DR MUIRIS HOUSTON
RESEARCHERS FROM the National University of Ireland Galway (NUIG) have made a significant breakthrough by identifying a new blood test that can identify how a woman with breast cancer is responding to treatment.
The newly developed test, by researchers from the universityâ€™s department of surgery, is also likely to act as an â€œearly warningâ€ system to alert doctors to any recurrence of the disease.
In what would be a huge development in cancer medicine, the test could replace mammography as the routine screening test for breast cancer in asymptomatic women.
The study results were presented last week to 12,000 delegates at the worldâ€™s biggest breast cancer conference in San Antonio in the US, where it created major interest among leading scientists. For the first time, the Galway researchers, led by Prof Michael Kerin, measured substances called microRNAs in the blood of patients with breast cancer. Their work found a link between specific types of miRNAs and the presence of breast cancer.
In addition, the research team showed that the blood levels of a novel tumour marker dropped sharply within two weeks of surgery for a breast tumour, an indication of the sensitivity of miRNAs as a measure of successful cancer treatment.
â€œThis early work suggests a combination of mir195 and Let7a [two specific types of microRNA] are sensitive markers for the presence of breast cancers in over 90 per cent of casesâ€, Prof Kerin told The Irish Times. â€œThis raises the possibility of their use in screening for breast cancer.â€
MicroRNAs are tiny fragments of genetic code which until recently had been considered of little relevance in the process whereby specific genes give a signal to produce different proteins in the body.
Now, however, they are known to be highly important as both suppressors and promoters of cancer growth, with both mir195 and Let7a powerful players in the development and propagation of breast cancer.
The research breakthrough is based on tests carried out on 83 breast cancer cases and 44 women without the disease who acted as controls.
The results show that levels of the two miRNA markers were over 10 times greater in the women with breast cancer than those without the disease. And blood levels of mir195 dropped significantly to the level found in the controls after the breast cancer had been surgically removed.
Carried out in the Health Research Board clinical research facility at NUIG by Dr Helen Heneghan, Dr Nicola Miller, Dr John Newell as well as Prof Kerin, the research was funded the National Breast Cancer Research Unit, the Irish Cancer Society, Molecular Medicine Ireland and other agencies.
Prof Kerin estimates that, subject to further work with international partners, the new test could be in routine use within the next two years.