[Serial measurements of serum carcinoembryonic antigen (CEA) and neuron-specific enolase (NSE) during chemotherapy of patients with inoperable lung cancer].

Serial measurements of serum CEA levels were analyzed in 226 patients with inoperable lung cancer (115 small cell carcinomas, 64 adenocarcinomas, 37 squamous cell carcinomas and 10 large cell carcinomas) during chemotherapy. Of all patients, 29.1% had pretreatment CEA levels greater than or equal to 5 ng/ml. In all of the patients with complete response, and 15 (68.2%) of 22 patients with partial response whose pretreatment CEA levels were 5 ng/ml or higher, CEA levels fell to below 5 ng/ml. All of 17 patients who showed a decrease greater than 50% in serum CEA levels during chemotherapy showed a shrinkage of more than 50% in the tumor burden. Serial serum CEA level measurements were useful as an indicator of response to chemotherapy in advanced lung cancer. Serial serum NSE levels were measured in 36 patients with small cell lung cancer. Pretreatment NSE levels were elevated to more than 10 ng/ml in 83.1% of all patients. A transient rise in serum NSE levels occurred in 22 out of 33 patients measured on the third day during initial chemotherapy. Serum NSE levels greater than or equal to 10 ng/ml declined to within the normal range in all patients responding to the chemotherapy. The survival in patients whose NSE levels (greater than or equal to 10 ng/ml) fell to within the normal range for more than four weeks was longer than that in other patients. Serial measurements of serum NSE levels were thus useful for monitoring the response to chemotherapy in cases of small cell lung cancer.