Significance of the serum carcinoembryonic antigen level during the follow-up of patients with completely resected non-small-cell lung cancer.

Objectives: The purpose of this study was to elucidate the detectability of recurrence and the prognostic significance of the serum carcinoembryonic antigen (CEA) levels in patients with completely resected non-small-cell lung cancer (NSCLC).

Methods: Five hundred and eighteen NSCLC patients who underwent complete resection at Aichi Cancer Center between April 2001 and March 2006 were enrolled in this study. The patient characteristics were as follows: the median age was 63 years; 331 tumours were classified as pathological stage I, 88 tumours were pathological stage II and 99 tumours were pathological stage III; 140 tumours were adenocarcinomas with epidermal growth factor receptor (EGFR) mutations, 268 tumours were adenocarcinomas with EGFR wild-type mutations and 110 tumours were other NSCLCs. The patients were divided into three groups: those with a normal CEA level before and 1-3 months after surgery (N group, n = 380), those with an elevated CEA level before surgery and a normal CEA level 1-3 months after surgery (HN group, n = 105) and those with an elevated CEA level 1-3 months after surgery regardless of the preoperative CEA level (H group, n = 33). The correlations between the changes in the serum CEA levels and the clinical outcomes were analysed.

Results: Recurrence developed in 122 patients (32%) in the N group, 49 patients (47%) in the HN group and 19 patients (58%) in the H group (P = 0.001). The sensitivity and specificity of an elevated serum CEA level during the follow-up period for detecting recurrence were 30 and 98% in the N group and 82 and 73% in the HN group, respectively. Twenty-seven asymptomatic recurrent tumours combined with an elevated serum CEA level were detected in the HN group. In the multivariate Cox regression analysis, the serum CEA level 1-3 months after surgery had prognostic value for overall survival.

Conclusions: In completely resected NSCLC patients, measuring the serum CEA level during the follow-up period is useful in patients in whom an elevated level normalizes after surgery, and the serum CEA level 1-3 months after surgery is considered to have prognostic significance regarding survival.