have developed a
new disposable device that could help identify patients with
advanced breast cancer awaiting drug therapy with trastuzumab, and
capture cancer cells that have an abnormal amount of the protein HER2
(typically found in aggressive breast cancers).
Thierry, of the Ian Wark Research Institute at the University of
South Australia, along with his colleagues, has created an elastic,
disposable microfluidic device that can efficiently catch the protein
HER2 – which is the tyrosine kinase human epidermal growth factor
receptor 2 -- found in "aggressive breast
cancers with poor prognosis."
only way to find out HER2 status in breast cancer patients now is
through fluorescence in situ hybridization (FISH) or
immunohistochemistry, both of which require biopsies. The problem
with biopsy-based testing is that it could lead to treatment that is
ineffective, because the HER2 status of the primary tumor in 20
percent of breast cancers differs from the HER2 status in that of a
metastatic tumor. This information has led to the idea of isolating
cells (CTCs), but this is difficult because circulating
tumor cells exist at very low ratios of 1 to 10 per billion blood
HER2 status is very critical because HER2 positive breast cancer
patients have benefitted from drug therapy with trastuzumab
(Herceptin), which are humanized monoclonal antibodies against HER2.
It also decreases recurrence risk by half. Also, the side effects and
cost (which is approximately $50,000 to $65,000 in the U.S.) makes it
a priority to identify patients who are HER2 positive.
Thierry and his colleagues' device
has the ability to detect the status of HER2 and help
capture circulating tumor cells. The device is made of organic
silicon found in most contact lenses, and polydimethylsiloxane
(PDMS), which are shampoos that are transparent, permeable to gasses,
and compatible with soft molding techniques. The device also contains
a polymeric layer on its surface, which has a large number of
reactive molecules in it. Through the use of a plasma-based
polymerization process, this layer can attach to proteins that are
able to catch cancer cells while leaving normal blood cells alone.
devices offer a unique opportunity to efficiently isolate CTCs from
patient's blood, thereby opening a window on the pathophysiology
and its progression," said Thierry. "We hope that our
device will provide a fast, reliable and affordable methodology to
establish HER2 status for breast cancer patients presenting
metastases, thereby enabling the selection of more potent therapy
based on trastuzumab.
are aiming to achieve clinical validation in the coming months and,
with the support of a fellowship from the Prostate Cancer Foundation
of Australia, to extend the study to the detection of aggressive
forms of prostate cancer."
device showed an 80 percent immuno-capture efficacy of HER2 positive
cells, and is also cheaper and easier to make than previous
microfabricated devices, which were developed to bind to cells of
epithelial tissues where the cancer originated, ultimately isolating