Does Physical Activity Have an Impact on Recurrence Dynamics in Early Breast Cancer Patients?

Abstract

Several studies have suggested that pre and/or postdiagnosis physical activity can reduce the risk of recurrence in breast cancer patients, however its effect according to follow-up time has not yet been investigated. We analyzed recurrence and mortality dynamics in randomized clinical trials (RCTs) from Australia and Canada. The combined Australian RCTs evaluated, at a median follow-up of 8.3 years, an 8-month pragmatic exercise intervention in 337 women with newly diagnosed breast cancer, while the Canadian RCT evaluated, at a median follow-up of 7.4 years, supervised aerobic or resistance exercise during chemotherapy in 242 patients. For each RCT, the control arm consisted of patients undergoing usual care. We estimated the event dynamics by the discrete hazard function, through flexible regression of yearly conditional event probabilities with generalized additive models. In the considered RCTs, the recurrence and mortality risk of patients enrolled in the physical activity arm were stably decreased at medium/long term after five year of follow-up. In the Australian RCTs where patients were recruited by urban versus rural area, the latter group did not display benefit from physical activity. Estimated odds ratios (95% confidence intervals) for disease-free survival (DFS) in urban women were 0.63 (0.22–1.85); 0.27 (0.079–0.90); 0.11 (0.013–0.96) at the 3rd, 5th and 7th year of follow-up, respectively. For rural women, DFS patterns were overlapping with odds ratios (ORs), approximating 1 at the different years of follow-up. Although not reaching statistical evidence, the estimates in the Canadian trial were in line with the results from the Australian urban women with ORs (95% CI) for DFS of 0.70 (0.33–1.50); 0.47 (0.19–1.18); 0.32 (0.077–1.29) at 3rd, 5th, 7th follow-up year, respectively. While we acknowledge that the analyzed RCTs were not designed for investigating disease recurrence over time, these results support the evidence that physical activity reduces the risk of developing medium-/long-term metastases. Additional translational research is needed to clarify the mechanisms underlying these observations.

Low physical activity in patients diagnosed with head and neck cancer

“…Less is reported about the effect on survival rate in HNC patients 3 . In patients with other cancers, physical activity interventions reduce risk of recurrence and mortality 4 . Further, pretreatment healthy behaviors (including physical activity) are associated with mortality in HNC patients 5 .…”

“… 3 In patients with other cancers, physical activity interventions reduce risk of recurrence and mortality. 4 Further, pretreatment healthy behaviors (including physical activity) are associated with mortality in HNC patients. 5 In addition, the effect of PA interventions on physical function, fatigue, muscle strength, and quality of life is greater in cancer patients with low pretreatment levels.…”

Late Recurrence in Breast Cancer: To Run after the Oxen or to Try to Close the Barn?

“…This activity was delivered, akin to drug administration, during and beyond standard treatments in early breast cancer patients. Moreover, this improvement emerges after about 5 years following primary treatment [ 52 ], suggesting that physical activity may exert its long-term effects on dormant metastases during their subclinical development. The unexpected therapeutic efficacy of an “unarmed” practice, such as that of physical exercise is for us a last prop to a conviction matured in decades of research.…”

From Oncological Paradigms to Non-Communicable Disease Pandemic. The Need of Recovery Human Biology Evolution

“…In particular, the need of a systemic approach further emerged from the observation that a physiological/metabolic activity realized by targeted physical exercise interventions may improve the disease outcomes in certain subsets of patients [32,33]. Of note, according to a recent analysis of the disease dynamics, this improvement emerges after about 5 years following primary treatment [34], suggesting that physical activity may exert its long-term effects on given types of dormant metastases during their subclinical development. These findings are in agreement with the hypothesis that skeletal muscle behaves as an immune/endocrine organ, capable of secreting cytokines into the circulatory system during physical activity, a finding that could even associate active skeletal muscles to the maintenance of a healthy immune system during ageing [35].…”

“…Hence, physical activity could be considered a component and biomarker of the homeostatic systems that ensure the maintenance of the state of health, functional both to individual life and to the fitness of the group in huntergatherer biology which is still mainly preserved. Its significant reduction in current societies, therefore, impacts on both levels and its highlighted effect on breast cancer prognosis [32][33][34] could be interpreted as a partial recovery of this homeostatic function linked to the deep biological need of healthy aging with its social reflection.…”