Clinical Thyroidology® for the Public

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Competing Risks of Death in Older Thyroid Cancer Patients

Clinical Thyroidology for the Public

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Most types of thyroid cancer have an excellent prognosis, with a 10 year survival of 85-90%. The exception to this is the rare anaplastic thyroid cancer, which represents less than 2% of all thyroid cancers but is very aggressive, with a 10-year survival of <5%. Thus, most thyroid cancer patients who do not have anaplastic cancer die of other causes and not related to the thyroid cancer. Further, more than 70% of all thyroid cancer deaths occur in patients who are 65 years and older, with an average age of 73 years. Older adults with thyroid cancer also have a higher risk of developing treatment-related complications, including complications from thyroid surgery, as well as heart complications and osteoporosis (thinning of the bones) due to the need to partially suppress TSH levels with thyroid hormone therapy. This age group has a higher risk of dying from other diseases as well, such as heart disease and chronic lung disease. Given the health and economic impact of thyroid cancer on older adults, the decision regarding the extent of the diagnostic tests and treatment needs to take into consideration the patients’ age, the burden of other medical conditions, and life expectancy in addition to the severity of the thyroid cancer in order to provide a more personalized patientcentered care.

The objective of this study was to determine whether older adults with thyroid cancer are more likely to die from thyroid cancer or other diseases, and determine factors associated with each.

Papaleontiou M et al. 2021 Competing causes of death in older adults with thyroid cancer. Thyroid. Epub 2021 Mar 25. PMID: 33764188.

This study examined two American databases: SEER (Surveillance, Epidemiology, and End Results), which provides information on cancer statistics for approximately 35% of the U.S. population; and Medicare health services claims, which provide billing information and diagnoses. More than 97% of older adults (aged 65 years and older) are eligible to enroll in Medicare, which covers claims for health services.

This SEER–Medicare database was used to identify all patients diagnosed with any type of thyroid cancer (papillary, follicular, Hürthle-cell, medullary, anaplastic, other) at age 66 years or older between 2000 and 2015. Patients with any previous cancer diagnosis were excluded.

The study included 21,509 patients with an average age of 72 years, the majority being female (70%) and White (80%). The duration of follow-up varied based on the type of thyroid cancer with a average follow-up of 50 months. As expected, the majority of thyroid cancers were papillary thyroid cancer (76%). Overall, 2644 (12.3%) of patients died from their thyroid cancer versus 4168 (19.4%) who died from other causes during the survey period.

A higher proportion of patients with the common types of thyroid cancer died from diseases other than thyroid cancer, this trend becoming more apparent over time. Patients with medullary thyroid cancer were more likely to die from their cancer within the first 6.25 years, while death from other causes became more likely later. Patients with anaplastic thyroid cancer had high mortality rates, with the highest rates of death in the first year after diagnosis.

Several factors were associated with death from thyroid cancer, including the thyroid cancer type other than papillary (especially anaplastic cancer), larger cancer size (especially tumors larger than 4 cm), and SEER cancer stage (the presence of regional or distant metastases). Male sex, Black and other pre-existing conditions (heart disease, chronic lower respiratory disease, Alzheimer’s disease and diabetes mellitus) were associated with death from other causes. Increasing age was associated with both increased death from thyroid cancer and death from other causes.

In adults of age 66 years and older with thyroid cancer, the likelihood of dying from thyroid cancer correlated with cancer characteristics, including cancer type, size, and stage, while the likelihood of dying from other diseases correlated with patient characteristics, including other medical problems. These results emphasize the importance of evaluating which older patients are expected to benefit from thyroid cancer diagnosis and treatment, especially in the context of other medical problems. This evaluation is essential to better understand the patient’s prognosis and provide personalized patient-centered care. For older patients with lower-risk thyroid cancer and multiple other diseases, thyroid cancer is very unlikely to shorten their lives and the benefits of an aggressive treatment may be minimal.

— Alina Gavrila, MD, MMSc


Papillary thyroid cancer: the most common type of thyroid cancer. There are 4 variants of papillary thyroid cancer: classic, follicular, tall-cell and noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP).

Follicular thyroid cancer: the second most common type of thyroid cancer.

Hurthle-cell cancer: a type of follicular thyroid cancer.

Medullary thyroid cancer (MTC): a relatively rare type of thyroid cancer that often runs in families. Medullary cancer arises from the C-cells in the thyroid.

Anaplastic thyroid cancer (ATC): a very rare but very aggressive type of thyroid cancer. In contrast to all other types of thyroid cancer, most patients with anaplastic thyroid cancer die of their cancer and do so within a few years.

Thyroid hormone therapy: patients with hypothyroidism are most often treated with Levothyroxine in order to return their thyroid hormone levels to normal. Replacement therapy means the goal is a TSH in the normal range and is the usual therapy. Suppressive therapy means that the goal is a TSH below the normal range and is used in thyroid cancer patients to prevent growth of any remaining cancer cells.

SEER: Surveillance, Epidemiology and End Results program, a nation-wide anonymous cancer registry generated by the National Cancer Institute that contains information on ~35% of the United States population. Website:

Cancer metastasis: spread of the cancer from the initial organ where it developed to other organs, such as the lungs and bone.