Certain respiratory infections could trigger a reawakening of dormant cancer cells in the body, according to a new study.

Hidden in the lungs of some breast cancer survivors are tumour cells that can remain dormant for decades — until they one day trigger a relapse. Now, experiments in mice show that these rogue cells can be roused from their slumber by common respiratory illnesses such as COVID-19 or the flu.

Mice with a handful of cancerous cells in their lungs experienced a 100-fold increase to this number after being infected with swine flu