[Serum neuron-specific enolase (NSE) in patients with small cell lung cancer--comparison with carcinoembryonic antigen (CEA)].

Serum neuron-specific enolase (NSE) was determined by RIA in 102 lung cancer patients. Serum NSE was elevated (greater than 10 ng/ml) in 72% (21 of 29 cases) of small cell lung cancer (SCLC) patients, which was a significantly higher positive rate than those in normal adult controls (0%, 0/48), noncancerous lung disease (17%, 4/24), squamous cell carcinoma (19%, 6/31) and adenocarcinoma (16%, 4/25) (p less than 0.05, respectively). There were no NSE-positive cases in stage I-II lung cancer patients. In SCLC, cases of extensive disease had a significantly higher NSE-positive rate (100%, 8/8) than those of limited disease (62%, 13/21) (p less than 0.05), suggesting that NSE levels were related to the bulk of the tumor. There was an excellent correlation between serum NSE and clinical response. Raised NSE levels were identified significantly more frequently than those of CEA in SCLC before chemotherapy and on relapse (or progression) (p less than 0.025, p less than 0.005, respectively). Thus, serum NSE determinations may be more useful than those of CEA for the staging and monitoring of SCLC.