In recent years, the incidence of thyroid cancer has been on the rise, and the results of some domestic provinces and cities show that thyroid cancer has ranked the first to eighth among malignant tumors in women, and the first among women in neighboring Korea. Therefore, thyroid cancer has gradually entered the ranks of common malignant tumors, and has been attracting more and more attention from the industry and even from the general public.
Due to the limitation of knowledge and professionalism, there are still some misconceptions about thyroid cancer and some hot topics to be solved, which we will analyze and interpret from the professional perspective.
Is the occurrence of thyroid cancer related to high iodine level and should all patients take non-iodized salt after surgery?
As with many other tumors, the pathogenesis of thyroid cancer is not yet certain. The inference of a link between increased incidence of thyroid cancer and salt iodization is not well founded and lacks sufficient evidence. Radiation, iodine overdose, genetic inheritance, adverse emotions, and hormone levels may all contribute to the development of thyroid cancer. However, there is no direct evidence that iodine overdose can cause thyroid cancer. Therefore, we advocate a balanced diet without excessive iodine supplementation or iodine deficiency. Iodine deficiency can cause many diseases, including thyroid cancer, and two types of thyroid cancer (follicular cancer and undifferentiated cancer) are also related to low iodine. Some patients believe that thyroid cancer is caused by high iodine levels, so when they have thyroid disease, especially after surgery for thyroid cancer, they pay close attention to the intake of iodine in their diet and prefer to use non-iodized salt. Since most thyroid cancer patients are in iodine-rich areas, a low iodine diet is recommended for thyroid cancer patients after surgery, but for patients in low iodine areas, there is no need to routinely consume non-iodized salt.
Do all thyroid nodules become malignant and need to be removed surgically?
There are some diseases that may be precancerous and require attention to avoid developing into malignant tumors; however, there are no definite precancerous lesions in the thyroid gland, only some diseases that may have some correlation. For example, the majority of thyroid nodules, which are of special concern, are not cancerous, and most of them do not require surgical treatment; only a very small number of tumors were benign in the past, but after long-term development they undergo dedifferentiation and eventually become malignant or even highly malignant tumors, but the majority of thyroid nodules will not develop into thyroid cancer. Even though the incidence of thyroid cancer is increasing, most thyroid cancers are in early stage with good prognosis, and even for some tiny intraglandular papillary thyroid cancers, close observation is theoretically possible and surgical treatment is not always required. Therefore, thyroid cancer should be treated rationally and without excessive panic.
Is it true that the more expensive the test for thyroid cancer, the better the diagnosis rate?
Ultrasound diagnosis is the most realistic and feasible method to diagnose thyroid cancer in China under the current situation. Along with the accumulation of clinical experience and academic promotion, the overall level of improvement has become a recent feature, and more and more hospitals in China are adopting TI-RADS grading or modified TI-RADS grading for thyroid cancer one after another, showing a good momentum. The good advantage of ultrasound technology in qualitative, quantitative and localized diagnosis, appropriately combined with puncture pathology examination, further improves the diagnosis rate and provides the most powerful guarantee for the determination of surgical plan, especially the implementation of individualized treatment plan. Other more expensive tests such as CT, MRI or even PET/CT only play a supplementary role in the diagnosis of certain types or more advanced thyroid cancer.
What is the significance of genetic diagnosis for thyroid cancer patients?
The era of molecular diagnosis and treatment of thyroid cancer is approaching, and several oncogenes have been reported to have an important relationship with the development of thyroid cancer. Genetic testing for some types of thyroid cancer has gradually become a routine molecular diagnosis method; with the continuous development of medical biology technology, genetic diagnosis and its mediated targeted biologic therapy have also brought benefits to patients with advanced thyroid cancer. The importance of genetic diagnosis as an important adjuvant diagnostic method is gradually emerging in clinical practice. In addition, genetic testing has important reference value for risk stratification, recurrence and metastasis, prognosis and even follow-up of thyroid cancer.
Should thyroid cancer be completely excised or part of the gland be preserved?
In our clinical work, we often encounter this question. Some patients think that they have thyroid cancer and must be completely removed and the whole thyroid gland must be cut out for insurance, while some patients think that the thyroid gland is a very important organ and ask the doctor to try to preserve some normal glands. In fact, both views are valid, but the specific situation should be based on the number, size and location of the tumor and the patient’s medical history, and a rationalized surgical plan should be adopted, neither a blind total excision nor an excessive number of glands should be preserved. Our surgical procedures only recommend a rational choice between lobectomy + isthmus and subtotal/tototal thyroidectomy, and each case varies from patient to patient. Therefore, surgical treatment of thyroid cancer should be individualized and rationalized according to the patient’s own condition, avoiding both under-treatment and over-treatment for the patient.
Should all thyroid cancers be treated with cervical lymph node dissection and what should be the extent of dissection?
According to current theories, cervical lymph node dissection in differentiated thyroid cancer is not the most critical factor in determining the prognosis, but the standardization of its surgical treatment should not be ignored. Some people believe that the greater the extent of clearance, the more thorough the treatment, while others believe that lymph nodes do not affect the prognosis and do not need to be routinely cleared at all. Then, we also advocate individualized and selective cervical lymph node dissection based on preoperative examination combined with patient history for whether lymph nodes are cleared or not and the extent of clearance. For patients requiring cervical lymph node dissection, we recommend individualized protocols based on ultrasound-mediated clinical N-staging and risk assessment, and should follow the concept of individualized treatment in the central region (VI), expanded central region (IIA, III, IV, VI), and total cervical lymph node dissection (II-VI).
Is thyroid surgery very risky and prone to serious complications?
The thyroid gland is located in the neck of human body, adjacent to important organs such as trachea esophagus, and it is also surrounded by important tissues such as the recurrent laryngeal nerve and parathyroid glands, so the surgical risk is relatively high, and once it is not handled properly, symptoms such as hoarseness and hypocalcemia may easily occur; cervical lymph node dissection may also affect some important neurovascular to some extent, but with the continuous improvement of surgical skills, functional surgery has shown good application in thyroid cancer However, with the continuous improvement of surgical skills, functional surgery has shown good prospects for application in the radical treatment of thyroid cancer, which preserves the function of human tissues to the maximum extent. At the same time, the development of surgical instruments and infrastructural advances such as ultrasonic knife, neuroprobe, nano-carbon technology, and endoscopy-assisted thyroid surgery, even robotic surgery, have continued to promote the development of thyroid surgery and reduce the occurrence of complications.
Thyroid cancer is a malignant tumor, should we all have radiotherapy after surgery?
There are four pathological types of thyroid cancer, among which differentiated thyroid cancer (papillary and follicular carcinoma) is the main type with good prognosis, and the main means of treatment is the classic “trilogy” of surgical treatment with endocrine and nuclear therapy. However, for poorly differentiated medullary carcinoma or undifferentiated carcinoma, some radiotherapy can be used if it cannot be controlled by surgery.
Do all thyroid cancers need comprehensive treatment and how valuable is it?
Although radiotherapy is rarely used in differentiated thyroid cancer, multidisciplinary treatment is necessary; endocrine therapy is the conventional adjuvant treatment for differentiated thyroid cancer after surgery, and long-term TSH suppression is beneficial to patients’ prognosis; meanwhile, for some patients with nuclear medicine indications, postoperative For patients with nuclear medicine indications, postoperative radioactive iodine therapy is also valuable to improve the prognosis of patients. For some advanced or poorly differentiated thyroid cancers, the increasing knowledge of tumors and the emergence of new drugs, including targeted drugs, have provided the possibility of multidisciplinary combination therapy for more tumors, and more and more clinical drug trials have brought hope for the treatment of thyroid cancer. Adjuvant medical therapy further reduces the possibility of recurrence and metastasis, and offers the opportunity to prolong life for some patients who are beyond the reach of surgical treatment in intermediate to advanced stages.