An Evidence-Based Approach to the Use of Predictive Biomarkers in the Treatment of Non- Small Cell Lung Cancer (NSCLC)

Recent advances in the treatment of non-small cell lung cancer (NSCLC) have led to improvements in patient survival and quality of life. It is unclear whether molecular abnormalities associated with NSCLC cell survival, growth and proliferation are useful in predicting treatment benefit. We conducted a systematic review to establish which biomarkers contribute meaningfully to the management of NSCLC. A team of researchers searched PubMed and conference proceedings (ASCO, ESMO, IASLC, USCAP) using MESH terms for NSCLC and randomized trials (RCT), plus keywords for variables of interest. Evidence from multiple RCTs confirmed that histologic subtype is prognostic for survival and predictive of treatment efficacy and/or toxicity in NSCLC. Likewise, activating mutations of the epidermal growth factor receptor (EGFR) are associated with benefit from EGFR tyrosine kinase inhibitors in patients with advanced non-squamous NSCLC and should be assessed routinely. No biomarkers to date reliably predict response to anti-Vascular Endothelial Growth Factor (VEGF) therapies. There are inconsistent data on the role of ERCC1, BRCA, Beta tubulin III, RRM1, K-RAS, or TP-53 in treatment decisions. These tests should not be routinely used in selecting treatment at this time, whereas EML4/ALK translocations predict responses to specific targeted agents, the optimal assessment of this molecular abnormality has yet to be established. Personalized care of patients with NSCLC based on biomarkers is increasingly important to both clinical practice and research.

[Prognostic and predictive biomarkers in non-small cell lung cancers. From conditioned registrations to routine molecular mapping of lung cancers: Methodological issues]

Targeted therapies booming and new efficacious cytotoxics emergence in non-small cell lung cancers (NSCLC) deeply changed prognosis in some subsets of patients experiencing long survival. A priori identification (at time of diagnosis) of patients the most beneficiating from those often costly therapies is the new issue in thoracic oncology. For EGFR tyosine kinase inhibitors (TKI), molecular targeting relies on EGFR mutations diagnosis, that led to the first conditioned molecular-based registration for a drug in thoracic oncology, that was made easier in France by French NCI huge effort to sponsor the 28 regional molecular biology platforms. For the majority of classical cytotoxics used in adjuvant treatment after lung cancer surgical resection, biomarkers relying on immunohistochemistry still need further prospective validation steps before routine use. Prospective validation studies aimed to evaluate the ability of those biomarkers to predict not only response to therapy, but also survival with a specific treatment (predictive value), need large phase 3 trials with centralized biomarker analyses and rigorous statistical methods. French Intergroup (IFCT) has initiated such studies that will help to validate new biomarkers that we may use routinely in lung cancer in near future.

The role of betaIII tubulin in predicting chemoresistance in non-small cell lung cancer

Lung cancer is a leading cause of death among adults. Non-small cell lung cancer (NSCLC) accounts for approximately 85% of all lung cancer cases. For more than half of all patients diagnosis does not occur until the disease has metastasised. At this advanced stage, the 5-year survival rate is just 15%. Platinum-based chemotherapy forms the backbone of treatment for patients with advanced NSCLC and forms an important component of the therapeutic regimen for many patients with earlier stage disease. However, although a number of agents are available to partner the platinum-based compounds, treatment selection is largely empiric, and chemoresistance is a considerable barrier to improving outcomes. The identification of biologic and other markers to guide treatment selection, thus ensuring patients receive the most effective regimen for their individual tumour and avoid exposure to toxic agents from which they are unlikely to benefit, will be critical to improve outcomes for patients with NSCLC. The development of alternative agents for those patients who express predictors of a negative clinical response is of vital importance. A variety of biomarkers are emerging, including expression of DNA repair enzymes, ribonucleotide subunits and betaIII tubulin. Treatment algorithms based on elucidation of such markers to guide treatment selection can already be envisaged. For example, those patients with high betaIII tubulin expression should be considered for epothilone therapy as an alternative to taxane-based regimens. The epothilones may be preferred option as the evidence suggests that these agents retain activity versus taxane-resistant cancers. This paper reviews the evidence base for betaIII tubulin expression as a prognostic and predictive biomarker in NSCLC and briefly explores the implications for clinical decision making of this and other emerging biomarkers.