Machine invented by NUS don traps cancer cells in blood samples

TESTING for cancer through a simple  blood test could be just a few years away.

A new machine which is able to capture cancer cells from small blood samples will be launched in the third quarter of this year.

The prototype is already being tested at the National Cancer Centre (NCC) until next year.

Developed by a bioengineer here, it will be quicker and easier than current methods.

The device can trap Circulating Tumour Cells (CTCs), which are rare cancer cells that break off from tumours and circulate in the blood streams of patients.

If a person’s blood is found to have CTCs, it is very likely that there is some form of cancer in his or her body.

Oncologists say that since CTCs can occur at any stage of cancer, it is possible to screen for CTCs to detect the disease, although CTCs are still being studied around the world.

Clinical studies in the United States show that patients suffering from certain types of cancer will also have fewer CTCs in their blood if their treatment is effective.

Current methods for capturing CTCs use biomarkers, which bind to the cancer cells. But the biomarking system does not work on all types of cancer cells, and the binding process may destroy or modify these cells.

Associate Professor Lim Chwee Teck, specialising in bioengineering at the National University of Singapore (NUS), uses a novel way to trap the CTCs.

By running blood samples through a biochip laced with micro-structures, he found he could filter CTCs intact from the blood cells in their “native state”.

“This is an area of technology that is causing some excitement among some clinicians,” Prof Lim said. “Now they can look at the genetic sequences or the chromosomes changes in the circulating tumour cells.”

This will help in cancer research as it allows clinicians to identify trends of cancer cell mutation, and how CTCs spread cancer to other areas of the body.

The technology is essentially a “liquid biopsy” that is nothing more invasive than a blood test, unlike current techniques, which involve removing tissue from the patient to be checked for cancer cells.

Prof Lim said Clearbridge BioMedics – a new set-up through which the NUS technology has been licensed by local investment company Clearbridge Accelerator – has successfully captured different types of CTCs, such as kidney and lung cancer cells. It will be running tests on breast and ovarian cancer cells next.

Cancer is currently the top killer in Singapore, as one out of four Singaporeans dies from it, with 24 people being diagnosed every day.

A total of 45,176 people were diagnosed with some form of cancer between 2003 and 2007.

With an ageing population, numbers can only go up and research on CTCs can lead to improved cancer treatments.

The NCC has already started running patients’ blood samples through the biochip prototype, said Dr Darren Lim, senior consultant in the centre’s department of medical oncology.

Dr Lim said the study is to demonstrate the usefulness of the biochip system for picking up CTCs, as compared to the biomarker systems which have been approved in the US.

By extracting CTCs and analysing them, Dr Lim hopes to be able to understand the genetics of the cancer cells.

“This is a competitive field that is developing rapidly. If we can understand the cancer biology better, we can try to treat cancer better,” he said.

Dr Lim also said potential applications in the near future can be for cancer patients who have surgery to remove tumours.

The machine can filter for CTCs to see if there are any in the blood, and to see if having CTCs means a higher chance of recurrence, which may indicate a need for additional treatment.

He is also looking forward to the new machine that Clearbridge BioMedics will be rolling out which can handle more samples simultaneously.

Other oncologists contacted felt that although this technology was an interesting development, it would still be some years before it could be adopted as a screening device.

Dr Wong Seng Weng, medical director of The Cancer Centre at the Singapore Medical Group, said such a device can help doctors in assessing the prognosis of a patient’s condition. “It would also be useful in guiding treatment. A decreasing CTC count during treatment would indicate that we are on the right track.”

Adjunct Associate Professor Goh Boon Cher from the department of haematology-oncology at the National University Cancer Institute Singapore, said that even if the blood test found the presence of CTCs, it would not give doctors enough information on what treatment to prescribe. “If you find the CTCs, what is the right thing to do clinically? This is not clear at present.”

Dr Lim said the device would complement current cancer detection and monitoring methods, in addition to opening doors for further research.

“It is promising technology and it has been experimented around the world via other methods. If we can show that this machine works and is a home-grown success, then it will be good for Singapore,” he said.