Bubble therapy to treat cancer

TINY bubbles that explode inside a tumour could be a radical new treatment for breast cancer.

The bubbles, each no bigger than a speck of dust, are filled with oxygen and injected in their thousands into cancerous tissue.

Once inside the tumour, the bubbles are ‘popped’ by firing sound waves at them through the skin.

The released oxygen dramatically improves the effectiveness of radiotherapy, which is used to treat many types of cancer.

Radiotherapy turns the oxygen in a tumour into corrosive molecules called free radicals, which attack and destroy all cells in the vicinity — in this case, cancer cells.

But most tumours are low on oxygen because they grow much faster than the oxygen-carrying blood vessels that supply them.

Thousands of women in the UK undergo radiotherapy for breast cancer every year. Although it can be very effective, it can also damage healthy tissue; common side-effects include sore skin, nausea, hair loss and diarrhoea.

A lack of oxygen in tumours can hamper the effectiveness of radiotherapy, meaning patients often need higher doses, or longer courses, of treatment to shrink tumours.

U. S. researchers at Thomas Jefferson University in Philadelphia tested whether the oxygen-filled bubbles could make the treatment more potent. They injected tiny oxygen bubbles (which are made from a type of fat) into the blood vessels supplying tumours in mice.

After a few minutes, when scans showed the bubbles were in the tumour, scientists zapped them with a beam of ultrasound fired through the skin.

Immediately afterwards, the tumours were treated with a beam of radiotherapy.

The results, published in January in the Journal Of Radiation Oncology, showed tumour cells were three times more likely to be destroyed by radiotherapy if oxygen bubbles were injected than if treated with radiotherapy alone. The researchers believe the technique could work for most solid tumours.

They’re now setting up a clinical trial in the U.S. to see if the same treatment will benefit 52 patients with liver cancer. The results are expected in 2020.

Dr Justine Alford, from Cancer Research UK, said the bubble technique could potentially ‘have a great impact for patients, particularly those with hardertotreat cancers such as pancreatic cancer’.