A new non-invasive method in Singapore, involving the harvest of circulating tumour cells, will help doctors monitor the progress of cancer patients to determine the effectiveness of chemotherapy.

Main: Cancer cells spread and grow through the body via the bloodstream as malignant cells in a human body. Image: 123rf.com Insert: Diagram demonstrating the isolation Image: National University Hospital and CellSievo

Circulating tumour cells (CTCs) are cancer cells that have sloughed off from the primary tumour into the bloodstream. They either die off in the blood or re-seed themselves and grow elsewhere in the body through a process called metastasis. A team in Singapore has now found a way to harvest these cells to determine if specific drug treatments are curbing the spread of cancer in individual patients.

Traditional methods of obtaining cancer cells from tumours — involving the use of small surgical tools — are highly invasive and often difficult to perform. In contrast, harvesting CTCs from blood is relatively easy and non-invasive. What’s more, patients’ blood can be drawn repeatedly to monitor their progress over time.

Compared to red and white blood cells, CTCs are extremely rare: there are no more than 100 CTCs per billion blood cells in a cancer patient. However, CTCs are usually bigger and much stiffer than blood cells. Taking advantage of this property, Mo-Huang Li and his colleagues at the bioengineering firm, CellSievo, have designed a tiny silicon sieve to trap and recover CTCs from patients with breast, prostate, colorectal or ovarian cancer.

Using harvested CTCs, Professor Evelyn Siew-Chuan Koay, Dr Leong Sai Mun and co-workers at the National University Hospital, Singapore analyse the molecular information they contain to determine whether a patient’s chemotherapy regimen is becoming ineffective at killing cancer cells. This allows the attending physician to change the treatment strategy if necessary to combat the further spread of cancer. It also saves the patient from any side effects due to prolonged exposure to ineffective drugs.

The researchers are now developing a diagnostic kit to detect the molecular markers that indicate whether a cancer drug is becoming ineffective. Their focus is on detecting the expression of microRNAs — small RNA molecules — that signal drug resistance in cancer cells. The team is also applying for a patent and hopes to launch its diagnostic kit for commercial use by 2017.

 

 

 

 

 

 

 

For further information contact:

Associate Professor Evelyn Siew-Chuan Koay and Dr Leong Sai Mun
Department of Laboratory Medicine
National University Hospital, Singapore
Email: evelyn_koay@nuhs.edu.sg
Email: sai_mun_leong@nuhs.edu.sg

Dr Mo-Huang Li
CellSievo Private Limited
Email: cellsievo@qq.com