A Doubly Dangerous Disease, A Singularly Ingenious Solution
A new ultrasound technique in clinical trial at NYU Langone Medical Center could become the first reliable method for early diagnosis of ovarian cancer, the fourth leading cause of death among women in America. The technique is the brainchild of David Fishman, M.D., Director of Gynecologic Oncology, Cancer Prevention, and Early Detection at the NYU Cancer Institute.
Ovarian epithelial cancer (EOC) is a doubly dangerous disease. It often appears with vague symptoms, or none at all, making it hard to catch in the earliest stages, when 90 percent of cases are cured. Instead, some 75 percent of women aren't diagnosed until stage III or IV, when the cancer becomes resistant to treatment, bringing the five-year survival rate down to 15 percent.
Dr. Fishman says that as he lost late-diagnosed patients year after year, the pain of watching them die was agonizing to him. "I became passionate about finding tests to save their lives," he says. After many a sleepless night spent pondering a solution, Dr. Fishman had a brainstorm: If ordinary ultrasound could be modified, the vasculature that feeds cancers as they grow could be analyzed. The problem was that while ultrasound captures large blood vessels, by the time those vessels are found in ovarian cancer, it's too late. What was needed was a method for sharpening resolution and capturing the "microvasculature" - the tiny blood vessels that develop before a mass needs large quantities of blood to fuel its growth.
In the field of oncology, no such technology existed. But cardiologists had something that fit the bill: a contrast agent measuring 5 to 7 microns in diameter, the size of a red blood cell. The agent, delivered intravenously, would flow through the bloodstream. When an ultrasound transducer was held over the ovary, Dr. Fishman reasoned, it would pick up the micro-vessels indicative of early OEC.
Dr. Fishman's prediction has been borne out. In a recent clinical trial of the technique, conducted with colleagues at Vanderbilt University, he reports that the ovary's microvasculature "lights up like a Christmas tree," with changes in cancer-related blood vessels easy to identify. Because this clinical trial represents a first test of the technology, Dr. Fishman and his team are only including women whose ovaries will be removed later for a host of reasons, such as a standard hysterectomy, so that they can double-check their results. First the ovary is examined through a transvaginal ultrasound (conducted with a transducer shaped to fit into the vagina.) Then the ovary itself is removed and physically examined.
So far, Dr. Fishman reports, his team has examined 120 ovaries and found every single cancer - 15 in all, including three located in the fallopian tubes. Of the cancers found, he adds, three were missed by conventional diagnostic techniques and picked up at the earliest stage, 1A, when his new contrast sonography was employed.
"Our goal now," says Dr. Fishman, "is to test 1,000 women with the technique. Were we lucky or is this real? If it's real, this could become as easy and common as a colonoscopy, a new standard of preventive care."
Originally published in News & Views, July/August 2008
