (9%) were ALK positive, 57 patients (19%) had KRAS mutation and 9 patients (3%) were ROS1 or BRAF positive. Patients with an actionable mutation (EGFR/ALK) had a survival advantage when compared with patients who were mutation negative (hazard ratio (HR) 0.49; 95% confidence interval (CI) 0.33-0.71; P < 0.01). Survival difference between mutation negative and mutation status unknown was not statistically significant when adjusted for confounding factors in a multivariate analysis (HR 1.29; 95% CI 0.97-1.78, P = 0.08).

CONCLUSION

In this prospective cohort, the presence of an actionable mutation was the strongest predictor of overall survival. These results confirm the importance of molecular testing and suggest likely survival benefit of identification and treatment of actionable oncogenes.

Performance of probe polymerization-conjunction-agarose gel electrophoresis in the rapid detection of KRAS gene mutation

This study aimed to develop a simple and rapid method to detect KRAS gene mutations for conventional clinical applications under laboratory conditions. The genotype of mutation sites was determined based on the occurrence of target bands in the corresponding lanes of the reaction tubes through polymerization-conjunction of the probes, probe purification and amplification, and agarose gel electrophoresis. Circulating DNA samples were obtained from the plasma of 72 patients with lung cancer, which were identified based on six mutation sites (G12S, G12R, G12C, G12D, G12A, and G12V) of codon 12 of the KRAS gene. The detection results were compared with direct sequencing data. The proposed detection method is characterized by simple operation, high specificity, and high sensitivity (2%). This method can detect the mutations of three samples at G12S, G12R, and G12A. In the direct sequencing spectra of these samples, the genotype could not be determined due to the lack of evident sequencing peaks that correspond to the basic group of mutations. In conclusion, a simple and rapid method was established based on probe polymerization-conjunction-agarose gel electrophoresis for detecting KRAS gene mutations. This method can be applied to the conventional mutation detection of inhomogeneous samples.

Palbociclib resistance confers dependence on an FGFR-MAP kinase-mTOR-driven pathway in KRAS-mutant non-small cell lung cancer

CDK4 is emerging as a target in KRAS-mutant non-small cell lung cancer (NSCLC). We demonstrate that KRAS-mutant NSCLC cell lines are initially sensitive to the CDK4/6 inhibitor palbociclib, but readily acquire resistance associated with increased expression of CDK6, D-type cyclins and cyclin E. Resistant cells also demonstrated increased ERK1/2 activity and sensitivity to MEK and ERK inhibitors. Moreover, MEK inhibition reduced the expression and activity of cell cycle proteins mediating palbociclib resistance. In resistant cells, ERK activated mTOR, driven in part by upstream FGFR1 signaling resulting from the extracellular secretion of FGF ligands. A genetically-engineered mouse model of KRAS-mutant NSCLC initially sensitive to palbociclib similarly developed acquired resistance with increased expression of cell cycle mediators, ERK1/2 and FGFR1. In this model, resistance was delayed with combined palbociclib and MEK inhibitor treatment. These findings implicate an FGFR1–MAP kinase–mTOR pathway resulting in increased expression of D-cyclins and CDK6 that confers palbociclib resistance and indicate that CDK4/6 inhibition acts to promote MAP kinase dependence.

Autochthonous murine models for the study of smoker and never-smoker associated lung cancers

Lung cancer accounts for the greatest number of cancer deaths in the world. Tobacco smoke-associated cancers constitute the majority of lung cancer cases but never-smoker cancers comprise a significant and increasing fraction of cases. Recent genomic and transcriptomic sequencing efforts of lung cancers have revealed distinct sets of genetic aberrations of smoker and never-smoker lung cancers that implicate disparate biology and therapeutic strategies. Autochthonous mouse models have contributed greatly to our understanding of lung cancer biology and identified novel therapeutic targets and strategies in the era of targeted therapy. With the emergence of immuno-oncology, mouse models may continue to serve as valuable platforms for novel biological insights and therapeutic strategies. Here, we will review the variety of available autochthonous mouse models of lung cancer, their relation to human smoker and never-smoker lung cancers, and their application to immuno-oncology and immune checkpoint blockade that is revolutionizing lung cancer therapy.

KRAS: Reasons for optimism in lung cancer

Despite being the most frequent gain-of-function genetic alteration in human cancer, KRAS mutation has to date offered only limited potential as a prognostic and predictive biomarker. Results from the phase III SELECT-1 trial in non-small cell lung cancer (NSCLC) recently added to a number of historical and more contemporary disappointments in targeting KRAS mutant disease, including farnesyl transferase inhibition and synthetic lethality partners such as STK33. This narrative review uses the context of these previous failures to demonstrate how the knowledge gained from these experiences can be used as a platform for exciting advances in NSCLC on the horizon. It now seems clear that mutational subtype (most commonly G12C) of individual mutations is of greater relevance than the categorical evaluation of KRAS mutation presence or otherwise. A number of direct small molecules targeted to these subtypes are in development and have shown promising biological activity, with some in the late stages of preclinical validation.

Targeted Molecular Treatments in Non-Small Cell Lung Cancer: A Clinical Guide for Oncologists

Targeted molecular treatments have changed the way non-small cell lung cancer (NSCLC) is managed. Epidermalgrowthfactorreceptor (EGFR),anaplasticlymphomakinase (ALK),v-rafmurine sarcoma viral oncogene homolog B1 (BRAF), and c-rosoncogene 1 (ROS1) mutations are now used to guide specific anti-cancer therapies to improve patient outcomes. New targeted molecular treatments are constantly being developed and evaluated as a means to improve efficacy, overcome resistance, or minimise toxicity. This review article summarises the current evidence for the efficacy, resistance mechanisms, and safety of targeted molecular treatments against specific mutations in NSCLC.

Clinicopathologic characteristics and survival outcome in patients with advanced lung adenocarcinoma and KRAS mutation

Kirsten rat sarcoma viral oncogene homolog (KRAS) mutations are one of the most common observed genetic events in lung adenocarcinoma. The present study aimed to characterize treatment patterns and to estimate survival for patients in China with advanced lung adenocarcinoma and KRAS mutation. We identified KRAS-mutant lung adenocarcinoma between February 2013 and June 2017 in Zhejiang Cancer Hospital. Patients' characteristics and treatment outcomes were analyzed. A total of 159 lung adenocarcinoma were included, and 26 (16.4%) patients harbored KRAS mutations. Compared to KRAS-wild patients, patients with KRAS-mutant tumors were more likely to be smokers (76.9% vs. 51.9%, P = 0.029). Median tumor mutation burden (TMB) was significantly higher in the KRAS-mutant cohort than in the KRAS-wild cohort (5.4 vs. 4.2 mutations/megabases; P=0.041). Of the 93 patients receiving first-line chemotherapy, the median progression-free survival (PFS) in the KRAS-mutant group was significantly shorter than in the KRAS-wild group (1.5 vs. 7.2 months; P<0.001). The median overall survival (OS) in the KRAS-mutant group was also significantly shorter than in the KRAS-wild group (hazard ratio for progression or death for patients with KRAS mutation, 3.260; 95% CI, 1.516 to 7.013; P=0.001). In summary, our findings have several important implications for the molecular characterization and therapeutic outcome of lung adenocarcinoma initiated by oncogenic KRAS. Since the number of KRAS-mutant lung cancer is considerable, it should be taken seriously in clinical diagnosis and treatment. KRAS-mutant lung adenocarcinoma was not sensitive to chemotherapy, new and effective drugs targeting the KRAS pathway are in urgent need.

Distribution of KRAS, DDR2, and TP53 gene mutations in lung cancer: An analysis of Iranian patients

Purpose

Lung cancer is the deadliest known cancer in the world, with the highest number of mutations in proto-oncogenes and tumor suppressor genes. Therefore, this study was conducted to determine the status of hotspot regions in DDR2 and KRAS genes for the first time, as well as in TP53 gene, in lung cancer patients within the Iranian population.

Experimental design

The mutations in exon 2 of KRAS, exon 18 of DDR2, and exons 5–6 of TP53 genes were screened in lung cancer samples, including non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC) using PCR and sequencing techniques.

Results

Analysis of the KRAS gene showed only a G12C variation in one large cell carcinoma (LCC) patient, whereas variants were not found in adenocarcinoma (ADC) and squamous cell carcinoma (SCC) cases. The Q808H variation in the DDR2 gene was detected in one SCC sample, while no variant was seen in the ADC and LCC subtypes. Variations in the TP53 gene were seen in all NSCLC subtypes, including six ADC (13.63%), seven SCC (15.9%) and two LCC (4.54%). Forty-eight variants were found in the TP53 gene. Of these, 15 variants were found in coding regions V147A, V157F, Q167Q, D186G, H193R, T211T, F212L and P222P, 33 variants in intronic regions rs1625895 (HGVS: c.672+62A>G), rs766856111 (HGVS: c.672+6G>A) and two new variants (c.560-12A>G and c.672+86T>C).

Conclusions

In conclusion, KRAS, DDR2, and TP53 variants were detected in 2%, 2.17% and 79.54% of all cases, respectively. The frequency of DDR2 mutation is nearly close to other studies, while KRAS and TP53 mutation frequencies are lower and higher than other populations, respectively. Three new putative pathogenic variants, for the first time, have been detected in Iranian patients with lung cancer, including Q808H in DDR2, F212L, and D186G in coding regions of TP53. In addition, we observed five novel benign variants, including Q167Q, P222P and T211T in coding sequence, and c.560-12A>G and c.672+86T>C, in intronic region of TP53. Mutations of KRAS and DDR2 were found in LCC and SCC subtypes, respectively, whereas mutations of TP53 were seen in SCC and ADC subtypes with higher frequencies and LCC subtype with lower frequency. Therefore, Iranian lung cancer patients can benefit from mutational analysis before starting the conventional treatment. A better understanding of the biology of these genes and their mutations will be critical for developing future targeted therapies.

KRAS-Mutant non-small cell lung cancer: From biology to therapy

In patients with non-small cell lung cancer (NSCLC), the most frequent oncogene driver mutation in Western countries is Kirsten rat sarcoma viral oncogene homolog (KRAS), and KRAS-mutant NSCLC is associated with smoking. There are various sources of biological heterogeneity of KRAS-mutant NSCLC, including different genotypes that may be associated with specific clinical outcomes, the presence of other co-mutations that exhibit different biological features and drug sensitivity patterns, and mutant allelic content. The efficacy of chemotherapy in patients with KRAS-mutant NSCLC is generally poor and numerous novel therapeutic strategies have been developed. These approaches include targeting KRAS membrane associations, targeting downstream signalling pathways, the use of KRAS synthetic lethality, direct targeting of KRAS, and immunotherapy. Of these, immunotherapy may be one of the most promising treatment approaches for patients with KRAS-mutant NSCLC. Recent data also suggest the potential for distinct efficacy of immunotherapy according to the presence of other co-mutations. In view of the biological heterogeneity of KRAS-mutant NSCLC, treatment will likely need to be individualised and, in future, may require the use of rational combinations of treatment, many of which are currently under investigation.

The prognostic effect of single and multiple cancer-related somatic mutations in resected non-small-cell lung cancer

INTRODUCTION

Somatic mutations are becoming increasingly important biomarkers for treatment selection and outcome in patients with non-small-cell lung cancer (NSCLC). The role of multiple somatic mutations in early-stage NSCLC is unclear.

METHODS

Tissue from 214 patients with resected NSCLC at the Princess Margaret Cancer Centre was analyzed by next-generation sequencing by Mi-SEQ or Sequenom multiplex platforms. Associations between mutation status, baseline patient characteristics and outcomes (disease-free survival (DFS) after surgical resection and overall survival (OS)) were investigated.

RESULTS

Somatic mutations were identified in 184 patients with resected stage I-III NSCLC: None (n = 30), single (n = 101) and multiple (≥2, n = 83). Multiple mutations were significantly associated with younger age (p = 0.0006), female sex (p = 0.012), smoking status (p = 0.002) and adenocarcinoma histology (p = 0.0001).TP53, KRAS and EGFR were the most common mutations. TP53 mutation was the most frequent co-mutation occurring in 72% of patients with multiple mutations. In resected stage I-III patients, multiple mutations were significantly associated with worse DFS (HR = 2.56, p = 0.003) but not OS on univariate analysis. Patients with KRAS and EGFR mutations were also associated with shorter DFS (HR = 2.52, p = 0.016 and HR = 4.37, p = 0.001 respectively) but no OS difference. TP53 mutation was associated with both shorter DFS (HR = 2.21, p = 0.02) and OS (HR = 3.08, p = 0.02). In subgroup univariate analysis, poorer DFS was associated with multiple mutations (p = 0.0015), EGFR (HR = 3.14, p = 0.006), and TP53 (HR = 2.46, p = 0.018) in patients with stage I disease.

CONCLUSION

The presence of known somatic mutations is associated with worse DFS in resected NSCLC. The differences are both statistically significant and clinically relevant. The presence of EGFR, KRAS and TP53 mutations was also associated with adverse outcomes. Larger datasets are required to validate whether mutational status is an independent prognostic factor in early stage NSCLC.

De novo lipogenesis represents a therapeutic target in mutant Kras non-small cell lung cancer

Oncogenic Kras mutations are one of the most common alterations in non-small cell lung cancer and are associated with poor response to treatment and reduced survival. Driver oncogenes, such as Kras are now appreciated for their ability to promote tumor growth via up-regulation of anabolic pathways. Therefore, we wanted to identify metabolic vulnerabilities in Kras-mutant lung cancer. Using the Kras LSL-G12D lung cancer model, we show that mutant Kras drives a lipogenic gene-expression program. Stable-isotope analysis reveals that mutant Kras promotes de novo fatty acid synthesis in vitro and in vivo. The importance of fatty acid synthesis in Kras-induced tumorigenesis was evident by decreased tumor formation in Kras LSL-G12D mice after treatment with a fatty acid synthesis inhibitor. Importantly, with gain and loss of function models of mutant Kras, we demonstrate that mutant Kras potentiates the growth inhibitory effects of several fatty acid synthesis inhibitors. These studies highlight the potential to target mutant Kras tumors by taking advantage of the lipogenic phenotype induced by mutant Kras.-Singh, A., Ruiz, C., Bhalla, K., Haley, J. A., Li, Q. K., Acquaah-Mensah, G., Montal, E., Sudini, K. R., Skoulidis, F., Wistuba, I. I., Papadimitrakopoulou, V., Heymach, J. V., Boros, L. G., Gabrielson, E., Carretero, J., Wong, K.-k., Haley, J. D., Biswal, S., Girnun, G. D. De novo lipogenesis represents a therapeutic target in mutant Kras non-small cell lung cancer.

Feasibility of endobronchial ultrasound transbronchial needle aspiration for massively parallel next-generation sequencing in thoracic cancer patients

INTRODUCTION

Next-generation sequencing (NGS) allows for the identification of a growing number of therapeutic and prognostic molecular targets. However, NGS typically requires greater quantities of DNA than traditional molecular testing does. Endobronchial ultrasound transbronchial needle aspiration (EBUS-TBNA) is a minimally invasive procedure used to sample central thoracic lesions, but it is not well established whether this technique provides sufficient material for NGS.

METHODS

We performed a retrospective review of EBUS-TBNA at our institution (3/1/14-9/28/16). NGS was performed using a comprehensive hybrid-capture based assay (MSK-IMPACT) that detects >340 gene mutations. Samples found to be diagnostic for malignancy and for which MSK-IMPACT had been attempted were identified. Pathologic and clinical data were obtained from the medical record, and the results of MSK-IMPACT were examined.

RESULTS

In total, 784 EBUS-TBNA procedures were performed during the study period. MSK-IMPACT was requested for 115 malignant samples and was successful for 99 (86.1%), identifying an average of 12.7 mutations at a mean coverage depth of 806X. NGS was performed on paraffin-embedded cell blocks in 93 cases (93.9%) and on cell-free DNA in needle rinse fluid in 6 cases. The success rate of the assay improved significantly from the first third of cases (76.3%), to 92.3% for the final one-third of cases (p < 0.05).

CONCLUSIONS

EBUS-TBNA reliably provided adequate tissue for hybrid capture NGS, and is a suitable option for comprehensive NGS testing in patients with thoracic malignancies.

The classification of lung cancers and their degree of malignancy by FTIR, PCA-LDA analysis, and a physics-based computational model

Lung cancer has the highest mortality rate of all malignant tumours. The current effects of cancer treatment, as well as its diagnostics, are unsatisfactory. Therefore it is very important to introduce modern diagnostic tools, which will allow for rapid classification of lung cancers and their degree of malignancy. For this purpose, the authors propose the use of Fourier Transform InfraRed (FTIR) spectroscopy combined with Principal Component Analysis-Linear Discriminant Analysis (PCA-LDA) and a physics-based computational model. The results obtained for lung cancer tissues, adenocarcinoma and squamous cell carcinoma FTIR spectra, show a shift in wavenumbers compared to control tissue FTIR spectra. Furthermore, in the FTIR spectra of adenocarcinoma there are no peaks corresponding to glutamate or phospholipid functional groups. Moreover, in the case of G2 and G3 malignancy of adenocarcinoma lung cancer, the absence of an OH groups peak was noticed. Thus, it seems that FTIR spectroscopy is a valuable tool to classify lung cancer and to determine the degree of its malignancy.

Prognostic value of tumor mutations in radically treated locally advanced non-small cell lung cancer patients

Introduction

Chemo-radiation is standard treatment in locally advanced non-small cell lung cancers (NSCLC). The prognostic value of mutations has been poorly explored in this population.

RESULTS

Clinical data were collected from 190 patients and mutational profiles were obtained in 78 of them; 58 (74%) were males, 31 (40%) current smokers, 47/31 stage IIIA/IIIB and 40 (51%) adenocarcinoma. The following mutations were identified: EGFR 12% (9/78), KRAS 15% (12/78), BRAF 5% (3/65), PI3KCA 2% (1/57), NRAS 3% (1/32), and ALK+ (FISH) 4% (2/51). HER2 was not detected. Median follow-up was 3.1 years. Overall survival was evaluated by group; no significant differences were identified in median overall survival (p = 0.21), with 29.4 months for the EGFR/ALK group (n = 11), 12.8 months for other mutations (n = 17), and 23.4 months for wild-type (n = 50). The EGFR/ALK and other mutations groups had poorer median progression-free survival (9.6 and 6.0 months) compared to the wild-type group (12.0 months; multivariate hazard ratio 2.0 [95% CI, 0.9–4.2] and 2.8 [95% CI, 1.5–5.2] respectively, p = 0.003).

Materials and Methods

We retrospectively reviewed all patients receiving radical treatment for locally advanced NSCLC in a single institution between January 2002 and June 2013. Next generation sequencing was performed on DNA from paraffin-embedded tissue. ALK rearrangements were detected by immunohistochemistry and/or FISH. Mutational prognostic value for Kaplan-Meier survival parameters was determined by log-rank tests and Cox proportional hazards models.

Conclusions

Selected gene alterations may be associated with poorer progression-free survival in locally advanced radically treated NSCLC and their prognostic and/or predictive value merits further evaluation in a larger population.

Bone, muscle, and metabolic parameters predict survival in patients with synchronous bone metastases from lung cancers

BACKGROUND

Lung adenocarcinoma regularly induces bone metastases that are responsible for impaired quality of life as well as significant morbidity, including bone pain and fractures. We aimed at identifying whether bone and metabolic biomarkers were associated with the prognosis of lung adenocarcinoma patients with synchronous bone metastases.

PATIENTS AND METHODS

POUMOS is a prospective cohort of patients diagnosed with lung adenocarcinoma and synchronous bone metastases. All patients underwent biopsy of bone metastases to confirm diagnosis, including genotyping of oncogenic drivers such as EGFR and KRAS. Whole-body composition was assessed using DEXA scan. Serum levels of C-reactive protein, HbA1C, calcaemia, sCTX, and DKK1 were also measured.

RESULTS

Sixty four patients, aged (mean ± SD) 65 ± 11 years, were included. Thirty-nine (61%) patients had a good performance status (PS 0-1); 56% had >5 bone lesions, and 41% a weight-bearing bone (femour or tibia) involvement. Median overall survival was 7 months. In multivariate analysis, HbA1c (HR = 1.69 [1.10-2.63] per 0.5% decrease; p = .02), DKK1 (HR = 1.28 [1.01-1.61] per 10 ng/mL increase; p = .04), and hypercalcaemia (HR = 2.83 [1.10-7.30]; p = .03) were independently associated with poorer survival. In the subgroup of patients with DEXA, sarcopenia was also associated with poorer survival (HR = 2.96, 95%CI [1.40-6.27]; p = .005).

CONCLUSIONS

In patients with lung adenocarcinoma and synchronous bone metastases, bone, sarcopenia, and metabolic parameters were predictors of poor overall survival independently of common prognostic factors. We suggest that, in addition to oncological therapy, supportive treatment dedicated to bone metastases, muscle wasting, and energy metabolism are essential to improve prognosis.

KRAS oncogene in non-small cell lung cancer: clinical perspectives on the treatment of an old target

Lung neoplasms are the leading cause of death by cancer worldwide. Non-small cell lung cancer (NSCLC) constitutes more than 80% of all lung malignancies and the majority of patients present advanced disease at onset. However, in the last decade, multiple oncogenic driver alterations have been discovered and each of them represents a potential therapeutic target. Although KRAS mutations are the most frequently oncogene aberrations in lung adenocarcinoma patients, effective therapies targeting KRAS have yet to be developed. Moreover, the role of KRAS oncogene in NSCLC remains unclear and its predictive and prognostic impact remains controversial. The study of the underlying biology of KRAS in NSCLC patients could help to determine potential candidates to evaluate novel targeted agents and combinations that may allow a tailored treatment for these patients. The aim of this review is to update the current knowledge about KRAS-mutated lung adenocarcinoma, including a historical overview, the biology of the molecular pathways involved, the clinical relevance of KRAS mutations as a prognostic and predictive marker and the potential therapeutic approaches for a personalized treatment of KRAS-mutated NSCLC patients.

Targeting the RAS-dependent chemoresistance: The Warburg connection

RAS protein family members (KRAS4A, KRAS4B, HRAS and NRAS) function as GDP-GTP-regulated on-off switches, which regulate cytoplasmic-nuclear signaling networks ruling diverse normal cellular processes. Constitutive activating mutations in RAS genes are found in up to 30% of human cancers, and remarkably, the oncogenic Ras mutations and mutations in other components of Ras/MAPK signaling pathways seem to be mutually exclusive in most tumors, pointing out that deregulation of Ras-dependent signaling is an essential requirement for tumorigenesis. Up to 30% of solid tumors are known to have a mutated (abnormal) KRAS gene. Unfortunately, patients harboring mutated KRAS CRC are unlikely to benefit from anti-EGFR therapy. Moreover, it remains unclear that patients with KRAS wild-type CRC will definitely respond to such therapies. Although some clinically designed-strategies to modulate KRAS aberrant activation have been designed, all attempts to target KRAS have failed in the clinical assays and K-RAS has been assumed to be invulnerable to chemotherapeutic attack. Recently, different encouraging publications reported that ascorbate may have a selective antitumoral effect on KRAS mutant cancer cells. In this review we aim to describe the prevalence and importance of KRAS mutation in cancer and associated problems for the clinical handling of patients harboring these tumors. We highlight the role of mutated KRAS in boosting and keeping the tumor associated aberrant cell metabolism stating that further in-depth studies on the molecular mechanism of ascorbate to bypass mutated KRAS-related metabolic alterations may constitute a new pathway to design novel molecules in order handle tumor resistance to anti EGFR-therapies.

Ras-related protein Rap2c promotes the migration and invasion of human osteosarcoma cells

Ras-related protein (Rap)2a and Rap2b are members of the GTP-binding protein family, and serve an important function in tumor progression. However, the associations between Rap2c and cancer cell functions have not yet been reported. Osteosarcoma is a type of bone cancer; its high degree of invasion is considered to be a major treatment challenge. The present study first investigated the biological role of Rap2c in human osteosarcoma cells and investigated the underlying mechanism of Rap2c on osteosarcoma cell migration and invasion. The results of the present study demonstrated that Rap2c overexpression promoted the migratory and invasive ability of cancer cells, and increased the activity of matrix metalloproteinase-2 (MMP2). Correspondingly, the knockdown of Rap2c inhibited tumor cell migration and invasion, whereas alterations to Rap2c had no effect on osteosarcoma cell proliferation or rate of apoptosis. Furthermore, Rap2c overexpression may decrease the protein level of tissue inhibitor of metalloproteinases 2 and increase the phosphorylation level of protein kinase B (Akt). Collectively, these results indicated that Rap2c has a key function in tumor migration and invasion, and the Akt signaling pathway may be involved in Rap2c-induced MMP2 expression.

Predictive and Prognostic Implications of Mutation Profiling and Microsatellite Instability Status in Patients with Metastatic Colorectal Carcinoma

To investigate whether mutation profiling and microsatellite instability (MSI) status were associated with clinicopathological features and the prognosis in metastatic colorectal cancer (mCRC), mutations in RAS (including KRAS, NRAS, and HRAS) and BRAF were determined by Sanger sequencing. Tumor mismatch repair proteins and MSI status were examined using immunohistochemistry and polymerase chain reaction, respectively. The clinical value of these abnormalities was statistically analyzed, and prognostic value of different treatment regimens was also evaluated. Among 461 mCRC patients, mutations in RAS, BRAF, and MSI-high (MSI-H) status were observed in 45.3% (209/461), 5.6% (26/461), and 6.5% (30/461) of cases, respectively. Brain metastasis and high carcinoembryonic antigen level were highly correlated with KRAS mutation (P = 0.011 and P < 0.001), and tumors from females or located in the right colon tended to harbor BRAF mutation (P = 0.039 and P = 0.001). RAS/BRAF mutations may predict brain and/or lung metastases. Although neither clinical nor prognostic importance of MSI status was identified in our study, KRAS and BRAF mutations were demonstrated to be independent prognostic factors for overall survival and progression-free survival. Besides, in wild-type group, patients treated with chemotherapy plus targeted therapy exhibited the most favorable prognosis. Therefore, RAS/BRAF mutations may serve as indicators for prognosis and treatment options in mCRC.

Lung adenocarcinoma with Concurrent KRAS Mutation and ALK Rearrangement Responding to Crizotinib: Case Report

Chromosomal translocation resulting in the fusion between the echinoderm microtubule-associated protein-like 4 (EML4) gene and the anaplastic lymphoma kinase ( ALK) gene was recently identified as a novel genetic alteration in a subset of non-small cell lung cancer (NSCLC). EML4– ALK translocations are rare events associated with specific clinicopathological features, such as never or light smoking history, young age and adenocarcinoma with signet ring or acinar histology. Reports suggest ALK gene arrangements are mutually exclusive with EGFR and KRAS mutations. To the best of to our knowledge, this is the first case report of a patient with concurrent KRAS mutation and ALK translocation. This patient had an excellent response to crizotinib, suggesting that the ALK translocation was the oncogenic driver.

The regulation and function of microRNA-377/RASSF8 signaling axis in gastric cancer

Gastric cancer is a major cause of cancer-associated mortality worldwide. The aberrant expression of microRNA (miRNA) is involved in tumorigenesis. Ras proteins transfer information from the extracellular environment to internal cellular compartments and are essential in numerous signal transduction pathways. To investigate the regulation, function and clinical significance of the miRNA377/Ras association domain family (RASSF) 8 signaling axis in gastric cancer, reverse transcription-quantitative polymerase chain reaction, immunohistochemistry, cell counting kit-8, western blotting, and Transwell assays were used. The results revealed that expression of RASSF8 was significantly upregulated in normal gastric tissues compared with gastric cancer, which was further confirmed by immunohistochemical analysis, and its expression level was increased in normal gastric cells compared with gastric cancer cell lines. However, the expression of miR-377 was significantly upregulated in gastric cancer compared with normal gastric tissues. In addition, RASSF8 overexpression in BGC-823 gastric cancer cells significantly inhibited the proliferation, apoptosis and invasive abilities of cells. Whereas miR-377 attenuated these effects due to downregulated RASSF8 expression by directly targeting its 3′-untranslated region. Furthermore, in the current study, miR-377 was not able to reverse the effects of RASSF8 overexpression on gastric cancer cells. Collectively, the RASSF8 gene may represent a novel molecular target involved in gastric cancer development and may be useful in targeted therapy of patients with gastric cancer.

Analysis of the proliferative activity in lung adenocarcinomas with specific driver mutations

In the last decade it became evident that many lung adenocarcinomas (ADC) harbor key genetic alterations such as KRAS, EGFR or BRAF mutations as well as rearrangements of ROS1 or ALK that drive these tumors. In the present study we investigated whether different driver mutations of ADC result in different proliferation rates, which might have clinical impact, including resistance to therapy, recurrence and prognosis. We analyzed the proliferation index (PI) on full slides of surgically resected ADC (n = 230) with known genetic aberrations by means of immunohistochemistry and subsequent digital image analysis and correlated the results with clinicopathological variables including overall (OS) and disease free survival (DFS). We did not observe significant differences in OS or DFS regarding the KRAS or EGFR mutational status (P = 0.56). However, KRAS mutated ADC showed an increased PI compared to EGFR mutated ADC, and ADC with ALK translocations (P < 0.01). Subgroup analysis of EGFR mutated ADC showed a higher PI for tumors harboring a mutation in exon 18 and 20, compared to tumors with a mutation in exon 19 or 21. A PI of 11.5% was the best possible prognostic stratificator for OS (P = 0.01 in KRAS mutated and P < 0.01 in EGFR mutated ADC). In conclusion, the PI differs significantly among ADC with distinct driver mutations. This might explain the varying indications for a prognostic relevance of the PI observed in prior studies. Our study provides a basis for the establishment of a reliable and clinically meaningful PI threshold.

Personalised medicine for nonsmall cell lung cancer

After years of standard care prescribed to cancer patients without any selection except the primary site and histology of the tumour, the era of precision medicine has revolutionised cancer care. Personalised medicine refers to the selection of patients for specific treatment based on the presence of specific biomarkers which indicate sensitivity to corresponding targeted therapies and/or lower toxicity risk, such that patients will have the greatest chance of deriving benefit from the treatments. Here, we review personalised medicine for nonsmall cell lung cancer.

Nonmonotonic Pathway Gene Expression Analysis Reveals Oncogenic Role of p27/Kip1 at Intermediate Dose

The mechanistic basis by which the level of p27^Kip1 expression influences tumor aggressiveness and patient mortality remains unclear. To elucidate the competing tumor-suppressing and oncogenic effects of p27^Kip1 on gene expression in tumors, we analyzed the transcriptomes of squamous cell papilloma derived from Cdkn1b nullizygous, heterozygous, and wild-type mice. We developed a novel functional pathway analysis method capable of testing directional and nonmonotonic dose response. This analysis can reveal potential causal relationships that might have been missed by other nondirectional pathway analysis methods. Applying this method to capture dose-response curves in papilloma gene expression data, we show that several known cancer pathways are dominated by low-high-low gene expression responses to increasing p27 gene doses. The oncogene cyclin D1, whose expression is elevated at an intermediate p27 dose, is the most responsive gene shared by these cancer pathways. Therefore, intermediate levels of p27 may promote cellular processes favoring tumorigenesis-strikingly consistent with the dominance of heterozygous mutations in CDKN1B seen in human cancers. Our findings shed new light on regulatory mechanisms for both pro- and anti-tumorigenic roles of p27^Kip1. Functional pathway dose-response analysis provides a unique opportunity to uncover nonmonotonic patterns in biological systems.

Prognostic implication of EGFR gene mutations and histological classification in patients with resected stage I lung adenocarcinoma

Introduction

The prognostic value of epidermal growth factor receptor (EGFR) mutations and the correlation between EGFR mutations and the new International Association for the Study of Lung Cancer/American Thoracic Society/European Respiratory Society (IASLC/ATS/ERS) histological classification remain controversial. The current study aimed to investigate the pure prognostic role of EGFR mutations in treatment-naïve patients with resected stage I lung adenocarcinoma.

Methods

We retrospectively reviewed 373 patients with stage I pulmonary non-small-cell lung cancer who underwent complete surgical resection between January 2010 and May 2014. The tumors were classified according to IASLC/ATS/ERS criteria. EGFR mutation status was determined by established methods.

Results

A total of 120 patients were included for analysis; 87 had tumors with EGFR mutations and 33 had wild-type tumors. More low- and intermediate-grade tumors had EGFR mutations, and nearly half of the high-grade tumors were wild-type (75.7% versus 46.2%, p = 0.041). Patients with low-grade tumors had significantly greater median disease-free survival (DFS) (76.8 versus 13 months, p < 0.0001) and better overall survival (OS) (median OS not reached, p = 0.0003) than those with intermediate- and high-grade tumors. Tumor recurrence was 41.4% and 30.3% in mutant and wild-type patients. The 5-years survival rate was 54% and 71.2%. Multivariate analysis revealed that the new histological classification and the pathologic stage were independent predictors of both DFS and OS. EGFR mutation status had no prognostic implications.

Conclusion

Low grade tumors according to IASLC/ATS/ERS histological classification and the pathologic stage IA tumors of resected stage I lung adenocarcinomas independently predict better DFS and OS. EGFR mutations were frequently seen in histologically low- and intermediate-grade tumors but not a prognostic factor.

Exploitation of Gene Expression and Cancer Biomarkers in Paving the Path to Era of Personalized Medicine

Cancer therapy agents have been used extensively as cytotoxic drugs against tissue or organ of a specific type of cancer. With the better understanding of molecular mechanisms underlying carcinogenesis and cellular events during cancer progression and metastasis, it is now possible to use targeted therapy for these molecular events. Targeted therapy is able to identify cancer patients with dissimilar genetic defects at cellular level for the same cancer type and consequently requires individualized approach for treatment. Cancer therapy begins to shift steadily from the traditional approach of “one regimen for all patients” to a more individualized approach, through which each patient will be treated specifically according to their specific genetic defects. Personalized medicine accordingly requires identification of indicators or markers that guide in the decision making of such therapy to the chosen patients for more effective therapy. Cancer biomarkers are frequently used in clinical practice for diagnosis and prognosis, as well as identification of responsive patients and prediction of treatment response of cancer patient. The rapid breakthrough and development of microarray and sequencing technologies is probably the main tool for paving the way toward “individualized biomarker-driven cancer therapy” or “personalized medicine”. In this review, we aim to provide an updated knowledge and overview of the current landscape of cancer biomarkers and their role in personalized medicine, emphasizing the impact of genomics on the implementation of new potential targeted therapies and development of novel cancer biomarkers in improving the outcome of cancer therapy.

Establishment of highly metastatic KRAS mutant lung cancer cell sublines in long-term three-dimensional low attachment cultures

Decreased cell-substratum adhesion is crucially involved in metastasis. Previous studies demonstrated that lung cancer with floating cell clusters in histology is more likely to develop metastasis. In the present study, we investigated whether cancer cells in long-term, three-dimensional low attachment cultures acquire high metastatic potential; these cells were then used to examine the mechanisms underlying metastasis. Two KRAS-mutated adenocarcinoma cell lines (A549 and H441) were cultured and selected on ultra-low attachment culture dishes, and the resulting cells were defined as FL (for floating) sublines. Cancer cells were inoculated into NOD/SCID mice via an intracardiac injection, and metastasis was evaluated using luciferase-based imaging and histopathology. In vitro cell growth (in attachment or suspension cultures), migration, and invasion were assayed. A whole genomic analysis was performed to identify key molecular alterations in FL sublines. Upon detachment on low-binding dishes, parental cells initially formed rounded spheroids with limited growth activity. However, over time in cultures, cells gradually formed smaller spheroids that grew slowly, and, after 3–4 months, we obtained FL sublines that regained prominent growth potential in suspension cultures. On ordinary dishes, FL cells reattached and exhibited a more spindle-shaped morphology than parental cells. No marked differences were observed in cell growth with attachment, migration, or invasion between FL sublines and parental cell lines; however, FL cells exhibited markedly increased growth potential under suspended conditions in vitro and stronger metastatic abilities in vivo. A genomic analysis identified epithelial-mesenchymal transition (EMT) and c-Myc amplification in A549-FL and H441-FL cells, respectively, as candidate mechanisms for metastasis. The growth potential of FL cells was markedly inhibited by lentiviral ZEB1 knockdown in A549-FL cells and by the inhibition of c-Myc through lentiviral knockdown or the pharmacological inhibitor JQ1 in H441-FL cells. Long-term three-dimensional low attachment cultures may become a useful method for investigating the mechanisms underlying metastasis mediated by decreased cell-substratum adhesion.

KRAS mutation-positive mucinous adenocarcinoma originating in the thymus

Thymic carcinoma is a rare, aggressive disease with a low 5-year survival rate. The most common histological neoplastic thymic tumor subtype is squamous cell. We describe an interesting case of a 39-year-old woman who presented with mucinous adenocarcinoma that originated in the thymus and was treated via radical resection and venoplasty of the superior vena cava (SVC). Macroscopically, the resected tumor contained a solid region and multiple cysts with abundant mucin. Microscopic examination showed a papillary growth pattern of goblet cells with round nuclei. Based on the histopathological and immunohistochemical findings and other inspections, the tumor was eventually diagnosed as a mucinous adenocarcinoma of the thymus. It was classified as Masaoka-Koga stage III owing to tumor invasion into the left brachiocephalic vein and pericardium. Polymerase chain reaction identified a Kirsten rat sarcoma viral oncogene homolog (KRAS) G12V mutation in the tumor. There were no mutations in the epidermal growth factor (EGFR) gene or a fusion gene of the echinoderm microtubule-associated protein-like 4 (EML4) and the anaplastic lymphoma kinase (ALK). A year later, multiple lung metastases were detected, and the patient underwent chemotherapy. She is alive 34 months after the initial surgery. This is the first report of a KRAS mutation-positive mucinous adenocarcinoma originating in the thymus. The treatment, diagnosis, and pathological findings of the patient are discussed.

Rap2a serves as a potential prognostic indicator of renal cell carcinoma and promotes its migration and invasion through up-regulating p-Akt

Rap2a, a member of the small GTPase superfamily, belongs to Ras superfamily, and its function in cancer progression is still poorly understood. Our previous study indicated that the ectopic expression of Rap2a enhanced the migration and invasion ability of lung cancer cells. However, its expression and molecular mechanism on renal cell carcinoma (RCC) have not been characterized. This study explored the clinical significance and biological function of Rap2a in human RCC. The clinical relevance of Rap2a in RCC was evaluated by immunohistochemical staining using tissue microarray. Our data showed that Rap2a expression was dramatically increased in RCC tissues compared with normal renal tissues. The ectopic expression of Rap2a enhanced the migration and invasive ability of cancer cells. In contrast, downregulation of Rap2a inhibited cell invasion. Rap2a had no effect on the proliferation of RCC cell lines. Meanwhile, Rap2a can regulate the phosphorylation level of Akt in vitro. In vivo studies also showed that Rap2a positively regulated metastasis of renal cancer cells and the expression of p-Akt. These findings indicate that Rap2a promotes RCC metastasis and may serve as a candidate RCC prognostic marker and a potential therapeutic target.

KRAS Mutation Is a Significant Prognostic Factor in Early-stage Lung Adenocarcinoma

The potential clinical impact of KRAS and epidermal growth factor receptor (EGFR) mutations has been investigated in lung adenocarcinomas; however, their prognostic value remains controversial. In our study, we sought to investigate the prognostic significance of driver mutations using a large cohort of early-stage lung adenocarcinomas. We reviewed patients with pathologic early-stage, lymph node-negative, solitary lung adenocarcinoma who had undergone surgical resection (1995 to 2005; stage I/II=463/19). Tumors were classified according to the IASLC/ATS/ERS classification and genotyped by Sequenom MassARRAY system and polymerase chain reaction-based assays. In stage I disease, the Kaplan-Meier method and cumulative incidence of recurrence analyses were used to estimate the probability of overall survival (OS) and recurrence, respectively. Of all, 129 (27%) patients had mutations in KRAS, 86 (18%) in EGFR, 8 (2%) in BRAF, 8 (2%) in PIK3CA, 4 (1%) in NRAS, and 1 (0.2%) in AKT1. EGFR L858R mutation correlated with lepidic predominant histology (P=0.006), whereas exon 19 deletion correlated with acinar predominant histology (P<0.001). EGFR mutations were not detected in invasive mucinous adenocarcinomas (P=0.033). The 5-year OS of patients with KRAS-mutant tumors was significantly worse (n=124; 5-year OS, 63%) than those with KRAS wild-type (n=339; 77%; P<0.001). In solid predominant tumors, KRAS mutations correlated with worse OS (P=0.008) and increased risk of recurrence (P=0.005). On multivariate analysis, KRAS mutation was an independent prognosticator of OS in all patients (hazard ratio, 1.87; P<0.001) and recurrence in solid predominant tumors (hazard ratio, 4.73; P=0.012). In patients with resected stage I lung adenocarcinomas, KRAS mutation was an independent prognostic factor for OS and recurrence, especially in solid predominant tumors.

Rap2B promotes angiogenesis via PI3K/AKT/VEGF signaling pathway in human renal cell carcinoma

Human renal cell carcinoma which is a highly vascular tumor is the leading cause of death from urologic cancers. Angiogenesis has a pivotal role in oncogenesis and in the viability and expansion of renal cell carcinoma. Rap2B, as a small guanosine triphosphate–binding protein of the Ras family, was first discovered in the early 1990s during the screening of a platelet complementary DNA library. Previous studies have shown that Rap2B aberrantly expressed in human carcinogenesis and promoted the development of tumors via multiple signaling pathways. However, the function of Rap2B in tumor angiogenesis that is necessary for tumor growth and metastasis remains unknown. In this study, we examined the role of Rap2B in angiogenesis in renal cell carcinoma by Western blot, quantitative polymerase chain reaction, enzyme-linked immunosorbent assay, human umbilical vascular endothelial cells growth assay, and endothelial cell tube formation assay. We found that Rap2B promoted angiogenesis in vitro and in vivo. Moreover, our data illustrated that phosphoinositide 3-kinase/AKT signaling pathway is involved in Rap2B-mediated upregulation of vascular endothelial growth factor and renal cell carcinoma angiogenesis. Taken together, these results revealed that Rap2B promotes renal cell carcinoma angiogenesis via phosphoinositide 3-kinase/AKT/vascular endothelial growth factor signaling pathway, which suggests that Rap2B is a novel therapeutic target for renal cell carcinoma anti-angiogenesis therapy.

Pooled Analysis of the Prognostic and Predictive Effects of TP53 Comutation Status Combined With KRAS or EGFR Mutation in Early-Stage Resected Non-Small-Cell Lung Cancer in Four Trials of Adjuvant Chemotherapy

Purpose Our previous work evaluated individual prognostic and predictive roles of TP53, KRAS, and EGFR in non-small-cell lung cancer (NSCLC). In this analysis, we explore the prognostic and predictive roles of TP53/KRAS and TP53/EGFR comutations in randomized trials of adjuvant chemotherapy versus observation. Patients and Methods Mutation analyses (wild-type [WT] and mutant) for TP53, KRAS, and EGFR were determined in blinded fashion in multiple laboratories. Primary and secondary end points of pooled analysis were overall survival and disease-free survival. We evaluated the role of TP53/KRAS comutation in all patients and in the adenocarcinoma subgroup as well as the TP53/EGFR comutation in adenocarcinoma only through a multivariable Cox proportional hazards model stratified by trial. Results Of 3,533 patients with NSCLC, 1,181 (557 deaths) and 404 (170 deaths) were used for TP53/KRAS and TP53/EGFR analyses. For TP53/KRAS mutation status, no prognostic effect was observed ( P = .61), whereas a borderline predictive effect ( P = .04) was observed with a deleterious effect of chemotherapy with TP53/KRAS comutations versus WT/WT (hazard ratio, 2.49 [95% CI, 1.10 to 5.64]; P = .03). TP53/EGFR comutation in adenocarcinoma was neither prognostic ( P = .83), nor significantly predictive ( P = .86). Similar results were observed for both groups for disease-free survival. Conclusion We could identify no prognostic effect of the KRAS or EGFR driver and TP53 tumor suppressor comutation. Our observation of a potential negative predictive effect of TP53/KRAS comutation requires validation.

Ferroptosis: A Novel Anti-tumor Action for Cisplatin

Purpose

Ferroptosis is a new mode of regulated cell death, which is completely distinct from other cell death modes based on morphological, biochemical, and genetic criteria. This study evaluated the therapeutic role of ferroptosis in classic chemotherapy drugs, including the underlying mechanism.

Materials and Methods

Cell viabilitywas detected by using the methylthiazoltetrazlium dye uptake method. RNAiwas used to knockout iron-responsive element binding protein 2, and polymerase chain reaction, western blot was used to evaluate the efficiency. Intracellular reduced glutathione level and glutathione peroxidases activitywere determined by related assay kit. Intracellularreactive oxygen species levelswere determined by flowcytometry. Electron microscopywas used to observe ultrastructure changes in cell.

Results

Among five chemotherapeutic drugs screened in this study, cisplatin was found to be an inducer for both ferroptosis and apoptosis in A549 and HCT116 cells. The depletion of reduced glutathione caused by cisplatin and the inactivation of glutathione peroxidase played the vital role in the underlying mechanism. Besides, combination therapy of cisplatin and erastin showed significant synergistic effect on their anti-tumor activity.

Conclusion

Ferroptosis had great potential to become a new approach in anti-tumor therapies and make up for some classic drugs, which open up a new way for their utility in clinic.

Selumetinib Plus Docetaxel Compared With Docetaxel Alone and Progression-Free Survival in Patients With KRAS-Mutant Advanced Non-Small Cell Lung Cancer: The SELECT-1 Randomized Clinical Trial

Importance

There are no specifically approved targeted therapies for the most common genomically defined subset of non-small cell lung cancer (NSCLC), KRAS-mutant lung cancer.

Objective

To compare efficacy of the mitogen-activated protein kinase kinase (MEK) inhibitor selumetinib + docetaxel with docetaxel alone as a second-line therapy for advanced KRAS-mutant NSCLC.

Design, Setting, and Participants

Multinational, randomized clinical trial conducted at 202 sites across 25 countries from October 2013 through January 2016. Of 3323 patients with advanced NSCLC and disease progression following first-line anticancer therapy tested for a KRAS mutation, 866 were enrolled and 510 randomized. Primary reason for exclusion was ineligibility. The data cutoff date for analysis was June 7, 2016.

Interventions

Patients were randomized 1:1; 254 to receive selumetinib + docetaxel and 256 to receive placebo + docetaxel.

Main Outcomes and Measures

Primary end point was investigator assessed progression-free survival. Secondary end points included overall survival, objective response rate, duration of response, effects on disease-related symptoms, safety, and tolerability.

Results

Of 510 randomized patients (mean age, 61.4 years [SD, 8.3]; women, 207 [41%]), 505 patients (99%) received treatment and completed the study (251 received selumetinib + docetaxel; 254 received placebo + docetaxel). At the time of data cutoff, 447 patients (88%) had experienced a progression event and 346 deaths (68%) had occurred. Median progression-free survival was 3.9 months (interquartile range [IQR], 1.5-5.9) with selumetinib + docetaxel and 2.8 months (IQR, 1.4-5.5) with placebo + docetaxel (difference, 1.1 months; hazard ratio [HR], 0.93 [95% CI, 0.77-1.12]; P = .44). Median overall survival was 8.7 months (IQR, 3.6-16.8) with selumetinib + docetaxel and 7.9 months (IQR, 3.8-20.1) with placebo + docetaxel (difference, 0.9 months; HR, 1.05 [95% CI, 0.85-1.30]; P = .64). Objective response rate was 20.1% with selumetinib + docetaxel and 13.7% with placebo + docetaxel (difference, 6.4%; odds ratio, 1.61 [95% CI, 1.00-2.62]; P = .05). Median duration of response was 2.9 months (IQR, 1.7-4.8; 95% CI, 2.7-4.1) with selumetinib + docetaxel and 4.5 months (IQR, 2.3-7.3; 95% CI, 2.8-5.6) with placebo + docetaxel. Adverse events of grade 3 or higher were more frequent with selumetinib + docetaxel (169 adverse events [67%] for selumetinib + docetaxel vs 115 adverse events [45%] for placebo + docetaxel; difference, 22%).

Conclusions and Relevance

Among patients with previously treated advanced KRAS-mutant non-small cell lung cancer, addition of selumetinib to docetaxel did not improve progression-free survival compared with docetaxel alone.

Trial Registration

clinicaltrials.gov: NCT01933932.

KRAS G12C mutation as a poor prognostic marker of pemetrexed treatment in non-small cell lung cancer

BACKGROUND/AIMS

The predictive and prognostic value of KRAS mutation and its type of mutations in non-small cell lung cancer (NSCLC) are controversial. This clinical study was designed to investigate the predictive value of KRAS mutations and its mutation types to pemetrexed and gemcitabine based treatment.

METHODS

Advanced NSCLC patients tested for KRAS mutation (n = 334) were retrospectively reviewed and 252 patients with wild type epidermal growth factor receptor and no anaplastic lymphoma kinase fusion were enrolled for the analysis. KRAS mutations were observed in 45 subjects with mutation type as followed: G12C (n = 13), G12D (n = 12), G12V (n = 12), other (n = 8). Response rate (RR), progression-free survival (PFS), and overall survival (OS) of pemetrexed singlet and gemcitabine based chemotherapy were analysis.

RESULTS

Age, sex, performance status were well balanced between subjects with or without KRAS mutations. No difference was observed in RR. Hazard ratio (HR) of PFS for pemetrexed treated subjects with G12C mutation compared to subjects with KRAS wild type was 1.96 (95% confidential interval [CI], 1.01 to 3.79; p = 0.045), but other mutations failed to show clinical significance. By analysis done by PFS, compared to the subjects with transition mutation, HR was 1.48 (95% CI, 0.64 to 3.40; p = 0.360) for subjects with transversion mutation on pemetrexed treatment and 0.41 (95% CI, 0.19 to 0.87; p = 0.020) for subjects treated with gemcitabine based chemotherapy. No difference was observed in OS.

CONCLUSIONS

In this study, different drug sensitivity was observed according to the type of KRAS mutation. NSCLC subpopulations with different KRAS mutation type should be considered as different subgroups and optimal chemotherapy regimens should be searched in further confirmative studies.

Long Noncoding RNA XIST Promotes Osteosarcoma Progression by Targeting Ras-Related Protein RAP2B via miR-320b

Abnormal expression of long noncoding RNAs (lncRNAs) often contributes to the unrestricted growth and invasion of cancer cells. lncRNA X-inactive specific transcript (XIST) expression is upregulated in several cancers; however, its underlying mechanism in osteosarcoma (OS) has not been elucidated. In the present study, we found that XIST expression was significantly increased in OS tissues and cell lines by LncRNA Profiler and qRT-PCR. The effects of XIST and miR-320b on OS cell proliferation and invasion were studied by MTT and Transwell invasion assays. The competing relationship between XIST and miR-320b was confirmed by luciferase reporter assay. Our results showed that XIST knockdown strikingly inhibited cell proliferation and invasion. Furthermore, XIST could directly bind to miR-320b and repress miR-320b expression. Moreover, XIST overexpression significantly relieved the inhibition on OS cell proliferation and invasion mediated by miR-320b overexpression, which involved the derepression of Ras-related protein RAP2B. We propose that XIST is responsible for OS cell proliferation and invasion and that XIST exerts its function through the miR-320b/RAP2B axis. Our findings suggest that lncRNA XIST may be a candidate prognostic biomarker and a target for new therapies in OS patients.

Molecular biomarkers for lung adenocarcinoma

The identification of oncogenic driver alterations that underlie sensitivity to small inhibitors has led to growing interest in identifying additional targetable oncogenes in nonsmall cell lung cancer. Although the therapeutic impact of the discovery of these alterations has now been widely demonstrated, the epidemiological data associated with each of these biomarkers remain insufficiently studied. In this review, we discuss the techniques used to discover each of these candidate oncogenes, their prevalence in nonsmall cell lung cancer, and briefly outline the epidemiological features of the major oncogenes and ways in which their identification can determine therapeutic strategies.