Urology Times Innovation Celebration: Expert Insights - Episode 27
In this interview, Sanjay Patel, MD, discusses blue light cystoscopy for the detection of bladder cancer.
Urology Times® is celebrating its 50th anniversary in 2022. To mark the occasion, we are highlighting 50 of the top innovations and developments that have transformed the field of urology over the past 50 years. In this installment, Sanjay Patel, MD, discusses blue light cystoscopy for the detection of bladder cancer. Patel is an assistant professor of urology at the University of Oklahoma College of Medicine at OU Health Stephenson Cancer Center, Oklahoma City.
Bladder cancer diagnosis is heavily dependent on visualization, particularly in the eyes of the urologist, which makes it challenging sometimes, because all of us have different perceptions of what we see in different databanks in our brains about what tumors should look like. Sometimes, it's hard to see lesions in the bladder because the bladder is subject to inflammation, irritation from treatments, infection, and a variety of other factors.
Blue light cystoscopy was born out of the question, how can we better visualize these tumors? It was initially introduced in Europe with a drug called Hexvix (hexaminolevulinate acid), which is a protoporphyrin. When it's introduced in the bladder, it's taken up by cancer cells. When you shine blue light on it, it fluoresces the tissue red, so it's like someone takes a highlighter and highlights it. Initially, it was studied in Europe; it eventually made it to the US and is called Cysview here. Basically, it really helps improve visualization for bladder cancer.
What makes blue light cystoscopy a big innovation is that it really improves the quality of our [transurethral resection of the bladder tumor]. It helps improve detection, because you can see lesions you would have otherwise missed with the naked eye. That also ends up translating to a lower risk of recurrence, meaning you have fewer patients that have their cancer come back down the road, which then translates to improved cost, care, and quality of life in these patients. It's a huge game changer. There are numerous trials that say that if you use blue light cystoscopy, in about 25% of patients, it will help you pick up a tumor you otherwise would have missed with traditional white light cystoscopy. Numerous studies have shown that there are lower recurrence rates at 12 months; a meta-analysis showed that with blue light cystoscopy, the recurrence was lower at 34% vs 45% with standard white light cystoscopy.
Blue light cystoscopy has improved the detection of bladder cancer and lets us identify lesions we otherwise would have missed. Oftentimes, tumors can be lurking in the background and you just can't see them and identify them; blue light cystoscopy makes them appear red when you shine a blue light on them. Particularly, it's really important for patients that have [carcinoma in situ], which is a flat tumor and oftentimes challenging to see and oftentimes confused for inflammation. It's also really helpful with patients who have positive cytology and a negative cystoscopy. After BCG, I find it helpful because everything is typically inflamed, and it's hard to distinguish between inflammation and cancer. I think also in patients who have high-volume, multifocal tumors, it really helps you identify every nook and cranny of the bladder to make sure you can get every single tumor.
I think in the future, ultimately, anything that we can do to not perform cystoscopy for surveillance [will be beneficial]. I think if we can identify novel urinary markers that we can quantify, maybe genetic markers that can identify risk or risk stratify patients that are at high risk for recurrence, we can potentially scope those patients more often. If we identify patients who have less risk, we can scope them less often. Risk stratifying patients will be important. That's the magic bullet everyone's looking for—what type of urinary marker will help us with that. Specific with blue light cystoscopy, as I mentioned earlier, this protoporphyrin is taken up by those active cancer cells. There are some studies that have been done looking at exciting that tissue with different wavelengths of light, and actually exciting them so much that it kills those cells. That’s a unique way of doing it where you inject Cysview in the patient's bladder, and then excite it with different wavelengths of light so much that it actually kills those cells.