Background: The advent of multiple molecular targets in advanced non-small-cell lung cancer (NSCLC) has brought new treatments, but also new logistic and technical considerations, to the clinician. The small size of endoscopic biopsies and the increasing number of relevant but uncommon markers has increased the need for rational approaches to molecular testing. We present the results of clinical preselection before EML4-ALK testing in a German NSCLC cohort.
Methods: Patients with stage IV NSCLC were included. Clinicians were encouraged to consider screening epidermal growth factor receptor wild-type adenocarcinoma patients with a limited smoking history, relatively young age, or who had benefited from chemotherapy for a relatively long period. Break-apart fluorescence in situ hybridization using archived paraffin tissue was performed in a central facility.
Results: From April 2010 to September 2011 we included 61 patients: mean age 56.6 years, 41% women, 90% adenocarcinoma, 5% large-cell, and 5% squamous cell cancers. Only three patients had activating epidermal growth factor receptor mutations; 16.4% of patients were positive for EML4-ALK fusion. The anaplastic lymphoma kinase (ALK)-positive patients included 60% women, tended to be younger, had smoked less, and had received significantly more systemic therapy, on average 3.7 lines of treatment over 3 years, before ALK-testing compared with the ALK-negative patients. Long periods of progression-free survival were experienced by ALK-positive patients treated with pemetrexed, vinorelbine, or cetuximab.
Conclusions: EML4-ALK fusion is uncommon, reported in about 5% of NSCLC patients; however, clinical preselection increased the yield of testing to 16.4%. EML4-ALK positive patients seem to have distinct clinical features and show long responses to a number of systemic therapies.