Quirks & Quarks

Scientists unlock a key to why cancer spreads

By targeting the signals that cause tumours to metastasize, they think they can slow the spread.
The malignant breast cancer cells metastasized to the liver. Scientists have discovered the signaling process that causes densely packed cancer cells to break away from a tumor and spread the disease elsewhere in the body. (National Cancer Institute)

The main reason cancer can be deadly is because it spreads. In fact, 90 per cent of all cancer deaths are not caused by the original tumour. The real danger comes when those tumour cells invade other parts of the body - like the lungs, liver, or lymph nodes. That's when it gets the name we all dread: metastatic cancer.

When we fight cancer, we usually target those tumours — with radiation, surgery or chemo — hoping to get at the cancer before it spreads and becomes uncontrollable.  

But a team of American researchers is developing a new strategy. They're not targeting the tumour. Instead, they're targeting the spread — hoping to slow it down or stop it, right in its tracks.  

By studying tumours in 3-D, rather than the standard, flat petri dish, Dr. Hasini Jayatilaka — a post doctaral researcher at Johns Hopkins University, has discovered what triggers cancer cells to leave the original site and invade the rest of the body.