Physical activity levels of women with breast cancer during treatment: a case-control study

Introduction: Maintaining or increasing physical activity levels after a breast cancer diagnosis may contribute to reducing the risk of disease recurrence and improving survival among affected women. Objective: To compare the physical activity levels of women with breast cancer to those of healthy women of the same age group. Methods: A case control study was conducted between October 2021 and August 2022, including postmenopausal women aged 45 to 65 years. Women with breast cancer were recruited from the Goiânia Clinical Hospital, Goiás, Brazil. Approximately one age-matched control was selected from the general population for every 2.2 cases. Physical activity levels were assessed using the short version of the International Physical Activity Questionnaire. The final sample comprised 95 women, including 65 cases and 30 controls. Results: Among the cases, 40% (n = 26) were undergoing chemotherapy and 60% (n = 39) were receiving hormone therapy. Results: In the overall analysis, women with breast cancer presented significantly lower physical activity levels compared to the control group (median: 198 MET min/week; IQR: 0.00 – 547 vs. 606; IQR: 57.75 – 1062; p = 0.008). In the subgroup analysis, a statistically significant difference in physical activity levels was observed among the groups undergoing chemotherapy, hormone therapy, and the control group (p = 0.009). Conclusion: Women with breast cancer exhibit lower levels of physical activity compared to healthy women of the same age group. Randomized clinical trials and epidemiological studies are needed to establish causality.