Learning Center: Thyroid Cancer Outcomes, Spread to Distant Sites

Who this page is about

Last reviewed: November 8, 2026

This page covers adults with papillary or follicular (including oncocytic, formerly called Hürthle cell) thyroid cancer that has spread beyond the neck, most often to the lungs or bones. Distant spread is uncommon. Most people with thyroid cancer never develop it.

Treatment usually starts with total thyroidectomy, followed by radioactive iodine. The Radioactive Iodine Ablation and Radioiodine Uptake pages explain these steps.

Why this page shows outlook, not a treatment comparison

There are no fair comparisons of treatments for distant spread. Nearly everyone who can receive radioactive iodine does, and the people who cannot (because the cancer does not take up iodine, or because of other illnesses) are a very different group. So the graphic below groups people by how the cancer responded, which describes what to expect, rather than by which treatment they chose.

Response to radioactive iodine: the French long-term study

At Institut Gustave Roussy in France, 444 people with distant spread were treated from 1953 to 1994. Half had spread to the lungs only, a quarter to the bones only, and most of the rest to both.[1]

• Of the 295 people whose cancer took up radioactive iodine, 43% reached clear scans with treatment.

• Clear scans were more likely in people who were younger, had small spots, and had well-differentiated tumors.

• Clearing often took time. Almost half of the clear scans came more than 5 years after treatment started.

• Of those who reached clear scans, only 7% later had the cancer return.

• Alive at 10 years: 92% of those whose scans became clear, and 19% of those whose scans did not.

Survival in national data

A U.S. registry study (SEER) followed 1,991 people who already had distant spread when their thyroid cancer was diagnosed, from 1992 to 2018.[2]

• About half were alive without dying of thyroid cancer at 10 years.

• This figure did not change across the three decades (50.2%, 47.3% and 52.4%), even though survival for thyroid cancer overall rose slightly over the same period.

• Survival was lower in people aged 65 or older (28.1% at 10 years), in men, with larger tumors or lymph node spread, and with oncocytic cancer.

People who were not treated with surgery had lower survival in this study, but they were also older and often had other health problems, so this does not show what surgery itself added.

Other outcomes

Repeated radioactive iodine treatments can cause dry mouth, changes in taste, and, at high total doses, effects on blood counts and fertility. When the cancer no longer takes up iodine, other treatments, including radiation and drug treatments, are considered. Most people in these studies were treated before newer drug treatments came into wide use.

Key points

• Thyroid cancer that has spread to distant sites has a wide range of outlooks.

• Younger people with small spots that take up radioactive iodine do best; in one large study, those whose scans became clear had 92% survival at 10 years.

• Nationally, about half of people with distant spread at diagnosis were alive without dying of thyroid cancer at 10 years, and this has not changed in 30 years.

• These numbers describe groups of people, not treatment choices, and cannot predict how any one person will do.

References

1. Durante C, Haddy N, Baudin E, et al. Long-term outcome of 444 patients with distant metastases from papillary and follicular thyroid carcinoma: benefits and limits of radioiodine therapy. J Clin Endocrinol Metab. 2006;91(8):2892-2899. doi:10.1210/jc.2005-2838 PubMed 16684830

2. Wilhelm A, Conroy PC, Calthorpe L, et al. Disease-specific survival trends for patients presenting with differentiated thyroid cancer and distant metastases in the United States, 1992-2018. Thyroid. 2023;33(1):63-73. doi:10.1089/thy.2022.0353 PubMed 36413032