Objective: The aim of this study was to identify demographic and treatment-related factors associated with health-promoting behavior changes after a breast cancer diagnosis. Changes in health behaviors were also evaluated according to weight, exercise, diet and alcohol consumption patterns before breast cancer diagnosis.

Materials and methods: We examined self-reported behavior changes among 1415 women diagnosed with breast cancer in the NIEHS Sister Study cohort. Women reported changes in exercising, eating healthy foods, maintaining a healthy body weight, drinking alcohol, smoking, getting enough sleep, spending time with family and friends, and participating in breast cancer awareness events.

Results: On average, women were 3.7 years from their breast cancer diagnosis. Overall, 20-36% reported positive changes in exercise, eating healthy foods, maintaining a healthy weight, or alcohol consumption. However, 17% exercised less. With each 5-year increase in diagnosis age, women were 11-16% less likely to report positive change in each of these behaviors (OR = 0.84-0.89; p < 0.05), except alcohol consumption (OR = 0.97; CI: 0.81, 1.17). Women who underwent chemotherapy were more likely to report eating more healthy foods (OR = 1.47; 95% CI 1.16-1.86), drinking less alcohol (OR = 2.01; 95% CI: 1.01, 4.06), and sleeping enough (OR = 1.41; 95% CI: 1.04, 1.91). The majority of women (50-84%) reported no change in exercise, eating healthy foods, efforts to maintain a healthy weight, alcohol consumption, sleep patterns, or time spent with family or friends.

Conclusions: Many women reported no change in cancer survivorship guideline-supported behaviors after diagnosis. Positive changes were more common among younger women or those who underwent chemotherapy.