One of the cruelest features of cancer is recurrence — the disease returning years after seemingly successful treatment. New research reveals part of the hiding mechanism: dormant breast cancer cells shelter behind protective “shields” of other cells.
Researchers at the MRC Laboratory of Medical Sciences, Imperial College London and the UCL Genetics Institute used single-cell RNA sequencing and spatial transcriptomics to map breast tumors. They found dormant (“quiescent”) cancer cells — cells that enter a hibernation-like state under stress — sheltered within niches of CXCL10-positive macrophages (immune cells) and myofibroblastic cancer-associated fibroblasts (support cells). These surrounding cells appear to form physical and biological barriers that keep the immune system and drugs away. The work was published in Genome Medicine.
Why dormancy is dangerous
“Quiescent cancer cells are very dangerous. These cells can hide from chemotherapy,” said Dr. Alexis Barr of the MRC Laboratory of Medical Sciences. Because they aren’t rapidly dividing, they resist chemotherapy (which targets fast-growing cells) and can reactivate after treatment ends — seeding recurrence.
Why it matters
Understanding the hideout points to ways to flush cells out: disrupting the protective support cells, targeting the complement immune pathway active in these niches, and combination therapies that hit both dividing and dormant tumor regions. This is analytical research on tumor data, not yet a treatment — but by revealing where and how cancer hides, it maps a path toward preventing relapse.