Some cancer cells can enter a dormant, sleep-like state that helps them survive treatment. Instead of continuing to grow and divide, these cells become largely inactive, allowing them to avoid the effects of many cancer drugs.

In certain forms of cancer, including some types of lung cancer, stress hormones can trigger this response. Specialized proteins called glucocorticoid receptors detect those hormones inside tumor cells. Once activated, the receptors can push the cells into a dormant state where cell division slows dramatically. As a result, many therapies become far less effective.