Preliminary results indicated that this test had a number of false-negative results.

When the DNA inside of human cells undergoes certain alterations (mutations), the cells may develop into a cancer. The cancer cells may shed this DNA into the blood stream. This circulating tumor DNA (ctDNA) can be detected by very sensitive, specialized laboratory tests. Measurement of ctDNA has been shown to be useful for following patients with known cancer. The purpose of this study is to examine blood specimens for the presence of ctDNA in individuals without known cancer who are scheduled to undergo a fine needle aspiration biopsy of the thyroid gland because of one or more thyroid nodules in order to see if the ctDNA test can detect a cancer at a very early stage. The results of this study should help define the role of ctDNA in the detection of early stage thyroid cancer and to define how sensitive it is (i.e. how well it picks up cancer when it is present) and how specific it is (i.e. how often is ctDNA found in patients with benign thyroid nodules).

After the participants with thyroid nodules or other abnormalities have undergone the informed consent process, they will have 30 milliliters (approximately two tablespoons) of blood drawn. This will be done prior to the performance of the fine needle aspiration biopsy of the thyroid. If the patient has indicated a desire to receive the results of their test, they will receive a written description, as will their physician. The patients will be contacted yearly for up to 5 years by the study staff to learn whether they have been found to have a diagnosis of thyroid or other cancer.

Inclusion Criteria:

• 18 years of age or older;
• presence of one or more thyroid nodules who are going to have a fine needle aspiration biopsy performed as part of their normal care.

Exclusion Criteria:

• Prior history of cancer excluding basal cell carcinoma of the skin.

Individuals 18 year of age or older without a prior diagnosis of cancer who are going to undergo a fine needle aspiration biopsy of the thyroid gland as part of their standard care.

The patient's physician will receive the results and the patients have the option to also receive the results.