Neuron-specific enolase as a follow-up marker in small cell bronchial carcinoma. A prospective study in an unselected series.

The value of measurement of serum neuron-specific enolase (NSE) as a follow-up marker was investigated in 88 patients with small cell bronchial carcinoma. Of these, 42 had extensive disease and 46 had limited disease. The mean NSE levels before treatment, at response, and at recurrence in extensive disease were 107, 10, and 52 ng/ml, respectively, and the corresponding levels in limited disease were 35, 10, and 19 ng/ml, respectively. All differences were statistically clearly significant. However, the sensitivity of NSE in serum at response was 66% and at recurrence, 38%. The predictive value of an NSE decrease at response was 88%, and at recurrence, 72%. It is concluded that NSE changes during follow-up support the evaluation of the outcome but cannot be used as a monitoring agent in an individual patient.