Researchers publishing in Nature Cell Biology claim to have discovered a mechanism by which cancer cells can be programmed to spread and hide from chemotherapy.

Hypoxia is a known hallmark of solid tumors that triggers stress responses and induces resistance to chemotherapy and radiotherapy.

The new study suggests that hypoxic microenvironments in primary tumors give rise to dormant disseminated tumor cells (DTCs) that “hide” from therapy and may be a cause of disease relapse and poor outcomes.

These hypoxic tumor microenvironments not only produce DTCs that rapidly grow and spread, but also send a large proportion of them into a dormant state that makes them better able to evade chemotherapy.

The study suggests, therefore, that the poor prognoses associated with hypoxic tumors may arise not only because they produce more aggressive cancer cells, but also because they program many of them to enter a dormant state where they can hide from chemotherapy.