40 patients with early-stage colon cancer were involved in the US study, which was based on IGEN International Inc.'s Origen technology.
Surgeons obtained biopsy material using a technique called 'sentinel node mapping', adapted by Dr Anton J. Bilchik, at the John Wayne Cancer Institute (JWCI), California, USA.
This method identifies the lymph nodes most likely to be invaded by micrometastases.
The material was then analysed using the Origen-based genetic test and other methods, including conventional staging techniques.
|New test identified micrometastases in 12 of 26 'negative' lymph nodes|
|Journal of Clinical Oncology|
The sentinel nodes of 26 patients showed no signs of metastatic cancer by the non-Origen method, but the experimental Origen test identified micrometastases in 12 of these 26 patients, according to the study results published in the Journal of Clinical Oncology.
The positive results obtained with the Origen-based test are said to be significant for identifying metastases, because the same test was negative when used on cells from 25 healthy people and lymph nodes from 5 patients with benign conditions.
Researcher Dr Dave Hoon said: "We concluded that our multiplex assay provides a logistically practical and highly sensitive approach to detection of a variety of metastatic cancers in tissues and blood."
The test is designed to reveal cancer cells by detecting the activity of marker genes, which are dormant in normal cells, but under certain conditions are switched on in cancer cells.
The test detected expression of a different set of three marker genes by identifying molecules called 'messenger RNA', whose chemical sequence encodes a unique signature for each expressed gene. The experimental tests use the reverse transcriptase-polymerase chain reaction (RT-PCR), a technique that turns messenger RNA into DNA.
The RT-PCR methods developed by the JWCI investigators make millions of copies of DNA sequences that corresponded to chosen marker genes.
This process of amplification allows for precise identification of rare messenger RNA molecules through the use of Origen technology, which is more sensitive than other detection methods.
Report Copyright: Englemed Health News at http://www.internationalmedicalnews.com