What are the causes of thyroid cancer?

The development of malignancy is a long-term, complex, multifactorial, multistep process. In the vast majority of cases, there is no single factor that causes a tumor. As with most other cancers, the exact cause of thyroid cancer remains a mystery.

At present, we can only be certain that ionizing radiation and genetic factors play a role in the pathogenesis of a small percentage of patients. There are also factors, such as high or low iodine intake, high estrogen levels, thyroid secretion disorders, high-fat diet, and mood, that may be risk factors for thyroid cancer, but the evidence is not yet strong.

Ionizing radiation

Ionizing radiation can come from medical treatments, such as diagnostic imaging, nuclear medicine, and radiation oncology, and from safety incidents, such as nuclear leaks.

The thyroid gland in children is particularly sensitive to ionizing radiation, and the younger they are, the more susceptible they are.

Genetic factors

Some people with thyroid cancer carry some abnormal genes, but most do not inherit them. Some thyroid cancers are inherited, for example familial nonmedullary thyroid carcinoma (FNMTC) and hereditary medullary thyroid carcinoma (FMTC) are two types of inherited thyroid cancers. If one parent has the disease, there is a 50% chance that the child will inherit the “bad gene” and develop the disease.

Female factors

Female estrogen and progesterone are involved in the onset and progression of thyroid disease. Some scholars believe that estrogen itself has the potential to cause cancer. There are estrogen receptors in thyroid cancer tissue, and binding to estrogen can induce thyroid cancer. Estrogen may be an important contributing factor to thyroid cancer in women. The higher the level of estrogen in the body, the higher the incidence of thyroid cancer. In women 20 ~45 years old, estrogen is at a high level, and women in their 40s are a high incidence group for thyroid cancer.

So, are the cosmetics women commonly use associated with thyroid cancer?

There are no clinical trials that have confirmed a definite link between thyroid cancer and cosmetic use. However, doctors recommend that cosmetics should be used in moderation, and cosmetics containing estrogen should be used even less often. In addition to estrogen, many cosmetics contain toxic substances such as phthalic acid, mercury, lead, salicylic acid, preservatives, and artificial fragrances, some of which may cause cancer.

Disorders of thyroid secretion

Thyrotropin (thyroid stimulating hormone, TSH), secreted by the pituitary gland, is responsible for regulating thyroid cell proliferation and hormone secretion. If thyroid hormone (T3, T4) levels decrease, TSH secretion increases.

Some studies have suggested that elevated levels of thyroid hormones and TSH may be associated with thyroid cancer development. However, this relationship is not clear at this time and further research is needed to confirm it.