Background/Aims: A retrospective study was designed to evaluate the cl
inical significance of preoperative serum levels of carcino-embryonic
antigen (CEA) and CA72-4 in patients with advanced gastric adenocarcin
oma. Methodology: Pre-operative serum levels of CEA and CA72-4 were an
alyzed and compared with the proliferative activity of cancer cells, m
onitored in. terms of the number of argyrophilic nucleolar organizer r
egions (AgNORs) in tumors from 153 patients with resected gastric aden
ocarcinoma with serosal invasion. Results: Elevated levels of CEA were
frequently found in patients with lymph node metastasis and liver met
astasis. By contrast, elevated levels of CA72-4 were frequently found
in patients with peritoneal metastasis at the time of operation. A clo
se correlation was found between pre-operative levels of serum CA72-4
and the AgNOR scores of tumors. Even when apparently curative operatio
ns were performed, peritoneal metastasis occurred these were detected
quite soon, after apparently curative operations in patients with high
pre-operative serum levels of CA72-4 and tumors with high proliferati
ve activity. Conclusions: This phenomenon might explain the poor progn
osis of patients with high levels of CA72-4.