Carcinoembryonic antigen (CEA), neuron-specific enolase (NSE), and the BB isoenzyme of creatine kinase (CK-BB) were evaluated before therapy in the sera of 195 patients with histologically confirmed small cell lung cancer (SCLC) in a prospective multicenter trial. Forty-four percent (84 of 193) of all patients had CEA levels higher than 5 ng/ml, 66% (111 of 168) had NSE levels higher than 12.5 ng/ml, and 32% (40 of 123) had CK-BB levels higher than 10 ng/ml. Clear pathologic levels were less frequently observed. Significantly higher pretreatment titers for CEA, NSE, and CK-BB were found in patients with bone marrow and/or liver metastases. The most elevated marker levels were observed in the group of nonresponding patients with bone marrow and/or liver metastases. Only a slight correlation between the pretreatment CEA level and survival time could be observed. Patients with pathologic NSE (greater than or equal to 30 ng/ml) levels and, in particular, those with pathologic CK-BB (greater than or equal to 25 ng/ml) levels had a significantly shorter median survival than those with normal or elevated levels. In addition, a positive linear correlation between pretreatment NSE and CK-BB (n = 116, r = 0.54) levels was found, but CEA levels did not correlate with other marker levels. From these data it is concluded that pretreatment CEA, NSE, and CK-BB levels are helpful in the clinical management of a subset of patients with SCLC, i.e., those with bone marrow and/or liver metastases.
Cancer 62:125-134,1988.
UMOR MARKERS can be classified into several T groups: ( 1) carcinoembryonic antigens, (2) carcinomatous antigens, (3) minerals, (4) proteins, (5) products of cellular metabolism, (6) colony stimulating factors, (7) circulating immune complexes caused by immunogenic tumor associated antigens, (8) ectopically produced hormones, and (9) enzymes, isoenzymes, and enzyme variants. These markers can be useful in diagnosing and staging disease, in monitoring the therapeu-From the