Physical Activity and Functional Capacity of Breast Cancer Patients: Prospective Cohort Study

Introduction:  Women with breast cancer may experience a decrease in physical fitness, fatigue, and muscle weakness after oncological treatment.

Objective:  To analyze changes in the level of physical activity (PA) and functional capacity of patients since the diagnosis of breast cancer and after surgical treatment.

Method:  Prospective cohort study including women with indication of curative surgery for breast cancer. Patients were assessed at the beginning of the study and after breast cancer surgery. To assess self-reported PA, the IPAQ was used, and functional capacity was measured using three physical tests: a 30-second sit-to-stand test, a two-minute step test, and handgrip strength. The comparison of variables before and after surgical treatment was performed using the Wilcoxon test, and the effect size was evaluated using Cohen’s D.

Results:  A total of 655 women were included, with the majority in the age range ≤ 59 years old (62.9%), 49.6% with advanced clinical stage ≥ IIB, and 48.9% undergoing surgery as their first oncological treatment. After surgical treatment, there was a reduction in the level of total PA, walking, and moderate intensity PA (p < 0.001 and Cohen’s D = 0.31; 0.50; 0.15, respectively), as well as handgrip strength (p < 0.001; Cohen’s D = 0.38). An increase in aerobic capacity and lower limb resistance performance was observed (p < 0.001 in both tests, Cohen’s D = 0.23 and 0.39, respectively).

Conclusion:  Breast cancer patients showed an increase in aerobic capacity and lower limb resistance. However, they experienced a reduction in handgrip strength and a significant decrease in PA levels, particularly in walking, with a substantial impact on their physical well-being.

Key words:
Breast Neoplasms/surgery; Functional Status; Physical Fitness; Exercice Test