CTC Technology Detects Presence of Cancer and Serves as a Less Invasive Diagnostic Tool
February 7, 2012 -- Through direct research funding and data sharing, the Prostate Cancer Foundation funding has advanced the field of Circulating Tumor Cell (CTC) technology, which may soon deliver new gold standards for prostate cancer diagnostics and biomarkers.
Circulating tumor cells, found in patients’ bloodstreams, are shed from tumors and may be responsible for metastases. The ability to capture and analyze CTCs from a routine blood draw promises less invasive and better diagnostic tools for prostate and other cancers. CTC liquid biopsies can confirm the presence of cancer and provide a tool for researchers to distinguish between the numerous genotypes of prostate cancer, leading to personalized treatments.
In 2008, PCF granted a $2.25 million Challenge Award (made possible by the Charles Evans Foundation and Joel Pashcow through PCF’s Pro-Am Tennis Tournament) that helped fast-forward the development of CTC technology for prostate cancer. Dr. Daniel Haber and his team at the Massachusetts General Hospital and MIT researchers developed the Evans Test for prostate cancer by developing a device that can capture CTCs. The team’s micro-fluidic device holds great promise as a better diagnostics tool. It is also being used to assess patient response to treatment and may also provide a new endpoint for clinical trials.
Concurrently, a team at Scripps Research Institute and support through the new Physics Oncology Initiative of the National Cancer Institute, led by Dr. Peter Kuhn, Associate Professor of Cell Biology, has also been working on advancing CTC technology. Their work is focused on high-definition CTC technology, which allows visibility of cancer cell “clusters.” These clusters consist of two or more CTCs and often incorporate other nucleate cells from the blood, providing a better chance for cells to metastasize. Kuhn also shares, “our approach significantly boosts our ability to monitor, predict, and understand cancer progression, including metastasis, which is the major cause of death for cancer patients. And, the collaboration and cooperation of PCF and NCI is an important approach to making progress and working together.”
Scripps HD-CTC labels cells in a patient’s blood sample in a way that distinguishes possible CTCs from ordinary red and white blood cells. It then uses a digital microscope and an image-processing algorithm to isolate the suspect cells with sizes and shapes (“morphologies”) unlike those of healthy cells. The “Evans Test” created at Massachusetts General is a microfluidic device that is used to isolate and catch whole CTCs on a microchip covered with 78,000 micro posts. The tiny posts are coated with antibodies that bind to cancer cells. When blood is forced across the chip, the posts comb a few cancer cells out of billions of blood cells and held them for analysis. In trials, the microchip successfully captured CTCs in nearly all patients with lung, breast, prostate, pancreatic, and colon cancer.
Haber and Kuhn joined a 2011 global meeting sponsored by PCF to discuss their progress and share data.
The chip technology developed by Haber’s team has the ability to capture roughly one cancerous cell out of every one billion blood cells—most humans have roughly 10 billion blood cells. The key difference between the CTC biotechnology at Massachusetts General, vs. those at Scripps Research Institute, are described by Dr. Haber:
“Our device uses antibodies to capture CTCs as they flow through a microfluidic channel. The cells can be analyzed after they are captured. The technology created at Scripps Research Institute does not use antibodies to select cells, but instead plates them on a large surface, then uses high-definition imaging to find CTCs that are extremely rare. The techniques are complementary in that the Scripps technique would collect all cells (whether or not they express particular proteins on the cell surface), whereas our technology has a higher purity of cells that can be analyzed more easily.”
For patients facing a prostate cancer diagnosis, an FDA approved technology using CTCs, known as Cell Search technology, is available through Massachusetts General Hospital. For patients on the West Coast, Peter Kuhn reports. “Our team at Scripps Research Institute is expanding our program by asking very specific clinical questions, which are predominantly driven by our partners in oncology. Our HD-CTC test is still in the research phase but is currently being readied for commercial launch by Epic Sciences in La Jolla. We continue making an active effort to reach out to the patient community and are deeply indebted to all our patients who have helped us drive technology forward.”