Vagus nerve stimulation
Stimulation of the vagus nerve as a potential cancer treatment.
- Blood cancers
- Solid tumor
Why this trial?
Low vagus nerve activity is associated with a worse cancer prognosis. The vagus nerve is one of the twelve cranial nerves that extends throughout the human body (larynx, trachea, oesophagus, heart, lungs, stomach and abdominal organs) and performs a variety of important functions, such as stimulating the digestive system. It is also the most important nerve of the parasympathetic nervous system and helps calm your body after a stress response by slowing your heart rate and lowering your blood pressure.
The scientific understanding of how cancerous tumours and metastases are formed and develop has changed, and today a greater emphasis is placed on the immediate environment of the tumour cells within the body and the presence of a number of processes that make the prognosis worse. These processes are excessive inflammatory responses, oxidative stress and sympathetic neurotransmitters. The activity of the vagus nerve can change or counter these three processes.
Vagus nerve activity can be measured using the heart rate variability (HRV) that is recorded in an ECG (electrocardiogram). Various clinical studies have shown that a higher HRV is related to an improved prognosis (longer survival rates or lower tumour markers) for different types of cancer.
Vagus nerve stimulation could possibly bring a new treatment option to patients.
The pilot matched single-centre randomised-controlled trial started with validating the published data on the role of the vagus nerve in cancer in patients with 4 different cancers and confirming the relationship between HRV and cancer prognosis. Non-invasive approaches via deep paced breathing (HRV-biofeedback) and via non-invasive vagal nerve stimulation (VNS) were evaluated, and the first approach yielded the best results. In the final part of the project, a pilot study was initiated to evaluate if HRV-biofeedback may reduce the tumour marker CEA (CarcinoEmbryonic Antigen) and improve quality of life in 35 patients with stage 4 colon cancer.
Based on retrospective studies in 4 cancer types, a significant association between vagus nerve activity and prognosis in those cancer types was found and published in 3 scientific papers.
The pilot study in patients with advanced colon cancer did not recruit a sufficient number of patients and ended prematurely. Nevertheless, a trend was revealed, but it was not statistically significant, where CEA levels remained nearly unchanged in the controls, while a constant apparently declining pattern was shown in the HRV-biofeedback group. These preliminary results need to be confirmed in a large, randomised, controlled trial.
- Prof. Dr. Yori Gidron, Faculty of Medicine & Pharmacy, Research Group Neuroscience, Vrije Universiteit Brussel, Brussels, Belgium
- Vrije Universiteit Brussel, Brussels, Belgium
De Couck M, van Brummelen D, Schallier D, De Grève J, Gidron Y. (2013). The relationship between vagal nerve activity and clinical outcomes in prostate and non-small cell lung cancer patients. Oncology Reports; ;30, 2435-41.
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