BACKGROUND. The c-met protooncogene encodes the met protein, the recep
tor for scatter factor/hepatocyte growth factor, a growth factor that
modulates the motility and stable interaction of the epithelial cells.
This study assesses the expression of met receptor in breast carcinom
a and its prognostic value with respect to survival. METHODS, Immunofl
uorescence was used to evaluate 91 archival breast carcinoma specimens
using a polyclonal antibody to the cytoplasmic domain of the receptor
. Cases were scored by two pathologists on a percentage basis and then
converted to binary scores (positive or negative) on the basis of a b
imodal distribution. RESULTS, Strong expression of met was found in 20
invasive ductal breast tumor specimens (22%). The 5-year survival of
patients whose tumors showed decreased met expression was 89%, in cont
rast to a 52% 5-year survival rate in patients whose tumors expressed
met (P = 0.008). This trend also was observed in patients without lymp
h node metastases at presentation, in whom met negative patients had a
95% 5-year survival compared with only 62% for met positive patients
(P = 0.006) Multivariate analysis using the Cox proportional hazards m
odel showed met expression to be an independent predictor of survival,
with a predictive value nearly equivalent to that associated with lym
ph node status. CONCLUSIONS. The authors conclude that expression of m
et in patients with invasive ductal carcinoma of the breast is a stron
g, independent predictor of decreased survival and may be a useful pro
gnostic marker with which to identify a subset of patients with more a
ggressive disease. (C) 1998 American Cancer Society.