Active Surveillance and Surgery Outcomes in Low Risk Papillary Thyroid Cancer

Prior treatment

• History of prior thyroid surgery for any indication.

Other illness

• Metastatic thyroid cancer (lymph nodes or distant).
• Clinical signs, imaging, or laryngoscopy findings suggestive of locally advanced thyroid cancer (i.e. vocal cord paralysis due to the thyroid cancer or any clinical or radiographic signs of extrathyroidal invasion into adjacent structures such as the strap muscles of the neck, trachea or esophagus).
• Known/suspected poorly differentiated or non-papillary thyroid cancer.
• Medically unfit for surgery due to severe co-morbidity. Severe comorbidity may include another active malignancy with limited life expectancy of \< 1 year).
• Unable/unwilling to provide informed consent for the study or comply with study follow-up procedures due to current active physical limitations/medical co-morbidity, cognitive, or psychiatric impairment substance abuse, or other reasons.

Other

• The primary PTC being on the trachea or immediately adjacent to the recurrent laryngeal nerve, and with progression would be deemed to be at high risk of growth into these critical structures.
• Pregnancy at the time of study enrollment.

• Patients 18 years of age or older.
• Newly diagnosed previously surgically untreated papillary thyroid cancer (PTC) or suspicious for PTC on fine needle aspiration biopsy of the thyroid. PTC must be \< 2 cm in maximal diameter on thyroid ultrasound.
• The absence of metastatic cervical lymphadenopathy or gross extrathyroidal extension of PTC, as confirmed on neck ultrasound imaging.
• The absence of other current absolute indication for thyroid or parathyroid surgery (e.g. severe hyperthyroidism that cannot be controlled medically, large goitre with severe compressive symptoms, or primary hyperthyroidism meeting surgical criteria).