How glowing dye that clings to cancer cells gives doctors ‘second pair of eyes’

A patient undergoing robot-assisted surgery to remove the prostate in the ProMOTE study. Photo: Professor Alastair Lamb/University of Oxford/PA Wire

The dye, which has been developed for prostate cancer but could be adapted to other forms of the disease, shows up areas of cancerous tissue not picked up by the naked eye during surgery.

This allows doctors to remove far more of the cancer in real-time, and slashes the chance of the disease coming back.

Cancer Research UK, which funded the scientists, said full clinical trials are underway to find out if surgery with the marker dye removes more prostate cancer and preserves more healthy tissue than existing surgical techniques.

Professor Freddie Hamdy.

In an initial study, 23 men with prostate cancer were injected with the marker dye before undergoing surgery to remove their prostates.

The fluorescent dye showed up the cancer cells and where they had spread into other tissues, such as the pelvis and lymph nodes.

A special imaging system was used to shine a light on the prostate and nearby regions, making the prostate cancer cells glow.

Being able to see such detail meant the surgeons could remove cancer cells whilst preserving healthy tissue.

Surgery professor, Freddie Hamdy, from the University of Oxford and lead author of the study, said: “We are giving the surgeon a second pair of eyes to see where the cancer cells are and if they have spread.

“It’s the first time we’ve managed to see such fine details of prostate cancer in real-time during surgery.

“With this technique, we can strip all the cancer away, including the cells that have spread from the tumour – which could give it the chance to come back later.

“It also allows us to preserve as much of the healthy structures around the prostate as we can, to reduce unnecessary life-changing side-effects like incontinence and erectile dysfunction.

“Prostate surgery is life-changing. We want patients to leave the operating theatre knowing that we have done everything possible to eradicate their cancer and give them the best quality of life afterwards.

“I believe this technique makes that possibility a reality.”

The new technique works by combining the dye with a targeting molecule known as IR800-IAB2M.

The dye and marker molecule attach themselves to a protein called prostate-specific membrane antigen (PSMA), commonly found on the surface of prostate cancer cells.

This combined approach was developed by Oxford scientists in collaboration with ImaginAb Inc., a company based in Inglewood, California.

In the future, experts hope the marker dye could be used for other types of cancer, by switching the protein it uses to attach itself to cancer cells.

The imaging system for seeing glowing cancer cells could also be integrated into the robot-assisted tools used for prostate surgery.

Dr Iain Foulkes, executive director of research and innovation at Cancer Research UK, said: “Surgery can effectively cure cancers when they are removed at an early stage.

“But, in those early stages, it’s near impossible to tell by eye which cancers have spread locally and which have not.

“We need better tools to spot cancers which have started to spread further.

“The combined marker dye and imaging system that this research has developed could fundamentally transform how we treat prostate cancer in the future.”