77173-3

LOINC code 77173-3 identifies "Hepatocyte growth factor receptor Ag [Presence] in Tissue by Immune stain". The stain is interpreted as positive if 50% or more of the tumor cells show moderate to strong (2+, 3+) membranous staining, indicating MET amplification. MET amplification (positive) has been seen in approximately 22% of non-small-cell lung cases with acquired resistance to anti-EGFR inhibitors. Recent Phase II clinical trails (OAM4558g) results were released at ASCO in 2011 showed that patients who were c-MET positive (2+ or 3+) lived twice as long without disease progression (PFS) when they received MetMAb therapy in combination with erlotinib versus receiving erlotinib alone.

This code measures Hepatocyte growth factor receptor Ag in Tiss. It belongs to the PATH class in the LOINC classification.

LOINC (Logical Observation Identifiers Names and Codes) is a universal standard for identifying laboratory and clinical observations. It is maintained by the Regenstrief Institute and used worldwide for health data exchange.