Annual Review 2010/11 – Understanding why cancer spreads and why it can come back

In our second highlight from our Annual Review, we talk about our progress towards understanding cancer spread and developing treatments that could stop cancer returning, allowing more people to get the ‘all clear’ once and for all.

‘Yes, you’re cured.’ These are words that every patient longs to hear after cancer treatment. But no doctor can say with absolute certainty that all the cancer cells have been destroyed, and all too often the disease will return. We want to take away the fear of cancer spreading or coming back, by understanding why this happens and finding ways to stop it.

We are the only cancer charity in the UK with the knowledge and expertise to do this for every type of cancer, and this year we have made some significant discoveries.

Why does cancer spread?

One of the biggest challenges in successfully treating cancer is preventing it from spreading around the body and controlling cancer that has already spread – around nine out of ten cancer deaths are caused by the disease spreading.

Our scientists are using innovative techniques to explore how and why it happens. This is revealing opportunities to develop new treatments designed to stop cancer in its tracks:

• Our researchers have revealed more about the signals that drive skin cancer to spread, opening new avenues of research to tackle the disease. They found that when a gene which normally acts as a brake on cell movement is turned off, it can cause the skin cancer to become more aggressive, enabling it to spread to the lungs.
• Our scientists discovered more about how tumours of the nervous system can spread along nerves. They found they might do this by mimicking signals that normally guide the growth of nerve cells that are being repaired. This insight could help researchers identify ways to stop this type of cancer spread.
• We have revealed how two genes can ‘hijack’ part of the body’s natural defences against cancer helping the disease to grow and spread.

In future we may be able to prevent cancer spreading by determining which patients will benefit from drugs that either stimulate or suppress the body’s defences.

– Dr Marcos Vidal, from our Beatson Institute

Why does cancer come back?

Our research into stem cells is revealing why some cancers are resistant to treatment and can return.

Cancer stem cells are normal stem cells which have become faulty. Stem cells have the potential to develop into many different cell types in the body. They also have the unique property of being able to multiply indefinitely to make more cells.

They’re found in a number of different cancers, including breast, bowel and prostate cancer, and leukaemia.

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Many researchers think that cancer stem cells are the driving force behind some cancers, producing large numbers of ‘bulk’ cells which make up tumours. While radiotherapy and chemotherapy kill off these bulk cells, they are less effective against the more resistant cancer stem cells. This could explain why some cancers come back, as these resistant cells start multiplying again after treatment.

• Our scientists have made discoveries about stem cells in the gut. They now understand more about how these stem cells grow and divide, which could one day lead to better treatments for people with bowel cancer.
• We have established a Cancer Stem Cell Consortium. We hand-picked world-class research groups to collaborate on unravelling the role of cancer stem cells in breast, prostate and head and neck cancers. This research will identify important leads for more effective treatments for a range of cancers.

By specifically targeting cancer stem cells our team hope to develop new treatments for cancers that are currently hard to beat.

– Professor Fiona Watt, leader of the Cancer Stem Cell Consortium from our Cambridge Research Institute

Living with the uncertainty

Wendy McQuilkin, 58, from Oxfordshire has had breast cancer three times

I felt numb when they found it during a routine mammogram. I was successfully treated with tamoxifen and was fine for six years but it was always at the back of my mind. Then I was diagnosed with aggressive cancer in the other breast which had also gone into the first lymph gland. I was devastated that I had to have a mastectomy followed by chemotherapy and radiotherapy, and when I decided to have the other breast removed a couple of years later, they did find the beginnings of cancer.

Now I’m fine apart from a few aches and pains. The fear of cancer returning stays with you, but it helps to talk about it and I feel lucky to see my grandchildren grow up. If it wasn’t for research into new treatments I wouldn’t be here.

Ozy