Physical Activity Before, During, and After Chemotherapy for High-Risk Breast Cancer: Relationships With Survival

Abstract

<jats:title>Abstract</jats:title> <jats:sec> <jats:title>Background</jats:title> <jats:p>Although physical activity has been consistently associated with reduced breast cancer mortality, evidence is largely based on data collected at one occasion. We examined how pre- and postdiagnosis physical activity was associated with survival outcomes in high-risk breast cancer patients.</jats:p> </jats:sec> <jats:sec> <jats:title>Methods</jats:title> <jats:p>Included were 1340 patients enrolled in the Diet, Exercise, Lifestyle and Cancer Prognosis (DELCaP) Study, a prospective study of lifestyle and prognosis ancillary to a SWOG clinical trial (S0221). Activity before diagnosis, during treatment, and at 1- and 2-year intervals after enrollment was collected. Patients were categorized according to the Physical Activity Guidelines for Americans as meeting the minimum guidelines (yes/no) and incrementally as inactive, low active, moderately active (meeting the guidelines), or high active.</jats:p> </jats:sec> <jats:sec> <jats:title>Results</jats:title> <jats:p>In joint-exposure analyses, patients meeting the guidelines before and 1 year after diagnosis experienced statistically significant reductions in hazards of recurrence (hazard ratio [HR] = 0.59, 95% confidence interval [CI] = 0.42 to 0.82) and mortality (HR = 0.51, 95% CI = 0.34–0.77); associations were stronger at 2-year follow-up for recurrence (HR = 0.45, 95% CI = 0.31 to 0.65) and mortality (HR = 0.32, 95% CI = 0.19 to 0.52). In time-dependent analyses, factoring in activity from all time points, we observed striking associations with mortality for low- (HR = 0.41, 95% CI = 0.24 to 0.68), moderate- (HR = 0.42, 95% CI = 0.23 to 0.76), and high-active patients (HR = 0.31, 95% CI = 0.18 to 0.53).</jats:p> </jats:sec> <jats:sec> <jats:title>Conclusions</jats:title> <jats:p>Meeting the minimum guidelines for physical activity both before diagnosis and after treatment appears to be associated with statistically significantly reduced hazards of recurrence and mortality among breast cancer patients. When considering activity from all time points, including during treatment, lower volumes of regular activity were associated with similar overall survival advantages as meeting and exceeding the guidelines.</jats:p> </jats:sec>

A systematic review of the biological mechanisms linking physical activity and breast cancer

“…Leisure-time physical activity is associated with lower risks of 13 types of cancer [ 5 ], and exercise-associated reduction in breast cancer risk has been apparent in early-stage breast cancer patients [ 6 ]. In addition, high-risk breast cancer patients meeting the minimum Physical Activity Guidelines for Americans [ 9 ] experienced 50% reduced hazards of recurrence and mortality [ 7 ]. Therefore, epidemiological evidence supports that leisure-time physical activity and structured exercise before and after breast cancer diagnosis contribute to reducing the risk of breast cancer recurrence and mortality.…”

The Gut Microbiota: A Potential Gateway to Improved Health Outcomes in Breast Cancer Treatment and Survivorship

“…Interestingly, those who performed comparatively lower levels of activity prediagnosis, during treatment, and postdiagnosis experienced similar benefits to those who performed higher levels of activity at each time point [159]. This indicates that even smaller amounts of regular physical activity yield significant benefits for this population [159]. It is also important to note that those who did not meet guidelines prediagnosis but met them 2 years postdiagnosis still experienced a 46% decreased risk of recurrence and 43% decreased risk of mortality [159].…”

“…Observational data demonstrates a linkage between self-reported exercise and reduced rates of development and recurrence of several cancers [156]. A prospective study of women with breast cancer found that meeting the minimum guidelines for physical activity both before and after diagnosis is associated with significantly reduced risk of recurrence or mortality [159]. Interestingly, those who performed comparatively lower levels of activity prediagnosis, during treatment, and postdiagnosis experienced similar benefits to those who performed higher levels of activity at each time point [159].…”

“…A prospective study of women with breast cancer found that meeting the minimum guidelines for physical activity both before and after diagnosis is associated with significantly reduced risk of recurrence or mortality [159]. Interestingly, those who performed comparatively lower levels of activity prediagnosis, during treatment, and postdiagnosis experienced similar benefits to those who performed higher levels of activity at each time point [159]. This indicates that even smaller amounts of regular physical activity yield significant benefits for this population [159].…”

“…This indicates that even smaller amounts of regular physical activity yield significant benefits for this population [159]. It is also important to note that those who did not meet guidelines prediagnosis but met them 2 years postdiagnosis still experienced a 46% decreased risk of recurrence and 43% decreased risk of mortality [159].…”