Worrying whether a solid tissue tumor might spread elsewhere in the body represents one of the biggest unknowns for many cancer patients, according to Peter Kuhn, an associate professor of cell biology at The Scripps Research Institute in San Diego.
“As long as the disease is confined to the primary tumor, the oncologists can deal with it,” he says. “It’s only when it successfully starts spreading through the blood to distant sites that all hell breaks loose.”
In a step to unravel this mystery, a research team headed by Kuhn and diagnostic pathologist Kelly Bethel recently unveiled what Kuhn calls a “next-generation technology” for detecting and analyzing circulating tumor cells (CTCs) in patients’ blood samples. Their findings, published earlier this month in the journal Physical Biology, represent an encouraging opening in the development of a new diagnostic. Their technique for imaging and analyzing CTCs appears to be far more sensitive than existing blood tests, and may soon yield the kind of detailed information about individual cases that’s only available from certain types of invasive surgical biopsies.
In addition to helping doctors better understand the process of metastasis in patients, Kuhn says the test aims at being used some day to detect cancer in people who are unaware they have it.
“My favorite description is really that this is a blood fluid biopsy of the disease,” Kuhn says. “The reason why this is really important is because for the first time that we know of, we can monitor the cancer at the tissue level repeatedly in real time without risk to the patient.”
The approach developed by Kuhn’s team involves spreading a layer of all nucleated cells found in a blood sample onto a glass surface, and adding fluorescent antibodies to cytokeratin, an essential component of CTCs. The technology then uses a digital microscope and an image-processing algorithm to scan the slide for clumps of aberrant fluorescence. The process requires high-performance computing to help analyze and manage the data, and high-definition imaging to help cellular pathologists identify and analyze any of those fluorescent clumps that signify circulating tumor cells.
Kuhn’s group also licensed the technology to San Diego-based Epic Sciences, a startup formed in mid-2008 to commercialize the high-definition CTC technology.
