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The advent of PD-(L)1 and CTLA-4 immune check point inhibitors (CPIs) has dramatically changed the treatment landscape of advanced non-small-cell lung cancer (NSCLC). For up to a quarter of patients with advanced NSCLC, CPIs have the potential to induce durable responses with long-term survival outcomes. Since the approval of first-line pembrolizumab for patients whose tumors express a PD-L1 ≥ 50%, several pivotal first-line CPI-based phase 3 studies have been conducted investigating combination treatments combining CPIs with chemotherapy (ChT) or combining different CPIs with or without ChT. As a result, there has been an increase in front-line treatment options for advanced NSCLC, and treatment algorithms are changing very quickly. In fit patients with advanced NSCLC, combination treatments including CPI and ChT are considered the new standard of care with improved clinical outcomes. CPI combination treatments are well tolerated and quality of life also seems to be better when CPIs are implemented in the first-line setting. The aim of this review is to provide a summary of the recently published first-line phase 3 studies investigating CPIs as monotherapy or in combination with other CPIs or ChT in advanced NSCLC, and to suggest possible treatment algorithms.

Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) represent the standard of care for advanced non-small cell lung cancer (NSCLC) patients whose tumor harbors an activating EGFR mutation. The vast majority of patients will experience disease control with an EGFR-TKI but inevitably all patients will progress, often within a year of treatment. There is no current standard of care for this scenario but, in clinical practice, most of the patients will be offered platinum-based doublet chemotherapy. In some situations, continuation of the EGFR-TKI beyond radiological progression, with or without use of local treatments in case of oligo-progressive disease, represents a reasonable therapeutic option. The aim of this review is to describe the different treatment strategies that have been developed to tackle progression on EGFR-TKIs, including specific clinical scenarios and novel agents designed to tackle the common T790M resistance mutation.

Non-small cell lung cancer (NSCLC) is a heterogeneous disease, caused by the presence of different clinically relevant molecular subtypes. Genetic mutations are emerging as potential biomarkers of response and treatment selection in patients with NSCLC. Over the past few years, activating mutations of epidermal growth factor receptor (EGFR) have been recognized as the most important predictor of response to EGFR tyrosine kinase inhibitors (TKIs) such as gefitinib and erlotinib and also as a favourable prognostic factor. The RAS genes, including H-RAS, K-RAS and N-RAS, encode a family of proteins regulating cell growth, differentiation and apoptosis. Mutations in the K-RAS gene, mainly in codons 12 and 13, have been found in 20-30% of NSCLC tumor samples and occur most commonly, but not exclusively, in adenocarcinoma histology and in heavy smokers. In NSCLC, the presence of K-RAS mutations has generally been considered to be associated with worse prognosis and resistance to systemic therapy in the adjuvant as well as the metastatic setting. In early stage NSCLC, the prognostic role of K-RAS mutations has been evaluated in several studies without definitive conclusion. On the other hand, in advanced NSCLC, the presence of K-RAS mutations identifies a subgroup of patients who do not respond to EGFR-TKI therapy but, at the same time, a positive survival effect from EGFR-TKIs cannot be excluded in these patients. Similarly, K-RAS mutational status does not predict benefit from the anti-EGFR monoclonal antibody cetuximab, highlighting the biological difference between lung cancer and colorectal cancer. As a result of the lack of conclusive data, K-RAS mutations do not represent a validated biomarker for the negative selection of patients who are candidates for anti-EGFR therapy. The aim of this article is to review and discuss the data on the prognostic and predictive value of K-RAS mutations in NSCLC.

The epidermal growth factor receptor (EGFR) mutation is the first recognized molecular target in non-small cell lung cancer that makes personalized therapy feasible. This molecular alteration has been demonstrated to be more frequent in Asians, non-smokers and patients with adenocarcinoma histology. Several retrospective and subgroup analyses of phase III trials have shown the single agent, erlotinib, to be associated with higher response rates and longer progression-free survival in patients harbouring an EGFR mutation. Two prospective randomized phase III studies from China and Europe have confirmed the role of first-line erlotinib in patients with the mutations. Erlotinib has also been evaluated in combination with chemotherapy in either a concurrent or intercalated regimen. Earlier trials were limited by little information on the EGFR mutational status of the enrolled patients, and an ongoing phase III trial with translational biomarker analysis will provide more comprehensive data on the combination.

Small cell lung cancer (SCLC) represents approximately 13% of all lung cancer diagnoses and the incidence has reduced over the last 20 years. Treatment of SCLC remains challenging because of its rapid growth, early dissemination and development of drug resistance during the course of the disease. Chemotherapy remains the cornerstone of treatment for limited (LD) and extensive disease (ED), with concurrent chemotherapy and radical thoracic radiotherapy representing the best treatment option for fit patients with LD. Platinum-based chemotherapy is the treatment of choice in fit patients with good organ function, and the radiosensitizing effect of cisplatin is critically important for concurrent chemoradiotherapy in LD. Anthracycline-containing regimens represent a viable alternative for patients where platinum-based chemotherapy is contraindicated. Patients who relapse or progress after first-line chemotherapy have a very poor prognosis. Second-line therapy may produce a modest clinical benefit. Maintenance chemotherapy has not been shown to convincingly improve outcomes for SCLC. A number of targeted agents have been investigated in LD and ED, mostly in unselected populations, with disappointing results. Prophylactic cranial irradiation has been shown to reduce the incidence of brain metastases and prolong survival for both LD and ED without negative impact on quality of life (QOL) and cognitive function. Ongoing trials will shed some light on the impact of thoracic radiotherapy on QOL, symptom control and survival in ED SCLC patients who benefitted from first-line chemotherapy.