Test-tube tumours offer cancer treatment hope

Replicas of cancer patients’ tumours grown in a laboratory can be used to test which drugs are likely to be most effective, a study has found.

Personalised mini-tumours were able to predict in every case when a drug would be useless and were almost as good at showing which drugs would be most effective, scientists said.

The idea is to replicate each patient’s cancer in a test tube to ensure that medication is tailored to them.

Genetic profiling of tumours is increasingly used to shape treatments to individual cases and scientists hope to combine this with the mini-tumour tests to identify the ideal regime.

Biopsy samples from 71 patients with advanced cancers were allowed to grow in test tubes and 55 drugs were tested on them. Scientists compared how these mini-tumours responded to how patients fared on the same medicines.

Nicola Valeri, who led the study at the Institute of Cancer Research in London, said: "Recreating patients’ tumours in the laboratory gave us an extremely promising way to predict whether a drug would work for a patient. We were able to look in incredible detail at how tumours responded to drugs."

He reports in the journal Science that mini-tumours were 100 per cent accurate in telling when a drug would not work, and identified medicines that would shrink the real tumour 88 per cent of the time.

Cancer usually develops resistance to treatment, but Dr Valeri found that the minitumours evolved in response to drugs in the same way as real ones, making him optimistic that the method could help guide treatment.

"Once a cancer has spread and stopped responding to standard treatments, we face a race against time to find a drug that might slow the progression," he said.

"We looked at tumours from patients with cancers of the digestive system, but the technique could be applied to a wide variety of cancer types."

"Liquid biopsies", which use blood tests to track tumours as they evolve in response to treatment, are being developed to help to monitor the effectiveness of treatment as cancer mutates.

Dr Valeri said the next step was to use liquid biopsies to create mini-tumours from cells circulating in the blood, so combining the benefit of both approaches. Other experts cautioned that it was unclear whether a single biopsy would capture how much an advanced cancer had mutated, meaning several mini-tumours might be necessary.

However, Paul Workman, chief executive of the Institute of Cancer Research, said: "This study has shown that testing drugs on replica tumours before they are given to patients is not only possible, but predicts how a patient will respond more accurately than simply looking at the cancer’s DNA."