Prognosis and staging of differentiated thyroid carcinoma
THE CONTEXT
Differentiated thyroid carcinoma generally has an excellent prognosis, but age, tumour extent and distant spread substantially alter individual risk.
Survival risk
•
Older age, large tumours, extrathyroid extension and distant metastases are associated with worse survival.
•
In a young patient with a low-risk tumour, the risk of death after appropriate treatment is almost zero.
•
In an older patient with a high-risk tumour, such as one with extrathyroid extension or distant metastases, the risk of death may be as high as 55% at 5 years.
•
Older patients with low-risk tumours and younger patients with high-risk tumours form an intermediate-risk group.
Significance of nodal metastases
•
In younger patients, nodal metastases predict recurrence but not death because recurrent neck disease can almost always be successfully salvaged.
•
In older patients, neck metastases, particularly in the lateral neck, can mark distant metastases and have adverse implications for both recurrence and death.
American Joint Committee on Cancer staging described in the source
•
Patients younger than 55 years are stage I unless distant metastases are present, when they are stage II.
•
Older patients with T1N0M0 disease are stage I; those with T2N0M0 disease are stage II.
•
Nodal disease or T3 disease upstages older patients to stage II.
•
Older patients with locally invasive primary disease designated T4, or with distant metastases, are stage IV.