WILMINGTON ENDOCRINOLO

GY PRESENTS

PROSPECTIVE STUDY

SUMMARY

HASH IMOTO’S

THYROID

ITIS

AND T

HYROID

CANCER:

I S T

HERE ANY L

INK?

ASSOCIATION

OF HASHIMOTO’S

THYROIDITIS WITH

THYROID CANCER

WI L

M I NGT O N E

N D O C R I NO LO GY ’ S

LAT E S T R

E S E A RC H

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

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

l

NORMAL THYROID GLAND VS. HASHIMOTO GLAND

A normal thyroid gland has a smooth texture and Hashimoto gland has a rough and irregular texture

WHY IS HASHIMOTO’S THYROIDITIS IMPORTANT?

• It is the most common cause for hypothyroidism

• Due to probable link with thyroid cancer

FOLLOW-UP

TO OUR 2011

RETROSPECTIVE

STUDY

PUBLISHED IN ENDOCRIN

E PRACTICE

OFFICIAL JO

URNAL OF AACE

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

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

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

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 significanceSurgery 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

• 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

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

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)

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

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