They say a picture is worth a thousand words. For bladder-cancer surgeons, an image can be worth many lives.
That's because a crucial method for detecting bladder cancer is to produce images that allow surgeons to identify abnormal-looking tissue, a method called cystoscopy. In a study published yesterday in Science Translational Medicine, Stanford researchers developed a new way to image the bladder that they say could detect bladder cancer with more accuracy and sensitivity than the standard methods. As described in our press release:
The researchers identified a protein known as CD47 as a molecular imaging target to distinguish bladder cancer from benign tissues. In the future, this technique could improve bladder cancer detection, guide more precise cancer surgery and reduce unnecessary biopsies, therefore increasing cancer patients’ quality of life.
Identifying cancerous tumors can be challenging — some bladder cancer treatments cause inflammation, which looks very similar to abnormal, cancerous tissue. The only way to know for sure is to perform a biopsy, which can be stressful for the patient. As co-senior author Joseph Liao, MD, explained:
Our motivation is to improve optical diagnosis of bladder cancer that can better differentiate cancer from non-cancer, which is exceedingly challenging at times. Molecular imaging offers the possibility of real-time cancer detection at the molecular level during diagnostic cystoscopy and tumor resection.
For their work, the researchers looked for a target that would distinguish cancer cells from benign cells and found it in CD47, a protein on a cell's surface that cancer cells produce in higher quantities than normal cells. In previous work, co-senior author Irving Weissman, MD, developed a CD47 antibody that binds to the cancer cell's surface and blocks the signal. They hypothesized it would be a good imaging target. More from our release:
To test their hypothesis, the researchers added a fluorescent molecule to an antibody that binds to CD47. The modified antibodies were then introduced into intact bladders, which had been surgically removed from patients with invasive bladder cancer. Because they bladders were kept in good condition, the study’s imaging methods mirrored the way an urologist might use with a real patient.
After 30 minutes, they rinsed the bladder, so only the antibodies that bound to the CD47 protein remained. When they shine the tumor was exposed to with fluorescent light, the cancer cells “lit up” whereas normal or inflamed cells did not.
“Our goal through better imaging is to deliver a higher- quality cancer surgery and better cancer outcomes,” Liao told me. “I am very excited about the potential to translate our findings to the clinics in the near future.”
Previously: Healing hands: My experience being treated for bladder cancer, Drug may prevent bladder cancer progression, say Stanford researchers, Cellular culprit identified for invasive bladder cancer, according to Stanford study and Mathematical technique used to identify bladder cancer marker
Photo of Liao by Norbert von der Groeben
