Most patients with lung cancer have non-small cell lung cancer (NSCLC) subtype and have advanced disease at the time of diagnosis. Improvements in both first-line and subsequent therapies are allowing longer survival and enhanced quality of life for these patients. The median overall survival observed in many second-line trials is approximately 9 months, and many patients receive further therapy after second-line therapy. The cytotoxic agents pemetrexed and docetaxel and the epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) erlotinib and gefitinib are standard second-line therapies. For patients with EGFR mutation, a TKI is the favored second-line therapy if not already used in first-line therapy. For patients without the EGFR mutation, TKIs are an option, but many oncologists favor cytotoxic therapy. The inhibitor of the EML4/ALK fusion protein, crizotinib, has recently become a standard second-line treatment for patients with the gene rearrangement and has promise for patients with the ROS1 rearrangement. The Oncologist 2013;18:947-953Implications for Practice: The landscape of first-line treatment has generated challenges for clinical decisions in second-line therapy. For the patient treated with standard chemotherapy in the first line who has a treatable molecular change, this change should be targeted. More specifically, the patient with an epidermal growth factor receptor (EGFR) mutation should be treated with an EGFR tyrosine kinase inhibitor, and the patient with EML4/ALK rearrangement should be treated with crizotinib. However, these agents are increasingly being used in the first line, and most patients do not have these molecular changes. This leaves the clinician with many challenging questions regarding second-line therapy. How should the patient without treatable mutations be treated? Which clinical trials are most promising? How should the patient treated with a targeted agent in the first line be treated in the second line? This review addresses these issues, exploring the key existing data available to help guide informed clinical decisions.
INTRODUCTIONLung cancer is the leading cause of cancer-related mortality in the United States and in the world [1,2]. Most patients have the non-small cell lung cancer (NSCLC) subtype and have advanced-stage disease at the time of diagnosis. The standard first-line therapy for advanced disease (defined as stage IIIB or IV) is a platinum doublet alone or with a targeted agent such as bevacizumab for four to six cycles [3]. Chemotherapy extends overall survival (OS), reduces disease-related symptoms, and improves quality of life (QoL). Historically, after completion of four to six cycles of platinum-based therapy, patients were observed, and at the time of radiographic or clinical evidence of disease progression, therapy was re-initiated. Approximately 30% of patients experience disease progression during firstline chemotherapy, and all patients with initial disease control will eventually experience disease progression and requ...