Source:
http://www.uphs.upenn.edu/news/News_...ACTT_print.htm
The relevant bits:
"Philadelphia, PA) - Researchers at the
University of Pennsylvania School of Medicine have developed a paradigm-shifting method for detecting small amounts of proteins in the blood. Applications of this method will make discerning low-abundance molecules associated with cancers (such as breast cancer)..."
The lab of
Mark I. Greene MD, PhD, the John Eckman Professor of Medical Science..."developed mouse models that carry cancer cells overexpressing Her2/neu. When these cells are implanted into animals they form tumors exactly like breast tumors in humans. Using ELISA, the researchers could not detect Her2/neu from mouse blood until the tumors reached an inoperable size, but with the new FACTT technology they could detect Her2/Neu in some mice when tumors were barely visible and within two days of implantation. These results indicate that it is possible to detect tumors at very early stages so that tumor emergence or reoccurrence can be rapidly treated or even prevented."
"Greene’s laboratory established many of the principles of targeted therapy for Her2/neu tumors and the prototype antibodies that led to the development of Herceptin, a similar antibody molecule that was created by Genentech. The Greene laboratory also previously showed that early treatment of Her2/neu tumors with targeted monoclonal antibodies in animal models led to far more significant prevention of tumor growth as well as tumor emergence and reoccurrence."
"Patients who test positive for Her2/neu using FISH or IHC have responsive rates of about 35 percent to the cancer drug Herceptin. Monitoring Her2/neu status from the blood with a powerful technology such as FACTT represents an alternative approach compared to IHC or FISH, say the researchers.
Pre-treatment Her2/neu levels correlate with tumor size and the extent of disease. Post-treatment Her2/neu levels predict disease-specific survival. A more sensitive assay could more accurately allow treatment of humans with breast cancer and allow treatment more quickly if the tumor reoccurs.
The researchers collected blood samples from healthy women and breast cancer patients who did or did not overexpress Her2/neu, as detected by IHC and FISH. When using the new FACTT method her2/neu positive cancer patients showed dramatically elevated Her2/neu levels (average: 384 ng/ml), while the level in Her2/neu-negative breast cancer patients (19.5 ng/ml) were close to the levels of the healthy control participants (16.6 ng/ml).
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..."
“The critical issue arises when women are diagnosed with early breast cancer,” adds Greene. “They often have a lumpectomy and are sometimes treated with radiation or chemotherapy, but despite this conventional therapy the cancer still can occasionally reoccur,” says Greene. Detection of very early recurrence is important and Greene feels the power of this technology will facilitate recognizing early phases of tumor emergence.
Rational targeted therapy has shown in animal models - over 10 years ago - and more recently in clinical trials that treatment of small or incipient tumors is a way to prevent tumor emergence or reoccurrence. “Prevention of the consequences of recurrence is critical since treating advanced tumors is very complex and difficult,” concludes Greene."
Greene stresses that early treatment is far more effective than treating advanced tumors with the same antibodies. Recent clinical trials support the notion that early treatment prevents tumor reoccurrence in women with breast tumors. FACTT technology represents a way to couple early diagnosis with early treatment to prevent tumor emergence.
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