Urologists Study Fluorescent Dye, Blue Light to Detect Bladder Tumors
January 11, 2005
One of the challenges urologic surgeons face when treating early bladder cancers is that they can’t see tiny tumors during procedures to remove larger tumors. Missing the tiny tumors increases the chances that the cancer could recur, sometimes as early as three months after treatment.
Urologists at the James P. Wilmot Cancer Center are joining an international clinical study of a new photosensitizer – a liquid dye inserted into the bladder -- to improve detection of small tumors that will likely grow after surgery.
The photosensitizer, when placed in the bladder, makes cancer cells glow bright pink under a blue light. This makes it easier for surgeons to see and remove during cystoscopic procedures. A cystoscopy involves insertion of a thin, lighted instrument, a cystoscope, into the urethra and bladder for examination and tissue samples can be removed and examined.
Hexvix, or hexyl aminolevulinate, is similar to a chemical found naturally in the body and contains porphyrins. Cancer cells absorb this substance faster than healthy cells, and they turn fluorescent pink when the cystoscope light changes from white to blue.
“The change in color is dramatic and this lets us see tiny tumors or satellite tumors that we wouldn’t have seen before with traditional white lighting during cystoscopy,” says Edward M. Messing, M.D., urology chair, at the Wilmot Cancer Center at the University of Rochester Medical Center. The Wilmot Cancer Center is the only upstate New York site testing this new technique.
The randomized Phase III study of hexvix, the new drug, will enroll 620 people in the United States, Canada and Europe, including about 30 in Rochester. Hexvix, developed by PhotoCure ASA of Norway, is used in European countries and this study may open its use to patients in the United States. PhotoCure is funding this study.
The American Cancer Society estimates 60,240 new cases of bladder cancer will be diagnosed in the U.S. this year. Bladder cancer is more common among men than women and more common among whites than blacks. When found and treated early, the chances for survival are very good. About 12,710 Americans will die of the disease.