Lung cancer trends: smoking, obesity, and sex assessed in the Staten Island University’s lung cancer patients

INTRODUCTION: The incidence of lung cancer in the United States decreased by 1.8% from 1991 to 2005 while it increased by 0.5% in females. We assessed whether nonsmokers afflicted with lung cancer at Staten Island University Hospital are disproportionately female in comparison to national averages. We also evaluated different factors including race, histology, and body mass index (BMI) in correlation with smoking history. METHODS: A retrospective chart review was conducted from 2005 to 2011 on 857 patients. Patients were divided into two groups according to their smoking status: current or ever-smokers, and former or never-smokers. A chi-square test for categorical data and multivariate logistic regression analyses was used to study the relation between BMI and the other clinical and demographic data. RESULTS: Forty-nine percent of patients were men and 51% were women with a mean age at diagnosis of 67.8 years. Current smokers were most common (50.2%) followed by ever-smokers (18.2%), former smokers (15.8%) and never-smokers (15.6%). Forty eight percent had stage IV lung cancer upon presentation. Never-smokers with lung cancer were 24 times more likely to be females. However, the proportion of female former smokers (31.6%) was lower than the proportion of male former smokers (68.4%) (P=0.001). There was no significant association between American Joint Committee on Cancer (AJCC) stage, sex, race, and histological type in the two smoking groups. Current/ever-smokers tended to be younger at age of diagnosis (P=0.0003). BMI was lower in the current/ever-smokers (26.8 kg/m(2)) versus former/never-smokers (28.8) in males (P=0.0005). BMI was significantly higher in males (30.26) versus females (25.25) in the never-smoker category (P=0.004). Current smokers, compared to others, had a lower BMI in males (26.4 versus 28.3; P=0.0001) and females (25.5 versus 26.9; P=0.013) but the mean BMI for all groups was in the overweight/obese range. CONCLUSION: Our population of lung cancer patients although demographically distinct, reflects a similar proportion of afflicted nonsmokers to the national population. Smoking is a major risk factor for lung cancer, but there is also a possible direct correlation with BMI that would support obesity as a potential risk factor for lung cancer.