The role of genetic testing in the prediction of response to EGFR inhibitors in NSCLC

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.

The Outer Retinal Membrane Protein 1 Could Inhibit Lung Cancer Progression as a Tumor Suppressor

Some related reports indicate that the outer retinal membrane protein 1 (ROM1) functions importantly in the regulation of the biological process of tumor. Nevertheless, studies towards the role of ROM1 in lung cancer are few. Here, our data demonstrated that ROM1 displayed a relation with lung cancer tumorigenesis and development. In the Tumor Genome Atlas (TCGA) cohort, reduced ROM1 level was observed in lung cancer tissues, instead of normal tissues. After bioinformatics analysis, the data revealed that ROM1 level was associated with the tumor stage. Additional results indicated that highly expressed ROM1 exhibited a positive correlation with the overall survival rate, and ROM1 was probably a promising prognostic biomarker of lung cancer. Additionally, our results indicated that knocking out ROM1 could promote cell proliferation, migration, and invasion. Our data conclusively demonstrated that ROM1 modulated lung cancer tumorigenesis and development, as a prognosis and treatment biomarker.

Expression of EGFR and molecules downstream to PI3K/Akt, Raf-1-MEK-1-MAP (Erk1/2), and JAK (STAT3) pathways in invasive lung adenocarcinomas resected at a single institution

Therapies targeting EGFR are effective in treating tumors that harbor molecular alterations; however, there is heterogeneity in long-term response to these therapies. We retrospectively analyzed protein expression of EGFR, Stat3, phospho-Akt, and phospho-Erk1/2 by immunohistochemistry in a series of resected cases from a single institution, correlated with clinicopathological variables. There were 96 patients, with the majority of cases being of low stage tumors (17 pT1a, 23 pT1b, 30 pT2a, and 18 pT2b). Histologic subtypes were 45 acinar predominant, 2 cribriform, 25 solid, 7 papillary, 11 lepidic, and 4 mucinous tumors. The EGFR score was higher in tumors with vascular invasion (P = 0.013), in solid and cribriform acinar histology, and in high stage tumors (P = 0.006 and P = 0.01). EGFR was more likely overexpressed in solid compared to lepidic tumors (P = 0.02). Acinar tumors had the highest rate of ERK1/2 positivity (19%). There was a strong correlation among positivity for ERCC1 and other markers, including STAT3 (P = 0.003), Akt (P = 0.02), and ERK1/ERK2 (P = 0.0005). Expression of molecules downstream to EGFR varied from 12% to 31% of tumors; however, the expression did not directly correlate to EGFR expression, which may suggest activation of the cascades through different pathways. The correlation of protein expression and the new lung adenocarcinoma classification may help in the understanding of activated pathways of each tumor type, which may act in the oncogenesis and drug resistance of these tumors.

Cytology-based gene mutation tests to predict response to anti-epidermal growth factor receptor therapy: a review

Recent therapeutic progresses in nonsmall cell lung cancer (NSCLC) and in colorectal cancer (CRC) are based on agents that specifically target the epidermal growth factor receptor (EGFR). To identify the patients most likely to benefit from such therapies, EGFR or KRAS gene mutation tests are mandatory, respectively, in NSCLC and in CRC. In patients with locally advanced or metastatic disease, exploiting cytological samples for these tests avoids not curative surgery. Here, we review the studies that have applied gene mutation assays on cytological samples of NSCLC and CRC to select patients for anti-EGFR therapy. We argue that the standard of quality of gene mutation tests on cytological samples is closely dependent on the extent of the cytopathologist's involvement.

CFL1 expression levels as a prognostic and drug resistance marker in nonsmall cell lung cancer

BACKGROUND

Nonsmall cell lung cancer (NSCLC) is the major determinant of overall cancer mortality worldwide. Despite progress in molecular research, current treatments offer limited benefits. Because NSCLC generates early metastasis, and this behavior requires great cell motility, herein the authors assessed the potential value of CFL1 gene (main member of the invasion/metastasis pathway) as a prognostic and predictive NSCLC biomarker.

METHODS

Metadata analysis of tumor tissue microarray was applied to examine expression of CFL1 in archival lung cancer samples from 111 patients, and its clinicopathologic significance was investigated. The robustness of the finding was validated using another independent data set. Finally, the authors assayed in vitro the role of CFL1 levels in tumor invasiveness and drug resistance using 6 human NSCLC cell lines with different basal degrees of CFL1 gene expression.

RESULTS

CFL1 levels in biopsies discriminate between good and bad prognosis at early tumor stages (IA, IB, and IIA/B), where high CFL1 levels are correlated with lower overall survival rate (P<.0001). Biomarker performance was further analyzed by immunohistochemistry, hazard ratio (P<.001), and receiver-operating characteristic curve (area=0.787; P<.001). High CFL1 mRNA levels and protein content are positively correlated with cellular invasiveness (determined by Matrigel Invasion Chamber System) and resistance (2-fold increase in drug 50% growth inhibition dose) against a list of 22 alkylating agents. Hierarchical clustering analysis of the CFL1 gene network had the same robustness for stratified NSCLC patients.

CONCLUSIONS

This study indicates that the CFL1 gene and its functional gene network can be used as prognostic biomarkers for NSCLC and could also guide chemotherapeutic interventions.