Portable Filter-based Microdevice Detects Circulating Tumor Cells
Proof of Metastasis and Therapy Efficacy
In what could be a critical shift in the way tumor cells are detected in the blood of cancer patients, doctors at the Miller School have devised a novel blood filter that could signal that the cancer has spread, and indicate the efficacy of a therapy sooner than is now possible.
Determining whether a patient is experiencing metastasis – spreading of the cancer to other organs – is one of the great challenges for physicians. It is well known that circulating tumor cells (CTC) can be present in the blood of patients who have no other overt evidence of metastasis or who have undergone complete surgical removal of a tumor. This established theory is the reason for adjuvant chemotherapy – giving chemotherapy to patients with the goal of eradicating CTCs that have gone undetected. Further, several recent studies have shown that CTCs can be used to rapidly determine if cancer treatments are working, often after even the first course of therapy.
A group of scientists and physicians, led by Richard J. Cote, M.D., professor and chair of pathology at the University of Miami Miller School of Medicine, has developed a novel filter-based microdevice that detects and characterizes circulating tumor cells, which “could transform the way cancer is diagnosed and treated,” says Cote. Their findings have been published in the September 28 online issue of Clinical Cancer Research, a journal of the American Association for Cancer Research.
CTCs can indicate disease progression and can be used to monitor the efficacy of cancer therapy. However, an efficient and sensitive method of capturing and analyzing CTCs has not been available. The portable microfilter device developed by Cote and Ram Datar, Ph.D., associate professor of pathology and member of the Sylvester Comprehensive Cancer Center, in collaboration with Yu-Chong Tai, Ph.D., professor of electrical engineering at the California Institute of Technology, works much like any filter.
Tumor cells are larger than normal blood cells. Just as any filter allows smaller particles to pass through, this portable microdevice allows normal blood cells to pass through, while trapping the larger tumor cells. In tests carried out in collaboration with investigators from Memorial Sloan-Kettering Cancer Center and the University of Chicago, the device captured more than 90 percent of CTCs present in blood samples. When compared with the only Food and Drug Administration-approved method for CTC detection, the microfilter device proved far more effective and efficient in capturing and evaluating tumor cells from the blood of patients with cancer.
The captured cells can be detected and analyzed directly on the microfilter device, providing clinicians with an efficient and reliable method of cancer identification. Cote, a member of the Sylvester Comprehensive Cancer Center, says not only is the device faster, more efficient and less expensive than any other known method, it can also be used for virtually every type of solid tumor. “It can fundamentally change the way we manage cancer,” he adds.
Right now, the microfilter device is being used to test blood samples from 250 patients enrolled in a multi-site clinical trial examining a novel prostate cancer therapy. Proposals are also under way to test its use in many other studies.
The study is “Portable Filter-Based Microdevice for Detection and Characterization of Circulating Tumor Cells,” authored by Henry K. Lin, Ph.D., Oak Ridge National Laboratory, Oak Ridge, Tennessee; Siyang Zheng, Ph.D., Pennsylvania State University, University Park, Pennsylvania; Anthony J. Williams, University of Miami Miller School of Medicine, Miami, Florida; Marija Balic, Ph.D., Medical University of Graz, Graz, Austria; Susan Groshen, Ph.D., University of Southern California Keck School of Medicine, Los Angeles, California; Howard I. Scher, M.D., Memorial Sloan-Kettering Cancer Center, New York, New York; Martin Fleisher, Ph.D., Memorial Sloan-Kettering Cancer Center, New York, New York; Walter Stadler, M.D., University of Chicago Pritzker School of Medicine, Chicago, Illinois; Ram H. Datar, Ph.D., University of Miami Miller School of Medicine, Miami, Florida; Yu-Chong Tai, Ph.D., California Institute of Technology, Pasadena, California; Richard J. Cote, M.D., University of Miami Miller School of Medicine