Thyroid cancer is often called good cancer. This is because thyroid cancer progresses relatively slowly and metastases are rare. Compared to other cancers, thyroid cancer is known to be more likely to be cured. There is even a saying that people with thyroid cancer live longer than the average person. Surprisingly, this is a claim that has its own statistical basis. In fact, as announced by the Korea National Cancer Information Center, when the 5-year survival rate of the general population is 100%, the 5-year survival rate of thyroid cancer patients was 100.4%. So, is thyroid cancer really a good cancer?
What is Thyroid Cancer?
The thyroid gland is one of the endocrine organs. The thyroid gland produces, stores, and releases thyroid hormones into the blood whenever necessary. Thyroid hormone is essential for humans, and it plays a role in maintaining proper function of all organs by promoting metabolic processes in the human body. For example, it generates heat to keep body temperature constant, or to help develop the brain and bone growth of the fetus and newborn.
The thyroid gland is located in the front of the neck. Now let’s touch the protruding part in the middle of the front of your neck. This is called thyroid cartilage. The thyroid gland is 2 to 3 cm below the thyroid cartilage. The approximate length of the thyroid gland is 4~5cm, the width is 1~2cm, the thickness is 2~3cm, and the weight is about 15~20g. Of course, there are differences according to age and gender. The overall shape of the thyroid gland is butterfly-shaped, consisting of the left and right lobes and the isthmus connecting the two.
A lump on the thyroid gland is called a thyroid nodule or tumor. Thyroid tumors are again divided into benign tumors and malignant tumors, and malignant tumors are thyroid cancer. Benign tumors literally have a good course, so they grow slowly and are only cosmetically unfavorable, and do not affect our body because they do not spread elsewhere. On the other hand, if thyroid cancer is left untreated, cancer cells can spread to other places, leading to death. These thyroid cancers account for around 5% of all thyroid tumors.
What are Symptoms of Thyroid Cancer?
In fact, most of thyroid cancer has no obvious symptoms. The most common symptom is a painless neck mass. Therefore, if there is something like a mass on the front of the neck, it is necessary to test for thyroid cancer. If there are symptoms such as a throat or difficulty breathing due to the recent rapid increase in size, the possibility of thyroid cancer should be evaluated.
However, in fact, it is much more often diagnosed as thyroid cancer by accidentally finding a thyroid nodule during a medical examination and examining it, rather than a patient who finds a mass in the neck and visits it recently. Most of these cases have no symptoms until they are diagnosed.
How to Diagnose Thyroid Cancer?
First of all, the doctor will use an ultrasound scan to check for nodules in the thyroid gland. If a nodule is found, it is determined whether it is cancer based on whether it is calcareous, the horizontal/vertical ratio, the boundary of the nodule, and the size. In particular, if the nodule is calcified, it is likely cancer. Calcification is a trace of inflammation or wounds at the site, and cancer usually develops at the site of inflammation. In addition, the thyroid gland with thyroid cancer is observed to be a little longer in length on average compared to the normal thyroid gland.
Then, fine needle aspiration, FNA, and biopsy are performed. If the nodule is positive on the biopsy, first follow-up the nodule. If you do so and the nodules do not go away, perform an ultrasound examination and fine acupuncture again. If the biopsy is diagnosed as malignant, surgery is performed to remove it.
If the biopsy does not determine the presence of thyroid cancer, a thyroid scan is necessary. Radioactive iodine is administered to confirm the distribution of radioactive iodine in the thyroid gland. Nodules in which radioactive iodine is not absorbed are called cold/hypofunction. On the other hand, a nodule in which radioactive iodine is absorbed beyond normal is called a hot/hyperfunction nodule. If a non-functional nodule is found, it is diagnosed as thyroid cancer and surgery is performed. If a hyperfunctional nodule is found, it is followed up through periodic thyroid hormone tests.
How to Treat Thyroid Cancer?
Treatment methods for thyroid cancer include surgery, radioactive iodine treatment, thyroid hormone treatment, external radiation irradiation, and anticancer treatment. Unlike other cancers, most thyroid cancers are curable and have a good prognosis. Even if metastases have occurred, good results can be expected with active treatment.
The most important treatment method for thyroid cancer is surgery. Some or all of the thyroid gland is removed depending on the type and size of thyroid cancer, and the age and stage of the patient. If the entire thyroid gland is excised, thyroid hormone is not secreted, so thyroid hormone must be supplemented for life. Some small thyroid cancers can be treated only by surgery, but radioactive iodine therapy may be additionally performed when the possibility of recurrence is high.
Is Thyroid Cancer Really Good Cancer?
The reason thyroid cancer is called a good cancer is that the disease progresses slowly and is rarely life-threatening. In addition, those diagnosed with thyroid cancer became more thorough in their own health care, which led to a slight increase in the 5-year survival rate than the general population. Of course, thyroid cancer itself did not increase life expectancy.
Also, regarding this 5-year survival rate, there are opinions that the criterion of 5 years for thyroid cancer, which can take 10 to 30 years to recurrence, is not very meaningful. This means that just being able to endure five years safely does not mean that it is completely resolved.
On the other hand, the public perception that thyroid cancer treatment results are good has also played a part in spreading the belief that thyroid cancer is a good cancer. However, the excellent treatment results for thyroid cancer are also affected by the early detection and treatment of small thyroid cancer due to the development of ultrasound diagnostic equipment.
In short, mention that thyroid cancer is a good cancer is true only when constant management and regular examination are premised. This is why thyroid cancer, like any other cancer, requires attention.