Longitudinal association of physical activity with quality of life domains among malaysian breast cancer survivors

The widely documented benefits of physical activity (PA) for breast cancer (BC) survivors include reductions in morbidity and mortality and enhanced quality of life (QOL). This study examined QOL changes over time and the association between PA and QOL. A prospective cohort study followed 133 BC survivors at baseline, one year and three years after diagnosis. PA was measured using the Global Physical Activity Questionnaire (GPAQ), and QOL was assessed using the European Organization for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaires. PA levels were classified as active (≥ 600 MET-min/week) or inactive (< 600 MET-min/week) per WHO recommendations. Generalised Estimating Equations (GEE) were used to analyse the associations between PA and QOL domains over time. The study followed 133 women (mean age of 56.9 years) at baseline, one year, and three years. PA levels declined over time, with active survivors dropping from 48.1% at baseline to 35.3% at three years. Overall, QOL declined over time. Global health status decreased from 77.8 (SD = 12.9) at baseline to 71.1 (SD = 17.0) at three years (p < 0.001). Physical functioning dropped from 95.1 (SD = 11.5) to 88.7 (SD = 13.4) (p < 0.001), and cognitive functioning from 87.3 (SD = 15.6) to 80.6 (SD = 18.8) (p = 0.001). Fatigue increased from 11.8 (SD = 15.1) at baseline to 17.2 (SD = 16.2) at three years (p = 0.006). Insomnia was the most severe symptom with the highest mean score of 18.55 among all the symptom scales. From baseline to 3 years, systemic therapy side effects increased from 6.30 to 10.06 (p = 0.001); arm symptoms from 8.60 to 14.62 (p = 0.010). Higher PA levels were associated with improved role functioning. Additionally, PA at one year improved constipation symptoms. This study highlights significant declines in PA and QOL among Malaysian BC survivors, with PA showing a protective effect on specific QOL domains. Future research is needed to develop effective interventions to promote long-term PA maintenance.