By pathology, thyroid cancer can be divided into: papillary thyroid cancer, follicular thyroid cancer, medullary cancer and anaplastic cancer. Among them, papillary thyroid cancer and follicular thyroid cancer are collectively referred to as differentiated thyroid cancer. Their degree of differentiation and characteristics are relatively close to normal thyroid tissue, and they can absorb iodine like normal thyroid cells.
Differentiated thyroid cancer loves to “eat” iodine. Iodine-131 is a “companion” of ordinary iodine, but it can release beta rays, which are not very penetrating, but Destructive power. The iodine-131 that enters the body “mixes itself with ordinary iodine” and does what it wants to differentiated thyroid cancer. When differentiated thyroid cancer cells absorb it together with ordinary iodine, it will continue to emit beta rays. Irradiation of differentiated thyroid cancer cells makes the differentiated thyroid cancer cells unknowingly “apoptosis”.
At present, for differentiated thyroid cancer internationally, the standard treatment of “surgical thyroidectomy + selective iodine-131 therapy + thyroxine replacement” is generally adopted, among which iodine-131 therapy is to prevent thyroid cancer Important adjuvant therapy for postoperative recurrence and metastasis of cancer. However, in patients with low-risk differentiated thyroid cancer undergoing thyroidectomy, there is no direct evidence that postoperative use of iodine-131 is beneficial.
To this end, researchers from France conducted a prospective randomized phase 3 trial in which patients with low-risk differentiated thyroid cancer undergoing thyroidectomy were assigned to injection of recombinant human thyroxine After radioactive iodine (1.1GBq) ablation therapy (radioactive iodine group) or no postoperative radioactive iodine therapy (no radioactive iodine group). The primary objective was to assess whether no radioactive iodine therapy was non-inferior to radioactive iodine therapy over a 3-year period. The results were published in the journal NEJM.
Of the 730 patients evaluable 3 years after randomization, 95.6% (95% CI, 93.0-97.5) in the non-radioactive iodine group were event-free, radioactive iodine-free The iodine group was 95.9% (95% CI, 93.3-97.7), a difference of -0.3% (two-sided 90% CI, -2.7-2.2), a result that met the noninferiority criteria.
Related events included structural or functional abnormalities in 8 patients and biological abnormalities in 23 patients within 3 years. Events were more frequent in patients with postoperative serum thyroglobulin levels greater than 1 ng/mL during thyroid hormone therapy. Molecular changes were similar in patients with and without events.
In conclusion, in low-risk thyroid cancer patients undergoing thyroidectomy, a follow-up strategy without radioactive iodine was non-inferior to those with functional, structural, and biological events at 3 years Ablation strategies for radioactive iodine.
References:
Thyroidectomy without Radioiodine in Patients with Low-Risk Thyroid Cancer. N Engl J Med 2022; 386:923-932. DOI: 10.1056/NEJMoa2111953
Writing | Dr. Apathy
Edit | Swagpp
