This scarring can occur years after the women undergo radiotherapy to treat breast cancer.

In recent years, advances in radiotherapy treatment have meant that the likelihood of women developing radiation fibrosis has fallen.

However, it can still occur and doctors cannot offer women guarantees that they will not have any scarring.

Cell damage

While doctors do not know what causes radiation fibrosis, they suspect it may be caused by the continuous release of free radicals triggered by radiotherapy.

Free radicals spread like a kind of biological rust and can cause havoc in cells, even damaging DNA.

Antioxidants can mop up these potentially damaging molecules.

Professor John Yarnold and colleagues at the Institute of Cancer Research are now looking to see if the antioxidant properties in grapes could have a role to play.

"Grape seeds contain a mixture of compounds called flavanoids, also found in other fruits and vegetables," said Professor Yarnold.

"They have antioxidant properties that may be superior to known antioxidants like vitamin E or C.

"There have already been promising small scale trials with antioxidants, but I believe grape seed extract has interesting potential."

Tissue hardening

The doctors are planning to recruit 72 patients initially. Half will be given tablets containing grape seed extract while the others will receive a dummy pill.

This will enable the researchers to determine if the grape seed extract can protect women from fibrosis.

Professor Yarnold said: "Radiotherapy is followed over the years by tissue hardening and tenderness in the breast and underlying muscles in some women.

"We aim to test if grape seed extract reverses these changes and improves patients' quality of life."

He added: "If successful, we aim to conduct further clinical trials in radiotherapy patients cured of other cancers where fibrosis may cause other serious medical problems."

Sir Paul Nurse, chief executive of Cancer Research UK which is funding the study, said: "We hope this trial will eventually lead to a treatment for patients who previously had no respite from the symptoms of radiation fibrosis."