CEA mRNA did not appear to correlate with metastasis because its expression in the primary colon cancers with metastases (Dukes' stage D tumor) was not always increased.
Hitherto anti-CEA monoclonal antibodies (MAbs), normally of mouse origin, have been used primarily for clinical diagnosis of colorectal cancer, either as a tumor marker in serum to monitor tumor recurrence, or latterly as a means to localize in vivo CEA-bearing tumors, and metastases in patients.
A cell line producing carcinoembryonic antigen (CEA) and neuron-specific enolase (NSE) has been established from pleural effusion of the pulmonary metastatic tumor.
Western blot analysis showed that the size of the recombinant CEA secreted by the transfected human cells is identical to that of reference CEA purified from human colon carcinomas metastases (about 200 kD).
There was no significant relation between the prevalence of CEA cDNA amplification and serum CEA level or metastasis volume in patients with liver metastasis.
Collectively these results suggest that the basal and interferon-stimulated expression of BGP transcripts may be regulated in a manner similar to CEA and that a potential role in the process of metastasis may be inferred.
Although the precise mechanism of CEA gene regulation in hepatocytes remains to be proven, the CEA gene in the metastatic tumor of the liver seems to affect CEA expression in the surrounding hepatocytes facilitating liver metastasis in colorectal carcinoma.
Moreover, CEA transcripts in peritoneal washes in patients with synchronous peritoneal metastasis were more than 50-fold higher than in those without metastasis.
In CRC patients, positive CEA mRNA findings were correlated with local spread (chi(2) = 14.6, p<0.01), lymph node (chi(2) = 18.95, p<0.001) and distant metastasis (chi(2) = 11.3, p<0.001).
Pilot long-term longitudinal studies conducted before and after surgery identified some patients with CEA mRNA in blood cells that were negative for all serum markers, who eventually developed clinical metastatic disease.
In the current study, serum levels of the carbohydrate antigen 15-3 (CA 15-3) and carcinoembryonic antigen (CEA) were determined preoperatively in 364 breast cancer patients with no clinical signs of metastasis.
The expression of mammaglobin mRNA and CEA mRNA was then compared in axillary lymph nodes from 248 consecutive breast cancer patients, 89 with histologically documented lymph node metastasis and 159 without histological evidence of metastatic disease.
This study evaluated the ability of quantitative reverse-transcriptase polymerase chain reaction to quantitate lymph node occult metastases with carcinoembryonic antigen messenger RNA as a tumor marker.
The significance of CEA mRNA levels in both materials, as a predictive factor of peritoneal metastasis, was explored by univariate and multivariate analyses.
During 3 years of follow-up, 2 patients whose peripheral blood had carcinoembryonic antigen and CD44 variant mRNA also had distant metastases (lung or spleen).
Many gene products have been associated with the colon cancer cells' ability to metastasize to the liver, including carcinoembryonic antigen (CEA) and mucins.
Our experiments performed in nu/nu mice suggest that CEACAM5 supports the growth of primary tumors, but is not involved in the formation of metastases by colon cancer cells.
Altogether, aberrant p16 methylation in plasma and elevated serum CEA level were associated with advanced tumor stage (p=0.033), tumor size (p=0.022) and extensive nodal metastasis (p=0.003).