What happens when cancer spreads?

Jade Goody cancer battle | When cancer spreads

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One of the reasons cancer is so difficult to cure is that it often spreads from the original site to another part of the body.

In Jade Goody's case, her cervical cancer has now spread to her bowel, liver and groin.

When cancer spreads and starts growing somewhere new, it's called 'secondary cancer'. This is opposed to 'primary cancer' where the tumour begins in the body.

How does cancer spread?

There are three main ways that cancer moves through the body.
1. Local spread - moving to nearby body tissue
2. Through blood - cancer cells detach themselves from the primary tumour and then slip through blood vessel walls into the bloodstream. This is far more difficult than in sounds and only around 1 in many thousands of cells actually manage it.
3. Through the lymphatic system - this happens in a similar way to spread through the bloodstream. The lymphatic system works rather like blood circulation, but carries a colourless liquid called lymph. The system helps to filter blood and fight infections. Cancer cells move through this in much the same way they do through the bloodstream.

Where will a cancer spread to?

Whether it's in the lymph or blood, cancer cells usually stop at the first place they get stuck - this is often the capillary network, the smaller blood vessels near major organs.

Most blood flows from organs via the lungs, which makes it the most common place for secondary cancer.

Blood from the digestive organs flows to the liver first, making the liver the second most common area for cancer to spread to.

It's also common for cancer to spread to the lymph nodes nearest the original tumour - this explains why Jade's cancer has moved to her bowel and groin - given how close it is to the cervix.