Glowing Dye Enhances Prostate Cancer Surgery

According to a study supported by Cancer Research UK, a glowing marker dye that adheres to prostate cancer cells may make it easier for surgeons to remove the tumors in real time.

Researchers funded by Cancer Research UK, with locations at the University of Oxford’s Nuffield Department of Surgical Sciences, Department of Oncology, Oxford University Hospitals, and Oxford NIHR Biomedical Research Centre, used fluorescent dye linked to a unique marker molecule to provide a “second pair of eyes” for surgeons performing prostate cancer surgery.

Before having their prostates removed surgically, twenty-three men with prostate cancer received injections of the marker dye. Not visible to the unaided eye or detected by other clinical techniques, the marker color identified regions of malignant tissue.

The color gave the surgeons the ability to remove all malignant tissues while protecting good ones, perhaps lowering the likelihood that the cancer will return. After surgery, there are fewer potentially fatal side effects when healthy tissues are preserved.

Using a dye and targeting molecule called IR800-IAB2M, surgeons may view the tumor’s borders and locate any cell clusters that have moved to other pelvic tissues and lymph nodes. This helps the surgeon remove all malignant tissue while leaving the prostate’s surrounding healthy tissue intact. This minimizes the potential of the patient experiencing life-altering side effects following the procedure and significantly lowers the likelihood that the cancer will return in the future.

The dye and marker molecule work by attaching themselves to a protein called Prostate-Specific Membrane Antigen (PSMA) commonly found on the surface of prostate cancer cells.

The “minibody,” a tinier form of an antibody that can only attach to PSMA and not to any other molecule, is what makes up the marker molecule. The Oxford researchers worked with ImaginAb Inc., a California-based business, to produce the dye and marker molecular combination.

In the initial phase of the ProMOTE research, which was released today, Monday, June 10, 23, men who had been diagnosed with prostate cancer received fluorescent dye injections prior to having their prostates surgically removed using a robot, a procedure known as a radical prostatectomy. Prostate cancer cells were made to glow by surgeons using an imaging device that exposed the prostate and surrounding tissues to a certain kind of light. An engineering group at the University of Oxford under the direction of Professor Borivoj Vojnovic created the imaging system.

The dye was able to detect cell groupings that were invisible to the human eye that had expanded away from the tumor in a few of the research participants.

Although this marker dye is still in the early stages of clinical research, surgeons may eventually utilize it on a regular basis to see every aspect of the malignancy when removing the prostate.

Prostate surgery robot aided instruments may have an imaging device to view glowing cancer cells. By altering the protein that the marker dye utilizes to bind to cancer cells, it may also be utilized to treat other forms of cancer.

In comparison to current surgical techniques, more clinical trials involving larger patient groups are currently being conducted to determine whether the technique removes more prostate cancer and maintains more healthy pelvic tissue.

With 52,300 new instances of prostate cancer reported annually*, it is the most frequent malignancy among males in the UK.

Among the 23 men who participated in the study was David Butler, a retired sales development manager from Southmoor in Oxfordshire, who is 77 years old. In November 2018, a fortuitous chat with his general practitioner resulted in a startling diagnosis of prostate cancer.

“I had literally no symptoms apart from needing to pee more quickly whenever I did go to the toilet. Had I not told my GP about it, I might not have caught my cancer until it was much further down the line.

“Very strangely, I was relaxed about the diagnosis. I had a sense that the consultant was going to tell me it was bad news – so I wanted to be positive and face up to it. I think the staff thought I was taking it extremely well!

“I had several biopsies and scans but one scan – the PSMA PET scan – revealed that the cancer was starting to spread from the prostate. It was in the lymph nodes, it was in loads of places near to the prostate. That information proved vital to the doctors to get the cancer treated quickly.”

Using this ground-breaking method, David had his prostate removed in January 2019 along with many lymph nodes and other malignant tissues. Due to an associated cardiac problem, he had a stroke immediately after the surgery, which made his recuperation difficult. After a full recovery and five years, he has not had cancer.

“If you’re not positive, life will come up and bite you, so you’ve got to enjoy every moment. I’ve been told I don’t look my age which is a great compliment!

“I am a very lucky man to have had the life I’ve had. I’ve dealt with a lot health-wise but I’ve had excellent treatment too.

“I retired early to make the most of life’s pleasures – gardening, playing bowls and walking. Taking part in the PROMOTE study has allowed me to have many more of those pleasures for years to come.”

Nuffield Professor of Surgery at the University of Oxford and lead author of the study, Professor Freddie Hamdy, 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.”

“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.

We hope that this new technique continues to show promise in future trials. It is exciting that we could soon have access to surgical tools which could reliably eradicate prostate and other cancers and give people longer, healthier lives free from the disease.”- Dr. Iain Foulkes, Executive Director of Research and Innovation at Cancer Research UK

For more information: First-in-man study of the PSMA Minibody IR800-IAB2M for molecularly targeted intraoperative fluorescence guidance during radical prostatectomy, European Journal of Nuclear Medicine and Molecular Imaging, https://doi.org/10.1007/s00259-024-06713-x