Systematic review and network meta-analysis of first-line therapy for advanced EGFR-positive non-small-cell lung cancer

Survival outcomes of east Asian patients with advanced non-small cell lung cancer treated with first-line EGFR tyrosine kinase inhibitors: A network meta-analysis of real-world evidence

BACKGROUND

The comparative efficacies of different generation tyrosine kinase inhibitors (TKIs) in epidermal growth factor receptor (EGFR)-mutated advanced non-small cell lung cancer (NSCLC) remain largely unknown. Moreover, whether one EGFR-TKI confers superior survival remains unclear, especially in East Asians. We conducted a network meta-analysis (NMA) comparing the survival outcomes of East Asian patients with advanced NSCLC treated with first-line EGFR-TKIs.

METHODS

The NMA included observational real-world evidence studies on adult patients with EGFR-mutated advanced NSCLC who received first (gefitinib and erlotinib), second (afatinib), or third (osimertinib) generation EGFR-TKIs as frontline therapy. Studies were identified through an online bibliographic search of Medline articles in the PubMed, SCOPUS, Web of Science, and Cochrane Library databases.

RESULTS

For overall survival (OS), afatinib had significantly better hazard ratios (HRs) than osimertinib (HR: 0.46, 95% confidence interval [CI]: 0.23-0.91), gefitinib (HR: 0.56, 95% CI: 0.43-0.72), and erlotinib (HR: 0.71, 95% CI: 0.54-0.92). For progression-free survival (PFS), afatinib had significantly better HRs than gefitinib (HR: 0.45, 95% CI: 0.36-0.56) and erlotinib (HR: 0.63, 95% CI: 0.49-0.81). Moreover, afatinib was most likely to achieve the longest OS (81.3%), followed by erlotinib (13%), osimertinib, and gefitinib. Furthermore, afatinib was most likely to achieve the longest PFS (48.3%), followed by osimertinib (34.9%) and erlotinib.

CONCLUSIONS

This real-world evidence shows that afatinib confers better survival than other first-line EGFR-TKIs in East Asian patients with advanced NSCLC.

Cost-effectiveness analysis of the first-line EGFR-TKIs in patients with advanced EGFR-mutated non-small-cell lung cancer

AIM

To evaluate the cost-effectiveness of first-line treatments, such as erlotinib, gefitinib, afatinib, dacomitinib, and osimertinib, for patients diagnosed with stage IIIB/IV NSCLC harboring EGFR mutations.

MATERIALS & METHODS

A partitioned survival model was developed to estimate quality-adjusted life-year (QALY) and incremental cost-effectiveness ratio (ICER) from the perspective of the Spanish National Health System. Two Bayesian NMAs were performed independently, by using the polynomial fraction method to fit Kaplan-Meier curves for overall survival and progression-free survival. Deterministic and probabilistic sensitivity analyses were performed to evaluate the uncertainty.

RESULTS

The ICER was calculated for the four first-line treatments by comparing them with gefitinib, and the ratios obtained were as follows: €166,416/QALY for osimertinib, €183,682/QALY for dacomitinib, €167,554/QALY for afatinib, €36,196/QALY for erlotinib. It was seen that patients who received osimertinib presented higher QALYs (0.49), followed by dacomitinib (0.33), afatinib (0.32), erlotinib (0.31), and gefitinib (0.28).

CONCLUSIONS

Gefitinib is the most cost-effective treatment. In terms of QALYs gained, Osimertinib was more effective than all other TKIs. Nevertheless, with a Spanish threshold of €24,000/QALY, the reduction in the acquisition cost of osimertinib will have to be greater than 70%, to obtain a cost-effectiveness alternative.

The Position of EGF Deprivation in the Management of Advanced Non-Small Cell Lung Cancer

Advanced non-small cell lung cancer (NSCLC) has faced a therapeutic revolution with the advent of tyrosine kinase inhibitors (TKIs) and immune checkpoints inhibitors (ICIs) approved for first and subsequent therapies. CIMAvax-EGF is a chemical conjugate between human-recombinant EGF and P64, a recombinant protein from Neisseria meningitides, which induces neutralizing antibodies against EGF. In the last 15 years, it has been extensively evaluated in advanced NSCLC patients. CIMAvax-EGF is safe, even after extended use, and able to keep EGF serum concentration below detectable levels. In a randomized phase III study, CIMAvax-EGF increased median overall survival of advanced NSCLC patients with at least stable disease after front-line chemotherapy. Patients bearing squamous-cell or adenocarcinomas and serum EGF concentration above 870 pg/ml had better survival compared to control patients treated with best supportive care as maintenance, confirming tumors' sensitivity to the EGF depletion. This manuscript reviews the state-of-the-art NSCLC therapy and proposes the most promising scenarios for evaluating CIMAvax-EGF, particularly in combination with TKIs or ICIs. We hypothesize that the optimal combination of CIMAvax-EGF with established therapies can further contribute to transform advanced cancer into a manageable chronic disease, compatible with years of good quality of life.

Efficacy and Safety of EGFR Inhibitors in the Treatment of EGFRPositive NSCLC Patients: A Meta-Analysis

BACKGROUND

We compared the response rates, survival rates, and safety profile of epidermal growth factor receptor (EGFR) inhibitors with non-targeted chemotherapy and older EGFR inhibitors when used to treat advanced non-small cell lung cancer (NSCLC) patients with activating EGFR mutations.

METHODS

We searched PubMed, Cochrane Central Register of Controlled Trials, and clinicaltrial.- gov for randomized controlled trials published until 11-Feb-2020. Treatment outcomes were compared between EGFR inhibitor and pooled comparator; a subgroup analysis compared outcomes between EGFR inhibitor and non-targeted chemotherapy, and between newer and older EGFR inhibitors.

RESULTS

Twenty-one studies with 4,250 unique patients were included. Significantly higher objective response rate (ORR) (odds ratio (OR) 2.28; 95% CI 2.00-2.61), higher disease control rate (DCR) (OR 2.3; 95% CI 1.88-3.06), and longer progression-free survival (PFS) (Hazard ratio (HR) 0.56; 95% CI 0.52-0.60) were observed in the EGFR inhibitor group compared to the pooled comparator group. Subgroup analysis revealed that the ORR, DCR, and PFS were significantly higher with EGFR inhibitors than non-targeted chemotherapy, and only PFS (and not ORR and DCR) was significantly longer with newer EGFR inhibitors than the older EGFR inhibitors. Overall survival (OS) was not significantly different between EGFR inhibitors and pooled comparator (HR 0.91; 95% CI 0.83-1.00) as well as in either of the subgroup analyses. Adverse events ≥ grade 3 and treatment discontinuation were significantly higher with non-targeted chemotherapy compared to the EGFR inhibitors.

CONCLUSION

The benefits of prolongation of ORR, DCR, and PFS might not imply significantly improved OS after therapy with EGFR inhibitors when compared with non-targeted chemotherapy or older EGFR inhibitors.

Trilobatin Induces Apoptosis and Attenuates Stemness Phenotype of Acquired Gefitinib Resistant Lung Cancer Cells via Suppression of NF-κB Pathway

Trilobatin is a common type of flavonoids compounds derived from Lithocarpus polystachyus Rehd leaves. Previous report suggests that trilobatin was potentially involved in pro-and anticancer, antioxidative and anti-hyperglycemic activities. Here, we investigated the anticancer efficiency of trilobatin on gefitinib resistant lung cancer cells. In this study, MTT assays, EdU incorporation assays, DAPI staining, tumor sphere formation assays, immunofluorescent staining and Western blot analysis were performed to explore the functional role of trilobatin on gefitinib resistant lung cancer cells. The results showed that trilobatin inhibits proliferation of gefitinib resistant lung cancer cells. In addition, the proportions of apoptotic cells were increased along with down-regulated expression levels of Bcl-2 and mitochondrial Cytochrome C while up-regulated Bax, Cleaved Caspase-3, -9, and cytosolic Cytochrome C expression. Moreover, trilobatin decreased tumor sphere formation and expression levels of multiple stemness markers (ALDH1, CD133, Nanog, and ABCG2) in gefitinib resistant lung cancer cells. Furthermore, investigation of the mechanism indicated that trilobatin suppressed activity of NF-κB via decreasing constitutive phosphorylation of NF-κB p65 and IκB-α in gefitinib resistant lung cancer cells. All these results indicate that trilobatin induces apoptosis and attenuates stemness phenotype of gefitinib resistant lung cancer cells, involved with, or partly, the suppression of NF-κB activity.

HIF-1 Inhibitor YC-1 Reverses the Acquired Resistance of EGFR-Mutant HCC827 Cell Line with MET Amplification to Gefitinib

Background

Acquired resistance occurred in the majority of nonsmall cell lung cancer (NSCLC) patients receiving epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) therapy, and this may be related to the activation of the HIF-1 pathway. Therefore, we examined the influence of the hypoxia-inducible factor-1 (HIF-1) pathway inhibition on the sensitivity of HCC827 gefitinib-resistant (HCC827 GR) cells with MET amplification to gefitinib.

Methods

We established HCC827 GR cell line with MET amplification and set four groups with different treatment. An MTT assay, a colony formation analysis, and a wound healing assay were performed to determine the sensitivity change of HCC827 GR cells after different treatments. HIF-1α, p-EGFR, and p-Met levels were detected with western blot. Correlations among HIF-1α, p-EGFR, and p-Met levels of HCC827 GR cells with different treatments were analyzed with Pearson's correlation analysis.

Results

HIF-1 inhibitor YC-1 enhanced the sensitivity of HCC827 GR cells to gefitinib. p-Met level was correlated with HIF-1α level, while there was no correlation between p-Met level and p-EGFR level.

Conclusion

HIF-1 inhibitor YC-1 is able to reverse the acquired resistance of HCC827 GR to gefitinib, and the regulation of the HIF-1 pathway on MET may be one of the mechanisms.

Prognostic impact of maximum standardized uptake value on 18 F-FDG PET/CT imaging of the primary lung lesion on survival in advanced non-small cell lung cancer: A retrospective study

Background

Positron emission tomography/computed tomography (PET/CT) has been recognized for diagnosing and staging lung cancer, but the prognostic value of standardized uptake value (SUV) on ¹⁸F‐FDG PET/CT imaging in patients with advanced non‐small cell lung cancer (NSCLC) remains controversial.

Methods

We performed a retrospective analysis of patients with advanced NSCLC who had undergone ¹⁸F‐FDG PET/CT before systemic treatment between June 2012 and June 2016. The relationship between the maximum SUV (SUVmax) of the pulmonary lesion and lesion size was evaluated via Spearman's correlation analysis. We collected patients' clinical and pathological data. Univariate and multivariate analyses were performed to analyze the factors influencing survival.

Results

We included 157 patients with advanced NSCLC. Among these, 135 died, 13 survived, and nine were lost to follow‐up (median follow‐up period, 69 months). SUVmax was correlated with lesion size and was significantly greater for tumors ≥3 cm than for tumors <3 cm (10.2 ± 5.4 vs. 5.6 ± 3.3, t = −6.709, p = 0.000). Univariate analysis showed that survival was associated with gender, tumor size, epidermal growth factor receptor gene mutation or anaplastic lymphoma kinase rearrangement, SUVmax of the primary lung lesion, and treatment lines. Multivariate analysis showed a significant correlation between SUVmax of the primary lung lesion and survival. The mortality risk of patients with SUVmax ≤6 was 35% lower than that of patients with SUVmax >6 (HR = 0.651, 95% confidence interval, 0.436–0.972; Wald value, 4.400; p = 0.036).

Conclusions

The SUVmax of the primary lung lesion on PET/CT is significantly correlated with survival in treatment‐naive patients with advanced NSCLC.

Click Conjugation of Boron Dipyrromethene (BODIPY) Fluorophores to EGFR-Targeting Linear and Cyclic Peptides

Through a simple 1,3-cycloaddition reaction, three BODIPY-peptide conjugates that target the extracellular domain of the epidermal growth factor receptor (EGFR) were prepared and their ability for binding to EGFR was investigated. The peptide ligands K(N₃)LARLLT and its cyclic analog cyclo(K(N₃)larllt, previously shown to have high affinity for binding to the extracellular domain of EGFR, were conjugated to alkynyl-functionalized BODIPY dyes 1 and 2 via a copper-catalyzed click reaction. This reaction produced conjugates 3, 4, and 5 in high yields (70–82%). In vitro studies using human carcinoma HEp2 cells that overexpress EGFR demonstrated high cellular uptake, particularly for the cyclic peptide conjugate 5, and low cytotoxicity in light (~1 J·cm⁻²) and darkness. Surface plasmon resonance (SPR) results show binding affinity of the three BODIPY-peptide conjugates for EGFR, particularly for 5 bearing the cyclic peptide. Competitive binding studies using three cell lines with different expressions of EGFR show that 5 binds specifically to EGFR-overexpressing colon cancer cells. Among the three conjugates, 5 bearing the cyclic peptide exhibited the highest affinity for binding to the EGFR protein.

The cost-effectiveness of dacomitinib in first-line treatment of advanced/metastatic epidermal growth factor receptor mutation-positive non-small-cell lung cancer (EGFRm NSCLC) in Sweden

AIMS

Although the benefit of first-line epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) over chemotherapy in EGFR mutation-positive (EGFRm) non-small-cell lung cancer (NSCLC) has been demonstrated in clinical trials, the optimal treatment sequence remains unclear. The objective of our study was to evaluate the cost-effectiveness of dacomitinib in Sweden vs afatinib and osimertinib in first-line treatment of EGFRm NSCLC.

MATERIALS AND METHODS

A partitioned survival model was developed with three health states: progression-free, post-progression, and death. Progression-free and overall survival curves were used to inform movements between states. Clinical data were taken from randomized trials, compared via a network meta-analysis (NMA). Utility data were taken from published studies and costs from national Swedish sources. The model used a 15-year time horizon and a Swedish healthcare payer perspective. Sensitivity and scenario analyses were performed.

RESULTS

The base-case analysis showed that dacomitinib accrued a total of 2.10 quality-adjusted life-years (QALYs) at a total cost of Swedish krona (SEK) 874,615. The incremental cost-effectiveness ratio (ICER) for dacomitinib vs afatinib was SEK 461,556 per QALY gained. The ICER of osimertinib vs dacomitinib, where the small QALY gains of the former came at a high additional cost, was SEK 11,444,709. Deterministic and probabilistic sensitivity analyses confirmed the robustness of these results; changes to drug and medical resource use costs and overall survival had the greatest impact on ICER estimates.

LIMITATIONS

This model is subject to uncertainty associated with extrapolating long-term treatment effects from shorter trial follow-up periods, although this would also be a limitation when using direct comparison or time-dependent hazard ratios. The NMA was limited by the use of indirect comparison, although sensitivity analyses supported the robustness of our findings.

CONCLUSIONS

Our model demonstrated that dacomitinib is cost-effective for first-line EGFRm NSCLC treatment in Sweden vs afatinib and osimertinib.

Systematic Review and Network Meta-Analysis of Immune Checkpoint Inhibitors in Combination with Chemotherapy as a First-Line Therapy for Extensive-Stage Small Cell Carcinoma

Patients with extensive-stage small cell lung cancer (ED-SCLC) have a very short survival time even if they receive standard cytotoxic chemotherapy with etoposide and platinum (EP). Several randomized controlled trials have shown that patients with ED-SCLC who received a combination of EP plus immune checkpoint inhibitors (ICIs) had superior survival compared with those who received EP alone. We conducted a systematic review and network meta-analysis to provide a ranking of ICIs for our primary endpoints in terms of overall survival (OS), progression free survival (PFS), and objective response rate (ORR), as well as our secondary endpoint in terms of adverse events. The fractional polynomial model was used to evaluate the adjusted hazard ratios for the survival indicators (OS and PFS). Treatment rank was estimated using the surface under the cumulative ranking curve (SUCRA), as well as the probability of being best (Prbest) reference. EP plus nivolumab, atezolizumab or durvalumab had significant benefits compared with EP alone in terms of OS (Hazard Ratio HR = 0.67, 95% Confidence Interval CI = 0.46-0.98 for nivolumab, HR = 0.70, 95% CI = 0.54-0.91 for atezolizumab, HR = 0.73, 95% CI = 0.59-0.90 for durvalumab) but no significant differences were observed for pembrolizumab or ipilimumab. The probability of nivolumab being ranked first among all treatment arms was highest (SCURA = 78.7%, Prbest = 46.7%). All EP plus ICI combinations had a longer PFS compared with EP alone (HR = 0.65, 95% CI = 0.46-0.92 for nivolumab, HR = 0.77, 95% CI = 0.61-0.96 for atezolizumab, HR = 0.78, 95% CI = 0.65-0.94 for durvalumab, HR = 0.75, 95% CI = 0.61-0.92 for pembrolizumab), and nivolumab was ranked first in terms of PFS (SCURA = 85.0%, Prbest = 66.8%). In addition, nivolumab had the highest probability of grade 3-4 adverse events (SUCRA = 84.8%) in our study. We found that nivolumab had the best PFS and OS in all combinations of ICIs and EP, but nivolumab also had the highest probability of grade 3-4 adverse events in our network meta-analysis. Further head-to head large-scale phase III randomized controlled studies are needed to verify our conclusions.

Network meta analysis of first-line therapy for advanced EGFR mutation positive non-small-cell lung cancer: updated overall survival

Aim: To update overall survival (OS) results from a previous network meta analysis comparing the relative clinical efficacy of epidermal growth factor receptor-targeted tyrosine kinase inhibitors ( EGFR TKIs) for EGFR mutation positive ( EGFR+) advanced non-small-cell lung cancer (NSCLC). Materials & methods: A Bayesian network meta analysis was conducted using updated/mature randomized controlled trial OS results in response to first-line EGFR TKI therapies. Results: Dacomitinib showed a numerical improvement of OS relative to other EGFR TKIs: afatinib (hazard ratio [HR]: 0.87; 95% credible interval [CrI]: 0.61–1.24), erlotinib (HR: 0.79; 95% CrI: 0.44–1.42), gefitinib (HR: 0.75; 95% CrI: 0.59–0.95) and osimertinib (HR: 0.94; 95% CrI: 0.68–1.29). Conclusion: Dacomitinib should be considered as a first-line treatment option for patients diagnosed with advanced EGFR+ NSCLC.

Licochalcone A inhibits EGFR signalling and translationally suppresses survivin expression in human cancer cells

Dysfunction of epidermal growth factor receptor (EGFR) signalling plays a critical role in the oncogenesis of non–small‐cell lung cancer (NSCLC). Here, we reported the natural product, licochalcone A, exhibited a profound anti‐tumour efficacy through directly targeting EGFR signalling. Licochalcone A inhibited in vitro cell growth, colony formation and in vivo tumour growth of either wild‐type (WT) or activating mutation EGFR‐expressed NSCLC cells. Licochalcone A bound with L858R single‐site mutation, exon 19 deletion, L858R/T790M mutation and WT EGFR ex vivo, and impaired EGFR kinase activity both in vitro and in NSCLC cells. The in silico docking study further indicated that licochalcone A interacted with both WT and mutant EGFRs. Moreover, licochalcone A induced apoptosis and decreased survivin protein robustly in NSCLC cells. Mechanistically, we found that treatment with licochalcone A translationally suppressed survivin through inhibiting EGFR downstream kinases ERK1/2 and Akt. Depletion of the translation initiation complex by eIF4E knockdown effectively inhibited survivin expression. In contrast, knockdown of 4E‐BP1 showed the opposite effect and dramatically enhanced survivin protein level. Overall, our data indicate that targeting survivin might be an alternative strategy to sensitize EGFR‐targeted therapy.

Network meta-analyses for EGFR mutation-positive non-small-cell lung cancer: systematic review and overview of methods and shortcomings

Aim: To perform a review of network meta-analyses (NMAs) for the first-line treatment of EGFR mutation-positive non-small-cell lung cancer, and to provide an overview of methodological approaches and potential shortcomings. Materials & methods: We conducted a systematic review of NMAs and evaluated their methodologies, including inclusion/exclusion criteria, information sources, results and outcomes, and statistical methodologies. Results: We identified ten published NMAs using five archetypical network structures. Despite similar objectives, there was substantial variability in the number of trials included in each NMA and in the relative treatment efficacy of the tyrosine kinase inhibitors. Conclusion: We identified methodological issues to explain differences in the findings, criteria for inclusion in NMAs and the degree of lumping of treatments. These factors should be given particular consideration in future research.

Indirect analysis of first-line therapy for advanced non-small-cell lung cancer with activating mutations in a Japanese population

Background: Five EGFR-tyrosine kinase inhibitors (EGFR TKIs) are currently available in the first-line setting for non-small-cell lung cancer (NSCLC) in Japan. The aim here was to compare the relative efficacy of EGFR TKIs in the Japanese population. Materials & methods: A systematic review identified randomized controlled trials examining the efficacy of first-line EGFR TKIs. A Bayesian network meta-analysis was used to assess these EGFR TKI comparisons for progression-free survival (PFS). Results: A total of seven randomized controlled trials were identified and considered for network meta-analysis. Dacomitinib showed a trend toward improved PFS versus all comparators. Conclusion: Dacomitinib demonstrated a trend toward improved PFS and therefore, should be considered one of the standard first-line therapies for Japanese patients diagnosed with EGFR+ non-small-cell lung cancer.

Cost-effectiveness analysis of first and second-generation EGFR tyrosine kinase inhibitors as first line of treatment for patients with NSCLC harboring EGFR mutations

BACKGROUND

Tyrosine-kinase inhibitors (TKIs) have become the cornerstone treatment of patients with non-small cell lung cancer that harbor oncogenic EGFR mutations. The counterpart of these drugs is the financial burden that they impose, which often creates a barrier for accessing treatment in developing countries. The aim if the present study was to compare the cost-effectiveness of three different first and second generation TKIs.

METHODS

We designed a retrospective cost-effectiveness analysis of three different TKIs (afatinib, erlotinib, and gefitinib) administered as first-line therapy for patients with NSCLC that harbor EGFR mutations.

RESULTS

We included 99 patients with the following TKI treatment; 40 treated with afatinib, 33 with gefitinib, and 26 with erlotinib. Median PFS was not significantly different between treatment groups; 15.4 months (95% CI 9.3-19.5) for afatinib; 9.0 months (95% CI 6.3- NA) for erlotinib; and 10.0 months (95% CI 7.46-14.6) for gefitinib. Overall survival was also similar between groups: 29.1 months (95% CI 25.4-NA) for afatinib; 27.1 months (95% CI 17.1- NA) for erlotinib; and 23.7 months (95% CI 18.6-NA) for gefitinib. There was a statistically significant difference between the mean TKIs costs; being afatinib the most expensive treatment. This difference was observed in the daily cost of treatment (p < 0.01), as well as the total cost of treatment (p = 0.00095). Cost-effectiveness analysis determined that afatinib was a better cost-effective option when compared with first-generation TKIs (erlotinib and gefitinib).

CONCLUSION

In our population, erlotinib, afatinib, and gefitinib were statistically equally effective in terms of OS and PFS for the treatment of patients with advanced EGFR-mutated NSCLC population. Owing to its marginally increased PFS and OS, the cost-effectiveness analysis determined that afatinib was a slightly better cost-effective option when compared with first-generation TKIs (erlotinib and gefitinib).

Targeting EGFR Overexpression at the Surface of Colorectal Cancer Cells by Exploiting Amidated BODIPY-Peptide Conjugates

Three BODIPY-peptide conjugates designed to target the epidermal growth factor receptor (EGFR) at the extracellular domain were synthesized, and their specificity for binding to EGFR was investigated. Peptide sequences containing seven amino acids, GLARLLT (2) and KLARLLT (4), and 13 amino acids, GYHWYGYTPQNVI (3), were conjugated to carboxyl BODIPY dye (1) by amide bond formation in up to 73% yields. The BODIPY-peptide conjugates and their "parent" peptides were determined to bind to EGFR experimentally using SPR analysis and were further investigated using computational methods (AutoDock). Results of SPR, competitive binding and docking studies propose that conjugate 6 including the GYHWYGYTPQNVI sequence binds to EGFR more effectively than conjugates 5 and 7, bearing the smaller peptide sequences. Findings in human carcinoma HEp2 cells overexpressing EGFR showed nontoxic behavior in the presence of activated light (1.5 J cm^-2 ) and in the absence of light for all BODIPYs. Furthermore, conjugate 6 showed about five-fold higher accumulation within HEp2 cells compared with conjugates 5 and 7, localizing preferentially in the cell ER and lysosomes. Our findings suggest that BODIPY-peptide conjugate 6 is a promising contrast agent for detection of colorectal cancer and potentially other EGFR-overexpressing cancers.

Modulation of proliferation factors in lung adenocarcinoma with an analysis of the transcriptional consequences of genomic EGFR activation

Genes of the pre-replication, pre-initiation and replisome complexes duplicate the genome from many sites once in a normal cell cycle. This study examines complex components in lung adenocarcinoma (LUAD) closely, correlating changes in the genome and transcriptome with proliferation and overall survival. Molecular subtypes (The Cancer Genome Atlas (TCGA), 2014) based on copy number, DNA methylation, and mRNA expression had variable proliferation levels, the highest correlating with decreased survival. A pattern of increased expression typified by POLE2 and POLQ was found for multiple replication factors over thirty-seven tumor types. EGFR altered cases unanticipatedly inversely correlated with proliferation factor expression in LUAD, Colon adenocarcinoma, and Cancer Cell Line Encyclopedia cell lines, but not in glioblastoma or breast cancer. Activation mutations did not uniformly correlate with proliferation, most cases were pre-metastatic. A gene expression profile was identified, and pathway involvement considered. Significantly, results suggest EGFR over expression and activation are early alterations that likely stall the replication complex through PCNA phosphorylation creating replication stress responsible for DNA damage response and further mutation, but does not promote increased proliferation itself. An argument is presented that the mechanism driving lethality in this tumor cohort could differ from over proliferation seen in other LUAD.