Background: There is little general agreement concerning the effectiveness of serum carcinoembryonic antigen (CEA) as a prognostic indicator for non-small cell lung cancer (NSCLC) in clinical stage I patients. We conducted a retrospective study to investigate the relationship between serum CEA level and survival.
Methods: We assessed 297 consecutive patients with clinical stage I NSCLC who underwent surgical resection at Toneyama National Hospital from 1985 to 1998. Serum CEA levels were measured with an enzyme-linked immunosorbent assay kit with the upper limit of normal defined as 7.0 ng/mL based on the 95% specificity level for benign lung disease, in our hospital.
Results: There were 56 (19%) patients with serum CEA greater than 7.0 ng/mL. The high CEA group had a median survival time of 50 months and a 5-year survival rate of 49% compared with a 5-year survival rate of 72% (p < 0.0001) for the normal CEA group (n = 241). Patients with postoperatively high CEA levels (n = 15) had the worse prognosis (median survival time 35 months, and 5-year survival 18%) compared with patients whose levels returned to normal (n = 41, median survival time 8.8 months, and 5-year survival 68%; p = 0.01). These differences were also observed in patients with pathologic stage I or II tumors but not in those with pathologic stage III or IV tumors.
Conclusions: Serum CEA level is a useful predictor of survival for patients with clinical stage I NSCLC, and a persistently high CEA level after surgery is an especially strong indicator of a very poor prognosis.