Minimising cancer care damage

Radiotherapy can kill healthy issue as well as tumours

Scientists have discovered how healthy tissue is damaged by cancer treatments.

The breakthrough could pave the way for the safe use of more intensive therapies.

Cancer is often treated by drugs or radiation therapy.

However, both can lead to damage of healthy tissues.

This means that doctors can only give patients strictly controlled doses.

This technique has the potential to protect normal tissues and to enhance treatment effects

Dr Lesley Walker

Part of the problem is that scientists did not know which healthy cells within the organs targeted for treatment triggered the tissue damage.

Researchers at the Memorial Sloan-Kettering Cancer Center in the US carried out experiments on mice who were given radiotherapy.

Blood vessels

They discovered that the crucial cells are those that line the small blood vessels in the gut. They are known as endothelial cells.

Using drugs and gene technology, the researchers have developed ways to prevent both the death of the cells and the subsequent tissue damage.

At present, damage to the gut is one of the factors that limits the intensity of radiotherapy and chemotherapy treatments.

At high doses, these treatments cause side effects such as diarrhoea and infection, which can be fatal.

It was previously assumed that the cells damaged by cancer therapies were the stem cells in the gut tissue.

But in the current experiment, researchers found that the blood vessels are actually the target.

They were then able to give the mice higher doses of radiation therapy with no ill effect by blocking a mechanism by which endothelial cells communicate with each other.

The same technique could eventually work for human cancers, especially those that are treated with abdominal radiation therapy such as gastrointestinal, genitourinary, and gynaecological tumours.

Researcher Dr Richard Kolesnick said: "The question we need to ask is whether we will be able to use this new knowledge to protect the blood vessels of healthy tissue or to more effectively target the blood vessels of tumour tissue."

Dr Lesley Walker, of the Cancer Research Campaign, told BBC News Online: "It is interesting how important endothelial cells are becoming in strategies for cancer treatments.

"This technique has the potential to protect normal tissues and to enhance treatment effects."

The research is published in the journal Science.