British scientists believe they have found a way to help more patients to beat cancer.

Dr Raj Chopra and colleagues from Cancer Research UK have developed a new technique for transplanting stem cells into patients with leukaemia and lymphoma.

Stem cells are the body's 'master cells' and transplants can help to kill cancer tumours.

The end point is a treatment with the potential to be doubly effective

Dr Raj Chopra

The treatment is sometimes used in patients with these diseases who do not respond to conventional treatment.

However, the transplants are often followed by high-dose chemotherapy. This can cause side-effects and can kill the stem cells.

Resistant

But the Cancer Research UK team, who work at the Paterson Institute, in Manchester, have succeeded in genetically engineering cells to make them resistant to chemotherapy.

They used a virus to attach a gene called Atase to the cells. This gene protects them against the toxic effects of the treatment.

They believe combining these cells, which are taken from donated bone marrow, with high-dose chemotherapy double's the action against cancer.

This is because the chemotherapy not only targets the cancer cells but also attacks the patient's own stem cells.

This leaves only the transplanted stem cells, which multiply to fill the gaps and strengthening the anti-cancer immune response.

"The immune response is entirely generated by the cells we've transplanted," Dr Chopra said.

"The higher the proportion of donated stem cells, the stronger will be the immune system's anti-cancer effect. The end point is a treatment with the potential to be doubly effective."

Dr John Toy, medical director of Cancer Research UK said: "There's a real need to develop innovative new treatments for those patients whose cancers are resistant to conventional therapies.

"Dr Chopra's research combines two of the most exciting areas of medical science - stem cell research and gene therapy - to create a clever potential treatment which may end up saving lives."