Non-small cell lung cancer in never smokers: a clinical entity to be identified

Abstract

OBJECTIVES:It has been recognized that patients with non-small cell lung cancer who are lifelong never-smokers constitute a distinct clinical entity. The aim of this study was to assess clinical risk factors for survival among never-smokers with non-small cell lung cancer.METHODS:All consecutive non-small cell lung cancer patients diagnosed (n = 285) between May 2005 and May 2009 were included. The clinical characteristics of never-smokers and ever-smokers (former and current) were compared using chi-squared or Student's t tests. Survival curves were calculated using the Kaplan-Meier method, and log-rank tests were used for survival comparisons. A Cox proportional hazards regression analysis was evaluated by adjusting for age (continuous variable), gender (female vs. male), smoking status (never- vs. ever-smoker), the Karnofsky Performance Status Scale (continuous variable), histological type (adenocarcinoma vs. non-adenocarcinoma), AJCC staging (early vs. advanced staging), and treatment (chemotherapy and/or radiotherapy vs. the best treatment support).RESULTS:Of the 285 non-small cell lung cancer patients, 56 patients were never-smokers. Univariate analyses indicated that the never-smoker patients were more likely to be female (68% vs. 32%) and have adenocarcinoma (70% vs. 51%). Overall median survival was 15.7 months (95% CI: 13.2 to 18.2). The never-smoker patients had a better survival rate than their counterpart, the ever-smokers. Never-smoker status, higher Karnofsky Performance Status, early staging, and treatment were independent and favorable prognostic factors for survival after adjusting for age, gender, and adenocarcinoma in multivariate analysis.CONCLUSIONS:Epidemiological differences exist between never- and ever-smokers with lung cancer. Overall survival among never-smokers was found to be higher and independent of gender and histological type.

The Impact of a Negative History of Smoking on Survival in Patients with Non-Small Cell Lung Cancer Detected with Clinic-based Screening Programs

“…Never-smokers constituted 33.3% of the NSCLC patients evaluated in our study, which is comparable with previous findings (13,18,19). The proportion of patients with NSCLC who have never smoked has been reported to be 32.8% in Japan (13), 32.4% in Singapore (18) and 24.5% in Brazil (19).…”

“…There is now strong evidence that lung cancer in never-smokers shows different patterns compared to those observed in ever-smokers (15,16). It has been recognized that patients with non-small cell lung cancer (NSCLC) who are lifelong never-smokers constitute a distinct clinical entity (17,18). Only very little is known about the clinical outcomes of never-smoking patients with NSCLC detected with clinicbased screening programs (7).…”

Evaluation of pulmonary nodules in Asian population

“…A total of 31.6% of lung cancer patients and 54.5% of lung cancer patients with adenocarcinoma histology have been reported as never smokers in Singapore (8). This data is consistent with other studies in Asian population (9)(10)(11). Hence, in one third of the lung cancer patients and half of the adenocarcinoma lung patients, keying in "0" for smoking in the calculator, this predictor may falsely diminish contribution toward predicting malignancy.…”

Tobacco Smoking and Lung Cancer : Perception Changing Facts = تدخين التبغ و سرطان الرئة : إدراك تغير الحقائق

“…Multivariate analysis of factors related to OS, using the Cox regression for never-smokers, was highly significant (HR 0.58; P 0.047) without any influence of female gender or adenocarcinoma. 80 In a subgroup analysis of the Chinese OPTIMAL trial, the P value for the interaction test between various smoking statuses was 0.34, favouring the TKI in never-smokers.…”