Cancer suppresses appetite through sensory nerves

Cancer-related weight loss (known as cachexia) is a serious problem. It reduces quality of life, makes treatments less effective and contributes to mortality. Until now, cachexia was largely seen as a consequence of inflammation and metabolic disruption. The study, published in Science, adds a new mechanism: sensory neurons, the nerves that send signals from the body to the brain.

Diet changes how nerves respond

The researchers found that a dietary switch altered the behaviour of sensory neurons around tumours. Those neurons appear to relay signals to the brain that suppress appetite. These are mouse studies; whether the same mechanism operates in humans has not yet been confirmed.

When the activity of these specific nerve cells was blocked, the animals’ appetite increased and their weight stabilised. This suggests that the nerves play an active role in sustaining cachexia, rather than simply reacting passively to the tumour.

What this means for cancer patients

Cachexia is difficult to treat, partly because its causes are multiple. The finding that sensory neurons contribute to appetite suppression gives researchers a new target. In principle, treatments aimed at this nerve pathway could restore appetite in patients with cancer-related weight loss.

This remains a finding from animal research. The authors are cautious about drawing conclusions for humans. The study does, however, provide mechanistic insight that may be important for future clinical development, especially given the lack of effective treatments for cachexia.

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