Research published in the journal Breast Cancer Research suggests that tumor cells circulating in the blood of metastatic patients could give as accurate a genomic read-out as tumor biopsies. First discovered for their diagnostic potential in 2004, circulating tumor cells are beginning to be used in the clinic to help guide treatment decisions and track a patient’s progress as disease develops. Although other studies have pooled the collected CTCs and compared their genetic signature to that of the primary tumor, this is the first study to look at the genomic signature of individual tumor cells in circulation.
The researchers compared tissue biopsies surgically removed from two patients with inflammatory breast cancer with circulating tumor cells (CTCs). Breast tissue samples from both patients showed a specific mutation in a region of a cancer-driving gene, p53. The authors studied this mutation in several CTCs isolated from both patients. They found that in several of the CTCs collected, the mutations matched with the tumor biopsy. In one patient, some of circulating tumor cells had an additional mutation.
“Our work suggests that these cancer cells in the blood also accurately reflect the genetic status of the parent tumor or its metastases, potentially giving us a new source of genomic information to guide treatment,” says the article’s first author, Sandra V. Fernandez, PhD.
Although further work analyzing a greater number of genes and samples is needed, the study shows that CTCs offer the possibility of capturing the most current genomic information in an easy-to-obtain sample such as blood, thus helping guide treatment decisions. It also suggests that it may be necessary to test more than one cell for the most accurate reading, as the CTC population appears to be heterogeneous. Read the study.
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