MRI-based technique developed in Cambridge could predict response of ovarian cancer to treatment

An MRI-based imaging technique developed at the University of Cambridge could be used to predict the response of ovarian cancer tumours to treatment.

In patient-derived cell models, the technique rapidly reveals how well it is working, in patient-derived cell models.

Called hyperpolarised carbon-13 imaging, it can increase the detected signal in an MRI scanner by more than 10,000 times.

In 2017, Cambridge Independent readers helped us to raise £96,000 to fund a study of hyperpolarisation by the Cancer Research UK Cambridge Institute through our Rapid Scan Appeal.

Now scientists have found the technique can distinguish between two different subtypes of ovarian cancer to reveal their sensitivities to treatment.

They used it to study patient-derived cell models that closely mimic the behaviour of human high grade serous ovarian cancer, which is most common lethal form of the disease.

They were able to tell whether a tumour is sensitive or resistant to Carboplatin, one of the standard first-line chemotherapy treatments for ovarian cancer.

This will help oncologists to predict how well a patient will respond to treatment and to see how well it is working within the first 48 hours.

“This technique tells us how aggressive an ovarian cancer tumour is, and could allow doctors to assess multiple tumours in a patient to give a more holistic assessment of disease prognosis so the most appropriate treatment can be selected,” said Professor Kevin Brindle in the University of Cambridge’s Department of Biochemistry, senior author of the report.

With current tests, patients typically wait for weeks or months to find out whether their cancer is responding to treatment. But the rapid feedback from this technique will help oncologists adjust and personalise treatment for each patient within days.

The study compared hyperpolarised imaging with results from widely-used Positron Emission Tomography (PET) scans. PET did not pick up the metabolic differences between different tumour subtypes, so could not predict the type of tumour present.

Ovarian cancer patients often have multiple tumours throughout their abdomen and it is not possible to take biopsies of all of them. But they may be of different subtypes that respond differently to treatment.

MRI is non-invasive and the hyperpolarised imaging technique will allow oncologists to examine all the tumours at once.

Prof Brindle, who also works at the CRUK Cambridge Institute, added: “We can image a tumour pre-treatment to predict how likely it is to respond, and then we can image again immediately after treatment to confirm whether it has indeed responded. This will help doctors to select the most appropriate treatment for each patient and adjust this as necessary.

“One of the questions cancer patients ask most often is whether their treatment is working. If oncologists can speed their patients onto the best treatment, then it’s clearly of benefit.”

The next step will be to trial the technique in ovarian cancer patients within the next few years.

The technique uses an injectable solution containing a ‘labelled’ form of the naturally occurring molecule pyruvate, which enters cells. The scan shows the rate at which it is broken down - or metabolised – into a molecule called lactate, and this reveals the tumour subtype and therefore its sensitivity to treatment.

This study is published in the journal Oncogene.

Prof Brindle has been developing this imaging technique to investigate different cancers for two decades, including breast, prostate and glioblastoma - a common and aggressive type of brain tumour that also has different subtypes that vary in their metabolism, which can be imaged to predict their response to treatment.

The first clinical study in Cambridge, published in 2020, was in breast cancer patients.

Each year about 7,500 women in the UK are diagnosed with ovarian cancer and about 5,000 of these will have the most aggressive form, called high-grade serous ovarian cancer (HGSOC).

The cure rate for all forms of ovarian cancer is very low. Currently. only 43 per cent of women in England survive five years beyond diagnosis.

This is partly because symptoms can easily be missed, allowing the disease to spread before a woman is diagnosed, which makes imaging and treatment challenging.

The research was funded by Cancer Research UK.