PET-CT scans use a special camera combined with small amounts of radioactive materials called radiotracers to image different types of cancer. PET-CT scans are used widely in cancer hospitals to assess the stage of a patient’s tumour, whether the patient is responding to treatment and in some cases what treatment to give.
In the clinic, the radiotracer links radioactivity to sugar, a tracer known as fluorodeoxyglucose or FDG. As cancers are especially hungry for nutrients including sugar to help them grow and proliferate, they take up more of this radioactive sugar than surrounding tissues and thereby ‘light’ up on the PET scan images.
New radiotracers are now being developed which may give us different information about a tumour. One of these new tracers is Fluciclovine (18F), a drug which links radioactivity to a tumour’s consumption of amino acids rather than sugar. This is because amino acids are also taken up in large quantities by cancer cells to help them grow and proliferate.
The breast cancer trial FRONTIER has been investigating the potential of Fluciclovine to help provide information on the underlying character of breast tumours. Fluciclovine is already used to identify recurrent prostate cancer, and one of the objectives of FRONTIER is to see if Fluciclovine works in breast cancers as it does in prostate. It is hoped that it may help distinguish between different breast cancer receptor subtypes. Additionally, the study also attempts to understand if particular genetic switches are turned on in the tumour which might allow us to use this imaging technique to pick out the right treatment for patients.
For example understanding if a tumour prefers amino acids over sugar could be important in deciding what treatment to use, such as those that inhibit the metabolism of the amino acid, glutamine, in tumours. Drugs which target the glutamine metabolism pathway in cancer cells are already in clinical development, such as GLUD, GLS or IDH inhibitors.
Results from the FRONTIER study are expected later this year, and we hope it will be a step towards helping clinicians to improve the staging of a patient’s breast cancer and identifying which patients will benefit most from different treatments.
An example of how Fluciclovine appears in colour on PET-CT scans, with yellow arrows pointing towards the tumour
About this study
The FRONTIER study began in March 2017 to investigate the efficacy of Fluciclovine as a radiotracer in 40 breast cancer patients.
Dr Simon Lord’s work focuses on the development of new drugs to treat breast cancer. He also leads a number of clinical studies assessing how novel metabolic imaging signatures may reflect tumour biology.
The study is co-led by Dr Simon Lord, alongside Prof Adrian Harris & Prof Fergus Gleeson, Dept of Oncology. It is funded by the Oxford Cancer Imaging Centre and the CRUK Oxford Centre. Fluciclovine supply was supported by Blue Earth Diagnostics.
This study is sponsored by the University of Oxford and managed by the Oncology Clinical Trials Office.