Sleeping cancer cells? yes, you heard that right!
Following surgery and/or chemotherapy, we always assume that cancer has been treated after series of diagnostic tests to ensure that no cancer cells are detectable. While this is often the case for some cancer patients, some are not too lucky. And unfortunately, there is a relapse of the disease some years after.
This is because a subset of tumour cells don’t grow rapidly as others, and are said to be in a dormant state. They are therefore resistant to chemotherapy treatment as they are not rapidly dividing.
This phenomenon is now experimentally proven to be true. Current research suggests that cancer alternatively uses the ”accelerator” and ”brake” in order to proliferate and survive. This means that cancer cells at some point grows exponentially, reduces in tumour volume (dormancy), and increases in tumour volume again (rapid growth). During it’s period of rapid growth, the patient is presented with symptoms, which necessitate treatment – surgery for most solid tumours.
Although surgery is often successful, some unfortunate patients experience relapse of the tumour. Here, combination therapy such as chemotherapy and hormonal therapy is used to treat the cancer. Although this may prove successful, some patients might still be presented with cancer after some years of dormancy.
These dormant cells are often undetectable even with the most sophisticated detection devices such as PET scan. Cancer cells utilises this period of dormancy to alter its genetic makeup and prepare for the next stage of disease progression with the aims of evading the immune system, resist anti-cancer treatment and invade surrounding tissues and metastasize to distant organs.
It’s therefore, very important to detect these dorman cells, but the fact that they are very small, non-dividing and very asymptomatic makes it difficult to detect them.
So What’s the way forward?
Interestingly, current research is providing insight into the characteristics of cancer dormancy. In collaboration with the BC Cancer Agency, Dr Francesco Crea of the Open University is currently looking at the RNA produced by dormant and proliferating cancer cells. Research conducted in his lab show that dorman cancer cells specifically produce a type of small RNAs that can be measured in urine and blood samples.
Dr Francesco and others are currently working to develop a new diagnostic tools to detect these small RNAs and they believe that, if successful, it would help clinicians to quickly and easily detect dormant tumour cells before they become too big to be effectively treated.
But how do we treat these cells post detection. The good news is that results from current research suggest hat these dormant cancer cells might possess some weak spots. In one experiment, it’s proven that some NSAIDS could potentially stop these tumour cell types from altering their genetic makeup, and hence leave them in their ”slumber”.
A personal thought:
I am of the opinion that developing a technique that can efficiently detect this dormant but potentially dangerous cancer cells is promising, and might give hope to some patients whose cancer would always relapse. Again, it would help to prevent cancer by way of early detection and hence treatment.
The article above is modified from THECONVERSATION.