Toh CK, Ong WS, Lim WT, Tan DSW, Ng QS, Kanesvaran R, Seow WJ, Ang MK, Tan EH. A Decade of Never-smokers Among Lung Cancer Patients-Increasing Trend and Improved Survival.
Clin Lung Cancer 2018;
19:e539-e550. [PMID:
29627315 DOI:
10.1016/j.cllc.2018.03.013]
[Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Revised: 02/28/2018] [Accepted: 03/12/2018] [Indexed: 11/25/2022]
Abstract
BACKGROUND
It is not known whether clinicopathologic characteristics, treatment, and survival of never-smokers among lung cancer incident cases have changed over time. We assessed the trend and overall survival (OS) of these patients within our institution during a 10-year period.
PATIENTS AND METHODS
We reviewed 2 cohorts of non-small-cell lung cancer patients with a diagnosis from 1999 to 2002 and from 2008 to 2011. The patient characteristics and OS were compared by smoking status within each cohort and between the 2 cohorts over time.
RESULTS
Of the 992 patients in the 1999-2002 cohort and the 1318 patients in the 2008-2011 cohort, 902 and 1272 had a known smoking status, respectively. The proportion of never-smokers increased from 31% in 1999-2002 to 48% in 2008-2011 (P < .001). Within both cohorts, the differences in characteristics among never-, former-, and current-smokers have remained largely constant over time. A greater proportion of never-smokers had Eastern Cooperative Oncology Group performance status 0 to 1 and adenocarcinoma. The median OS increased from 15.5 months in 1999-2002 to 24.9 months in 2008-2011 (P = .001) for never-smokers, 12.3 to 15.9 months (P = .150) for former-smokers, and 10.5 to 13.9 months (P = .011) for current-smokers. The larger survival improvement among never-smokers was likely accounted for by the larger increase in never-smokers who were treated with tyrosine kinase inhibitors and pemetrexed over time.
CONCLUSION
We found an increasing trend of never-smokers among incident lung cancer cases and improved survival for these patients during a 10-year period. The documentation of smoking status in any national cancer registry is vital to estimate the true incidence of lung cancer among never-smokers over time.
Collapse