Hashimoto's thyroiditis is an autoimmune condition where the immune system attacks the thyroid gland, reducing hormone production and commonly causing hypothyroidism. This prospective study investigated whether the known link between Hashimoto's and thyroid cancer is specific to certain thyroid antibodies. The study found that elevated thyroglobulin antibodies (TgAb) were a risk factor for thyroid cancer in patients with thyroid nodules, but thyroid peroxidase antibodies (TPOAb) showed little variation between cancerous and benign nodules. The results suggest the association between Hashimoto's and thyroid cancer is specific to TgAb levels.

3. WHAT IS HASHIMOTO’S THYROIDITIS?
• Patients who have one or more elevated thyroid antibodies (TPOAb, TgAb)
have Hashimoto’s thyroiditis
• On ultrasound, patients with an inflamed thyroid gland also may have
Hashimoto’s thyroiditis, even if the antibodies are not yet detectable on
labwork

4. Hashimoto's disease, an autoimmune condition, is the most common cause of hypothyroidism. In
this case the immune system mistakenly targets and damages the thyroid gland, so not enough
hormones are produced. Hashimoto’s disease is often inherited.
Source: http://www.medicinenet.com
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5. NORMAL THYROID GLAND VS. HASHIMOTO GLAND
A normal thyroid gland has a smooth texture and Hashimoto gland has a rough and irregular texture

6. WHY IS HASHIMOTO’S THYROIDITIS IMPORTANT?
• It is the most common cause for hypothyroidism
• Due to probable link with thyroid cancer

8. WHAT IS THIS PROSPECTIVE STUDY ABOUT?
• It investigates the possibility that the link between Hashimoto’s
thyroiditis and thyroid cancer is antibody specific
• Prospective studies are the gold standard in medicine

9. HYPOTHESIS
• 2 retrospective studies reported an association between Hashimoto’s
disease and thyroid cancer in patients with thyroid nodules
• These studies demonstrated a link between TgAb and thyroid cancer
• TPOAb is not a link even though it’s a more sensitive marker for
Hashimoto’s
• Hypothesis: Hashimoto’s thyroiditis’ link with thyroid cancer is antibody
specific

10. DETAILS OF THE STUDY
• 2100 patients initially in the study
• Patients had single or multiple thyroid nodules ≥5 mm
• 18+ years old
• Prior to FNA, bloodwork was done to obtain TSH, Free
T4, Free T3, TgAb and TPOAb levels

11. AFTER THE THYROID NODULE BIOPSY…
• 2023 patients remained in the study
• Surgery recommended for patients with FNA results that were positive for malignancy,
highly suspicious for follicular neoplasm, or follicular cells of undetermined significance
Surgery also recommended for patients with 2 non-diagnostic or benign FNAs with 2 or
more ultrasound features suggestive of thyroid cancer or increased size
• 461 had a thyroidectomy and, of these, 233 diagnosed with thyroid cancer

12. • Statistical analysis was performed on the 2023 patients (2699 nodules) that
were included in the study
• Data for the 1790 patients with no cancer was compared with that of the 233
patients with thyroid cancer
STATISTICAL ANALYSIS

13. STATISTICAL RESULTS
• Thyroglobulin Antibody (TgAb) was an independent risk factor for thyroid
cancer
• Elevated TgAb found in 20.6% of malignant nodules compared to 10.2%
of benign
• This means that if you have thyroid nodules AND elevated Tg antibody, you
are at 2.5 times higher risk for thyroid cancer

14. RESULTS OF THE STUDY
• Examining the 233 patients diagnosed with thyroid cancer showed:
 Elevated TgAb found in 20.6% of malignant nodules compared to
10.2% of benign
 Thyroid Peroxidase Antibody (TPOAb) had little variation (31.33%
malignant vs 26.7% benign)

15. ADDITIONAL RESULTS
• TSH >1 µlU/ml was predictor for higher risk of cancer
• Young age: malignant patients average 45.33 years old
• Gender not statistically significant: while males tested positive for thyroid cancer more
often than females, 84% of the study’s subjects were female
• 41% of thyroid cancer nodules <10 mm in diameter

16. CONCLUSIONS
• While this study suggests association between Hashimoto’s and thyroid cancer is antibody
specific, the cause of this is not known
• Larger study would determine if a TgAb threshold exists
• The relationship between thyroid cancer and inflammation is still not fully understood, this
study demonstrated TgAb levels and TSH ≥1 µlU/ml can serve as significant predictors for
thyroid cancer.
• TgAb may lead to nodule formation or be closely related to a specific inflammatory response.
Further investigation into antibody specificity may lead to a better understanding of nodule
production