A blood test could provide a simple way to monitor cancer
Cancer is a wily enemy. It mutates and spreads within the body and becomes resistant to treatment. Understanding and counteracting this tricksy behaviour is the greatest challenge for researchers and doctors, and is the key to bringing forward lasting cancer cures.
Thanks to advances in technology, we’re now starting to map out cancer’s underlying genetic landscape. In theory, if doctors knew exactly which gene faults were driving a patient’s cancer, they could give them the most appropriate targeted treatment.
And as well as selecting the therapy with the best chances of working, it’s also important to know whether the disease is responding to treatment or not as fast as possible, so doctors can decide on the best course of action – for example, whether to continue with a particular drug or switch to a different one.
But there’s a problem with this approach. Monitoring how well a patient’s cancer is responding is not a simple job. At a minimum, it requires regular scans or other tests. On top of this, analysing a tumour’s genes requires having a sample of it, usually taken as a biopsy with surgery, as well as access to tests that can provide meaningful results in a short timeframe. And if the cancer has spread to a multitude of locations in the body, it’s simply not possible to biopsy them all.
As an extra kicker, we now know that a single tumour can house cancer cells with a range of different gene faults – a characteristic that scientists refer to as “intra-tumoural heterogeneity”, but could also be described in rather more unpublishable words. And secondary cancers that have sprung up elsewhere in the body also have differences in their genetic makeup compared to the initial tumour.
The problems seem almost insurmountable – it’s a bit like trying to attack a shape-shifting army that we can’t properly see. But, as you might hope, research is coming to the rescue.
Building on work we talked about last year, scientists at our Cambridge Institute have made a significant step forward in developing a relatively simple genetic blood test that can monitor breast cancer as it progresses.
They’ve published their results in a paper in the New England Journal of Medicine, and although the title – “Analysis of circulating tumor DNA to monitor metastatic breast cancer” – may not set your heart racing, the contents are certainly inspiring for all of us hoping for progress in cancer research.