Every year, around 2, 000 to 3, 000 people in Germany contract thyroid cancer - making it one of the rarer malignant tumors. On average, women are affected 3 times more frequently than men. There are different forms with different prognosis. Since Germany is an iodine deficient area, there are comparatively many people who have an enlarged or nodularly altered thyroid gland - scientists assume 10 percent. In rare cases, a tumor can hide behind it, which initially receives no attention. Symptoms usually appear only at an advanced stage.
Which types of cancer are there and who is affected?
- Papillary thyroid cancer: 35 to 60% of malignant thyroid tumors; 3 times as many women as men affected; Patients mostly over 40 years. Forecast good to very good.
- Follicular thyroid carcinoma: 25 to 40% of malignant thyroid tumors, women affected 3 times more frequently; Patients usually between 40 and 50 years old.
- Medullary thyroid carcinoma: Based on the C cells that make up the hormone calcitonin. It accounts for 5 to 10% of tumors, and women and men are about equally affected. The age of onset is around 40 to 50 years. The prognosis is good to fair.
- Undifferentiated (anaplastic) thyroid carcinoma: The cell type is not determinable. It accounts for about 10 to 20% of thyroid carcinomas. There are twice as many women affected; the age of onset is around 50 years. The prognosis is poor, as metastases are set very early and the tumor is poorly responsive to therapy.
- Other: These are all other forms that can be found in the thyroid, for example, cancer of surface cells or metastases of other tumors. The prognosis depends on the underlying disease.
How does thyroid cancer develop?
The exact causes are as with most cancers until today unknown. However, there are some factors known to trigger thyroid cancer.
An important issue is years of iodine deficiency - it is believed that it increases the risk of developing thyroid cancer by a factor of two. In particular, follicular carcinoma is more common in people with thyroid enlargement due to iodine deficiency.
On the other hand hereditary factors play a role especially in medullary thyroid carcinoma. Not infrequently, this tumor is associated with hormonal disorders and tumors of other organs. It has long been known that the thyroid gland reacts very sensitively to ionizing radiation. For example, a significant increase in the number of thyroid cancers was reported in survivors after dropping bombs in Hiroshima or in victims of the Chernobyl nuclear disaster.
How is the disease expressed?
Often there are no symptoms for a long time. First indication is usually the rapid growth of the thyroid gland, possibly nodes are palpable. There may be difficulty swallowing. The adjacent lymph nodes can also be enlarged and thus lead to pressure, swallowing or neck pain.
Later, the voice nerve can be pulled off, causing hoarseness. If there is a tumor that produces hormones, they can cause symptoms, as in hyperthyroidism.
How is the diagnosis made?
After collecting the medical history, the doctor will first scan the thyroid and surrounding lymph nodes. An important investigation is ultrasound. This allows you to determine the size of the thyroid gland, nodules, cysts and other tissue changes.
With a scintigraphy, the function of the thyroid gland can be visualized by means of radiolabelled contrast agent. Malignant nodules are usually "cold", meaning they produce no hormones unlike normal tissue. With a targeted puncture, cell material from suspicious areas can be removed with a fine needle and evaluated under the microscope.
If the suspicion of a tumor is confirmed, computer tomography and bone scintigraphy are used to detect dislocations of secondary tumors. In addition, blood is taken and examined for hormones and other substances. For certain tumors, a family screening is performed to determine the hereditary predisposition.
Which therapy is there?
The most important treatment is the most complete removal of the thyroid and adjacent lymph nodes. About 4 weeks after surgery radioiodine therapy follows to destroy metastases or remaining tissue remnants. For this purpose, radioactive iodine is swallowed in a capsule that accumulates in the appropriate tissue, this irradiated locally and thus destroyed.
This treatment may need to be repeated. It may also be a radiation therapy performed from the outside. Subsequently, the affected person must take thyroid hormones for life as tablets and undergo biannual, then annual check-ups for 10 years.