Radioactive iodine ablation was not linked to improved
10-year survival outcomes in a cohort of patients with low-risk differentiated
thyroid cancer, according to recent results.
The study was conducted because the American Thyroid
Association and European Thyroid Association guidelines cannot recommend for or
against radioactive iodine ablation after surgery in patients with low-risk
differentiated thyroid cancer. The aim was to determine the survival benefit of
radioactive iodine ablation in 1,298 patients with this cancer.
Eligible patients had been treated between 1975 and
2005. Outcomes included overall survival and disease-free survival according to
radioactive iodine ablation.
The median follow-up duration was 10.3 years.
There were 911 patients who received radioactive iodine
ablation after surgery vs. 387 patients who did not receive this treatment
after surgery.
Univariate analysis results indicated that the 10-year
overall survival was 94.6% in the ablation group and 95.8% in the non-ablation
group (P=.006). Ten-year disease-free survival was 88.7% in the ablation
group and 93.1% in the non-ablation group (P=.001).
Significant associations were observed between
radioactive iodine ablation and all clinical factors, except sex.
Multivariate analysis results indicated no significant
or independent link between overall survival and radioactive iodine ablation
(P=.243). Similarly, no link was observed between ablation and
disease-free survival (P=.2659).
Further stratification was conducted based on propensity
score. Results of this Cox univariate analysis indicated that overall survival
did not differ with ablation status (P=.3524), with an HR for
radioactive iodine ablation of 0.75 (95% CI, 0.4-1.38). Results of the same
analysis indicated that disease-free survival did not differ (P=.48),
with a stratified univariate HR of 1.11 (95% CI, 0.73-1.7).
The researchers concluded that the study failed to prove
any survival benefit of radioactive iodine ablation after surgery in patients
with low-risk differentiated thyroid cancer.