ABSTRACT
Background: Obesity is an emerging leading
cause of morbidity and mortality in the US and the relationship between
obesity, tobacco, and survival in NSCLC is unclear. Methods: Data (n = 87,631)
were obtained from linkage of the 1996-2007 Florida Cancer Data System to the
Agency for Health Care Administration database providing procedure and
diagnoses codes. Survival time was calculated from date of diagnosis to date of
death. Smoking status was categorized as never, current, and former. Obesity
(yes/no) = ICD9 code BMI > 30 kg/m2, cachexia = ICD9 code “wasting
syndrome”, & non-obese = non-obese & non cachectic. Cox proportional
regression models used to predict survival; demographic, clinical, treatment
factors, & comorbidities were included in adjusted models with smoking
status and obesity as the main factors. Results: The majority of patients (pts)
were either former (49%) or current (40%) smokers, & non-obese (88%). 6.8%
of pts were obese & 4.8% of pts were cachectic. There were significant
differences between survival curves and median survival (months) for obese vs.
non-obese vs. cachectic pts. (20 vs 10 vs. 7.9; P < 0.001). Former and
current smokers had shorter median survival than never smokers (10.8 & 9.2
vs. 11.9; P < 0.001). Survival rates (%) at 1-yr (60.1 vs. 45.2 vs. 37.7; P
< 0.001), 5-yr (30.3 vs. 15.4 vs. 9.5; P < 0.001), 10-yr (18.1 vs. 7.6
vs. 2.7; P < 0.001) were better for obese vs. non-obese and cachectic pts
respectively. Independent predictor of worse survival in the unadjusted model
was former (HR 1.08; P < 0.001) and current (HR 1.20; P < 0.001) smokers
compared to never. Obese and non-obese pts had better survival vs. cachexia
pts. (HR 0.52; P < 0.001 and HR 0.80, p < 0.001 respectively) and obese
had better survival than Non-obese pts (HR 0.65, p < 0.001). In the adjusted
model, controlling for extensive variables and comorbidities, former (HR 1.11;
P < 0.001) and current (HR 1.19; P < 0.001) smokers still had
significantly worse survival vs. never smokers. Obese patients still had better
survival (HR 0.87; P < 0.001, and HR 0.88, p < 0.001) vs. cachexia
patients and non-obese respectively, survival rate was not significantly
different compare non-obese with cachexia. Conclusions: Our results show that
being a former or current smoker worsens survival while obesity improved
survival when compared with cachexia patients or Non-obese.
Share and Cite:
Hansra, D. , Koru-Sengul, T. , Zhao, W. , Miao, F. , Monedero, A. , Tannenbaum, S. , Lee, D. , Hurley, J. and Byrne, M. (2016) Effects of Obesity and Smoking on Survival in Non-Small Cell Lung Cancer.
Open Journal of Epidemiology,
6, 128-139. doi:
10.4236/ojepi.2016.62013.