Biopsies that are used to locate surrounding tumor cells (CTC), which cause metastases, by extracting a total or partial sample of tissue, are still a diagnostic procedure with some limitations. The number of CTCs captured is not always sufficient, which leads to an inaccurate assessment of the heterogeneity of the cells.
Scientists from the University of Michigan, in the United States, have designed a portable device capable of capturing CTC that allows the analysis of larger blood volumes than classical biopsy samples. The system, presented in the journal Nature, is validated in canine models that show the ability to detect 1 to 2% of the total blood for 2 hours.
Compared to serial blood draws, the researchers say this technology could potentially be used to analyze a large number of CTCs that break off from the primary tumor and circulate through the lymphatic channels and blood. This would facilitate the translation of analytical information in future clinical decisions. The study's lead author, Daniel F. Hayes, highlights its scope: "By getting enough cancer cells from the blood, we can use them to know the biology of the tumor and determine how to deal with it."
This device has dimensions of 6.98 cm by 5.08 and by 2.54, which is connected by a catheter to the vein of a patient. Hayes predicts that this innovation could be tested in humans within three or five years: "It is the epitome of precision medicine, something very exciting for the field of oncology at the moment," he says.
Although they were identified more than 150 years ago, CTCs have been difficult to detect, enumerate and characterize until recently. In addition, they are extremely rare. In a single 7.5 ml tube of whole blood taken from a patient with metastatic breast cancer, it is unusual to identify more than 10 CTCs among billions of erythrocytes and millions of leukocytes present.