Breast cancer vaccine hope thanks to stem cells that kill tumours File photo

A vaccine that slashes the risk of developing cancer could be on the horizon, researchers announced.

They have found a way of ‘priming’ the immune system to spot, attack and kill off breast tumour cells.

By taking a sample of blood, altering the stem cells within it, and injecting it back into the body, they boosted the ability of the immune system to tackle cancer.

The concept worked in tests on mice – but it will be some time before a vaccine could be available to humans.

The researchers, from Stanford University in California, hope in time anyone could be protected against cancer. Individuals would receive a vaccine comprising their own altered blood cells ‘as a way to prevent the development of cancers months or years later’.

The technique could also be used to treat cancer patients – either after surgery to make sure tumours do not come back, or as a way of boosting the immune system to defeat cancer that is already established.

The process uses stem cells – ‘blank’ cells which can easily be altered after extraction from blood samples.

The Stanford team looked for a particular type, induced pluripotent stem cells (iPS), which they irradiated to make them similar to cancer cells.

When injected into the body, the scientists found these cells prepared the immune system to recognise cancer cells.

‘When we immunised an animal with genetically matching iPS cells, the immune system could be primed to reject the development of tumours in the future,’ said lead researcher Joseph Wu. ‘Pending replication in humans, our findings indicate these cells may one day serve as a true patient-specific cancer vaccine.’

In his team’s trial, mice injected with stem cells managed to ward off breast cancer. The rodents were vaccinated with the stem cells and then cancer cells were injected, which grew into breast tumours within a week.

The tumours were rejected by 70 % of the vaccinated mice and became significantly smaller in the remaining 30%

Similar results were obtained when the researchers transplanted lung cancer cells into mice. Dr Wu said: ‘Although much research remains to be done, the concept itself is pretty simple. We would take your blood, make iPS cells and then inject the cells to prevent future cancers. I’m very excited about the future possibilities.’

Dr Nigel Kooreman, who is lead author of the study, said: ‘These cells, as a component of our proposed vaccine, have strong immunogenic properties that provoke a system-wide, cancer-specific immune response.

‘We believe this approach has exciting clinical potential.’

Dr Richard Berks of the Breast Cancer Now charity said: ‘The potential of using stem cells to create a cancer vaccine is really exciting. That these stem cells could train the immune system on their own to attack tumours may even give this innovative approach the edge over other types of immunotherapy in development.

‘However, this research has so far only been carried out in mice, and so further studies using human cells are required before we know whether this approach might work in patients.

‘It’s essential patients receive the most appropriate treatments for them, and immunotherapy is an exciting avenue of research that is already showing great promise in treating other types of cancer.’

The Stanford findings were published in the Cell Stem Cell journal.