Résumé
Background: This study assessed the prevalence and risk factors of unhealthy behaviors among survivors of early-stage breast cancer.Methods: Women (n = 9556) from the CANcer TOxicity cohort (NCT01993498) were included. Physical activity (PA), tobacco and alcohol consumption, and body mass index were assessed at diagnosis and at years 1 and 2 after diagnosis. A behavior was defined as unhealthy if patients failed to meet PA recommendations (≥10 metabolic equivalent task hours per week), reduce/quit tobacco, or decrease alcohol consumption to less than daily, or if they gained substantial weight over time. Multivariable-adjusted generalized estimating equations explored associations with unhealthy behaviors.Results: At diagnosis, 41.7% of patients were inactive, 18.2% currently used tobacco, 14.6% consumed alcohol daily, and 48.9% were overweight or obese. At years 1 and 2, unhealthy PA behavior was reported among 37.0% and 35.6% of patients, respectively, unhealthy tobacco use behavior was reported among 11.4% and 9.5%, respectively, and unhealthy alcohol behavior was reported among 13.1% and 12.6%, respectively. In comparison with the previous assessment, 9.4% and 5.9% of underweight and normal-weight patients had transitioned to the overweight or obese category at years 1 and 2, respectively, and 15.4% and 16.2% of overweight and obese patients had gained ≥5% of their weight at years 1 and 2, respectively. One in 3 current tobacco smokers and 1 in 10 daily alcohol users reported improved behaviors after diagnosis. Older women (5-year increment) were more likely to be inactive (adjusted odds ratio [aOR], 1.03; 95% confidence interval [CI], 1.01-1.05) and report unhealthy alcohol behavior (aOR, 1.28; 95% CI, 1.23-1.33) but were less likely to engage in unhealthy tobacco use (aOR, 0.81; 95% CI, 0.78-0.85). Being at risk for depression (vs not being at risk for depression) was associated with reduced odds of unhealthy tobacco use (aOR, 0.67; 95% CI, 0.46-0.97) and with a higher likelihood of unhealthy alcohol behavior (aOR, 1.58; 95% CI, 1.14-2.19). Women with a college education (vs a primary school education) less frequently reported an unhealthy PA behavior (aOR, 0.61; 95% CI, 0.51-0.73) and were more likely to report unhealthy alcohol behavior (aOR, 1.85; 95% CI, 1.37-2.49). Receipt of chemotherapy (vs not receiving chemotherapy) was associated with higher odds of gaining weight (aOR, 1.51; 95% CI, 1.23-1.87) among those who were overweight or obese at diagnosis.Conclusions: The majority of women were adherent to healthy lifestyle behaviors at the time of their breast cancer diagnosis, but a significant subset was nonadherent. Unhealthy behaviors tended to persist after the breast cancer diagnosis, having varying clinical, psychological, sociodemographic, and treatment-related determinants. This study will inform more targeted interventions to promote optimal health.