Autonomic dysfunction in early breast cancer: Incidence, clinical importance, and underlying mechanisms

Abstract

Autonomic dysfunction represents a loss of normal autonomic control of the cardiovascular system associated with both sympathetic nervous system overdrive and reduced efficacy of the parasympathetic nervous system. Autonomic dysfunction is a strong predictor of future coronary heart disease, vascular disease, and sudden cardiac death. In the current review, we will discuss the clinical importance of autonomic dysfunction as a cardiovascular risk marker among breast cancer patients. We will review the effects of antineoplastic therapy on autonomic function, as well as discuss secondary exposures, such as psychological stress, sleep disturbances, weight gain/metabolic derangements, and loss of cardiorespiratory fitness, which may negatively impact autonomic function in breast cancer patients. Lastly, we review potential strategies to improve autonomic function in this population. The perspective can help guide new therapeutic interventions to promote longevity and cardiovascular health among breast cancer survivors.

Figure. Potential mechanisms associated with both autonomic dysfunction and increased cardiovascular disease (CVD) risk in breast cancer patients

Breast cancer diagnosis is associated with therapy-induced cardiovascular injury and lifestyle perturbations leading to increased activation of the sympathetic nervous system (SNS) and decreased activation of the parasympathetic nervous system (PNS). In turn, this autonomic imbalance triggers the hypothalamic-pituitary-adrenal (HPA) axis, the renin-angiotensin-aldosterone system (RAAS), and the endocannabinoid system, leading to oxidative stress, reduced vasodilation, inflammation, and atherosclerosis progression that promotes CVD.