engleski

Do tumor markers help? Results with and without the use of tumor markers in cytologically indeterminate thyroid lesions

Aim: We investigated if the use of two tumor markers, galectin-3 and CD44v6, could improve diagnostic accuracy of fine needle aspiration cytology (FNAC) in indeterminate thyroid lesions. Methods: 351 patients with cytologically indeterminate lesions [cellular follicular lesion/suspicious follicular neoplasm/suspicious Hürthle cell neoplasm (CFP/sFN/sHCN), Hürthle cell neoplasm (HCN), and follicular neoplasm (FN)] and surgical follow up were investigated. 251 patients had FNAC diagnoses made without help of tumor markers and the rest of 100 patients had FNAC diagnoses made with a known expression of tumor markers, galectin-3 and CD44v6, determined by the reverse transcription (RT)-PCR method. We investigated the risk of malignancy in both groups of patients (separately by the type of FNAC diagnosis), and then compare the risk of malignancy in patients with negative tumor markers, patients with at least one positive tumor marker and with patients without RT-PCR results. Results: Overall risk of malignancy in all 351 patients with cytologically indeterminate lesions was 6.8%. In the group of patients with FNAC diagnosis made without RT-PCR, there were 140 diagnoses of CFP/sFN/sHCN with the risk of malignancy of 4.2%, 92 diagnoses of FN with the risk of malignancy of 13.0%, and 19 diagnoses of HCN with the risk of malignancy of 5.2%. In the group of patients with FNAC diagnosis made with RT-PCR, there were 49 diagnoses of CFP/sFN/sHCN with the risk of malignancy of 2.0%, 40 diagnoses of FN with the risk of malignancy of 7.5%, and 11 diagnoses of HCN with the risk of malignancy of 9.0%. The risks of malignancy in these two groups didn’t differ significantly (p>0.05). In the group of patients with at least one positive tumor marker (N=69), the risk of malignancy was 3.1% for diagnoses of CFP/sFN/sHCN, 11.1% for diagnoses of FN, and 10.0% for diagnoses of HCN. The risk of malignancy in this group of patients didn’t differ significantly (p>0.05) from the risk of malignancy in the previous two groups of patients. In the group of patients with negative tumor markers (N=31) there were no malignancies. Although there was a strong tendency (p≈0.10) we found no statistically significant (p>0.05) difference between the group of patients with negative tumor markers and the other three groups of patients according to the risk of malignancy. Conclusion: The use of tumor markers, galectin-3 and CD44v6, determined by RT-PCR improves only sensitivity of FNAC in cytologically indeterminate thyroid lesions. In most patients with cytologically indeterminate lesions, and negative both tumor markers, conservative approach is advisable.

galectin-3; CD44v6; fine needle aspiration cytology; reverse transcriptase polymerase chain reaction; thyroid; cytologically indeterminate lesions

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