Research into Radiotherapy Resistance in Prostate Cancer

The Urology Foundation funded exciting research aimed at identifying possible biomarkers that might help to identify prostate cancer tumours which are resistant to radiotherapy.

Background:

Radiotherapy is an essential tool in the management of prostate cancer but a proportion of tumours are resistant to radiotherapy. This
contributes to relapse in 20-40% of prostate cancer patients.

Typically, it is only possible to tell if radiotherapy has been successful after or towards the end of treatment. There is no current way for
clinicians to easily tell if the tumour is responding well to this treatment.

For people who have a tumour that is resistant to radiotherapy it means:
• They are exposed to treatment that is ineffective but still entails side effects and impacts their quality of life.
• Precious time and clinical resources are wasted.
• There is a delay in administering other therapies, which can contribute to tumour progression

The Research:

We therefore funded Dr Arran Turnbull’s ‘Pilot Study to Identify Predictive and Prognostic Biomarkers of Response to Radiotherapy in
Prostate Cancer’, kindly supported by the John Black Charitable Foundation. Based at the Edinburgh Cancer Research Centre at the University of Edinburgh, Dr Turnbull’s research has the potential to be game changing.

The pilot study aimed to address this clinical problem by identifying biomarkers of radioresistance, so that radiotherapy response can be monitored and non responsive patients can be identified early, allowing for alternative treatment strategies.

To do this, they developed in vitro models of radioresistance and studied their response to radiation in comparison to matched cells that responded well to radiotherapy. Specifically, they sought to identify secreted biomarkers, as circulating molecules would be more easily detected in blood or urine samples. They focused on proteins secreted 24 hours after radiotherapy as this would fit best with the typical treatment strategy (where patients attend clinic at 24 hour intervals for daily fractions of radiotherapy).

This work has provided greater insight into the biology of radioresistant disease and Dr Turnbull’s team has been able to
identify and validate a group of candidate biomarkers of radioresistance. While further validation needs to be undertaken,
we’re encouraged by the research and what this could mean for the treatment of prostate cancer in the future.