Tumor Markers in Thyroid Carcinoma With Pulmonary Metastases After Thyroidectomy

Background: The present study investigated several tumor markers in patients receiving multiple radioiodine treatments after thyroidectomy for differentiated thyroid carcinoma (DTC). Methods: Serological tests for tumor markers (Tg, CFEA, CA125, CA19-9, CA72-4, and Cyfra 21-1) were performed in 57 patients with pulmonary metastases (subjects) and 76 patients without distant metastases (controls). Results: Serum thyroglobulin was much higher in the subjects than in the controls (median, 595.0 versus 5.4 mu g/L, P 0.001). There were no differences in both concentrations and sensitivities of CEA, CA125, CA19-9, CA72-4, and Cyfra 21-1 between the 2 groups (all P>0.05). CA72-4 was positive in 20.3% with more positive cases in those having received higher doses (cutoff dose 25.9 GBq, 36.8% versus 13.7%, P=0.003). Conclusion: These tumor markers are not likely progression-related and are not recommended for the follow up of DTC patients unless other malignancies are indicated. The high sensitivity of CA72-4 may be related to radiation damage to the gastrointestinal mucosa.