Radioactive iodine timing does not affect overall survival in papillary thyroid carcinoma
Overall survival in patients with high-risk papillary thyroid carcinoma is not affected by timing of post-thyroidectomy radioactive iodine therapy, study data show.
Paritosh Suman, MD, of the department of surgery, University of Chicago – NorthShore University HealthSystem, and colleagues evaluated data from the National Cancer Database on 9,706 patients with papillary thyroid carcinoma undergoing near/subtotal or total thyroidectomy and radioactive iodine (RAI) therapy to determine the effect of the timing of initial RAI therapy on overall survival.
Early RAI therapy was given within 3 months after thyroidectomy, and delayed RAI therapy was given between 3 and 12 months after thyroidectomy.
Early RAI therapy was given to 88% of patients, and mean timing for early RAI was 47.9 days and 134 days for delayed RAI.
An increased chance of delayed RAI was associated with tumors larger than 4 cm, follicular variant papillary thyroid carcinoma, uninsured patients and black race. An increased likelihood of early RAI therapy was associated with performance of a total thyroidectomy in comparison with near/subtotal thyroidectomy, a cervical lymph node dissection and presence of cervical lymph node metastasis.
Mean survival was 74.7 months, and tumors larger than 4 cm, increasing age, male sex, aggressive papillary thyroid carcinoma variants, positive margins and low income levels were associated with an increased risk for death. Overall survival was not affected by RAI timing in adjusted Cox multivariable analysis (HR = 1.26; 95% CI, 0.98-1.62). No difference in overall survival was found with early or delayed RAI (HR = 1.29; 95% CI, 0.91-1.81).
“Early or delayed administration of the initial RAI therapy after thyroidectomy does not impact overall survival in [papillary thyroid carcinoma] patients with high-risk disease,” the researchers wrote. “The conventional 3 months’ limit for post-thyroidectomy RAI therapy is not associated with any survival difference. Additionally, other weekly or monthly time points for RAI therapy are also not significantly associated with any change in long-term survival. Clinicians could consider these findings in accommodating patients’ preferences, disease factors and optimal utilization of health care resources when recommending RAI therapy.” – by Amber Cox
Disclosure: The researchers report no relevant financial disclosures.