The worry that breast cancer may someday return is a troubling source of anxiety for many survivors of the disease. It’s understandable why, since most relapses and metastatic cancers (cancers that have spread) aren’t started by new tumours.
Rather, they’re caused by sleeper cancer cells that suddenly awaken. These “dormant” cancer cells usually colonise places such as the lungs or bones, waiting for the optimal conditions to spring back to life.
