Objective: To compare the survival rate of people with papillary thyroid cancer limited to the thyroid gland who have not had immediate, definitive treatment for their thyroid cancer with the survival rate of those who have had such treatment.
Design: Cohort study of incident cancer cases and initial treatment data from the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) program. Data on cause of death was taken from the National Vital Statistics System.
Patients: Patients with papillary thyroid cancer limited to the thyroid gland.
Main outcome measure: Cancer-specific survival.
Results: Of all eligible people in the data (n = 35,663), 1.2% did not undergo immediate, definitive treatment (n = 440). The life table estimate of their 20-year cancer-specific survival rate was 97% (95% confidence interval [CI], 96%-100%). The corresponding estimate for the patients who did receive treatment was 99% (95% CI, 93%-100%). Among those who did not receive immediate, definitive treatment, 6 died from their cancer. This number is not statistically different from the number of thyroid cancer deaths in the treated group over the same period (n = 161) (P = .09).
Conclusion: Papillary thyroid cancers of any size that are limited to the thyroid gland (no extraglandular extension or lymph node metastases at presentation) have favorable outcomes whether or not they are treated in the first year after diagnosis and whether they are treated by hemithyroidectomy or total thyroidectomy.