Screening for Epidermal Growth Factor Receptor Mutations in Lung Cancer
August 19th, 2009
Activating mutations in the epidermal growth factor receptor gene (EGFR) confer hypersensitivity to the tyrosine kinase inhibitors gefitinib and erlotinib in patients with advanced non–small-cell lung cancer. We evaluated the feasibility of large-scale screening for EGFR mutations in such patients and analyzed the association between the mutations and the outcome of erlotinib treatment.
At 7:27 am on October 13th, 2009 Gregory D. Pawelski said:
EGF is Epidermal Growth Factor. EGF is a receptor on many normal tissues/cells, and also on many cancer cells. It is a growth hormone, locally secreted by cells. It attaches to a receptor on the cell membrane called EGFR (Epidermal Growth Factor Receptor). It then activates so-called signalling pathways within the cell, a cascade of biochemical events, leading to cell growth/proliferation/division.
A new class of anti-cancer drugs selectively “targets” cells within the body that have a specific molecular defect that is believed to cause dangerous cell behaviors such as uncontrolled proliferative growth and high metastatic potential, behaviors that are associated with aggressive cancer. The defect occurs within the interior of the cell in a region that is called the tyrosine kinase domain and it involves a complicated chemical process called EGFR signaling.
The drugs are called anti-EGFR drugs or tyrosine kinase inhibitors. When the drugs work, they can be highly beneficial, causing tumor shrinkage or promoting stable disease and extending survival. However, targeted therapy drugs like tyrosine kinase inhibitors only work for a small percentage of the patients who receive them. Further, the drugs are expensive and have been associated with toxic side effects.
Although no molecular (gene-based) test has been proven to tell reliably who will benefit from anti-EGFR treatment, cellular-based testing has been shown to correlate highly with patient response to anti-EGFR treatment and with overall patient survival. Reported prospectively, this type of testing reliably identifies patients who do or do not respond to treatment with anti-EGFR drugs and also those who achieve superior survival after treatment.
Some of these targeted drugs are Tarceva (erlotnib), Iressa (gefitinib), Nexavar (sorafenib), and Sutent (sunitinib).
Source: Cell Function Analysis