Harbour believes the test should allow ocular oncologists to quickly evaluate the risks associated with particular tumors and to begin treatment the moment they can detect any spread of the cancer.
Melanoma of the eye is relatively rare, diagnosed in about 2,000 people in the United States each year. Advances in treatment have allowed surgeons to preserve patients' vision, but when cancer spreads beyond the eye, it often is deadly.
About a decade ago, Harbour, the Paul A. Cibis Distinguished Professor of Ophthalmology and Visual Sciences, began using gene expression profiling to monitor the activity of thousands of genes in and around ocular melanoma tumors.
"At the time, we were surprised to see that based on these gene expression profiles, the tumors clustered into two groups that corresponded, almost perfectly, to patients whose cancer spread and those whose cancer was confined within the eye," says Harbour, who directs Washington University's Center for Ocular Oncology. "Tumors with a class 1 gene expression profile, or 'signature,' very rarely spread, but those with a class 2 profile frequently develop into metastatic cancer."
Initially, Harbour's group identified differences in approximately 1,000 genes between class 1 and class 2 tumors, but they whittled down that number, hoping to develop a simple test that could be used easily by ophthalmologists. Eventually, they settled on about a dozen genes that could be evaluated in tumor samples collected with a needle biopsy.
"We went through a number of sophisticated algorithms and validations, and we came up with a group of 12 genes," he says. "We also included three more genes that don't change whether they are in tumor tissue or healthy tissue. Those genes act as our 'controls' in this prognos
|Contact: Jim Dryden|
Washington University School of Medicine