Counting tumour cells in blood samples before and after treatment for advanced neuroendocrine tumours could provide a ‘snapshot’ of how well patients are responding within weeks of starting treatment, according to results from research by BRC-supported researchers.
Patient with liver metastases from pancreatic neuroendocrine tumour which responds to chemotherapy, as seen on CT scan performed 25 weeks after starting treatment. Before treatment 430 circulating tumour cells (CTCs) are present (example bottom left), but by 7 weeks there are only 2 CTCs. In this case CTCs demonstrate benefit from treatment long before conventional radiology confirmation.
The study, coordinated by researchers from the Cancer Research UK and the National Institute for Health Research Experimental Cancer Medicine Centre (ECMC) at UCL Cancer Institute, is the largest of its kind and the first to demonstrate how monitoring cancer cells circulating in the blood can be used to predict treatment success for this rare cancer-type, which most commonly affects the gut or pancreas. Results from the study were presented at the American Society for Clinical Oncology’s recent cancer conference
Patients found to have circulating tumour cells (CTCs) in the blood at the start of treatment were around eight times more likely to die from their disease, compared to those with undetectable CTC levels.
Study leader Dr Tim Meyer, who is supported by the BRC and who directs UCL ECMC, said: “By using state-of-the-art technology to count individual tumour cells circulating in the blood stream, we’ve been able to show how a simple blood test could help monitor treatment response and predict how fast the disease will progress. Doctors normally rely on CT or MRI scans to tell them if a treatment is working, but cutting-edge CTC testing can provide an overall snapshot of the tumour’s development, without the need to wait for changes in its size to become visible on scans.
“Although these findings are preliminary, CTC testing is already showing promise in advanced breast, prostate and colorectal cancers and, on the basis of these results, is being incorporated into several trials involving patients with neuroendocrine cancers. This will help uncover ways of determining the impact of treatment on a cellular level, helping tailor treatment to individual patients."
The researchers analysed blood samples from 118 patients with advanced neuroendocrine cancers attending the Royal Free Hospital. They compared the numbers of individual tumour cells present in samples taken before and after treatment.
Patients whose CTC levels fell by more than two thirds within five weeks of starting a new treatment tended to have the best outcomes, while those whose CTC levels rose by more than a third did the worst.
This research was supported by the NIHR University College London Hospitals Biomedical Research Centre. The Experimental Cancer Medicine Centre (ECMC) network is jointly supported by Cancer Research UK, the National Institute for Health Research in England, and the Departments of Health of Scotland, Wales and Northern Ireland.
