What causes thyroid cancer?

What causes thyroid cancer? Thyroid diseases are common in life. For example, the occurrence of hyperthyroidism and hypothyroidism will have a lot of impact on the patient's life. Thyroid cancer is the most serious thyroid disease. So what causes thyroid cancer?

Etiology and pathology

The exact cause of the disease is still difficult to determine, but based on epidemiological surveys, experimental tumor studies and clinical observations, the occurrence of thyroid cancer may be related to the following factors.

(I) Genetic factors: About 5% to 10% of medullary thyroid cancers have a clear family history and are often associated with pheochromocytoma and other diseases. It is speculated that the occurrence of this type of cancer may be related to chromosomal genetic factors.

(II) Iodine and TSH Excessive or insufficient iodine intake can change the structure and function of the thyroid gland. For example, the incidence of thyroid cancer in the endemic goiter-endemic area of ​​Switzerland is 2ermil, 20 times higher than that in non-endemic areas such as Berlin. On the contrary, a high-iodine diet can also easily induce thyroid cancer. Iceland and Japan are countries with the highest iodine intake, and their thyroid cancer detection rates are higher than those in other countries. This may be related to the factors that stimulate TSH to proliferate the thyroid gland. Experiments have shown that long-term TSH stimulation can promote thyroid hyperplasia, form nodules and cancer.

(III) Other thyroid lesions Clinically, there are reports of thyroid adenocarcinoma, chronic thyroiditis, nodular goiter or certain toxic goiters becoming cancerous, but the relationship between these thyroid lesions and thyroid cancer is still difficult to confirm. Taking thyroid adenoma as an example, the vast majority of thyroid adenomas are follicular, and only 2% are papillary; if thyroid cancer is transformed from adenoma, the vast majority should be follicular, but in fact more than half of thyroid cancers are papillary, so it is speculated that the incidence of thyroid adenoma cancer is also very small.

(IV) Radiation damage: X-rays to the thyroid gland of experimental mice can induce thyroid cancer in animals. Experiments have shown that 131I can change the metabolism of thyroid cells, deform the nucleus, and greatly reduce the synthesis of thyroid hormones. It can be seen that radiation can cause abnormal division of thyroid cells, leading to cancer; on the other hand, it can damage the thyroid gland and prevent it from producing endocrine hormones. The resulting large amount of thyroid stimulating hormone (TSH) secretion can also promote thyroid cell cancer.