A longitudinal study of physical activity in patients with breast cancer: A latent transition analysis.

[OBJECTIVE] To identify physical activity (PA) subgroups among patients with breast cancer, examine transition probabilities between groups over time, and determine influencing factors for targeted rehabilitation.

[METHODS] Using convenience sampling, PA was assessed in 204 patients with breast cancer from three Shanghai tertiary hospitals between May 2022 and December 2023. Data were collected at diagnosis (T0), during chemotherapy (T1), and at 3-month (T2) and 6-month (T3) follow-ups after chemotherapy. Tools included a general information questionnaire, the short-form International Physical Activity Questionnaire and the Exercise Self-Efficacy Scale. Latent transition analysis (LTA) identified PA trajectories and explore factors.

[RESULTS] LTA identified three PA categories: "Moderate-to-Vigorous PA Compliance (MVC) Group", "Walking-based PA Compliance (WC) Group" and "Sedentary Lifestyle (SL) Group". MVC Group demonstrated high stability from T1 to T2 (100%) and T2 to T3 (99.8%). WC Group was likely to transition to MVC Group from T1 to T2 (53.9%) but largely reverted by T3 (47.3%). SL Group had a higher probability of transitioning to MVC Group from T1 to T2 (54.1%) and was likely to remain there at T3 (61.1%). Transition probabilities highlight a critical intervention window from chemotherapy initiation to 3 months after chemotherapy. Influencing factors included exercise self-efficacy, education level, average monthly income, and current chemotherapy course ( < 0.05).

[CONCLUSIONS] Three distinct PA patterns emerged, highlighting a critical intervention window from chemotherapy initiation to 3 months after chemotherapy. PA declined during chemotherapy but increased afterward, emphasizing the need for personalized strategies to sustain long-term improvement.