Survival among Never-Smokers with Lung Cancer in the Cancer Care Outcomes Research and Surveillance Study

Abstract

Rationale: Differences in patient characteristics and outcomes have been observed among current, former, and never-smokers with lung cancer, but most prior studies included few never-smokers and were not prospective. Objectives:We used data from a large, prospective study of lung cancer care and outcomes in the United States to compare characteristics of never-smokers and smokers with lung cancer and to examine survival among the never-smokers.Methods: Smoking status at diagnosis was determined by selfreport and survival was determined from medical records and cancer registries, with follow-up through June 2010 or later. Cox regression was used to examine the association between smoking and survival, and to identify predictors of survival among never-smokers.Measurements and Main Results: Among 3,410 patients with lung cancer diagnosed between September 1, 2003 and October 14, 2005 who completed a baseline patient survey, there were 274 neversmokers (8%), 1,612 former smokers (47%), 1,496 current smokers or smokers who quit recently (44%), and 28 with missing information about smoking status (,1%). Never-smokers appeared more likely than former and current/recent smokers to be female and of Asian or Hispanic race/ethnicity, and to have adenocarcinoma histology, fewer comorbidities, private insurance, and higher income and education. Compared with never-smokers, the adjusted hazard of death from any cause was 29% higher among former smokers (hazard ratio, 1.29; 95% confidence interval, 1.08-1.55), and 39% higher among current/recent smokers (hazard ratio, 1.39; 95% confidence interval, 1.16-1.67). Factors predicting worse overall survival among never-smokers included Hispanic ethnicity, severe comorbidity, undifferentiated histology, and regional or distant stage. Neversmoking Hispanics appeared more likely to have regional or advanced disease at diagnosis and less likely to undergo surgical resection, although these differences were not statistically significant.Conclusions: Never-smokers with lung cancer are more likely than ever-smokers to be female, Asian or Hispanic, and more advantaged socioeconomically, suggesting possible etiologic differences in lung cancer by smoking status. Among never-smokers, Hispanics with lung cancer had worse survival than non-Hispanic whites.

Clinical characteristics and survival in non-small cell lung cancer patients by smoking history: a population-based cohort study

“…The present study confirms the findings from previous studies that adenocarcinoma and EGFR-mutations are overrepresented among lung cancer patients without a history of smoking [6,7,9,11,[14][15][16][17][18][19][20][21][22][24][25][26][41][42][43]. To the best of our knowledge, this was the first nationwide Nordic populationbased study finding a higher proportion of EGFR-mutations in never-smokers compared to ever smokers.…”

“…In line with results from most previous studies [7,11,12,16,19,26], never-smokers were older at diagnosis compared to current smokers and former smokers. The observed higher proportion of both younger (<50 years) and older patients (80 years) among never-smoking has, to the best of our knowledge, never been observed before.…”

“…Higher survival in never-smokers, both cause-specific and overall, remained in stages I-II and IV disease. These findings of higher unadjusted survival in never-smokers confirm results from previous studies conducted in different populations and settings [10][11][12]15,17,22,26]. The lower adjusted hazards for never-smokers also confirms the findings of previous studies [11,15,17,26].…”

“…The overrepresentation of women in this group is also confirmed [7][8][9][10][11][12][14][15][16][17][18][20][21][22]24,26], and supports the notion of the presence of sex-based differences either in vulnerability to non-tobacco associated lung cancer or in exposure to other risk factors, such as environmental tobacco smoke. Due to observed sex imbalances, there has been considerable interest surrounding the possible role of oestrogen [6,9,34,35].…”

Evaluation of Staging at Diagnosis and Its Relationship with Survival Duration in Nonsmall Cell Lung Cancer Cases in Southern India

“…An earlier study has demonstrated that ever-smokers had poorer survival rates than never-smokers, and current smoking was a significant prognostic factor of a poor prognosis in the study population. 10 Similarly, another study by Clément-Duchêne et al 11 opined that improved survival in nonsmokers was probably related to factors like female gender, Asian race, and higher incidence of adenocarcinoma. 11 In a review on "lung cancer in never smokers" by Subramanian and Govindan, 12 it has been shown that adenocarcinoma is the predominant subtype and improved response rates to epidermal growth factor receptor-tyrosine kinase inhibitors 12 like gefitinib and erlotinib in nonsmokers.…”