Metastatic characteristics and prognosis of non-small cell lung cancer

Abstract

Objective To analyze the specificity of metastatic sites and prognostic differences of different metastatic patterns in non-small cell lung cancer (NSCLC) based on a large population-based dataset. Methods The metastatic NSCLC patients diagnosed between 2010 and 2014 were collected from the Surveillance, Epidemiology, and End Results (SEER) database. Kaplan-Meier survival analysis and log-rank test were used for survival analysis, and Cox proportional hazard model was performed to determine the factors related to improved overall survival (OS). Results A total of 38 755 NSCLC cases with metastases to bone, liver, brain and/or lungs were collected from the SEER database. At the time of diagnosis, 93.89% of the patients were over the age of 50 years, and the caucasian accounted for 77.38%. Among all enrolled cases, the moderately differentiated tumors (grade Ⅱ) accounted for 12.50%, and those with poor differentiation (grade Ⅲ) for 25.55%. The major histological subtype was adenocarcinoma, accounting for 72.52%. The most common single metastatic site was bone (22.43%), and the least common was liver (5.87%) for NSCLC. As for multi-site metastases, bone and lung was the most common 2-site metastasis (7.40%), and bone, liver and lung was the most common 3-site metastasis (3.16%). An isolated liver metastasis had the worst OS among single metastasis (P < 0.001). Furthermore, for patients with multi-site metastases, liver combined metastases had worst OS among various combinations(P < 0.001). Conclusion For NSCLC, bone is the most commonly targeted site, no matter for single- or multi-organ metastases. NSCLC patients with metastasis to liver alone or in combination with other organs have a poorer prognosis, while isolated lung metastasis has the best outcomes.

Keywords

• metastatic pattern
• prognosis
• seer database
• non-small cell lung cancer
• histological subtype