This is a prospective observational study.

1. In the first part of the study, consenting eligible adult patients with low risk papillary thyroid cancer that is confined to the thyroid, are provided verbal and written information about their disease and the option of active surveillance (close monitoring with intention to treat if disease progresses or if the patient changes her/his mind), as an alternative to thyroid surgery (thyroidectomy - traditional standard of care). Patients are free to make their own disease management choice (ie. active surveillance or thyroidectomy) and the investigators are examining how often patients choose each of these options. The investigators are also examining the reasons for their choice.
2. In the second part of the study, consenting, eligible patients who completed the preceding part of the study and chose either a) active surveillance, or b) thyroid surgery, are tracked with respect to clinical and psychosocial outcomes as well as quality of life. Patients who chose active surveillance are free to change their mind and have surgery at any point, even if the disease does not progress. The primary study outcome is decision regret at one year, in the respective groups of patients who chose active surveillance or thyroidectomy.

This is a prospective observational study, consisting of multiple parts.

1. In the first part of the study, eligible, consenting adult patients with low risk papillary thyroid cancer who have not had thyroid surgery, are provided with verbal and written information about the disease prognosis, surgical treatment outcomes, and the option of active surveillance (close monitoring with the intention of treatment if there is disease progression or if the patient changes her/his mind), as an alternative to immediately proceeding with thyroidectomy. The primary outcome of this part of the study is the final disease management decision of the patient (ie. active surveillance or thyroid surgery) and we are also examining patients' reasons for their choice.
2. In the second part of this study, eligible consenting patients who completed the preceding part of the study and chose either: a) active surveillance, or b) thyroid surgery, are tracked with respect to disease, treatment, psychosocial outcomes, and quality of life. For patients under active surveillance, clinical follow-up is conducted at a participating study institution. For patients who choose surgery, surgery and related clinical follow-up may be performed at any institution (of the patient's choice), however, the thyroid cancer-related medical records are regularly reviewed. Questionnaires are mailed to patients at one year. The primary outcome for this study is decision regret (on the decision for active surveillance or surgery) at one year after initiating the disease management decision (ie. active surveillance or surgery). As the decision for surgery or active surveillance is up to the patient and the proportion of patients in each group is unknown, the results in respective groups will be reported separately for the primary analysis (and only compared if sufficient numbers are available in each group).

Inclusion Criteria:

1. Patients 18 years of age or older
2. Newly diagnosed previously untreated papillary thyroid cancer (PTC) (fine needle aspiration biopsy positive for PTC or suspicious for PTC).
3. PTC must be less than 2 cm in maximal diameter on thyroid ultrasound
4. No evidence of metastatic cervical lymphadenopathy on ultrasound imaging of the neck (or other neck imaging) and no known distant metastatic thyroid cancer.
5. No other absolute indications for thyroid or parathyroid surgery
6. Permission for review of thyroid cancer-related medical records

Exclusion Criteria:

1. Regional or distant metastatic thyroid cancer
2. History of prior thyroid cancer surgery
3. High risk location of the PTC (e.g. adjacent to the recurrent laryngeal nerve or trachea)
4. The patient has clinical signs, imaging, or indirect laryngoscopy findings suggestive of locally advanced thyroid cancer (i.e. vocal cord paralysis or any clinical or radiographic signs of extrathyroidal invasion into adjacent structures such as the strap muscles of the neck, trachea or esophagus)
5. Known or suspected poorly differentiated or non-papillary thyroid cancer
6. Medically unfit for surgery due to co-morbidity
7. Another active malignancy with limited life expectancy of < 1 year.
8. Pregnancy at the time of study enrollment.
9. Other absolute indication for thyroid or parathyroid surgery
10. Unable to provide informed consent for the study or comply with study follow-up procedures due to current severe active cognitive or psychiatric impairment, substance abuse, or other reasons.

Consenting individuals aged 18 years of age or older with papillary thyroid cancer (PTC) who have a primary tumor that is <2cm in maximal diameter, and fine needle aspiration biopsy is positive or suspicious for PTC. The tumor must be confined to the thyroid (no metastatic disease) and not considered in a high risk location (e.g. adjacent to the recurrent laryngeal nerve or trachea). The patient must have no prior surgical treatment for thyroid cancer.

We are in discussions with other groups doing active surveillance research, and in future, may share data with such groups. Final plan not yet established.