Identifying patients at risk of early postoperative recurrence of lung cancer: a new use of the old CEA test

Background In the current study, we report the carcinoembryonic antigen (CEA) capability to predict early tumor relapses after a pulmonary resection for nonsmall cell lung cancer (NSCLC). Methods We studied 118 consecutive NSCLC patients who were clinically judged operable and were eventually operated upon. Anthropometric, clinical, and CEA data along with the results of both preoperative and postoperative stage classifications were recorded. All patients were followed up for at least 1 year after surgery and the time to the first clinical recurrence recorded. Receiver-operating characteristic (ROC) curves and diagnostic formulas were used for data analysis. Results In this series the CEA test was among the most accurate methods to predict an early postoperative recurrence (ROC area: 0.72, 95% confidence interval [CI]: 0.60 to 0.85, p = 0.001; accuracy rate for CEA at the threshold of 10 ng/mL: 83%, CI: 76% to 90%). Also predictive was the postoperative pathologic stage of disease (ROC area: 0.68, CI: 0.56 to 0.80, p = 0.007). In tumors pathologically classified in stage Ia to IIb, a preoperative CEA level higher than 10 ng/mL was associated with a 67% probability of tumor relapse. In the same stages of disease, a CEA level less than 10 ng/mL increased the baseline probability of no recurrence from 80% to 88%. Conclusions In operable patients with NSCLC the frequency of abnormal serum concentrations of CEA is low (17% in our series). However, it is important to identify such a small group of high-risk patients as many of them (in our study, 55% and 70% of those with a CEA value in excess of, respectively, 5 and 10 ng/mL) will develop an early postoperative recurrence. Such patients should be investigated preoperatively by mediastinoscopy or positron emission tomography in even in the absence of suspicious symptoms and signs. Then after an apparently successful operation, they should be carefully followed up. These patients could represent a suitable target for neoadjuvant clinical trials of selected high-risk groups.