Sydney researchers have had a dramatic breakthrough in the fight against a rare but deadly childhood cancer.

‘Neuroblastoma’ accounts for less than 10% of all childhood cancers but 15% of all deaths, because of its ability to quickly spread throughout a child's body.

Neuroblastoma is often highly metastatic, which means that cancer cells can spread from the primary tumour site to other organs.

Metastatic disease is difficult to cure and is a major cause of death for neuroblastoma patients.

Scientists have now found 'switching off' a protein in cancer cells, can stop it spreading which could a discovery that could make the disease much easier to treat.

Professor Maria Kavallaris from the Children’s Cancer Institute told 7News: "It's not just that it spreads, when it starts spreading those tumour cells are highly resistant."

Now researchers at the Children's Cancer Institute Australia may have found a way to head that off.

If a key protein called 'stathmin' is suppressed or 'switched off' it can reduce the migration of cancer by a remarkable 71%.

But more work and funding are needed.

Little Sienna Jones died at the age of two from the rare disease.

She was nine-months-old when diagnosed and after extensive treatment, she went into remission but soon relapsed.

Her mum Lucy Jones told 7News: "My daughter should still be here and she still could be, had more research been done earlier, without question about it, and it's all money-related."

To help, visit Children’s Cancer Institute Australia

Pictures of Sienna Jones