Pretreatment serum levels of the tumor markers carcinoembryonic antigen (CEA), CA 50, and CA 19-9 in 95 patients with squamous cell carcinoma of the esophagus and 32 age-matched controls were compared. Thirty-nine percent of the cancer patients showed elevated ( 2 5 Wgg/l) serum CEA levels, 41% had elevated (217 U/ml) CA 50 levels, and 13% showed elevated (237 U/ml) CA 19-9 levels. The tumor markers showed a considerable degree of complementarity, and combined tumor marker analysis increased the sensitivity to 59%. Raised CEA levels were found significantly more frequently in intrathoracically localized tumors than in cervical cancers. Patients surviving less than 6 months showed a higher rate of elevated CEA assays than those who survived 6 to 18 months. No certain correlation was established between tumor marker elevation and tumor stage or tumor differentiation.
Cancer 622281-2286,1988.
UMOR MARKERS, ANTIGENIC EPITOPES Of Cells and T cellular products, are related to the presence of malignant tumors. Detection of tumor markers could offer an accessible method for screening risk groups in order to achieve an early diagnosis of cancer, to contribute to an adequate staging in expressing the tumor burden, and to help evaluate effects of therapy as well as to reveal metastases or local recurrences. Tumor markers may be oncofetal antigens such as alpha-fetoprotein (AFP) and carcinoembryonic antigen (CEA), hormones such as human chorionic gonadotropin (HCG), enzymes such as prostatic acid phosphatase (PAP), or tissue-associated antigens. The latter are often carbohydrate antigenic determinants, glycolipids, or glycoproteins of the cell membrane that have changed during oncogenic transformation. The development of rhe hybridoma technique has made it possible to produce monoclonal antibodies (Mab) specific to tumor-associated antigens and to quantify these antigens in nanogram amounts by immunoassays.