Liquid biopsy tracks lung cancer
Scientists have shown how a lung cancer patient's blood sample could be used to monitor and predict their response to treatment, which may pave the way for personalized medicine for the disease. The recent study also offers a method to test new therapies in the lab and to better understand how tumors become resistant to drugs.
Small cell lung cancer (SCLC) is an aggressive disease with poor survival. New treatments are desperately needed. In many cases the tumor is inoperable and biopsies are difficult to obtain, giving scientists few samples with which to study the disease.
Now research has looked at the potential of using circulating tumor cells (CTCs) to investigate a patient's disease in a minimally invasive manner. CTCs are cells that have broken off from the tumor and are circulating in the blood. The research was carried out at Cancer Research United Kingdom's Manchester Institute, based at The University of Manchester and part of the Manchester Cancer Research Centre.
The researchers, working closely with lung specialist and Medical Oncologist Fiona Blackhall, PhD, FRCP, at The Christie National Health Service Foundation Trust in Manchester, United Kingdom, found that patients with SCLC had many more CTCs in a small sample of their blood than patients with other types of cancer. Importantly, the number of CTCs for each patient was related to their survival, as patients with fewer CTCs in their blood lived longer.
“Access to sufficient tumor tissue is a major barrier to us fully understanding the biology of SCLC. This liquid biopsy is straightforward and not invasive so can be easily repeated and will allow us to study the genetics of each lung cancer patient's individual tumor. It also means that we may have a feasible way of monitoring patient response to therapy, hopefully allowing us to personalize and tailor individual treatment plans to each patient,” said senior investigator Caroline Dive, BPharm, PhD.
In addition, the team was able to use these CTCs to grow tumor models in mice, which they termed CTC-derived explants (CDXs). When they treated these mice with the same chemotherapy drugs as the SCLC patients they showed that the CDXs responded in the same way as each donor patient. The study was published in Nature Medicine (2014; doi:10.1038/nm.3600).
“We can use these models to help us understand why so many SCLC patients acquire resistance to chemotherapy and to search for and test potential new targeted treatments,” added Dive.