Immunotherapy is a relatively young approach to cancer treatment. It basically empowers the body's own immune system to fight cancer cells. However, not all patients respond to immunotherapy very well and sometimes it is just not worth it. But how could we know when immunotherapy is worth a shot? Scientists at UCL have developed a new tool, which could help.
Choosing cancer therapy is very important, because there is no time to waste. The sooner the treatment starts, the better results you can expect. Immunotherapy is one of the options, but it only works if certain criteria are met. For example, immune system T cells need to be present in the cancerous tumour. How can doctors know if this criteria is met? Well, a new tool might help. Scientists found that they can estimate the fraction of T cells in cancerous tumours just by analysing DNA sequencing data from patients’ cancerous tumours.
DNA sequencing of cancerous tumour cells is performed quite frequently, because it allows tracing the evolutionary history of how individual tumours have developed. Now scientists found that they are able to look back through that evolutionary history of a tumour and see certain signals that show the loss of T cell receptor excision circles needed for T cell maturation. This allowed scientists to estimate the number of T cells that are still present in the tumour and could fight cancerous cells if encouraged by immunotherapy.
Why is it important to know how many T cells are present in the tumour? Well, immunotherapy enhances the ability of T cells to destroy cancer cells. The more T cells there are present in the tumour, the more cancer cells can be destroyed. A type of immunotherapy, called checkpoint inhibitors, remove obstacles for T cells to kill cancer cells, but it wouldn’t work if there are no T cells available in the tumour. Dr Robert Bentham, first author of the study, said: “Quantifying T cell infiltration directly from DNA sequencing provides greater predictive power of patient response to treatment without the need for additional data. Indeed, the process we’ve developed can be done without additional time or cost, beyond standard DNA sequencing.” Before this tool is made available for clinical use, it will be developed further. Then it might be useful in treating some other diseases as well, not just cancer.
Immunotherapy is one of the more effective cancer treatments right now. In many cases, it is the only thing that can save the patient. And in the future, as new immunotherapy drugs are developed, it might become the treatment of choice for many different types of cancer. We just need to know when to apply it and these new tools may help.