Physical activity status in relation to quality of life and dietary habits in breast cancer survivors: subset analyses of KROG 14-09 nationwide questionnaire study

Purpose We investigated the relationship of physical activity with dietary habits and quality of life (QoL) in breast cancer survivors in accordance with the recommendations of the American Cancer Society. Methods Data of 928 breast cancer survivors were obtained from the KROG 14-09 study to measure QoL in early phase after adjuvant radiotherapy. According to the extent of physical activity, survivors were divided into four groups: inactivity (0–149 min/week, N = 144), regular activity (150–450 min/week, N = 309), moderate activity (451–900 min/week, N = 229), and marked activity (901–1800 min/week, N = 164) excluding hyperactivity (> 1800 min/week, N = 82) as it is a difficult condition to recommend to survivors. Global physical activity questionnaire, 5-dimensional questionnaire by EuroQoL (EQ-5D-3L), QoL Questionnaire–breast cancer (QLQ-BR23) from EORTC, and dietary habits were surveyed. A linear-to-linear association test for EQ-5D-3L and Kruskal–Wallis analysis for QLQ-BR23 and dietary habit were conducted. Results Overall, 15.5% respondents (144/928) were classified as physically inactive. The trends of frequent intake of fruits ( p = 0.001) and vegetable ( p = 0.005) and reluctance toward fatty food ( p < 0.001) were observed in physically active groups. Mobility ( p = 0.021) and anxiety ( p = 0.030) of EQ-5D-3L, and systemic therapy side effect (p = 0.027) and future perspective ( p = 0.008) of QLQ-BR23 were better in physically active groups besides body image ( p = 0.003) for the survivors with breast-conserving surgery. However, moderate and marked activities did not further improve QoL than regular activity. Conclusion Physicians and care-givers have to pay attention to inactive survivors to boost their physical activity, thereby facilitating a better QoL and dietary habit.