Never-Smoker Lung Cancer Is Increasing

ABSTRACT

PURPOSE: Lung cancer has been the leading cause of death in South Korea since the year 2000. Adenocarcinoma became the most frequent type in the national survey of lung cancer since year 2005. MATERIALS AND METHODS: We analyzed 5,456 cases with lung cancer from 2004 to 2012 in a community cancer center. The mean age was 69.9 years, and 78.9% was male. RESULTS: Adenocarcinoma (ADC, 40.8%) was the most frequent type, followed by squamous cell carcinoma (SQC, 36.4%), small cell carcinoma (SCC, 14.8%) and non-small cell lung cancer (NSCLC) not otherwise specified (8.1%). In male patients, SQC was the most frequent type (43.5%), while ADC showed highest incidence in females (72.6%). Anatomic stage at diagnosis in NSCLC was I (10.3%), II (5.8%), IIIA (15.7%), IIIB (19.2%), and IV (49.0%). In SCC, 41.7% was in limited stage and 58.3% was diagnosed in extensive stage. The proportion of never smoker has been increased from 19.1% in 2004~2008 to 25.4% in 2009~2012. Never-smokers are more likely to be female (68.2% vs. 4.0%, p<0.001), have ADC (69.9% vs. 31.3%, p<0.001), and manifest as stage IV disease (58.5% vs. 45.2%, p<0.001), compared to smokers. Among 1,908 cases whose initial treatment was recorded, 42.5% received chemotherapy, 25.7% received radiation treatment, 20.5% received surgery and the remaining 11.3% received supportive cares only or transferred to other health care facilities. CONCLUSION: In conclusion, proportion of lung cancer in never-smoker is increasing. As screening for smokers will miss this growing population, we need to discover biomarkers to find high risk population of lung cancer.