Abstract 3009: Changes in recreational physical activity and prognosis in breast cancer survivors
Authors: Jung Audrey Y. , Behrens Sabine , Thoene Kathrin , Schmidt Martina , Steindorf Karen , Chang-Claude Jenny 
Published: August 2018

Aim: Recreational physical activity (PA) both before and after a breast cancer diagnosis has been reported to be associated with lower total mortality. Whether there is benefit in changing PA levels between pre- and post-diagnosis is unclear and has not received much attention. This study aimed to examine changes in recreational PA and overall mortality (OM) and breast cancer-specific mortality (BCSM). Methods: We used data from the MARIE (Mamma Carcinoma Risk factor Investigation) study, a prospective population-based patient cohort study conducted in Germany, where 3813 breast cancer patients, aged 50-70 at diagnosis, were recruited from 2002-2005 and followed-up with re-interview in 2009 (FUP1) and for vital status until June 30, 2015. Based on median cut-points, women were categorized by their PA behavior pre- and post-diagnosis and combined to create four groups: pre-diagnosis low/post-diagnosis low, pre-diagnosis low/post-diagnosis high, pre-diagnosis high/post-diagnosis low, pre-diagnosis high/post-diagnosis high. Cox proportional hazards regression models with delayed-entry were used to assess the associations between change in recreational physical activity, and OM and BCSM, adjusting for age, menopausal status, and prognostic factors. Those in the pre-diagnosis low/post-diagnosis low group served as the reference. Results: A total of 2,066 patients were included in the analysis. There were 139 deaths (54 from breast cancer) over a median follow-up time of 11.6 years. Median recreational PA levels at pre-diagnosis and post-diagnosis were 3.6 MET-hr/week and 0 MET-hr/week, respectively. Compared to women who had low recreational PA levels at pre-diagnosis and post-diagnosis, women who had low recreational PA levels at pre-diagnosis and high PA levels at post-diagnosis had lower risk of OM (HR 0.6 (95%CI 0.4-1.0)), and women who had high PA levels at pre-diagnosis and maintained high PA levels at post-diagnosis also had lower risk of OM (HR 0.6 (0.8-0.9)). There was no association between changes in recreational PA and OM for women who had high PA levels at pre-diagnosis and low PA levels at post-diagnosis (HR 0.8 (0.5-1.3)). There were also no statistically significant associations between changes in recreational PA and BCSM (compared to low/low, HRs for low/high 0.8 (0.4-1.7), high/low 0.9 (0.4-1.9), and high/high 0.7 (0.3-1.3)). Conclusion: Our study suggests that there may be benefits in increasing recreational PA after diagnosis of a breast cancer even for women who were not particularly physically active pre-diagnosis.

Citation Format: Audrey Y. Jung, Sabine Behrens, Kathrin Thoene, Martina Schmidt, Karen Steindorf, Jenny Chang-Claude. Changes in recreational physical activity and prognosis in breast cancer survivors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3009.