Scientists at The Institute of Cancer Research (ICR) in London believe they have found a way to detect men most likely to develop prostate cancer through genetic testing. According to their recent study, tests for genetic weaknesses in DNA repair genes could identify those that could benefit most from new, highly targeted nuclear "search-and-destroy" medicine.
The ICR's latest research has been published in the journal, European Urology. The report reveals analyses of tumour samples from males with advanced prostate cancer treated at The Royal Marsden NHS Foundation Trust. The analysis was designed to understand why some patients responded better than others to the emerging class of "nuclear" drugs containing a radioactive particle that kills cells and detects target molecules on its surface. It's felt that these radioactive treatments are proving more effective among prostate cancer patients who are no longer responding to chemotherapy.
Advancements in genetic testing technology have seen DNA analysis kits become affordable for consumers at home to find out more about their health and ancestry. However, at a scientific level, the ICR's studies have sought to use genetic technologies to identify protein molecules known as prostate-specific membrane antigen (PSMA), which is more prominent on the surface of cancer cells in some patients than others. Scientists have also recently utilised DNA microscopy to accurately reconstruct cells captured using fluorescence microscopes.
Could PSMA-targeted treatments pose the answer to prostate cancer sufferers with repair gene faults?
It was discovered that levels of PSMA on the surface of cancer cells were over four times as high in tumours where there were faults in DNA repair genes. Subsequently, early-stage screening of prostate cancer patients is being recommended to test for these genetic faults to highlight patients that would respond best to PSMA-targeted treatment.
Furthermore, the ICR's scientists believe there is a link between PSMA and maintaining the stability of the genome in cancer cells. They also feel that PSMA could be produced by cancerous tumours as a mechanism for survival due to defects in DNA repair genes. The study also indicates a blend of therapies with other medications that heighten the instability of genes could actually make prostate tumours more likely to respond positively to PSMA-targeted treatments. The next steps for this study will see the ICR's scientists determine whether testing for DNA repair faults is a sufficient way of pinpointing search-and-destroy treatment via clinical trials.
The future key role of the Centre for Cancer Drug Discovery
Overcoming drug resistance is one of the biggest campaigns for the ICR, with a £75 million investment in a new Centre for Cancer Drug Discovery. The new centre is designed to underpin its quest to improve learning around the targeting of cancer cells and the combination of drugs to heighten responses to treatments such as PSMA.
Professor Paul Workman, chief executive of the ICR, spoke excitedly about the "new wave" of PSMA-targeted treatments which incorporate a "homing signal" that seeks prostate cancer cells and attacks them sufficiently. Professor Workman concluded by suggesting that to incorporate PSMA-targeted treatments into clinics, a "good understanding" of the biology surrounding the response to such treatments was necessary to determine those who will most benefit.