Colorectal cancer is the number 1 killer in Singapore, being the most commonly diagnosed cancer in men (17%) and the second most in women (13%) as per the statistics of Singapore Cancer Society. This is commonly diagnosed among men and women aged 50 years and above. The diagnosis and treatment of colorectal cancer is assessed by conventional genetic testing for colorectal cancer.

For the genetic testing, a piece of tissue (tissue biopsy) from the affected part is excised by surgical procedure and genotyped to detect the genetic mutations. Researchers from the Institute of Bioengineering and Nanotechnology (IBN) of A*STAR, Singapore, developed a new liquid biopsy method to analyze cancer cells through blood testing. This nonsurgical method proved to be less invasive without pain and discomfort to the patients unlike the surgical method.

“IBN is interested in developing medical technologies that can make a difference to healthcare. We are excited about our liquid biopsy approach, which could make it easier for doctors to check and administer the appropriate drug treatment for cancer patients. Our technologies have been validated by Fortis Surgical Hospital and have been successfully licensed for clinical applications,” Professor Jackie Y. Ying, IBN Executive Director, said.

In this method, researchers fabricated a silicon microsieve (IBN’s microsieve) to capture the circulating tumor cells in blood. In most cases the tumor cells detach from the main or primary tumor and float in the blood stream travelling to other locations or parts of the body. This leads to the spreading of cancer to other locations or parts of the body called metastasis.

Microsieve measures 7.5 mm in diameter and with densely packed array of 90,000 pores can efficiently separate tumor cells from blood sample in just 5 minutes. In simple terms, micro sieve acts like a strainer to separate the tumor cells from blood. Ingenious design of the IBN’s microsieve allows the filtration of the large and stiff cancer cells through the fine pores allowing the normal blood cells to pass through. Also IBN has developed sensitive molecular assays to check for mutations in the key genes, KRAS and BRAF from the tumor cells captured by the microsieve. These assays were tested and proved to be highly accurate in 44 colorectal cancer patients who underwent surgery at Fortis Surgical Hospital.

Dr Min-Han Tan, IBN Team Leader and Principal Research Scientist, said: “As an oncologist and researcher, I believe care for our cancer patients can be improved through real-world innovation. Our work shows matching genetic mutations in the tumor tissue and corresponding circulating tumor cells of patients with colorectal cancer. This opens up an avenue for liquid biopsies, or the testing of cancer cells through blood, which we hope can reduce the need for invasive biopsies.”

Dr Poh-Koon Koh, Senior Consultant and Director, Colorectal Surgical Oncology & Cancer Genetics Service, Fortis Surgical Hospital, and Adjunct Clinician Scientist at IBN, shared, “In partnering IBN to set up the Fortis-IBN TissueBank, our aim was to create a resource that will allow cutting-edge research to benefit patients clinically. This liquid biopsy invention is an invaluable tool in our fight against colorectal cancer at the molecular level. The technique also allows a non-invasive means to obtain DNA material in tumors that are not easily or safely accessible through conventional biopsy techniques.”

The findings were recently published in the journal Molecular Oncology, representing a major milestone of the Fortis-IBN TissueBank established by IBN and Fortis Surgical Hospital in July 2012 to advance translational research in colorectal care. The IBN’s microsieve technology was licensed to CellSievo Pte Ltd, a spin-off company from IBN, in August 2011 for commercialization. The latest non-invasive genetic test was licensed to AITbiotech Pte Ltd, a Singapore-based biotechnology company, in January this year for development into a ready-to-use test kit.

The original publications can be accessed here:

http://rsc.li/1BqP7cM

http://bit.ly/1KNVqP8