1p pill for diabetes could limit harm of breast cancer drug

CHEAP diabetes pills could be used to minimise the side effects of breast cancer drugs for thousands of women, a study suggests.

Herceptin, an incredibly effective treatment for a particularly dangerous form of the cancer, has driven up survival rates since it was made available on the NHS 15 years ago.

But the treatment – one of the first gene- targeted ‘ wonder drugs’ – comes with severe side effects for about 15 per cent of those who take it.

These women develop heart problems, with their cardiac muscles unable to pump enough blood around their body.

Many even suffer potentially fatal heart failure.

Except for quitting Herceptin, until now there has been no treatment for the side effects.

However, scientists at Stanford University School of Medicine in California have now found that drugs such as metformin – which costs as little as 1p per pill – seem to ward off the impact of Herceptin on the heart. The pills are taken by thousands with diabetes. Herceptin is used for the HER2-positive form of breast cancer, affecting around 8,000 women in Britain every year.

The Stanford team, writing in Circulation medical journal, also developed a test that predicts whether a woman will react badly to Herceptin or not.

The research team used blood from three healthy participants and seven women with breast cancer, including five who had experienced cardiac dysfunction due to Herceptin.

They turned stem cells from the blood samples into heart cells.

When they applied Herceptin to the samples from the breast cancer patients who showed heart dysfunction, the cells contracted less vigorously. But when they applied Herceptin to the cells of breast cancer patients who had not suffered side effects, the cells showed little change.

Study leader professor Joseph Wu said: ‘ We could use this method to find out who’s going to develop chemo-related toxicity and who’s not.

‘And now we have an idea about the cardioprotective medications we can give them.’

Professor Wu said Herceptin disrupts the way the heart cells consumed energy.

The researchers then applied AMPK activators – the wider class of drug of which metformin is one – to the weakened cells.

The treated cells then ate up more glucose and contracted more vigorously. The scientists are now planning to do a study of patients who were taking metformin for diabetes while they were receiving Herceptin for breast cancer.

Professor Wu also advocated further lab testing of drugs on cells to reduce the time needed to bring the drugs to patients and to reduce cost.

‘Disrupts heart cells’