Early diagnosis of colorectal cancer, a frequent neoplasia in industri
alized countries, permits curative surgery. In this study we assessed
the clinical role of serum tumor markers determination in diagnosing,
staging, and grading colorectal cancer; the role of carcinoembryonic a
ntigen (CEA), CA 19-9, tissue polypeptide antigen (TPA) and CA 72-4 in
colorectal cancer follow-up was also assessed. In 114 patients with c
olorectal cancer, the oncofetal antigen CEA was compared with the memb
rane-associated glycoproteins CA 19-9, CA 242, and CA 72-4 and with th
e cytokeratins TPA, tissue polypeptide-specific antigen (TPS) and tiss
ue polypeptide monoclonal antigen (TPM). Overall, the most sensitive i
ndices were TPA and TPS (67% and 70%, respectively). Tumor stage influ
enced the levels of CEA, CA 19-9, and TPA, but not those of TPS, while
tumor grade influenced CEA and TPS, but not CA 72-4, TPA, and TPM. TP
A was the most sensitive index in identifying early or well-differenti
ated colorectal cancers. The sensitivity was enhanced when this marker
was determined in combination with CEA, in diagnosing both advanced a
nd early colorectal tumors. Seventy-seven patients were followed up af
ter therapy for at least 18 months. CEA was the most sensitive index o
f recurrence (58%); however, this sensitivity is too low to consider t
umor markers useful in colorectal cancer follow-up. (C) 1996 Wiley-Lis
s, Inc.