Using FACTT, nine out of 10 of the Her2/neu positive patients had elevated Her2/neu levels and one out of four in the Her2/neu negative group had elevated Her2/neu levels. Using ELISA only two out of 10 in the Her2/neu positive group showed elevated Her2/neu levels.
"Clearly the sensitivity of the ELISA assay does not satisfy the current need for the clinical detection of marker proteins that determine whether a patient has breast cancer or not," says Greene.
The researchers have also tried the FACTT method on other rare, but medically important molecules, such as the prion protein (for mad cow disease with Mansun Sy at Case Western University) and TNF-alpha (for autoimmune diseases), and will be developing tests for other cancer markers including lung cancer and colon cancer. All proteins tested so far with FACTT have been detected with an over 1000-fold higher sensitivity compared to current technologies.
The researchers say this points to FACTT's broad applicability and compatibility with current high-throughput testing technology. This, in turn, will facilitate the detection of rare markers and not-so-rare targets from much smaller sample volumes, as well as aid in monitoring marker levels at much earlier stages of disease.
"The importance of FACTT is that we can still get an accurate description of the number of molecules that cause disease even when other assays cannot," says Greene. The researchers surmise that FACTT could be used to monitor levels of Her2/neu in already-diagnosed breast cancer patients to monitor recurrence or treatment effectiveness.
"The critical issue arises when women are diagnosed with early breast cancer," adds Greene. "They often hav
Source:University of Pennsylvania School of Medicine