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

Targeting KRAS in non-small-cell lung cancer: recent progress and new approaches

Rat sarcoma (RAS) is the most frequently mutated oncogene in human cancer, with Kirsten rat sarcoma (KRAS) being the most commonly mutated RAS isoform. Overall, KRAS accounts for 85% of RAS mutations observed in human cancers and is present in 35% of lung adenocarcinomas (LUADs). While the use of targeted therapies and immune checkpoint inhibitors (CPIs) has drastically changed the treatment landscape of advanced non-small-cell lung cancer (NSCLC) in recent years, historic attempts to target KRAS (both direct and indirect approaches) have had little success, and no KRAS-specific targeted therapies have been approved to date for patients in this molecular subset of NSCLC. With the discovery by Ostrem, Shokat, and colleagues of the switch II pocket on the surface of the active and inactive forms of KRAS, we now have an improved understanding of the complex interactions involved in the RAS family of signaling proteins which has led to the development of a number of promising direct KRAS^G12C inhibitors, such as sotorasib and adagrasib. In previously treated patients with KRAS^G12C-mutant NSCLC, clinical activity has been shown for both sotorasib and adagrasib monotherapy; these data suggest promising new treatment options are on the horizon. With the stage now set for a new era in the treatment of KRAS^G12C-mutated NSCLC, many questions remain to be answered in order to further elucidate the mechanisms of resistance, how best to use combination strategies, and if KRAS^G12C inhibitors will have suitable activity in earlier lines of therapy for patients with advanced/metastatic NSCLC.

Immunotherapy in oncogene addicted non-small cell lung cancer

The use of immune checkpoint inhibitors (ICIs) targeting the programmed cell death-1 (PD-1) and programmed cell death ligand-1 (PD-L1) has led to notable changes in treatment strategies for patients with advanced non-small cell lung cancer (NSCLC) and now forms a part of standard of care treatment in patients with advanced disease. However, most patients do not respond to ICI monotherapy, which may be explained by significant variations in efficacy according to different immune and molecular profiles in tumours. Improved response rates have been observed in smokers and are associated with tumors that have high mutation loads, with a higher tendency to form neoantigens. This premise itself defies the eventual significance of ICIs for oncogene-driven NSCLC, which in general are more common in never smokers and potentially have reduced capacity for neoantigen formation. Furthermore, pivotal trials investigating ICIs in advanced NSCLC have usually excluded patients with oncogenic drivers, hence the outcome of these agents in this population is poorly characterized. In this article, we aim to review the most current evidence, encompassing clinical and preclinical data focused on a wide range of oncogene-addicted NSCLCs.

Targeting KRAS in Solid Tumors: Current Challenges and Future Opportunities of Novel KRAS Inhibitors

Activating mutations in RAS family proteins are found in ~25% of all human cancers. Different solid tumors are correlated with mutations in certain isoforms of RAS, with Kirsten RAS (KRAS) being the most frequently mutated isoform. Historically, KRAS has been acknowledged as “undruggable”, largely because the RAS proteins do not appear to present suitable pockets to which small inhibitory molecules can bind. However, this scenario has changed over the last years with the advent of novel KRAS inhibitors. In this review, we describe the role of KRAS mutation across different solid tumors, providing data on novel KRAS inhibitors currently under development and an updated overview of ongoing research in this field. A literature search was performed to select papers, abstracts, and oral presentation on KRAS inhibitory strategies in KRAS mutated solid tumors. Overall, the most promising therapeutic results have been obtained with molecules targeting KRAS G12C, thus paving the way for a significant therapeutic improvement in non-small cell lung cancer. Unfortunately, KRAS G12C mutation is rather uncommon in other solid tumors, namely pancreatic ductal adenocarcinoma and colorectal cancer. Several combination strategies are currently under evaluation in clinical trials, in order to bypass the resistance mechanisms responsible for the intrinsic resistance of mutated KRAS to the main therapeutic strategies adopted to date. Results suggest that the therapeutic scenario of KRAS has started to change, and further research will bring therapeutic results in this field.

miR-34c-3p targets CDK1 a synthetic lethality partner of KRAS in non-small cell lung cancer

Lung cancer is still the leading cause of death by cancer worldwide despite advances both in its detection and therapy. Multiple oncogenic driver alterations have been discovered, opening the prospective for new potential therapeutic targets. Among them, KRAS mutations represent the most frequent oncogene aberrations in non-small cell lung cancer (NSCLC) patients with a negative prognostic impact, but effective therapies targeting KRAS are not well characterized yet. Here, we demonstrate that the microRNA miR-34c-3p is a positive prognostic factor in KRAS-mutated NSCLC patients. Firstly, looking at the TGCA dataset, we found that high miR-34c-3p expression correlated with longer survival of KRAS-mutated NSCLC patients. In vitro assays on immortalized and patient-derived primary NSCLC cells revealed that miR-34c-3p overexpression increased apoptosis and lowered proliferation rate in KRASmut cells. Computational analysis and in vitro assays identified CDK1, one of the most promising lethal targets for KRAS-mutant cancer, as a target of miR-34c-3p. Moreover, the combination of CDK1 inhibition (mediated by RO3306) and miR-34c-3p overexpression resulted in an additive effect on the viability of KRASmut-expressing cells. Altogether, our findings demonstrate that miR-34c-3p is a novel biomarker that may allow tailored treatment for KRAS-mutated NSCLC patients.

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

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

Binimetinib, pemetrexed and cisplatin, followed by maintenance of binimetinib and pemetrexed in patients with advanced non-small cell lung cancer (NSCLC) and KRAS mutations. The phase 1B SAKK 19/16 trial

BACKGROUND

KRAS mutations are found in 20-25 % of non-squamous non-small cell lung cancer (NSCLC) and therapies targeting the RAS/MEK/ERK pathway are in development. We performed a multicenter open-label phase 1B trial to determine the recommended phase 2 dose and early antitumor activity of the MEK-inhibitor binimetinib combined with cisplatin and pemetrexed.

METHODS

Eligible patients (pts) had stage III-IV NSCLC unsuitable for curative treatment, KRAS exon 2 or 3 (codon 12, 13 or 61) mutations, no prior systemic therapy. Pts were enrolled into part 1: 3 + 3 design with dose escalation in 2 dose levels (DL) of binimetinib and part 2: expansion cohort at the maximum tolerated dose (MTD). Pts received 4 cycles of cisplatin 75 mg/m², pemetrexed 500 mg/m²and binimetinib 30 (DL1)/45 mg (DL2) orally twice a day (bid) d1-14 q3w followed by pemetrexed and binimetinib until progressive disease (PD) or unacceptable toxicity.

RESULTS

From May 2017 to Dec 2019, 18 pts (13 dose escalation, 5 expansion cohort) were enrolled. Median age was 60 (48-73, range). KRAS mutations were 87.5 % at codon 12. No DLT occurred in the dose escalation cohort. Median number of cycles was 2 (1-17, range). Treatment discontinuation was mainly due to PD (33 %) or pts/physicians' decision (27 %). Together with the expansion cohort, 16 pts were evaluable for safety. Most frequent treatment-related grade 3 AEs were lung infection (25 %), fatigue (19 %), anemia (19 %). Overall response rate among 9 evaluable pts receiving binimetinib at MTD (45 mg bid) was 33 % (7-70 %, 95 % CI). Median progression-free survival was 5.7 months (1.1-14.0, 95 % CI) and overall survival 6.5 months (1.8-NR, 95 % CI).

CONCLUSIONS

Pts treated with combination of cisplatin, pemetrexed and binimetinib presented no unexpected toxicity. No early signal of increased antitumor activity of binimetinib added to chemotherapy was observed in our pts population.

Association Between Triglyceride Glucose Index and Non-Small Cell Lung Cancer Risk in Chinese Population

Background

Numerous studies showed that insulin resistance (IR) was associated with cancer risk. However, few studies investigated the relationship between IR and non-small cell lung cancer (NSCLC). The aim of this study is to explore the association of triglyceride glucose (TyG) index, a simple surrogate marker of IR, with NSCLC risk.

Methods

791 histologically confirmed NSCLC cases and 787 controls were enrolled in the present study. Fasting blood glucose and triglyceride were measured. The TyG index was calculated as ln [fasting triglycerides (mg/dl) ×fasting glucose (mg/dl)/2]. Logistic regression analysis was performed to estimate the relationship between NSCLC risk and the TyG index.

Results

The TyG index was significantly higher in patients with NSCLC than that in controls (8.42 ± 0.55 vs 8.00 ± 0.45, P < 0.01). Logistic regression analysis showed that the TyG index (OR = 3.651, 95%CI 2.461–5.417, P < 0.001) was independently associated with NSCLC risk after adjusting for conventional risk factors. In addition, a continuous rise in the incidence of NSCLC was observed along the tertiles of the TyG index (29.4 vs 53.8 vs 67.2%, P < 0.001). However, there were no differences of the TyG index in different pathological or TNM stages. In receiver operating characteristic (ROC) curve analysis, the optimal cut-off level for the TyG index to predict incident NSCLC was 8.18, and the area under the ROC curve (AUROC) was 0.713(95% CI 0.688–0.738).

Conclusions

The TyG index is significantly correlated with NSCLC risk, and it may be suitable as a predictor for NSCLC.

The Hispanic paradox in non-small cell lung cancer

OBJECTIVE/BACKGROUND

According to the U.S. Census Bureau, 18% of the total population in the United States identified themselves as Hispanic in 2016 making it the largest minority group. This study aimed to evaluate the effect of Hispanic ethnicity on the overall survival of patients with non-small cell lung cancer (NSCLC) using a large national cancer database.

METHODS

We used the National Cancer Database to identify patients diagnosed with NSCLC between 2010 and 2015. The two comparative groups for this study were non-Hispanic Whites (NHWs) and Hispanics. The primary outcome was overall survival.

RESULTS

Of the 555,475 patients included in the study, 96.9% and 3.1% were NHWs and Hispanics with a median follow up of 12.6 months (interquartile range 4.1-30.6) and 12.1 months (interquartile range 3.8-29.5), respectively. Hispanics were more likely to be uninsured, and live in areas with lower median household income or education level. In the age-, sex-, and comorbidities-adjusted Cox model, the overall survival was significantly better in Hispanics compared with NHWs (hazard ratio [HR] 0.92, 95% confidence interval 0.90-0.93, p < .001). In a demographic, socioeconomic, clinical, and facility characteristics adjusted Cox model, Hispanics had further improvement in survival (HR 0.79, 95% confidence interval 0.78-0.81, p < .001). The survival advantage was seen in all cancer stages: Stage I-HR 0.76 (0.71-0.80), Stage II-HR 0.85 (0.79-0.92), Stage III-HR 0.81 (0.77-0.85), and Stage IV-HR 0.79 (0.77-0.81).

CONCLUSION

Hispanic ethnicity was associated with better survival in NSCLC. This survival advantage is likely the result of complex interactions amongst several physical, social, cultural, genomic, and environmental factors.

TTN/TP53 mutation might act as the predictor for chemotherapy response in lung adenocarcinoma and lung squamous carcinoma patients

BACKGROUND

Chemotherapy is the preferred treatment in many types of cancer including lung cancer. However, most of patients resist chemotherapy resulting in disease progressive and recurrence. Titin (TTN) mutation is proved as a beneficial role in lung squamous carcinoma (LUSC), but the predictive role on chemotherapy resistance of lung cancer is still limited and discussable.

METHODS

Clinical information and related somatic mutation profiles were obtained from The Cancer Genome Atlas (TCGA) database and analyzed by R-Studio using R-package. Overall survival (OS) curve and the association between gene mutation and clinical features were determined by GraphPad 6.0 software.

RESULTS

Available data including 563 lung adenocarcinoma (LUAD) and 505 LUSC subjects were included in this study. Among all patients, 205 out of 563 LUAD and 326 out of 505 LUSC patients displayed TTN gene mutation. When comparing the clinical features in TTN-mutated patients to patients without TTN mutation who received chemotherapy, the tumors were always located in the upper lung in LUAD patients with TTN mutation and most of TTN-mutated subjects were at low pathological stage, which was not observed in LUSC patients. However, patients with TTN-mutation, particularly missense mutation, had a higher chemosensitivity and longer OS period than that patients without TTN mutation in both LUAD and LUSC. Of note, LUAD and LUSC patients possessed favorable OS and better chemotherapy response benefiting from TTN/tumor protein 53 (TP53) double mutation compared to TTN and TP53 mutation alone, respectively. Additionally, TTN/TP53 double mutation-initiated high rate of chemotherapy response were largely concentrated within LUAD and LUSC patients whose anatomic neoplasm subdivision were located in the upper lung.

CONCLUSIONS

Collectively, TTN/TP53 co-mutation is possibly served as an effective predictor for OS and chemotherapy response in lung cancer.

RBM10 Regulates Tumor Apoptosis, Proliferation, and Metastasis

The RNA-binding motif protein 10 (RBM10) is involved in alternative splicing and modifies mRNA post-transcriptionally. RBM10 is abnormally expressed in the lung, breast, and colorectal cancer, female genital tumors, osteosarcoma, and other malignant tumors. It can inhibit proliferation, promote apoptosis, and inhibit invasion and metastasis. RBM10 has long been considered a tumor suppressor because it promotes apoptosis through the regulation of the MDM2-p53 negative feedback loop, Bcl-2, Bax, and other apoptotic proteins and inhibits proliferation through the Notch signaling and rap1a/Akt/CREB pathways. However, it has been recently demonstrated that RBM10 can also promote cancer. Given these different views, it is necessary to summarize the research progress of RBM10 in various fields to reasonably analyze the underlying molecular mechanisms, and provide new ideas and directions for the clinical research of RBM10 in various cancer types. In this review, we provide a new perspective on the reasons for these opposing effects on cancer biology, molecular mechanisms, research progress, and clinical value of RBM10.

Rap2B promotes the proliferation and migration of human glioma cells via activation of the ERK pathway

Glioma is one of the most common primary brain tumors and has a poor prognosis. Rap2B, a member of the Ras family of oncogenes, is highly expressed and promotes the progression of several tumors, including glioma. However, the mechanism underlying the role of Rap2B in glioma is not fully understood. In the present study, after transfection, Rap2B expression was detected by reverse transcription PCR and western blot analysis. Cell proliferation and cell migration assays were performed to determine the effects of Rap2B on the malignant biological behaviors of glioma cells. The changes of ERK pathway-associated proteins were examined by western blot analysis. Enzyme-linked immunosorbent assay (ELISA) and western blot analysis were utilized to detect the protein levels of matrix metalloproteinase (MMP)2 and MMP9. Then, The Cancer Genome Atlas database was used to determine the association between Rap2B expression and clinical parameters in patients with glioblastoma multiforme and low-grade glioma (LGG). Results revealed that Rap2B was highly expressed in human glioma compared with that in adjacent normal tissues and normal human astrocytes, and that silenced Rap2B led to a reduction of cell proliferation and migration ability in glioma cells. Conversely, overexpressed Rap2B in both U87 and U251 cells significantly enhanced these malignant activities. In addition, ELISA assay and western blotting showed that Rap2B increased MMP2 and MMP9 expression. The western blot assay revealed that Rap2B induced the phosphorylation of ERK in glioma cells. Furthermore, silencing the ERK pathway by SCH772984 led to the inhibition of Rap2B-mediated proliferation, migration and the reduction of MMP2 and MMP9 expression. Kaplan-Meier analysis revealed that increased Rap2B expression was associated with poorer survival of patients with LGG. These results demonstrated that Rap2B may participate in the processes of glioma cell proliferation and migration through enhancing MMP2 and MMP9 expression via the ERK pathway. Thus, Rap2B could potentially be used as a promising therapeutic target and prognostic biomarker in glioma.

KRAS G12C-mutated advanced non-small cell lung cancer: A real-world cohort from the German prospective, observational, nation-wide CRISP Registry (AIO-TRK-0315)

OBJECTIVES

After decades of unsuccessful efforts in inhibiting KRAS, promising clinical data targeting the mutation subtype G12C emerge. Since little is known about outcome with standard treatment of patients with G12C mutated non-small cell lung cancer (NSCLC), we analyzed a large, representative, real-world cohort from Germany.

PATIENTS AND METHODS

A total of 1039 patients with advanced KRAS-mutant or -wildtype NSCLC without druggable alterations have been recruited in the prospective, observational registry CRISP from 12/2015 to 06/2019 by 98 centers in Germany. Details on treatment, best response, and outcome were analyzed for patients with KRAS wildtype, G12C, and non-G12C mutations.

RESULTS

Within the study population, 160 (15.4 %) patients presented with KRAS G12C, 251 (24.2 %) with non-G12C mutations, 628 (60.4 %) with KRAS wildtype. High PD-L1 expression (Tumor Proportion Score, TPS > 50 %) was documented for 28.0 %, 43.5 %, and 28.9 % (wildtype, G12C, non-G12C) of the tested patients; 68.8 %, 89.3 %, and 87.7 % of the patients received first-line treatment combined with an immune checkpoint-inhibitor in 2019. TPS > 50 % vs. TPS < 1 % was associated with a significantly decreased risk of mortality in a multivariate Cox model (HR 0.39, 95 % CI 0.26-0.60, p=<0.001). There were no differences in clinical outcome between KRAS wildtype, G12C or non-G12C mutations and KRAS mutational status was not prognostic in the model.

CONCLUSION

Here we describe the so far largest prospectively recruited cohort of patients with advanced NSCLC and KRAS mutations, with special focus on the G12C mutation. These data constitute an extremely valuable historical control for upcoming clinical studies that employ KRAS inhibitors.

The effects of bisphosphonate and radiation therapy in bone-metastatic lung adenocarcinoma: the impact of KRAS mutation

Background

KRAS mutation is the most common genetic alteration in lung adenocarcinoma (LADC) in Western countries and is associated with worse outcome in bone-metastatic cases. Yet, to date, no effective treatment guidelines were developed for these patients. Accordingly, our aim was to investigate the impact of KRAS mutation on bisphosphonate (BTx) and radiation therapy (RTx) in bone-metastatic LADC patients.

Methods

Clinicopathological variables of 134 consecutive LADC patients with bone metastases at diagnosis and known KRAS status were retrospectively analyzed. The effects of BTx, RTx and KRAS mutation on overall survival (OS) were investigated.

Results

Of the total cohort, 93 patients were identified as KRAS wild-type (WT) (69.4%) and 41 (30.6%) as KRAS mutant patients. The presence of KRAS mutation was associated with significantly reduced median OS (5.1 vs. 10.2 months in KRAS WT patients; P=0.008). Irrespective of KRAS mutational status both BTx (P=0.007) and RTx (P=0.021) conferred a significant benefit for OS. Notably, however, when analyzing the patients with KRAS-mutant and KRAS WT tumors separately, the benefit from BTx and RTx on OS remained statistically significant only in KRAS WT patients (P=0.032 and P=0.031, respectively).

Conclusions

KRAS mutation is a strong negative prognostic factor in bone-metastatic LADC patients. Both BTx and RTx can increase the OS with a pronounced benefit for patients with KRAS WT tumors. Altogether, KRAS mutational status should be considered during therapeutic decision making in bone-metastatic LADC patients.

The improbable targeted therapy: KRAS as an emerging target in non-small cell lung cancer (NSCLC)

KRAS is a frequent oncogenic driver in solid tumors, including non-small cell lung cancer (NSCLC). It was previously thought to be an "undruggable" target due to the lack of deep binding pockets for specific small-molecule inhibitors. A better understanding of the mechanisms that drive KRAS transformation, improved KRAS-targeted drugs, and immunological approaches that aim at yielding immune responses against KRAS neoantigens have sparked a race for approved therapies. Few treatments are available for KRAS mutant NSCLC patients, and several approaches are being tested in clinicals trials to fill this void. Here, we review promising therapeutics tested for KRAS mutant NSCLC.

Molecular Epidemiology of the Main Druggable Genetic Alterations in Non-Small Cell Lung Cancer

Lung cancer is the leading cause of death for malignancy worldwide. Its molecular profiling has enriched our understanding of cancer initiation and progression and has become fundamental to provide guidance on treatment with targeted therapies. Testing the presence of driver mutations in specific genes in lung tumors has thus radically changed the clinical management and outcomes of the disease. Numerous studies performed with traditional sequencing methods have investigated the occurrence of such mutations in lung cancer, and new insights regarding their frequency and clinical significance are continuously provided with the use of last generation sequencing technologies. In this review, we discuss the molecular epidemiology of the main druggable genetic alterations in non-small cell lung cancer, namely EGFR, KRAS, BRAF, MET, and HER2 mutations or amplification, as well as ALK and ROS1 fusions. Furthermore, we investigated the predictive impact of these alterations on the outcomes of modern targeted therapies, their global prognostic significance, and their mutual interaction in cases of co-occurrence.

TRIM58 is a prognostic biomarker remodeling the tumor microenvironment in KRAS-driven lung adenocarcinoma

Aim: To comprehensively analyze the expression profiles of ubiquitin-related genes (URGs) and determine potential biomarkers in KRAS-driven lung adenocarcinoma (LUAD). Materials & methods: Differential expression analyses were performed between KRAS-wild and KRAS-mutant LUAD samples from The Cancer Genome Atlas database, and 34 URGs were screened out. ESTIMATE and CIBERSORT methods were used to calculate the ratio of immune and stromal components. Results & conclusion: TRIM58 was positively correlated with abundances of M2 macrophages and resting mast cells and negatively correlated with follicular helper T-cell abundances in KRAS-driven LUAD. TRIM58 was a potential prognosis-associated indicator for tumor microenvironment modulation and played a key role in TME-specific AS landscapes alterations in KRAS-driven LUAD.

The novel rexinoid MSU-42011 is effective for the treatment of preclinical Kras-driven lung cancer

Effective drugs are needed for lung cancer, as this disease remains the leading cause of cancer-related deaths. Rexinoids are promising drug candidates for cancer therapy because of their ability to modulate genes involved in inflammation, cell proliferation or differentiation, and apoptosis through activation of the retinoid X receptor (RXR). The only currently FDA-approved rexinoid, bexarotene, is ineffective as a single agent for treating epithelial cancers and induces hypertriglyceridemia. Here, we used a previously validated screening paradigm to evaluate 23 novel rexinoids for biomarkers related to efficacy and safety. These biomarkers include suppression of inducible nitric oxide synthase (iNOS) and induction of sterol regulatory element-binding protein (SREBP). Because of its potent iNOS suppression, low SREBP induction, and activation of RXR, MSU-42011 was selected as our lead compound. We next used MSU-42011 to treat established tumors in a clinically relevant Kras-driven mouse model of lung cancer. KRAS is one of the most common driver mutations in human lung cancer and correlates with aggressive disease progression and poor patient prognosis. Ultrasound imaging was used to detect and monitor tumor development and growth over time in the lungs of the A/J mice. MSU-42011 markedly decreased the tumor number, size, and histopathology of lung tumors compared to the control and bexarotene groups. Histological sections of lung tumors in mice treated with MSU-42011 exhibited reduced cell density and fewer actively proliferating cells compared to the control and bexarotene-treated tumors. Although bexarotene significantly (p < 0.01) elevated plasma triglycerides and cholesterol, treatment with MSU-42011 did not increase these biomarkers, demonstrating a more favorable toxicity profile in vivo. The combination of MSU-42011 and carboplatin and paclitaxel reduced macrophages in the lung and increased activation markers of CD8+T cells compared to the control groups. Our results validate our screening paradigm for in vitro testing of novel rexinoids and demonstrate the potential for MSU-42011 to be developed for the treatment of KRAS-driven lung cancer.

Genetic characterisation of sarcomatoid carcinomas reveals multiple novel actionable mutations and identifies KRAS mutation as a biomarker of poor prognosis

BACKGROUND

Sarcomatoid component occurs in various epithelial malignancies and is associated with an aggressive disease course and poor clinical outcome. As it is largely rare, the molecular events underlying sarcomatoid carcinomas (SCs) remain poorly characterised. Here, we performed targeted next-generation sequencing (NGS) on patients with surgically resected SCs comprising distinct tissues of origin.

METHODS

A total of 71 patients with pathological diagnosis of sarcomatoid carcinomas and underwent surgery were retrospectively enrolled in this study. Overall survival (OS) was defined as the time from surgery to death from any cause. Patients alive or lost to follow-up were censored. Genomic DNA from formalin-fixed paraffin-embedded samples was extracted for NGS and tumour mutation burden (TMB) analysis.

RESULTS

In general, SCs occurred more commonly in males, except those of the gallbladder. SCs of the lung and the larynx were associated with a higher proportion of smokers (p=0.0015). Alterations in TP53, RB1, TERT and KRAS were highly frequent, with KRAS mutations being a biomarker of poor prognosis (median OS=8 vs 16 months, p=0.03). Multiple alterations in potentially actionable genes, including ROS1 and NTRK1 fusions and ERBB2 amplification, were detected in the extra-pulmonary cohort. A relatively high proportion (30%) of patients with extra-pulmonary SC had high TMB, with a median of 5.39 mutations per Mb. Lastly, copy number variations were common in SCs, and were non-overlapping between the primary and metastatic tumours.

CONCLUSION

Taken together, our results suggest that comprehensive genetic testing may be necessary to inform treatment options and identify prognostic biomarkers.

Correlation Analysis Among the Level of IL-35, Microvessel Density, Lymphatic Vessel Density, and Prognosis in Non-Small Cell Lung Cancer

The aim of this study was to determine the expression of IL‐35 and the lymphatic vessel density (LVD) and microvessel density (MVD) in the pathological tissues from patients with non‐small cell lung cancer (NSCLC) and to analyze their correlation with other common clinical prognostic factors, as well as patients’ overall survival and progression‐free survival. We analyzed the pathological characteristics of 130 patients with NSCLC and determined the IL‐35 expression, MVD, and LVD changes in the pathological tissues by immunohistochemistry. The results showed that IL‐35 expression was significantly correlated with tumor differentiation, lymph node metastasis, T staging, LVD, and MVD (P < 0.05) but was not associated with age, sex, smoking, and other factors. Univariate analysis of risk models showed that age, lymph node metastasis, T stage, and high IL‐35 expression, LVD, and MVD were significantly associated with NSCLC prognosis (P < 0.05), whereas sex, smoking, and high differentiation were not correlated with prognosis. Multivariate analysis of the proportional risk model showed that the IL‐35 expression, lymph node metastasis, high LVD, and high MVD were significantly correlated with NSCLC prognosis (P < 0.05). In conclusion, IL‐35, MVD, and LVD may be independent prognostic markers. In addition, IL‐35 might represent a promising clinical drug target for the treatment of NSCLC.

KRAS oncogene may be another target conquered in non-small cell lung cancer (NSCLC)

Kirsten rat sarcoma viral oncogene homolog (KRAS) is one of the most common mutant oncogenes in non‐small cell lung cancer (NSCLC). The survival of patients with KRAS mutations may be much lower than patients without KRAS mutations. However, due to the complex structure and diverse biological properties, it is difficult to achieve specific inhibitors for the direct elimination of KRAS activity, making KRAS a challenging therapeutic target. At present, with the tireless efforts of medical research, including KRAS G12C inhibitors, immunotherapy and other combination strategies, this dilemma is expected to an end. In addition, inhibition of the downstream signaling pathways of KRAS may be a promising combination strategy. Given the rapid development of treatments, understanding the details will be important to determine the individualized treatment options, including combination therapy and potential resistance mechanisms.

The survival of patients with KRAS mutations may be much lower than patients without KRAS mutations. At present, with the tireless efforts of medical research, including KRAS G12C inhibitors, immunotherapy and other combination strategy, this dilemma of KRAS mutated NSCLC is expected to an end.

Clinical Characteristics, Treatments, and Concurrent Mutations in Non-Small Cell Lung Cancer Patients With NF1 Mutations

OBJECTIVES

Metastatic non-small cell lung cancer (mNSCLC) is characterized by complex genomic alterations. NF1 mutations may confer distinct clinical characteristics within NSCLC, and real-world evidence on concurrent mutations, treatment patterns, and health outcomes is lacking.

MATERIALS AND METHODS

This retrospective study was performed in patients with mNSCLC treated in the Flatiron Health network who underwent the FoundationOne tumor-sequencing. Anticancer therapies, concurrent mutations, real-world progression-free survival (rwPFS), and overall survival (OS) were assessed.

RESULTS

Of the 1663 patients, 103 patients were identified with NF1 mutation. Concurrent mutations with Ki-ras2 Kirsten rat sarcoma viral oncogene homolog (16.5%) and epidermal growth factor receptor fusion (6.8%) were the most frequent. In patients with NF1 mutation only (n = 57), 42% were women, 86% patients had smoking history, and 70% had non-squamous cell carcinoma type. Most (51%) of the patients with NF1 mutations received a single line of therapy versus other mutations and the overall treated population (44%). Platinum-based chemotherapy was the predominant first-line therapy, with programmed cell death-1/programmed cell death-ligand-1 inhibitors as subsequent lines of therapy. The NF1 mutation only group had numerically the shortest median rwPFS (82 days) than other mutation groups. Median OS for the NF1 mutation group in first, second, and third lines of therapy was 321, 498, and 210 days, respectively.

CONCLUSIONS

NF1 mutations confer distinct clinical characteristics in patients with mNSCLC. These patients may have different trajectories for progression and survival than seen for other mutations, experience less systemic therapy after first-line therapy, and may have shorter survival.

NEMPD: a network embedding-based method for predicting miRNA-disease associations by preserving behavior and attribute information

Background

As an important non-coding RNA, microRNA (miRNA) plays a significant role in a series of life processes and is closely associated with a variety of Human diseases. Hence, identification of potential miRNA-disease associations can make great contributions to the research and treatment of Human diseases. However, to our knowledge, many existing computational methods only utilize the single type of known association information between miRNAs and diseases to predict their potential associations, without focusing on their interactions or associations with other types of molecules.

Results

In this paper, we propose a network embedding-based method for predicting miRNA-disease associations by preserving behavior and attribute information. Firstly, a heterogeneous network is constructed by integrating known associations among miRNA, protein and disease, and the network representation method Learning Graph Representations with Global Structural Information (GraRep) is implemented to learn the behavior information of miRNAs and diseases in the network. Then, the behavior information of miRNAs and diseases is combined with the attribute information of them to represent miRNA-disease association pairs. Finally, the prediction model is established based on the Random Forest algorithm. Under the five-fold cross validation, the proposed NEMPD model obtained average 85.41% prediction accuracy with 80.96% sensitivity at the AUC of 91.58%. Furthermore, the performance of NEMPD is also validated by the case studies. Among the top 50 predicted disease-related miRNAs, 48 (breast neoplasms), 47 (colon neoplasms), 47 (lung neoplasms) were confirmed by two other databases.

Conclusions

The proposed NEMPD model has a good performance in predicting the potential associations between miRNAs and diseases, and has great potency in the field of miRNA-disease association prediction in the future.

Polyisoprenylated Cysteinyl Amide Inhibitors Deplete K-Ras and Induce Caspase-dependent Apoptosis in Lung Cancer Cells

BACKGROUND

Non-small cell lung cancers (NSCLC) harboring mutation-induced dysregulation of Ras signaling present some of the most difficult-to-manage cases, since directly targeting the constitutively active mutant Ras proteins has not resulted in clinically useful drugs. Therefore, modulating Ras activity for targeted treatment of cancer remains an urgent healthcare need.

OBJECTIVE

In the current study, we investigated a novel class of compounds, the polyisoprenylated cysteinyl amide inhibitors (PCAIs), for their anticancer molecular mechanisms using the NSCLC cell panel with K-Ras and/or other mutant genes.

METHODS

The effect of the PCAIs on intracellular K-Ras levels, cell viability, apoptosis, spheroid and colony formation were determined.

RESULTS

Treatment of the lung cancer cells with the PCAIs, NSL-RD-035, NSL-BA-036, NSL-BA- 040 and NSL-BA-055 resulted in concentration-dependent cell death in both K-Ras mutant (A549, NCI-H460, and NCI-H1573), N-Ras mutant (NCI-H1299) and other (NCI-H661, NCI-H1975, NCIH1563) NSCLC cells. The PCAIs at 1.0 -10 μM induced the degeneration of 3D spheroid cultures, inhibited clonogenic cell growth and induced marked apoptosis via the extrinsic pathway. The most potent of the PCAIs, NSL-BA-055, at 5 μM induced a seven-fold increase in the activity of caspase- 3/7 and a 75% selective depletion of K-Ras protein levels relative to GAPDH in A549 cells that correlated with PCAIs-induced apoptosis. NSL-BA-040 and NSL-BA-055 also induced the phosphorylation of MAP kinase (ERK 1/2).

CONCLUSION

Taken together, PCAIs may be potentially useful as targeted therapies that suppress NSCLC progression through disruption of Ras-mediated growth signaling.

In silico and saturation transfer difference NMR approaches to unravel the binding mode of an andrographolide derivative to K-Ras oncoprotein

Background: Andrographolide and its benzylidene derivatives, SRJ09 and SRJ23, potentially bind oncogenic K-Ras to exert anticancer activity. Their molecular interactions with K-Ras oncoproteins that lead to effective biological activity are of major interest. Methods & results: In silico docking and molecular dynamics simulation were performed using Glide and Desmond, respectively; while saturation transfer difference NMR was performed using GDP-bound K-RasG12V. SRJ23 was found to bind strongly and selectively to K-RasG12V, by anchoring to a binding pocket (namely p2) principally via hydrogen bond and hydrophobic interactions. The saturation transfer difference NMR analysis revealed the proximity of protons of functional moieties in SRJ23 to K-RasG12V, suggesting positive binding. Conclusion: SRJ23 binds strongly and interacts stably with K-RasG12V to exhibit its inhibitory activity.

Role of immunotherapy and co-mutations on KRAS-mutant non-small cell lung cancer survival

Background

KRAS mutations reported in non-small cell lung cancer (NSCLC) represent a significant percentage of patients diagnosed with NSCLC. However, there still remains no therapeutic option designed to target KRAS. In an era with immunotherapy as a dominant treatment option in metastatic NSCLC, the role of immunotherapy in

KRAS

mutated patients is not clear.

Methods

Eligible patients diagnosed with NSCLC and found to have a KRAS mutation were identified in an institutional lung cancer database. Demographic, clinical, and molecular data was collected and analyzed.

Results

A total of 60 patients were identified for this retrospective analysis. Majority of patients were Caucasian (73%), diagnosed with stage IV (70%) adenocarcinoma (87%), and had a KRAS codon 12 mutation (78%). Twenty percent of patients were treated with immunotherapy. Median overall survival was 28 months in the cohort and patients who received immunotherapy were found to have better survival versus those who did not (33 vs. 22 months, P=0.31). Furthermore, there was an association between high survival and patients who received immunotherapy (P=0.007).

Conclusions

Patients with KRAS mutations have a unique co-mutation phenotype that requires further investigation. Immunotherapy seems to be an effective choice of treatment for KRAS positive patients in any treatment-line setting and yields better outcomes than conventional chemotherapy. The relationship between immunotherapy and KRAS mutations requires further studies to confirm survival advantage.

Risk Stratification of Locally Advanced Non-Small Cell Lung Cancer (NSCLC) Patients Treated with Chemo-Radiotherapy: An Institutional Analysis

Background

The purpose of this study was to determine which factors predicted survival and to derive a risk prediction model for patients with locally advanced non-small cell lung cancer (NSCLC) receiving concurrent chemo-radiotherapy (cCRT).

Methods

This investigation included 149 patients with locally advanced NSCLC who were treated with cCRT at Stony Brook University Hospital between 2007 and 2015. A finite set of demographic, clinical, and treatment variables were evaluated as independent prognostic factors. Kaplan–Meier survival curves were generated, and log rank tests were used to evaluate difference in survival between groups. To derive a risk score for mortality, a machine learning approach was utilized. To maximize statistical power while examining replicability, the sample was split into discovery (n=99) and replication (n=50) subsamples. Elastic-net regression was used to identify a linear prediction model. Youden’s index was used to identify appropriate cutoffs. Cox proportional hazards regression was used to examine mortality risk; model concordance and hazards ratios were reported.

Results

One-quarter of the patients survived for three years after initiation of cCRT. Prognostic factors for survival in the discovery group included age, sex, smoking status, albumin, histology, largest tumor size, number of nodal stations, stage, induction therapy, and radiation dose. The derived model had good risk predictive accuracy (C=0.70). Median survival time was shorter in the high-risk group (0.93 years) vs the low-risk group (2.40 years). Similar findings were noted in the replication sample with strong model accuracy (C=0.69) and median survival time of 0.93 years and 2.03 years for the high- and low-risk groups, respectively.

Conclusion

This novel risk prediction model for overall survival in patients with stage III NSCLC highlights the importance of integrating patient, clinical, and treatment variables for accurately predicting outcomes. Clinicians can use this tool to make personalized treatment decisions for patients with locally advanced NSCLC treated with concurrent chemo-radiation.

KRAS mutation as a prognostic factor and predictive factor in advanced/metastatic non-small cell lung cancer: A systematic literature review and meta-analysis

KRAS (Kirsten Rat Sarcoma) is the most common oncogenic mutation detected in patients with non-small cell lung cancer (NSCLC). However, the role of KRAS as either a prognostic factor or predictive factor (modifier of treatment effects) in NSCLC is not well established at this time. This systematic literature review (SLR) and meta-analysis synthesized the available evidence regarding the role of KRAS mutation as a predictive factor and/or prognostic factor of survival and response outcomes in patients with advanced/metastatic (stage IIIB-IV) NSCLC. Relevant clinical trials and observational studies were identified by searching MEDLINE, Embase and Cochrane Register of Controlled Trials. Meta-analyses were performed using data extracted from multivariable and univariable analyses from clinical studies to assess the empirical evidence of KRAS mutation status as a prognostic or/and predicitive factor. 43 selected studies were identified by the SLR and included in this meta-analysis. Pairwise meta-analyses of hazard ratios (HRs) reported in randomized controlled trials (RCTs) did not demonstrate a significant prognostic effect of mutant KRAS on overall survival (OS) (HR=1.10; 95% CI [0.88, 1.38]) or progression free survival (PFS) (HR=1.03; 95% CI [0.80, 1.33]). However, when conducting meta-analyses on HRs reported in observational studies, a statistically significant negative prognostic effect of mutant KRAS was observed (OS HR=1.71; 95% CI [1.07, 2.84]; PFS HR=1.18; 95% CI [1.02, 1.36]). Meta-analyses of objective response rate (ORR) in RCTs demonstrated a negative prognostic effect of mutant KRAS (RR=0.38; 95% CI [0.16, 0.63]). Limited data were available to evaluate the role of KRAS mutation as a predictive factor. In conclusion, this research offers evidence that KRAS mutation may be a negative prognostic factor for survival and response outcomes in patients with advanced/metastatic NSCLC, but further research is needed to address conflicting results on the importance of KRAS mutations as a predictive factor.

Prognostic Value of KRAS Mutation Subtypes and PD-L1 Expression in Patients With Lung Adenocarcinoma

BACKGROUND

The prognostic value of different KRAS (Kirsten rat sarcoma viral oncogene) mutation subtypes and their association with programmed death ligand 1 (PD-L1) expression in lung adenocarcinoma (LADC) remain unclear. We examined the association of KRAS mutation subtypes with clinical outcomes and PD-L1 expression status.

PATIENTS AND METHODS

Patients diagnosed with KRAS-mutated LADC were evaluated for PD-L1 expression, cancer staging, overall survival (OS), and relapse-free survival.

RESULTS

A cohort of 254 KRAS-mutated LADC patients (median follow-up, 17 months) was studied. The 3 major subtypes of KRAS mutations were G12C (46.1%), G12V (21.7%), and G12D (15.7%). We found that all these subtypes had no impact on cancer stages, brain metastasis at diagnosis, OS, and relapse-free survival. Among this cohort, 33% of 94 patients who had PD-L1 staining data available had PD-L1-positive disease (≥ 1% of tumor cells). PD-L1 expression status was not significantly different among the 3 major mutation subtypes. Of interest, among patients with G12C mutation, positive PD-L1 expression was associated with significantly shorter OS (median survival, 5.7 vs. 12.8 months, P = .007). In multivariable analysis, PD-L1 positivity remained as an adverse factor for OS, with hazard ratio of 4.44 (P = .0007). PD-L1 status did not affect OS in other subtypes of mutations.

CONCLUSION

KRAS mutation subtype is not associated with patient clinical outcomes or PD-L1 expression status. However, PD-L1 positivity appears to negatively affect OS in LADC patients with G12C mutation. Further study is needed to confirm our observation and to determine if programmed cell death 1/PD-L1 antagonist may affect the clinical outcome of patients with different KRAS mutation subtypes.

Mutational Portrait of Lung Adenocarcinoma in Brazilian Patients: Past, Present, and Future of Molecular Profiling in the Clinic

Objectives: Approximately 60% of lung adenocarcinomas (LAs) carry mutations that can guide treatment with tyrosine-kinase inhibitors (TKI) and other targeted therapies. Data on activating mutations in EGFR and other tyrosine-kinase receptor (TKR) genes in highly admixed populations, such as that of Brazil, are scarce. In this study, we comprehensively analyzed the actionable alteration profile of LA in Brazilian patients.

Materials and Methods:EGFR driver mutation data were collected from a large Brazilian LA cohort covering an 8-year period of molecular testing in a single institution. Tests were performed using three distinct methods, and demographic and histopathological data were analyzed. For a subset of patients, driver mutations in KRAS, NRAS, and BRAF and gene fusions involving TKR genes (before TKI treatment) and EGFR T790M (after TKI treatment) were assessed.

Results:EGFR mutations were detected in 25% of 1,316 LAs evaluated, with exon 19 deletions and exon 21 L858R TKI sensitizing mutations representing 72.5% of all mutations. Mutation rates were higher in women and non-smokers (p < 0.001). Next-generation sequencing was very sensitive, with a lower rate of inconclusive results compared with Sanger sequencing and pyrosequencing. EGFR/RAS/BRAF hotspot gene panels were applied in 495 LA cases and detected oncogenic mutations in 51.3% of samples, most frequently in EGFR (22.4%) and KRAS (26.9%). In subgroups of 36 and 35 patients, gene fusions were detected in 11.1% of tumors and EGFR T790M resistance mutations were detected in 59% of plasma samples from patients previously treated with TKI, respectively.

Conclusion: This report provides the first comprehensive actionable alteration portrait of LA in Brazil. The high rate of actionable alterations in EGFR and other driver genes in LA reinforces the need to incorporate TKI guided by molecular diagnostics into clinical routines for patients in both public and private healthcare systems.

Real world outcomes in KRAS G12C mutation positive non-small cell lung cancer

BACKGROUND

KRAS mutations are found in 20-30 % of non-small cell lung cancers (NSCLC) and were traditionally considered undruggable. KRAS^G12C mutation confers sensitivity to KRAS^G12C covalent inhibitors, however its prognostic impact remains unclear. This study assesses the frequency, clinical features, prevalence of brain metastases and outcomes in KRAS^G12C NSCLC in a real-world setting.

METHODS

Patients enrolled in the prospective Thoracic Malignancies Cohort (TMC) between July 2012 to October 2019 with recurrent/metastatic non-squamous NSCLC, available KRAS results, and without EGFR/ALK/ROS1 gene aberrations, were selected. Data was extracted from TMC and patient records. Clinicopathologic features, treatment and overall survival (OS) was compared for KRAS wildtype (KRAS^WT) and KRAS mutated (KRAS^mut); and KRAS^G12C and other (KRAS^other) mutations.

RESULTS

Of 1386 NSCLC patients, 1040 were excluded: non-metastatic/recurrent (526); unknown KRAS status (356); ALK/EGFR/ROS1 positive (154); duplicate (4). Of 346 patients analysed, 144 (42 %) were KRAS^mut, of whom 65 (45 %) were KRAS^G12C. All patients with KRAS^G12C were active or ex-smokers, compared to 92 % of KRAS^other and 83 % of KRAS^WT. The prevalence of brain metastases during follow-up was similar between KRAS^mut and KRAS^WT (33 % vs 40 %, p = 0.17), and KRAS^G12C and KRAS^other (40 % vs 41 %, p = 0.74). The proportion of patients receiving one or multiple lines of systemic therapy was comparable. OS was similar between KRAS^mut and KRAS^WT (p = 0.54), and KRAS^G12C and KRAS^other (p = 0.39).

CONCLUSION

Patients with KRAS^mut and KRAS^WT, and KRAS^G12C and KRAS^other NSCLC have comparable clinical features, treatment and survival. While not prognostic, KRAS^G12C may be an important predictive biomarker as promising KRAS^G12C covalent inhibitors continue to be developed.

The prognostic value of Kirsten rat sarcoma viral oncogene homolog mutations in resected lung adenocarcinoma differs according to clinical features

BACKGROUND

The ninth edition of lung cancer staging system recommends that specific driver mutations should be considered as prognostic factors in survival models. This study comprehensively investigated the prognostic value of Kirsten rat sarcoma viral oncogene homolog (KRAS) mutation in patients with resected lung adenocarcinomas according to different clinicopathologic and radiologic characteristics.

METHODS

In total, 1464 patients with completely resected primary lung adenocarcinomas were examined for KRAS mutations from November 2008 to March 2015. Age, sex, smoking status, performance status, tumor-node-metastasis stage, radiologic features, and histologic subtypes were collected. Competing risk model was used to estimate the cumulative incidence rate of recurrence. Cox regression multivariable analyses on recurrence-free survival (RFS) and overall survival (OS) were performed.

RESULTS

KRAS mutations were more frequent in male subjects (P < .001), current/former smokers (P < .001), invasive mucinous adenocarcinoma (P < .001), and solid tumors (P < .001). In general, KRAS-mutated patients had greater cumulative recurrence rate (hazard ratio [HR], 1.95; 95% confidence interval [CI], 1.23-3.08; P < .001) and worse overall survival (OS; HR, 1.88; 95% CI, 1.23-2.87; P < .001) than KRAS wild-type patients. The OS (P < .001) of patients harboring KRAS-G12C/V mutations was shorter than that of other KRAS-mutated patients. Cox multivariable analyses demonstrated that KRAS mutations were independently associated with worse RFS (HR, 5.34; 95% CI, 2.53-11.89; P = .001) and OS (HR, 2.63; 95% CI, 1.03-6.76; P = .044) in part-solid lung adenocarcinomas. For stage I patients, Cox multivariable analyses revealed that KRAS mutation was an independent risk factor for RFS (HR, 2.05; 95% CI, 1.19-3.56; P = .010) and OS (HR, 2.38; 95% CI, 1.29-4.40; P = .005).

CONCLUSIONS

In this study, we revealed that KRAS mutations was an independent prognostic factor in part-solid tumors and in stage I lung adenocarcinomas. These findings may contribute to the ninth edition of lung cancer staging project.

Outcomes of Patients With Advanced NSCLC From the Intergroupe Francophone de Cancérologie Thoracique Biomarkers France Study by KRAS Mutation Subtypes

Introduction

KRAS mutations are detected in 20% to 30% of NSCLC. However, KRAS mutation subtypes may differently influence the outcome of patients with advanced NSCLC.

Methods

In the Biomarkers France study, 4894 KRAS mutations (26.2%) were detected in 4634 patients from the 17,664 enrolled patients with NSCLC. Survival and treatment data on noncurative stage III to IV NSCLC were available for 901 patients. First- and second-line treatment effects on progression-free survival and overall survival were analyzed according to the KRAS mutations subtype.

Results

Over 95% of patients with KRAS mutation were smokers or former smokers who were white (99.5%), presenting with adenocarcinoma (82.5%). The most common KRAS mutation subtype was G12C (374 patients; 41.5%), followed by G12V (168; 18.6%), G12D (131; 14.5%), G12A (62; 6.9%), G13C (45; 5.0%), G13D (31; 3.4%), and others (10; 1%). Approximately 21% of patients had transition mutation and 68.2% had a transversion mutation. G12D and transition mutations were predominant in never-smokers. The median overall survival for patients with KRAS-mutated NSCLC was 8.1 months (95% confidence interval [CI]: 7.5-9.5), without any differences according to the different KRAS subtypes mutations. The median progression-free survival was 4.6 months (95% CI: 4.2-5.1) for first-line treatment and 4.8 months (95% CI: 4.3-6.8) for second-line treatment, without any differences according to the different KRAS subtypes mutations.

Conclusions

KRAS mutation subtypes influenced neither treatment responses nor outcomes. The KRAS G12C mutation was detected in 41.5% of patients, who are now eligible for potent and specific G12C inhibitors.

Genotyping KRAS and EGFR Mutations in Greek Patients With Non-small-cell Lung Cancer: Incidence, Significance and Implications for Treatment

BACKGROUND/AIM

KRAS mutations are reported in 20-25% of non-small cell lung cancer (NSCLC) and their prognostic role is unclear. We studied KRAS and EGFR genotyping in Greek NSCLC patients.

PATIENTS AND METHODS

KRAS and EGFR genotypes were centrally evaluated in 421 NSCLC patients (diagnosed September 1998 -June 2013) and associated with clinicopathological parameters. Outcome comparisons were performed in 288 patients receiving first line treatment.

RESULTS

Most patients were male (78.6%), >60 years old (63.9%), current smokers (51.1%), with adenocarcinoma histology (63.9%). EGFR and KRAS mutations were found in 10.7% and 16.6% of all histologies, respectively, and in 14.9% and 21.9% of adenocarcinomas. At 4.5 years median follow-up, KRAS status was an independent negative prognostic factor for overall survival (OS, p=0.016). KRAS mutations conferred 80% increased risk of death in patients receiving first-line treatment (p=0.002).

CONCLUSION

The presence of KRAS mutations is an independent negative prognosticator among Greek NSCLC patients and an independent response predictor to first line treatment.

Pulmonary Administration: Strengthening the Value of Therapeutic Proximity

In recent years inhaled systems have shown momentum as patient-personalized therapies emerge. A significant improvement in terms of therapeutic efficacy and/or reduction adverse systemic effects is anticipated from their use owing these systems regional accumulation. Nevertheless, whatever safety and efficacy evidence required for inhaled formulations regulatory approval, it still poses an additional hurdle to gaining market access. In contrast with the formal intravenous medicines approval, the narrower adoption of pulmonary administration might rely on discrepancies in pre-clinical and clinical data provided by the marketing authorization holder to the regulatory authorities. Evidences of a diverse and inconsistent regulatory framework led to concerns over toxicity issues and respiratory safety. However, an overall trend to support general concepts of good practices exists. Current regulatory guidelines that supports PK/PD (pharmacokinetics/pharmacodynamic) assessment seeks attention threatening those inhaled formulations set to be approved in the coming years. A more complex scenario arises from the attempt of implementing nanomedicines for pulmonary administration. Cutting-edge image techniques could play a key role in supporting diverse stages of clinical development facilitating this pharmaceutics take off and speed to patients. The ongoing challenge in adapting conventional regulatory frameworks has proven to be tremendously difficult in an environment where market entry relies on multiple collections of evidence. This paper intention is to remind us that an acceptable pre-clinical toxicological program could emerge from, but not only, an accurate and robust data imaging collection. It is our conviction that if implemented, inhaled nanomedicines might have impact in multiple severe conditions, such as lung cancer, by fulfilling the opportunity for developing tailored treatments while solving dose-related toxicity issues; the most limiting threat in conventional lung cancer clinical management.

ZEB1 suppression sensitizes KRAS mutant cancers to MEK inhibition by an IL17RD-dependent mechanism

Mitogen-activated protein kinase (MAPK) kinase (MEK) inhibitors have failed to show clinical benefit in Kirsten rat sarcoma (KRAS) mutant lung cancer due to various resistance mechanisms. To identify differential therapeutic sensitivities between epithelial and mesenchymal lung tumors, we performed in vivo small hairpin RNA screens, proteomic profiling, and analysis of patient tumor datasets, which revealed an inverse correlation between mitogen-activated protein kinase (MAPK) signaling dependency and a zinc finger E-box binding homeobox 1 (ZEB1)-regulated epithelial-to-mesenchymal transition. Mechanistic studies determined that MAPK signaling dependency in epithelial lung cancer cells is due to the scaffold protein interleukin-17 receptor D (IL17RD), which is directly repressed by ZEB1. Lung tumors in multiple Kras mutant murine models with increased ZEB1 displayed low IL17RD expression, accompanied by MAPK-independent tumor growth and therapeutic resistance to MEK inhibition. Suppression of ZEB1 function with miR-200 expression or the histone deacetylase inhibitor mocetinostat sensitized resistant cancer cells to MEK inhibition and markedly reduced in vivo tumor growth, showing a promising combinatorial treatment strategy for KRAS mutant cancers. In human lung tumor samples, high ZEB1 and low IL17RD expression correlated with low MAPK signaling, presenting potential markers that predict patient response to MEK inhibitors.

FRA1 contributes to MEK-ERK pathway-dependent PD-L1 upregulation by KRAS mutation in premalignant human bronchial epithelial cells

Oncogenic KRAS mutations are frequently found in non-small cell lung carcinoma (NSCLC) and cause constitutive activation of the MEK-ERK pathway. Many cancer types have been shown to overexpress PD-L1 to escape immune surveillance. FRA1 is a MEK/ERK-dependent oncogenic transcription factor and a member of the AP-1 transcriptional factor superfamily. This study assesses the hypothesis that KRAS mutation directly regulates PD-L1 expression through the MEK-ERK pathway mediated by FRA1. Premalignant human bronchial epithelial cell (HBEC) lines harboring the KRAS mutation^V12, EGFR mutation, p53 knock-down, or both KRAS mutation and p53 knock-down were tested for levels of PD-L1, FRA1, and ERK activation (pERK). Our results showed that KRAS mutation alone, but not other genetic alterations, induced significantly higher expression of PD-L1 compared to its vector counterparts. The increased PD-L1 expression in the KRAS mutated cells was dramatically reduced by inhibition of ERK activation. Furthermore, the MEK-ERK pathway-dependent PD-L1 expression was markedly reduced by FRA1 silencing. Interestingly, FRA1 silencing led to inhibition of ERK activation, indicating that FRA1 plays a role in PD-L1 regulation via positive feedback of ERK activation. Correlation of PD-L1 and FRA1 mRNA expression was validated using human lung cancer specimens from The Cancer Genome Atlas (TCGA) and established NSCLC cell lines from Cancer Cell Line Encyclopedia (CCLE). FRA1 expression was significantly associated with PD-L1 expression, and high FRA1 expression was correlated with poor overall survival. Our findings suggest that oncogenic KRAS-driven PD-L1 expression is dependent on MEK-ERK and FRA1 in high risk, premalignant HBEC.

Impact of somatic mutations on prognosis in resected non-small-cell lung cancer: The Japan Molecular Epidemiology for lung cancer study

BACKGROUND

To report the follow up data and clinical outcomes of the JME study (UMIN 000008177), a prospective, multicenter, molecular epidemiology examination of 876 surgically resected non-small-cell lung cancer (NSCLC) cases, and the impact of somatic mutations (72 cancer-associated genes) on recurrence-free survival (RFS) and overall survival (OS).

METHODS

Patients were enrolled between July 2012 and December 2013, with follow up to 30th November 2017. A Cox proportional hazards model was used to assess the impact of gene mutations on RFS and OS, considering sex, smoking history, age, stage, histology, EGFR, KRAS, TP53, and number of coexisting mutations.

RESULTS

Of 876 patients, 172 had ≥2 somatic mutations. Median follow-up was 48.4 months. On multivariate analysis, number of coexisting mutations (≥2 vs 0 or 1, HR = 2.012, 95% CI: 1.488-2.695), age (≥70 vs <70 years, HR = 1.583, 95% CI: 1.229-2.049), gender (male vs female, HR = 1.503, 95% CI: 1.045-2.170) and pathological stage (II vs I, HR = 3.386, 95% CI: 2.447-4.646; ≥III vs I, HR = 6.307, 95% CI: 4.680-8.476) were significantly associated with RFS, while EGFR mutation (yes vs no, HR = 0.482, 95% CI: 0.309-0.736), number of coexisting mutations (≥2 vs 0 or 1, HR = 1.695, 95% CI: 1.143-2.467), age (≥70 vs <70 years, HR = 1.932, 95% CI: 1.385-2.726), and pathological stage (II vs I, HR = 2.209, 95% CI: 1.431-3.347; ≥III vs I, HR = 5.286, 95% CI: 3.682-7.566) were also significant for OS.

CONCLUSION

A smaller number of coexisting mutations, earlier stage, and younger age were associated with longer RFS and OS, while EGFR mutations were significantly associated with improved OS.

Association of promoter methylation of RASSF1A and KRAS mutations in non-small cell lung carcinoma in Kashmiri population (India)

BACKGROUND

Non-small cell lung carcinoma (NSCLC) incidence and progression is increasing because of genetic and epigenetic changes. The mutations in the Kirsten rat sarcoma (KRAS) are the most frequently oncogene aberrations in lung carcinoma patients. A candidate tumor suppressor gene (TSG) Ras Association Domain Family 1 Isoform A (RASSF1A), is silenced by promoter hypermethylation in several human malignancies including non-small cell lung carcinoma (NSCLC). We hypothesized that RASSF1A methylation and KRAS mutations may play an important role in NSCLC.

METHODS

Non-small cell lung carcinoma patients (n = 100) and equal number of healthy controls were assessed for activating KRAS (exon 2) mutations using allele-specific oligonucleotide polymerase chain reaction (ASO-PCR) and promoter hypermethylation of RASSF1A using methylation specific PCR.

RESULTS

The frequency of mutations in Kirsten rat sarcoma (KRAS) were found in 31% of NSCLC patients in the Kashmiri population and occur most commonly, but not exclusively, in adenocarcinoma histology and life-long smokers. The NSCLC patients in advanced stage reported the higher frequency of mutation in KRAS (exon 2). A significant higher frequency of this mutation was reported in patients with NSCLC (29.16%) who are positive for metastasis (P < 0.03). The frequencies of promoter hypermethylation at Ras Association Domain Family 1 Isoform A (RASSF1A) were 41% in cases and 3% in control samples. The frequency of KRAS mutation and RASSF1A promoter methylation were significantly different between adenocarcinomas (ADC) and squamous cell carcinomas (SCC) patients with NSCLC (P < 0.03). In addition, we reported that NSCLC patients having RASSF1A promoter methylation was significantly associated with smoking (P = 0.01). It was identified that NSCLC patients with RASSF1A promoter region hypermethylation had poorer survival and faster disease progression compared with those without hypermethylation of RASSF1A promoter region (P = 0.0001). The Median survivals among with cases containing promoter region hypermethylation of RASSF1A were 17.20 and 42.13 months for patients without promoter region hypermethylation of RASSF1A and the patients with KRAS mutation with or without hypermethylation of the promoter region of RASSF1A a tumor suppressor gene had poorer survival compared with those patients with wild type KRAS gene, with or without hypermethylation of RASSF1A promoter region. These differences were statistically significant based on Log-rank (Mantel-cox) test (P = 0.0001). The median survivals among patients with mutation in KRAS protooncogene were 16 months and 42 months for NSCLC patients with wild type KRAS gene.

CONCLUSIONS

The aberrant RASSF1A gene promoter methylation with the subsequent mutation in KRAS gene (exon 2) plays a significant role in the pathogenesis and disease progression of non-small cell lung carcinoma (NSCLC).

Clinical feasibility of NGS liquid biopsy analysis in NSCLC patients

Background

Analysis of circulating tumor nucleic acids in plasma of Non-Small Cell Lung Cancer (NSCLC) patients is the most widespread and documented form of "liquid biopsy" and provides real-time information on the molecular profile of the tumor without an invasive tissue biopsy.

Methods

Liquid biopsy analysis was requested by the referral physician in 121 NSCLC patients at diagnosis and was performed using a sensitive Next Generation Sequencing assay. Additionally, a comparative analysis of NSCLC patients at relapse following EGFR Tyrosine Kinase Inhibitor (TKIs) treatment was performed in 50 patients by both the cobas and NGS platforms.

Results

At least one mutation was identified in almost 49% of the cases by the NGS approach in NSCLC patients analyzed at diagnosis. In 36 cases with paired tissue available a high concordance of 86.11% was observed for clinically relevant mutations, with a Positive Predictive Value (PPV) of 88.89%. Furthermore, a concordance rate of 82% between cobas and the NGS approach for the EGFR sensitizing mutations (in exons 18, 19, 21) was observed in patients with acquired resistance to EGFR TKIs, while this concordance was 94% for the p.T790M mutation, with NGS being able to detect this mutation in three 3 additional patients.

Conclusions

This study indicates the feasibility of circulating tumor nucleic acids (ctNA) analysis as a tumor biopsy surrogate in clinical practice for NSCLC personalized treatment decision making. The use of new sensitive NGS techniques can reliably detect tumor-derived mutations in liquid biopsy and provide clinically relevant information both before and after targeted treatment in patients with NSCLC. Thus, it could aid physicians in treatment decision making in clinical practice.

Comprehensive analysis of genomic alterations detected by next-generation sequencing-based tissue and circulating tumor DNA assays in Chinese patients with non-small cell lung cancer

While tumor genotyping is the standard treatment for patients with non-small cell lung cancer (NSCLC), spatial and temporal tumor heterogeneity and insufficient specimens can lead to limitations in the use of tissue-based sequencing. Circulating tumor DNA (ctDNA) fully encompasses tumor-specific sequence alterations and offers an alternative to tissue sample biopsies. However, few studies have evaluated whether the frequency of multiple genomic alterations observed following ctDNA sequencing is similar to that observed following tissue sequencing in NSCLC. Therefore, in the present study, targeted next-generation sequencing (NGS) was performed on tissue and plasma ctDNA samples in 99 patients with NSCLC. Overall, the frequencies of genetic alterations detected in ctDNA were positively correlated with those detected via tissue profiling (r=0.812; P=0.022). Genomic data revealed significant mutual exclusivity between alterations in epidermal growth factor receptor (EGFR) and tumor protein 53 (TP53; P=0.020), and between alterations in EGFR and KRAS (P=0.008), as well as potential mutual exclusivity between alterations in EGFR and Erb-B2 receptor tyrosine kinase 2 (P=0.059). Furthermore, the EGFR mutant allele frequency (MAF) was positively correlated with the TP53 MAF in individual tumors (r=0.773; P=0.005), and there was a marked difference in the EGFR MAF between patients with and without the TP53 mutation (P=0.001). Levels of the tumor serum marker CA242 in patients with ctDNA-detectable mutations were higher compared with those in patients without ctDNA-detectable mutations. The data from the present study highlight the importance of tissue and plasma ctDNA screening by NGS to guide personalized therapy and promote the clinical management of patients with NSCLC.

KRAS Mutations Predict Response and Outcome in Advanced Lung Adenocarcinoma Patients Receiving First-Line Bevacizumab and Platinum-Based Chemotherapy

Bevacizumab, combined with platinum-based chemotherapy, has been widely used in the treatment of advanced-stage lung adenocarcinoma (LADC). Although KRAS (V-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog) mutation is the most common genetic alteration in human LADC and its role in promoting angiogenesis has been well established, its prognostic and predictive role in the above setting remains unclear. The association between KRAS exon 2 mutational status and clinicopathological variables including progression-free survival and overall survival (PFS and OS, respectively) was retrospectively analyzed in 501 Caucasian stage IIIB-IV LADC patients receiving first-line platinum-based chemotherapy (CHT) with or without bevacizumab (BEV). EGFR (epidermal growth factor receptor)-mutant cases were excluded. Of 247 BEV/CHT and 254 CHT patients, 95 (38.5%) and 75 (29.5%) had mutations in KRAS, respectively. KRAS mutation was associated with smoking (p = 0.008) and female gender (p = 0.002) in the BEV/CHT group. We found no difference in OS between patients with KRAS-mutant versus KRAS wild-type tumors in the CHT-alone group (p = 0.6771). Notably, patients with KRAS-mutant tumors demonstrated significantly shorter PFS (p = 0.0255) and OS (p = 0.0186) in response to BEV/CHT compared to KRAS wild-type patients. KRAS mutation was an independent predictor of shorter PFS (hazard ratio, 0.597; p = 0.011) and OS (hazard ratio, 0.645; p = 0.012) in the BEV/CHT group. G12D KRAS-mutant patients receiving BEV/CHT showed significantly shorter PFS (3.7 months versus 8.27 months in the G12/13x group; p = 0.0032) and OS (7.2 months versus 16.1 months in the G12/13x group; p = 0.0144). In this single-center, retrospective study, KRAS-mutant LADC patients receiving BEV/CHT treatment exhibited inferior PFS and OS compared to those with KRAS wild-type advanced LADC. G12D mutations may define a subset of KRAS-mutant LADC patients unsuitable for antiangiogenic therapy with BEV.

KRAS-Driven Lung Adenocarcinoma and B Cell Infiltration: Novel Insights for Immunotherapy

Non-small-cell lung cancer, histologically classified into adenocarcinoma (AD) and squamous cell carcinoma, is one of the most deadly malignancies worldwide. Lung AD (LUAD) could benefit of a plethora of target therapies and, in the last few years, also of immunotherapies. Here we focused on a real-life cohort of LUAD and The Cancer Genome Atlas (TCGA)-LUAD dataset aiming to gain insights into the immune contexture of such a malignancy. We explored the mutational status of 41 genes and the expression of 94 genes, related to immune-checkpoint, inflammation, and stromal microenvironment. Surprisingly, we found that our cohort has a very low mutational burden if we consider our panel as its surrogate. Regarding gene expression data, we identified 31 genes significantly deregulated in tumor tissues compared with a pool of normal samples. Unsupervised hierarchical clustering of the deregulated genes is able to identify two clusters of tumor samples, differently enriched in alterations in actionable genes. In particular, we identified a cluster enriched in patients carrying KRAS alterations. In silico deconvolution, that is the inferring of tumor microenvironment composition by gene expression data, through TIMER algorithm has been performed to explore immune microenvironment. Estimation performed on our gene expression matrix showed that B cell infiltration is lower in the KRAS-mutated enriched cluster, as in the TCGA-LUAD dataset. Such a finding has been validated in situ through immunohistochemistry in an independent cohort. Moreover, cases in LUAD-TCGA with low B cell infiltration have a significantly worse overall survival than those with higher levels. In the real-life cohort we observed that cases belonging to cluster enriched in KRAS-mutated patients have a poor outcome. LUAD driven by KRAS mutation represents an unmet clinical need, being refractory to pharmacological inhibition. Our results link KRAS mutations to B cell infiltration. Thus, the present findings could be helpful in a better definition of immunotherapeutic approaches for KRAS mutated patients.

SRC and MEK Co-inhibition Synergistically Enhances the Anti-tumor Effect in Both Non-small-cell Lung Cancer (NSCLC) and Erlotinib-Resistant NSCLC

Non-small-cell lung cancer (NSCLC) is the predominant form of lung cancer, and it is regulated by a complex signal transduction network. Single-agent targeted therapy often results in acquired resistance, which leads to treatment failure. In this study, we demonstrated that a combination of the kinase inhibitors trametinib and bosutinib can synergistically suppress the growth of NSCLC by inhibiting both the mitogen-activated protein kinase (MAPK) and proto-oncogene tyrosine-protein kinase (SRC) pathways. The combination was profiled against a panel of 22 NSCLC cell lines, including one erlotinib-resistant cell line, and this combination was found to show synergistic effects against 16 cell lines. NSCLC cell lines (HCC827, HCC827-erlotinib-resistant, and H1650) were treated with trametinib, bosutinib, or a combination of these drugs. The drug combination inhibited colony formation and induced cell apoptosis. A mechanism study showed that the phosphorylation of multiple kinases in the epidermal growth factor receptor (EGFR) signaling pathway in NSCLC was down-regulated. In addition, the combination significantly attenuated tumor growth of HCC827 xenografts with low toxicity. Our findings provide a theoretical basis for further study of the combination of MAPK and SRC pathway inhibitors in NSCLC, especially in the treatment of erlotinib-resistant NSCLC.

Clinical outcomes to pemetrexed-based versus non-pemetrexed-based platinum doublets in patients with KRAS-mutant advanced non-squamous non-small cell lung cancer

PURPOSE

KRAS mutation has been associated with enhanced dependency on the folate metabolism in preclinical studies. However, whether KRAS mutation correlates to increased sensitivity to pemetrexed in patients with advanced NSCLC is unknown.

METHODS

Patients with advanced non-squamous NSCLC who had a documented EGFR and ALK WT genotype with simultaneous KRAS mutation assessment were evaluated for clinical outcome to pemetrexed- and non-pemetrexed-based first-line platinum doublet according to KRAS mutation status.

RESULTS

Of 356 patients identified, 138 harbored a KRAS mutation. Among KRAS-mutant NSCLCs, those treated with platinum/pemetrexed (81/138) had significantly lower ORR (30.9% versus 47.4%, P = 0.05), DCR (51.8% versus 71.9%, P = 0.02) and shorter median progression-free survival [mPFS 4.1 versus 7.1 months, HR 1.48 (95% CI 1.03-2.12), P = 0.03] and median overall survival [mOS 9.7 versus 26.9 months, HR 1.93 (95% CI 1.27-2.94), P = 0.002] compared to those who received a non-pemetrexed-based platinum doublet (57/138). No difference in ORR, DCR, mPFS and mOS was observed between KRAS WT patients who received a pemetrexed-based (124/218) versus non-pemetrexed base platinum doublets (94/218). After adjusting for performance status, age and the presence of brain metastasis at baseline, treatment with pemetrexed-based platinum doublet was associated with an increased risk of death [HR 2.27 (95% CI 1.12-4.63), P = 0.02] among KRAS-mutant patients in multivariate analysis.

CONCLUSION

Patients with KRAS-mutant lung adenocarcinoma have a poorer outcome on pemetrexed-based first-line chemotherapy. Whether KRAS-mutant NSCLCs should be excluded from pemetrexed-containing regimens should be assessed prospectively.

p65BTK is a novel potential actionable target in KRAS-mutated/EGFR-wild type lung adenocarcinoma

BACKGROUND

Lung cancer is still the main cause of cancer death worldwide despite the availability of targeted therapies and immune-checkpoint inhibitors combined with chemotherapy. Cancer cell heterogeneity and primary or acquired resistance mechanisms cause the elusive behaviour of this cancer and new biomarkers and active drugs are urgently needed to overcome these limitations. p65BTK, a novel isoform of the Bruton Tyrosine Kinase may represent a new actionable target in non-small cell lung cancer (NSCLC).

METHODS

p65BTK expression was evaluated by immunohistochemistry in 382 NSCLC patients with complete clinico-pathological records including smoking habit, ALK and EGFR status, and in metastatic lymph nodes of 30 NSCLC patients. NSCLC cell lines mutated for p53 and/or a component of the RAS/MAPK pathway and primary lung cancer-derived cells from Kras/Trp53 null mice were used as a preclinical model. The effects of p65BTK inhibition by BTK Tyrosine Kinase Inhibitors (TKIs) (Ibrutinib, AVL-292, RN486) and first-generation EGFR-TKIs (Gefitinib, Erlotinib) on cell viability were evaluated by MTT. The effects of BTK-TKIs on cell growth and clonogenicity were assessed by crystal violet and colony assays, respectively. Cell toxicity assays were performed to study the effect of the combination of non-toxic concentrations of BTK-TKIs with EGFR-TKIs and standard-of-care (SOC) chemotherapy (Cisplatin, Gemcitabine, Pemetrexed).

RESULTS

p65BTK was significantly over-expressed in EGFR-wild type (wt) adenocarcinomas (AdC) from non-smoker patients and its expression was also preserved at the metastatic site. p65BTK was also over-expressed in cell lines mutated for KRAS or for a component of the RAS/MAPK pathway and in tumors from Kras/Trp53 null mice. BTK-TKIs were more effective than EGFR-TKIs in decreasing cancer cell viability and significantly impaired cell proliferation and clonogenicity. Moreover, non-toxic doses of BTK-TKIs re-sensitized drug-resistant NSCLC cell lines to both target- and SOC therapy, independently from EGFR/KRAS status.

CONCLUSIONS

p65BTK results as an emerging actionable target in non-smoking EGFR-wt AdC, also at advanced stages of disease. Notably, these patients are not eligible for EGFR-TKIs-based therapy due to a lack of EGFR mutation. The combination of BTK-TKIs with EGFR-TKIs is cytotoxic for EGFR-wt/KRAS-mutant/p53-null tumors and BTK-TKIs re-sensitizes drug-resistant NSCLC to SOC chemotherapy. Therefore, our data suggest that adding BTK-TKIs to SOC chemotherapy and EGFR-targeted therapy may open new avenues for clinical trials in currently untreatable NSCLC.

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.