Lung cancer in patients who have quit smoking

http://www.ncbi.nlm.nih.gov/pubmed/21352550

J Cardiothorac Surg. 2011 Feb 25;6(1):19. [Epub ahead of print]
High Prevalence of Lung Cancer in a Surgical Cohort of Lung Cancer Patients A Decade After Smoking Cessation.
Mong C, Garon EB, Fuller C, Mahtabifard A, Mirocha J, Mosenifar Z, McKenna R.

Abstract
ABSTRACT:

BACKGROUND: This study was designed to assess the prevalence of smoking at time of lung cancer diagnosis in a surgical patient cohort referred for cardiothoracic surgery.

METHODS: Retrospective study of lung cancer patients (n= 626) referred to three cardiothoracic surgeons at a tertiary care medical center in Southern California from January 2006 to December 2008. Relationships among years of smoking cessation, smoking status, and tumor histology were analyzed with Chi-square tests.

RESULTS: Seventy-seven percent (482) had a smoking history while 11.3% (71) were current smokers. The length of smoking cessation to cancer diagnosis was <1 year for 56 (13.6%), 1-10 years for 110 (26.8%), 11-20 years for 87 (21.2%), 21-30 years for 66 (16.1%), 31-40 years for 44 (10.7%), 41-50 years for 40 (9.7%) and 51-60 years for 8 (1.9%). The mean cessation was 18.1 +/- 15.7 years (n=411 former smokers). Fifty-nine percent had stage 1 disease and 68.0% had adenocarcinoma. Squamous cell carcinoma was more prevalent in smokers (15.6% vs. 8.3%, p= 0.028); adenocarcinoma was more prevalent in never-smokers (79.9% versus 64.3%, p= 0.0004). The prevalence of adenocarcinoma varied inversely with pack year (p < 0.0001) and directly with years of smoking cessation (p = 0.0005).

CONCLUSIONS: In a surgical lung cancer cohort, the majority of patients were smoking abstinent greater than one decade before the diagnosis of lung cancer.