Under a research project funded by Pancreatic Cancer UK, scientists have developed a blood test that could pick out patients with pancreatic cancer who require different types of treatment to delay progression of the disease.
During the study, which has been covered in the Times this week and published in the journal Oncotarget, researchers at the Institute of Cancer Research and the Royal Marsden NHS Foundation Trust measured levels of a molecule called miR-21 in the bloodstream. They found that levels of the molecule in the bloodstream accurately reflected the levels of the molecule in tumour biopsies – demonstrating that miR-21 is a reliable marker for the disease and could be used as a test to distinguish between high-risk patients with aggressive disease and those with slow-growing tumours.
The research team assessed the new test in a small phase II clinical trial. The study included 17 patients with locally advanced pancreatic cancer (inoperable pancreatic cancer which had not spread outside the pancreas), who received an initial round of chemotherapy followed by chemo-radiotherapy. They found that patients with low levels of miR-21 benefited from this sequential treatment, which controlled their tumours for an average of 12.7 months. Patients with high levels of miR-21 had much more aggressive tumours and the treatment failed after an average of only 3.5 months. These patients would instead require an alternative approach to their care.
Currently, locally advanced pancreatic cancer is diagnosed by CT or MRI scans, but the new study suggests patients could benefit from measurement of miR-21 levels in their blood to decide upon the best form of treatment.
Study co-leader Dr Chiara Braconi said: “We have developed a blood test for locally advanced pancreatic cancer that could identify which patients are most likely to benefit from the addition of chemo-radiotherapy after chemotherapy. This test represents a step towards improving treatment for a disease that is often detected late and is hard to diagnose, is resistant to treatment and has a very high mortality rate. Although our study is small, it explores the role of miR-21 as a marker for pancreatic cancer in a trial setting, and provides a rationale for testing miR-21 levels in larger groups of patients.”
Leanne Reynolds, Head of Research at Pancreatic Cancer UK, commented: "This is exciting early research which could lead to the development of a simple blood test to predict which patients are likely to respond best to the addition of chemo-radiotherapy after chemotherapy. This would be incredibly important for people affected by pancreatic cancer because the disease is often diagnosed very late and currently just five per cent of people live for five years or more after diagnosis. Finding ways to ensure that patients are provided with the most effective treatments is therefore vital.
“There is a way to go before this research could lead to a new test that could be used by doctors, but new and innovative research like this is essential to underpin future breakthroughs that are desperately needed in order to see a dramatic increase in survival rates. We’re extremely excited to be funding this research through our Research Innovation Fund and look forward to seeing the results develop."