We investigated the expression of VLA-2 in gastric cancers by immunohi
stochemistry using anti-integrin alpha 2 and beta 1 antibodies and the
data were compared with the pathological findings of each gastric can
cer. The specimens were stained with an immunohistological technique f
or integrin alpha 2 and beta 1 subunits. Tumors, simultaneously expres
sing both integrin alpha 2 and beta 1 subunits were defined as positiv
e for VLA-2. Tumors expressing either subunits of integrin alpha 2 or
beta 1 or those showing reduced expression of both subunits were defin
ed as VLA-2 negative tumors. In the 77 primary tumors, 55 (71%) were V
LA-2 positive. 38 (90%) of 42 tumors showing differentiated type inclu
ding tubular adenocarcinoma and papillary adenocarcinoma expressed VLA
-2, whereas 19 (55%) out of 35 undifferentiated type of cancers includ
ing poorly differentiated adenocarcinoma, mucinous carcinoma and signe
t ring cell carcinoma stained for VLA-2. In the undifferentiated type
of cancers, VLA-2 negative tumors had a significantly higher incidence
of vessel invasion than VLA-2 positive ones (p<0.05). VLA-2 negative
tumors showed a tendency to peritoneal dissemination, lymph node metas
tases, lymphatic invasion or invasion beyond the subserosal layer. In
the specimens of peritoneal dissemination, VLA-2 expression rate was f
ound in 56% (9/16), with a higher expression rate than that of primary
lesions. These data indicate that reduced expression of VLA-2 may str
ongly associate with vessel invasion especially in the undifferentiate
d type of adenocarcinoma of the stomach.