Cancer patients could soon be able to find if their chemotherapy is working and follow the disease in real time as it is cleared from their body, scientists believe.

A new technique can assess the effectiveness of cancer treatment just eight hours after the first drugs have been taken.

Currently cancer patients face an anxious wait to see whether drugs have worked because scans cannot detect if tumours are shrinking until several rounds of treatment have taken place.

But experts from the Brigham and Women’s Hospital in Boston, Massachusetts, in the United States, have developed an approach which can alert them to the death of cancer cells the moment the drugs being to work.

Using a nanoparticle that delivers cancer therapy and then glows green when cancer cells die, researchers were able to see whether a tumour is resistant or susceptible to chemotherapy or immunotherapy.

The finding, published in The Proceedings Of The National Academy Of Sciences, could one day mean that patients are not given more chemotherapy that does not respond to their cancer.

“Using this approach, the cells light up the moment a cancer drug starts working. We can determine if a cancer therapy is effective within hours of treatment,” said Dr Shiladitya Sengupta,a principal investigator in Brigham and Women’s Hospital Division of Bioengineering.

“Our long-term goal is to find a way to monitor outcomes very early so that we don’t give a chemotherapy drug to patients who are not responding to it.”

The technique takes advantage of the fact that when cancer cells die, an enzyme known as caspase is activated.

The researchers added a chemical to the drugs which glows green in the presence of the enzyme so that the treatment not only fights cancer but reports on its progress.

When they tested it on prostate cancer and skin cancer tumours they saw a huge increase in fluorescence when the tumours were sensitive to the drug. When the treatment was not working there was virtually no glow, suggesting that chemotherapy could be stopped earlier if it was ineffective, and patients switched to a different treatment.

The team also saw a significant increase in the fluorescent signal in tumours treated with the immunotherapy after five days.

The researchers now plan to see whether the findings can be tested in humans.