miR-141 and miR-200c as markers of overall survival in early stage non-small cell lung cancer adenocarcinoma

Background

Several treatments in non-small cell lung cancer (NSCLC) are histology-dependent, and the need for histology-related markers is increasing. MicroRNAs (miRNAs) are promising molecular markers in multiple cancers and show differences in expression depending on histological subtype. The miRNA family miR-200 has been associated with the regulation of epithelial-mesenchymal (EMT)/mesenchymal-epithelial transition (MET). EMT involves profound phenotypic changes that include the loss of cell-cell adhesion, the loss of cell polarity, and the acquisition of migratory and invasive properties that facilitates metastasis. A dual role for the miR-200 family in the prognosis of several tumors has been related to tumor cell origin. However, the prognostic role and function of miR-200 family in early-stage NSCLC adenocarcinoma and squamous cell carcinoma (SCC) have not been well established.

Methods

miRNA expression was determined using TaqMan assays in 155 tumors from resected NSCLC patients. Functional studies were conducted in three NSCLC cell lines: H23, A-549 and HCC-44.

Results

High miR-200c expression was associated with shorter overall survival (OS) in the entire cohort (p = 0.024). High miR-200c (p = 0.0004) and miR-141 (p = 0.009) expression correlated with shorter OS in adenocarcinoma – but not in SCC. In the multivariate analysis, a risk score based on miR-141 and miR-200c expression emerged as an independent prognostic factor for OS in the entire cohort (OR, 2.787; p = 0.033) and in adenocarcinoma patients (OR, 10.649; p = 0.002). Functional analyses showed that miR-200c, was related to mesenchymal-epithelial transition (MET) and affected cell migration and E-cadherin levels, while overexpression of miR-141 reduced KLF6 protein levels and produced an increase of secretion of VEGFA in vitro (H23, p = 0.04; A-549, p = 0.03; HCC-44, p = 0.02) and was associated with higher blood microvessel density in patient tumor samples (p<0.001).

Conclusion

High miR-141 and miR-200c expression are associated with shorter OS in NSCLC patients with adenocarcinoma through MET and angiogenesis.

New options for integrating antiangiogenic therapy and platinum-based first-line chemotherapy for advanced non-small-cell lung cancer

The essential role of angiogenesis in tumor growth and metastasis is well established. The key mediator of angiogenesis, vascular endothelial growth factor (VEGF), is a rational target for novel therapy. High VEGF levels correlate positively with reduced overall survival (OS) and relapse-free survival. Several molecular targeted agents that inhibit VEGF or its receptors are currently in late-stage development or available for the first-line treatment of advanced non-small-cell lung cancer (NSCLC). Bevacizumab is a humanized monoclonal antibody against VEGF that has proven efficacy when combined with different chemotherapy regimens. In the pivotal US phase III trial (E4599) combining bevacizumab with carboplatin/paclitaxel, significantly improved clinical outcomes were observed in terms of OS, progression-free survival (PFS), and response rate (RRs). Although the phase III AVAiL (Avastin in Lung Cancer) trial (BO17704) combining bevacizumab with cisplatin/gemcitabine also showed improved outcomes in terms of PFS and RR, OS data is immature. Bevacizumab is the first agent to improve clinical outcomes when combined with doublet chemotherapy and administered until disease progression. Herein, key clinical data from trials of antiangiogenic agents in the first-line treatment of NSCLC are discussed, with a focus on bevacizumab, currently the only approved antiangiogenic agent for the treatment of NSCLC. The optimal integration of these agents into current and future first-line treatment regimens will be discussed, stressing the importance of therapeutic administration until disease progression. The promising activity of antiangiogenic agents in the advanced disease setting, allied with growing understanding of their novel modes of action, holds therapeutic promise for their future application in early-stage disease.

Bevacizumab for the treatment of advanced non-small-cell lung cancer

Until recently, advances in non-small-cell lung cancer (NSCLC) care have been limited; new chemotherapy regimens have not significantly impacted patient survival. With our improved understanding of tumor biology, novel biological therapies targeting key tumorigenic processes targeting factors essential for tumor growth, such as angiogenesis, have been developed that improve patient outcomes beyond those achieved with chemotherapy alone. One of these, bevacizumab (Avastin), specifically targets VEGF, which is key to the malignant growth and progression of solid tumors. Bevacizumab-based therapy until progression significantly delays disease progression, has a well-characterized and acceptable safety profile in bevacizumab-eligible patients and was the first treatment to improve the overall survival of patients with advanced NSCLC beyond 1 year, a significant breakthrough in advanced NSCLC care. Furthermore, bevacizumab-based therapy significantly delays disease progression and has a well-characterized and acceptable safety profile. Based on these data, bevacizumab has received approval for the first-line treatment of NSCLC in the USA and Europe. A number of ongoing trials will potentially expand the eligible patient population for bevacizumab and further define its role in NSCLC treatment.

Systemic treatment for advanced (stage IIIb/IV) non-small cell lung cancer: more treatment options; more things to consider. Conclusion

Chemotherapy for non-small cell lung cancer (NSCLC) can prolong survival and improve quality of life, but the majority of advanced stage patients succumb to disease within 2 years, meaning that there is room for improvement. The standard chemotherapy for NSCLC involves one of a number of chemotherapy doublets that have been shown to improve survival when compared with single agents or best supportive care. These doublets are generally comparable in terms of efficacy, differing primarily in their toxicity profiles. However, encouraging new options may be approaching, including therapies targeted to specific patient subpopulations, and the use of combinations of current and new drugs to produce synergistic effects. Targeted therapies include the anti-epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) erlotinib and gefitinib, EGFR monoclonal antibody cetuximab, and vascular endothelial growth factor (VEGF) inhibitors such as sorafenib, a small molecule TKI, and bevacizumab, a recombinant monoclonal VEGF antibody. Most attempts to combine EGFR-targeted therapies with standard chemotherapy in NSCLC have produced poor results, possibly as a result of antagonism between EGFR TKIs and chemotherapy. Positive results with bevacizumab suggest that VEGF-rather than EGFR-targeted therapies may produce better results when combined with chemotherapy. Other new drugs being tested include enzastaurin, an oral serine threonine kinase inhibitor; vinflunine, a vinca alkaloid; dihydrofolate reductase inhibitors; and thymidylate synthase inhibitors. Combinations of therapies, especially those acting via different mechanisms, hold promise for improvements in survival, but careful testing is required to determine optimum combinations of available drugs and where new drugs fit into the armamentarium.