From the Research
Yes, anti-TPO antibodies can be present in thyroid malignancy, and high levels (>1300 IU/mL) may indicate multifocal papillary thyroid cancer in patients with Hashimoto's thyroiditis. Studies have shown that approximately 10-30% of patients with thyroid cancer may have detectable anti-TPO antibodies 1. The presence of these antibodies in thyroid cancer patients is often due to concurrent autoimmune thyroid disease, which can sometimes coexist with thyroid malignancy. In fact, there is some evidence suggesting that chronic autoimmune thyroiditis may be a risk factor for the development of papillary thyroid carcinoma in particular. However, anti-TPO antibodies are not used as diagnostic markers for thyroid cancer, and their presence alone does not indicate malignancy. For thyroid cancer diagnosis, fine needle aspiration biopsy remains the gold standard, along with ultrasound imaging and clinical evaluation. If anti-TPO antibodies are detected in a patient being evaluated for thyroid nodules, this finding should be interpreted in the context of other clinical and laboratory findings, as it may simply reflect underlying autoimmune thyroid disease rather than cancer. Some key points to consider:
- High TPOAb levels (>1300 IU/mL) are definitive indicators of multifocal PTC in HT patients, which may support surgical treatment with total thyroidectomy 2.
- Positive thyroid antibodies were not found to be a predictor of thyroid carcinoma overall, but in patients with benign FNAC, positive thyroid antibodies increased the risk of thyroid malignancy 1.
- The specificity of epitopes and binding constants of TPO with monoclonal antibodies (MAbs) may improve the differential diagnosis between different thyroid autoimmunities 3. It is essential to consider the clinical context and other diagnostic findings when interpreting the presence of anti-TPO antibodies in patients with thyroid nodules or suspected thyroid malignancy.