Second Primary Non-Small-Cell Lung Cancer After Head and Neck Cancer: A Population-Based Study of Clinical and Pathologic Characteristics and Survival Outcomes in 3597 Patients

A history of head and neck cancer (HNC) is associated with a survival decrement in patients who subsequently develop non small-cell lung cancer (NSCLC), compared with patients with primary NSCLC only. An increased proportion of localized stage NSCLC is diagnosed in HNC survivors compared with patients with primary NSCLC only, and this might affect subsequent NSCLC therapy selection. Introduction: Retrospective studies have shown an increased risk of second primary lung cancer in patients with a history of head and neck cancer (HNC). No population-based study has examined the overall survival (OS) outcomes of patients with second primary non-small-cell lung cancer (NSCLC) after HNC comparison with patients with first primary NSCLC. Patients and Methods: Individuals with histologically confirmed NSCLC diagnosed after non-metastatic squamous-cell carcinoma of the head and neck (HNC-NSCLC; n = 3597) were identified in Surveillance, Epidemiology, and End Results 18 registries (1988-2013). OS and baseline characteristics were compared in patients with first primary NSCLC (NSCLC-1; n = 365,551) in the same registries. Results: Squamous NSCLC was more common in HNC-NSCLC (n = 745 [64.1%] localized, n = 833 [71.9%] regional, and n = 811 [63.5%] distant) than in the NSCLC-1 (n = 30,901 [38.3%] localized, n = 50,557 [48.2%] regional, and n = 53,720 [29.8%] distant; P < .001). The leading cause of death in HNC-NSCLC was NSCLC (n = 2183; 60.6%), and median OS after localized, regional, and distant NSCLC diagnosis was 2.50 years, 1.17 years, and 5 months, respectively. For NSCLC-1, median OS was 4.58 years, 1.58 years, and 6 months, respectively. These differences were significant (P < .001). In multivariable analysis, a history of HNC remained associated with worse OS for localized (hazard ratio [HR], 1.40; 95% confidence interval [CI], 1.29-1.51; P < .001), regional (HR, 1.26; 95% CI, 1.19-1.35; P < .001) and distant (HR, 1.11; 95% CI, 1.04-1.18; P < .01) stage NSCLC. Conclusion: A history of HNC adversely affects OS in patients who subsequently develop NSCLC. This OS decrement might have implications for NSCLC surveillance and NSCLC therapy selection in this population. (C) 2019 Elsevier Inc. All rights reserved.