A research team led by scientists at the University of Texas MD Anderson Cancer Center (Houston, TX) have conducted what they believe to be the first study to use fluorescence in situ hybridization (FISH) to detect abnormal circulating cells with aberrations akin to found in non-small cell lung cancer.1 The researchers report that the FISH analysis detected up to 45,000 abnormal cells per milliliter of blood, while studies using the standard antibody-based epithelial method typically find fewer than 10 abnormal cells per milliliter.
Ruth Katz, professor in MD Anderson's Department of Pathology, says that because FISH is not limited to epithelial cells, it also picks up a variety of other cell types including mesenchymal cells (thought to be involved in the spread of primary cancer to other organs) and stem cell precursor cells.
The study used 12 probes (which target aberrations connected to lung cancer) to analyze 59 cases of non-small cell lung cancer and 24 controls, both smokers and non-smokers. Among the findings: Lung cancer patients had many times the number of these abnormal cells than volunteers in the closely matched control group, and cells containing certain abnormalities increase significantly as cancer progresses from early to advanced stages.
The researchers now plan to study larger numbers of patients to validate that circulating abnormal cells are related to disease stage, relapse and survival. They also will evaluate epithelial, mesenchymal, stem cell and blood and lymphocyte markers, combined with FISH, to track down the origin of circulating abnormal cells and their associated traits. Work is also underway to develop a clinical test based on FISH.
1. R. Katz et al., Clin Cancer Res 16 (15): 3976-3987 (2010)