Obesity is associated with poorer outcomes across multiple cancer types. Lifestyle behaviours (smoking, physical activity (PA) and alcohol) can improve outcomes among cancer survivors.
Cancer patients of all subtypes were cross-sectionally surveyed on their smoking, alcohol and PA levels, and their perceptions of these behaviours on quality of life (QoL), fatigue and survival (OS). Multivariable logistic regression models evaluated the association of BMI 1 year prior to diagnosis with behaviour changes and perceptions.
Of 1269 patients, 205 smoked at diagnosis and 44% quit at 1 year; 350 (at diagnosis) and 238 (at follow-up) met PA guidelines; 661 drank alcohol at diagnosis while 50% reduced consumption after. Median BMI was 25.8 (22% obese); 75%+ patients perceived PA as improving QoL and OS, while 70%+ described smoking and 55%+ described alcohol as worsening QoL and OS. At diagnosis, increased BMI was associated with ex-smoking (vs current smoking; P = 0.003), never using alcohol (vs former use; P = 0.05) and not meeting PA guidelines (P = 0.01). Among smokers at diagnosis, increased BMI was associated with smoking cessation (aOR = 1.08 per 1 unit BMI, P = 0.03) and perceptions that smoking worsens OS (aOR = 1.10, P = 0.04) and fatigue (aOR = 1.08, P = 0.08). Among those not meeting PA guidelines at diagnosis, increased BMI was associated with perceptions that PA worsens fatigue (OR = 1.02, P = 0.06) and is unsafe (OR = 1.04, P = 0.06), but were not associated with PA levels changes after diagnosis. Among drinkers at diagnosis, increased BMI was associated with perceiving alcohol to be less harmful (aOR = 0.93, P = 0.002) and less likely to worsen OS (aOR = 0.96, P = 0.04) and fatigue (aOR = 0.97, P = 0.09), but not with alcohol use changes after diagnosis. BMI was not associated with counselling rates; however, 66% of current smokers received cessation counselling while only 14% of current drinkers and 13% of those not meeting PA guidelines received counselling on their respective behaviours.
Obese patients were more likely to quit smoking and perceive it to be harmful but less likely to perceive alcohol as harmful. Survivorship programs should consider focusing on PA and alcohol counselling in obese patients.
Clinical trial identification
Legal entity responsible for the study
Princess Margaret Cancer Centre
All authors have declared no conflicts of interest.