Background: The aim of the present study was to evaluate the value of serum Carcinoembryonic Antigen (CEA) and CA125 antigen assay for monitoring the activity of non-small cell lung cancer (NSCLC) after curative surgical resection.
Patients and methods: Serum CEA and CA 125 were determined preoperatively and at every postoperative visit, in 113 patients with NSCLC (TNM stages I, II, IIIA). Both markers were assayed by magnetic particle enzyme immunoassay.
Results: Tumor recurrence was more frequent in patients with preoperative CA 125 levels above the cut-off (15 U/ml) (28 out of 47) (59.5%) than in those with low values (18 out of 66) (27.2%) (p < 0.001). The 36-month disease-free survival was lower for patients with elevated CA 125 (37%) than among those with low levels (72%) (p = 0.006). High CA 125 was an independent predictor of the risk of postoperative recurrence (Hazard Ratio: 3.02)(95% CI: 1.41-6.49). No relationship was detected between preoperative serum CEA and risk of recurrence. High preoperative CA125 indicated elevated risk for disseminated recurrence (Hazard Ratio: 7) (95% CI: 2.39-20.51), but not for locoregional failure. No significance was detected for CEA, either in locoregional or disseminated recurrence. Forty-six subjects (40.7%) developed tumor recurrence. At the diagnosis of relapse, serum CEA was elevated in 16 patients (34.7%) and CA125 in 26 (56.5%). Sensitivity was higher in the case of disseminated recurrence (63% for CA125 and 43.3% for CEA) and decreased in locoregional relapse (43.7% for CA125 and 18.7% for CEA). The specificity was 97% for CEA and 59% for CA125.
Conclusion: Serum CA125 is a useful prognostic marker in NSCLC. The predictive information is especially useful to estimate the risk of disseminated recurrence. Serial determinations of CEA and CA125 during the postoperative follow-up do not show enough sensitivity/specificity to recommend their use for diagnosis of tumor relapse.