Loading
In two mouse models of breast cancer, researchers traced a nerve circuit from the brain to nerves inside mammary tumours. Turning the circuit up sped tumour growth and turning it down slowed growth, but this has not been shown in people and does not mean anxiety caused anyone's cancer.
Xiong and colleagues studied an implanted 4T1 mouse mammary tumour model and the spontaneous MMTV-PyMT mouse model. Viral tracing connected sympathetic fibres in the tumour through the lateral paragigantocellular nucleus in the brainstem to corticotropin-releasing hormone neurons in the central medial amygdala.
Chemogenetic and optogenetic activation of this amygdala-to-brainstem circuit raised norepinephrine inside 4T1 tumours, changed immune-cell profiles and accelerated tumour growth. Inhibiting or ablating the same neurons produced changes in the opposite direction. The investigators also found that alprazolam reduced circuit activity and slowed mammary tumour growth in the mice.
Every causal experiment was in mice. The study did not test a human brain-to-cancer circuit, cancer recurrence or survival, and the authors state that clinical benefit remains unshown. Alprazolam is not an established cancer treatment. A separate seven-day preoperative propranolol trial in 60 people found tumour biomarker changes but did not test recurrence or survival, while a 2024 meta-analysis found no significant association between beta-blocker use and breast cancer recurrence or death.
This study provides causal evidence in mice that activity in a defined brain circuit can change a peripheral mammary tumour through autonomic and immune routes. It is a mechanism study, not evidence that anxiety controls human breast cancer and not a treatment recommendation.
Shares Journal of Clinical Investigation, Tumour microenvironment (TME).
Shares Electrical and synaptic integration of glioma into neural circuits, Cancer neuroscience (brain-to-cancer and nerve-tumour signalling).
Every source this page cites, grouped by who published it. Grouping is read from the web address, not assigned by hand.
A source that has moved or gone is reported by the weekly link check. /audit/