Physical activity before, during and after chemotherapy for high-risk breast cancer: relationships with survival
Although physical activity has been consistently associated with reduced breast cancer mortality, evidence is largely based upon data collected at one occasion. We examined how pre- and post-diagnosis physical activity was associated with survival outcomes in high-risk breast cancer patients.
Included were 1,340 patients enrolled in the DELCaP Study, a prospective study of lifestyle and prognosis ancillary to a SWOG clinical trial (S0221). Activity before diagnosis, during treatment, and at one-and two-year intervals after enrollment were collected. Patients were categorized according to the Physical Activity Guidelines as meeting the minimum Guidelines (yes/no) and incrementally as inactive, low-active, moderately active (meeting the Guidelines), or high-active.
In joint-exposure analyses, patients meeting the Guidelines before and one-year after diagnosis experienced statistically significant reductions in hazards of recurrence (HR=0.59, 95% CI: 0.42-0.82) and mortality (HR=0.51, 95% CI: 0.34-0.77); associations were stronger at two-year follow-up for recurrence (HR=0.45, 95% CI: 0.31-0.65) and mortality (HR=0.32, 95% CI: 0.19-0.52). In time-dependent analyses, factoring in activity from all time points, we observed striking associations with mortality for low- (HR = 0.41, 95% CI: 0.24-0.68), moderate- (HR = 0.42, 95% CI: 0.23-0.76), and high-active patients (HR=0.31, 95% CI: 0.18-0.53).
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.
Cannioto RA, Hutson A, Dighe S, McCann W, McCann SE, Zirpoli GR, Barlow W, Kelly KM, DeNysschen CA, Hershman DL, Unger JM, Moore HCF, Stewart JA, Isaacs C, Hobday TJ, Salim M, Hortobagyi GN, Gralow JR, Albain KS, Budd GT, Ambrosone CB. Physical activity before, during and after chemotherapy for high-risk breast cancer: relationships with survival. J Natl Cancer Inst. 2020 Apr 2.