Why cancer can come back years later - and how to stop it

"When Lisa Dutton was declared free of breast cancer in 2017, she took a moment to celebrate with family and friends, even though she knew her cancer journey might not be over. As many as one-third of people whose breast tumours are cleared see the disease come back, sometimes decades later. Many other cancers are known to recur in the years following an initial treatment, some at much higher rates."

"This would monitor her for sleeping cancer cells, which many researchers now think might explain at least some cancer recurrence. These dormant tumour cells evade initial treatment and move to other parts of the body. Instead of multiplying to form tumours right away - as is typical for metastatic cancer, in which cells spread from the main tumour - the dormant cells remain asleep. They are hidden from the immune system and not actively dividing. But later, they can reawaken and give rise to tumours."

Dormant disseminated tumour cells can persist after apparent successful cancer treatment and later reawaken to form metastases. These cells evade initial therapies, remain non-dividing and hide from the immune system while relocating to sites such as bone marrow. Estimates suggest about 30% of successfully treated people might harbour these cells, with unpublished work indicating higher rates. Detection efforts such as clinical monitoring trials aim to find sleeping cells, and multiple trials are now testing strategies to identify and treat dormant cells to prevent later cancer recurrence across breast, prostate, lung, colon and other cancers.

Read at Nature