A cancer breakthrough could provide a vital new way to stop the disease before it can spread.

Scientists have discovered that aggressive breast tumours look different – with many spikes coming out of them, rather like a conker.

Less aggressive breast tumours are more like a simple circle with hardly any spikes.

Experts now believe that it is the spikes on the outside of tumors that help breast cancer cells to migrate to other organs such as the lungs, liver, and brain. This migration often leads to a terminal diagnosis when the cancer has spread.

These spikes act like pathways extending from the tumor, providing cancer cells with a shortcut to access blood vessels and consequently travel throughout the body.

The discovery, based on the analysis of tumors from 30 breast cancer patients and 65 individuals with melanoma, could pave the way for the development of new drugs aimed at preventing the spread of cancer.

Professor Victoria Sanz Moreno, senior author of the research, from The Institute of Cancer Research, London, who led the study said: ‘If we can see these spiky tumours in people’s biopsies, then we can target their cancer cells with existing drugs, to help prevent cancer from spreading.

‘This could be part of a treatment plan, along with other drugs and chemotherapy, which might improve survival. We could also be able to slow down the spread in people who have terminal cancer.’

Scientists have discovered that aggressive breast tumours look different – with many spikes coming out of them, rather like a conker

A doctor surveys a mammogram- experts hope this new finding can help prevent the spread of breast cancer to vital organs

Tumours with many outer spikes – which are made of fibres in the ‘extracellular matrix’ surrounding the tumour (SUBS – must keep) – were found to change how cancer cells behaved.

Cancer cells within these spikes became rounder and tougher – perfect for travelling through the body.

Scientists were able to show that cancer cells like these, created in the lab using spike-like structures, were better able to spread into the lungs of mice.

When they searched for similar-looking cancer cells in people with different kinds of cancer, including breast cancer, pancreatic cancer and melanoma, the cancer patients who had these cells did not survive as long.

Those people who died more quickly had cancer cells with a more active set of genes controlling their cell shape and size (SUBS – must keep).

It is the spikes on tumours which appear to trigger this gene activity.

This knowledge could be very helpful, as there are already drugs available which could prevent the gene activity and kill the cells.

Cancer starts with a tumour, and when that tumour is removed through surgery or shrunk down using treatments like chemotherapy, someone no longer has cancer.

But when the cancer is caught too late, or the surgery or treatment don’t work perfectly, cells can escape the tumour and cause the cancer to spread.

A 3D illustration of a cancer cell

It is hoped that the breakthrough will see new breast cancer drugs developed

Although they can travel through fatty tissue or lymph nodes to spread, the most efficient way is for cancer cells to enter the bloodstream, which provides a super-highway to reach organs like the lungs or brain.

The spikes on tumours may link up to blood vessels, providing a quick, straight short-cut to get into the bloodstream.

But scientists don’t know if that is the case, because the tumours they analysed had been removed from people’s bodies.

However, regardless of whether they actually carry cancer cells all the way to blood vessels, the spikes appear to give cancer cells the tools they need to travel faster around the body.

The cells’ genes which contain the ‘instructions’ for their shape seem to be ‘dialled up’ like a dimmer switch to change their shape more quickly than normal.

Once they are rounder, evidence shows cancer cells can move faster and have harder exteriors, so they can squeeze through blood vessels without too much damage.

The findings could help doctors detect aggressive tumours earlier, based on the spiky collagen ‘scaffolding’ around them.

And it could help develop drugs which stop tumours becoming spiky – preventing cancer cells getting ready to spread.

If the cells do not spread and are kept within the tumour, then other drugs can successfully destroy them there.

The breakthrough, described in the journal Nature Communications, is the culmination of almost a decade of research.

Dr Oscar Maiques, who led the study from Barts Cancer Institute at Queen Mary University of London, said: ‘When clinicians biopsy the tumour, our research shows that what’s on the outside of the tumour is just as important as what’s in the centre – as this holds crucial information about whether a cancer is likely to spread.’