The most standardized treatment strategy for differentiated thyroid cancer (papillary/follicular/Xuitel cell carcinoma) includes surgery, iodine 131 to remove residual thyroid tissue or metastases, TSH suppression therapy, external irradiation, targeted therapy (sorafenib), etc. Currently, the first three are the most standardized treatment strategies, but it is necessary to decide whether to use all three modalities or selectively use some modalities depending on the disease. The standardized treatment of differentiated thyroid cancer has been described in detail in my previous articles, please refer to the article (Standardized treatment of thyroid cancer). Now I am going to elaborate on the extent and duration of postoperative TSH suppression treatment in the domestic and international treatment guidelines (or treatment protocols). The strategy of postoperative endocrine treatment for differentiated thyroid cancer is different in different guidelines or societies, and there is no consensus on the extent and duration of TSH suppression. In conclusion European guidelines (ETA) have a stronger degree and duration of suppression than American guidelines (ATA). Nowadays, it is controversial whether TSH suppression can improve prognosis and whether long-term suppression can lead to increased cardiovascular and skeletal adverse events and thus poor prognosis.
1. Classification of risk of recurrence or death after surgery for differentiated thyroid cancer (ATA)
The risk of postoperative recurrence is classified into three levels according to age, tumor size, presence of distant metastases, degree of local tumor invasion and completeness of surgical resection.
(1) Low risk group
①No local and distant metastasis.
② All tumors under the naked eye were removed.
(3) No tumor invasion of local structures.
④No invasive histological features of the tumor.
⑤ No 131I uptake foci outside the thyroid bed.
(2) Intermediate risk group
(1) Microscopic tumor invasion to soft tissues outside the envelope.
(2) Lymph node metastasis in the neck.
(3) 131I uptake foci outside the thyroid bed.
(3) High-risk group
①Tumor invasion to the outer envelope by the naked eye.
(ii) residual tumor.
③Distant metastasis.
2.The degree of TSH suppression
In the high-risk group (those with tumor residue or recurrence), TSH (thyrotropin) will be suppressed to less than 0.1 mU/L or undetectable after surgery with high dose of eugenol and will last for life; in the medium and high-risk group (without tumor residue), TSH will be suppressed to less than 0.1 mU/L and will last for 5-10 years. In low-risk patients, TSH is suppressed to 0.1-0.5 mU/L, or to the lower limit of the normal range (0.3-2.0 mU/L), but the European guidelines (ETA) still require a TSH of less than 0.1 mU/L for 3-5 years in the low-risk group, but in elderly patients, those with a previous history of heart disease, obesity, diabetes, and hypertension, long-term high-dose eugenol therapy can develop osteoporosis, angina, atrial fibrillation, ischemic heart disease, and cardiac insufficiency (heart failure), patients and physicians should weigh the balance between the efficacy and side effects of long-term TSH suppression therapy, and a large body of evidence-based medical evidence suggests that for the high-risk group TSH suppression therapy significantly improves disease-free survival and overall survival time, but recently the US ATA in its official journal thyroid ( However, a recent publication in the ATA’s official journal thyroid ( 2014) suggests that TSH suppressive therapy for differentiated thyroid cancer in the low- and intermediate-risk group does not reduce the risk of recurrence, but rather increases the risk of osteoporosis.
Previously, it was also published in the US that the side effects of TSH suppression therapy may be more threatening than papillary thyroid cancer. Therefore, the author believes that a comprehensive decision on the degree and duration of TSH suppression should be made based on the patient’s age, gender, previous history of heart disease, risk factors for heart disease (diabetes, hypertension, obesity, hyperlipidemia, long-term smoking, etc.), local invasion of the tumor, completeness of resection, presence of lymph nodes or distant metastases, postoperative TG value, tumor size, whether it is a highly invasive tumor type, and whether there is tumor recurrence or residual tumor. For tumor diameter less than 4 cm, complete resection, no extraperitoneal invasion, no lymph node or distant metastasis, non-highly aggressive histological type, no nuclein concentration outside the thyroid bed after iodine 131 treatment, TSH suppression should be between 0.1-0.5 mU/L, and patients should have no panic and angina. and other symptoms are appropriate.