Researchers of a new study have used tumor DNA dispersed in the blood to follow cancerous growths during their development and during treatment. The findings are available in the journal Nature Communications.
The pieces of DNA shed from dying tumour cells into the bloodstream of a patient with breast cancer that had propagated to other organs of her body were analysed and compared with the DNA obtained from surgical tumour samples (biopsies); the two samples were taken at the same point in time.
The findings show that the two groups of DNA matched with each other, implying that genetic modifications resulting from the development and treatment of the cancer followed the same trend and timing in both. This important finding provides evidence that tumour DNA in the blood can be used to monitor cancer in the body.
“This definitively shows that we can use blood-based DNA tests to track the progress of cancer in real time. The findings could change the way we monitor patients, and may be especially important for people with cancers that are difficult to reach, as taking a biopsy can sometimes be quite an invasive procedure,” says the lead author of the paper, Professor Carlos Caldas from the Cancer Research UK Cambridge Institute.
Furthermore, the researchers were also able to distinguish among the different secondary cancers, and to analyse the response of each of them to treatment.
“We were able to use the blood tests to map out the disease as it progressed. We now need to see if this works in more patients and other cancer types, but this is an exciting first step,” says Professor Caldas.
“Spotting tumour DNA in the bloodstream is a really promising area of research, and has the potential to give doctors valuable clues about a patient’s disease without having to take repeated tumour samples,” says Dr Kat Arney, science information manager at Cancer Research UK.
“For now, surgical biopsies still play an important role in diagnosing and monitoring cancers. But this work gives us a window into the future, where we’ll use less invasive techniques to track the disease in real time.”