The future of prostate cancer therapy may lie in a tiny, "sticky" silicon chip dubbed GEDI (Geometrically Enhanced Differential Immunocapture, pronounced like the "Star Wars" forces of good) that can identify and collect cancer cells from a patient’s bloodstream.
A team of researchers at Weill Cornell Medical College in New York City and Cornell’s College of Engineering in Ithaca has built the chip into a device that captures an unprecedentedly high concentration of rare cancer cells from metastatic prostate cancer patients for a quick, noninvasive analysis to determine the efficacy of the patients’ current chemotherapy. The ability to collect a relatively pure sample of circulating tumor cells (CTCs) may also enable research to better understand the biology of metastasis and develop new treatments, the researchers said.
Their work is described in a paper in the April 2012 issue of the journal PLoS ONE, and was announced in a press conference at Weill by Brian Kirby, associate professor of mechanical and aerospace engineering; David Nanus, M.D., the Mark W. Pasmantier Professor of Hematology and Oncology in Medicine; and Evi Giannakakou, associate professor of pharmacology. The team includes 12 other researchers from both campuses.
Metastatic cancer is cancer that has spread from the place where it first started -- in this case, the prostate -- to another place in the body, most commonly the lungs, bones and liver. Metastasis accounts for the majority of cancer-related deaths.
"We need to be able to match the drug to the patient and the tumor," said Nanus. But tumor cells habitually mutate and develop a resistance to a previously effective therapy. In the case of prostate cancer, three drugs are in common use, but the most effective one varies with the patient and the particular cancer.
Metastasis is believed to be caused by cells that detach from the primary prostate tumor, circulate in the bloodstream and seed new tumors. Extensive clinical research shows that a reliable CTC count is a strong predictor of overall survival in metastatic prostate cancer patients. However, since the incidence of CTCs can be very small -- one CTC per 100 million blood cells -- pure CTC capture is difficult.
"This really is a needle in a haystack," Kirby emphasized.