Clinical outcomes of stage-IV non-small-cell lung cancer in young patients and the impact of tumor markers

Introduction: Non-Small Cell Lung Cancer (NSCLC) diagnosed at a younger age have patterns of care, responses to treatment, and outcomes not entirely clear. A particular feature includes more advanced stages at diagnosis. Our objective was to characterize these young patients with advanced disease and evaluate the impact of targeted therapies.

Methods: Analyzing our cohort of 18,252 newly diagnosed NSCLC patients, we defined Young-age versus Norm-age based on the age distribution at the time of diagnosis. Stage-IV patients were investigated on their clinical information and outcomes; deaths were considered lung cancer-related. Primary outcome was overall survival (OS). Multivariate Cox models were built to evaluate independent prognostic factors in comparative age groups.

Results: We found 4,267 patients with stage-IV NSCLC (359 Young-age; 3,908 Norm-age). Young patients had predominance of females (52.6% vs. 43.3%, P = 0.001), never-smokers (43.2% vs. 14.8%, P < 0.001), and adenocarcinoma (73.5% vs. 62.5%, P < 0.001). Mean OS was 21.1 months in the Young and 15.1 months in Norm, respectively (P < 0.001). Young patients were more often treated with surgery (6.7% vs. 5.0%), chemotherapy (53.2% vs. 44.1%), and targeted therapy (10.6% vs. 5.7%). Molecular studies were assessed in patients when the mutation tests became clinically available (93 Young, 875 Norm) and revealed a critical role of targeted therapy in the improved survival of both age groups.

Discussion: Young patients with stage-IV NSCLC have a specific profile and benefit more when treated with surgery and targeted therapy. Molecular testing is critical in this population, where improved survival was identified. A more aggressive approach to this population needs to be considered.