THYROID CANCER TREATMENT IN GERMANY

Papillary carcinoma accounts for 70—80% of all thyroid cancers. The ratio of women to men is 3:1. Up to 5% of cases are hereditary. It is most often detected between the ages of 30 and 60. In elderly people the tumour is often more aggressive. Many papillary cancers contain follicular elements.

One third of patients are found to have regional lymph node involvement; metastases may be present in the lungs. In patients under 45 with a small tumour that does not extend beyond the thyroid capsule, the prognosis is very good.

Treatment:

• resection;
• radioactive iodine where indicated.

Surgery almost always leads to a complete cure. For an encapsulated tumour < 1.5 cm in size confined to one lobe of the thyroid gland, doctors usually perform a total thyroidectomy, although some specialists recommend removing only the affected lobe together with the isthmus. To reduce the risk of recurrence and to suppress the growth of any microscopic remnants of cancerous tissue, thyroid hormones are prescribed in doses that suppress the secretion of thyroid-stimulating hormone (TSH).

Tumours > 4 cm, as well as those spreading diffusely, require total thyroidectomy with postoperative ablation of the remaining thyroid tissue using high doses of radioactive iodine 131I; to enhance the effect of 131I it is given while the patient is hypothyroid or after injections of recombinant TSH. To destroy any residual thyroid tissue, 131I may be given repeatedly every 6-12 months. After treatment, l-thyroxine is prescribed in TSH-suppressive doses; measuring serum thyroglobulin helps to detect recurrent or persistent disease. Recurrence or continued tumour growth occurs in about 20—30% of patients, mainly the elderly.

Follicular carcinoma, including its Hürthle cell variant, accounts for about 15% of all thyroid cancers. It is more common in elderly people and in regions with iodine deficiency. Follicular carcinoma is more malignant than papillary carcinoma, spreads through the bloodstream and produces distant metastases.

As in papillary carcinoma, treatment consists of thyroidectomy followed by ablation of the residual thyroid tissue with radioactive iodine. Metastases show a considerably better response to radioactive iodine therapy than in papillary carcinoma. After treatment, TSH-suppressive doses of l-thyroxine are prescribed. Monitoring of serum thyroglobulin is essential in order to detect recurrence or continued tumour growth.

Medullary (solid) carcinoma accounts for about 3% of thyroid cancers and consists of parafollicular cells (C cells), which produce calcitonin. It may be sporadic (usually unilateral); however, it is often hereditary and caused by a mutation of the ret proto-oncogene. In hereditary disease, medullary carcinoma may occur either in isolation or as a component of multiple endocrine neoplasia (MEN) type 2A and 2B syndromes. Metastases spread along the lymphatic pathways to the lymph nodes of the neck and mediastinum and sometimes to the liver, lungs and bones.

Symptoms and signs of medullary carcinoma

Typically an asymptomatic thyroid nodule is found, although medullary carcinoma is now also diagnosed during routine screening of affected families with MEN type 2A or 2B, before any palpable tumour appears in the thyroid gland.

Patients with medullary carcinoma may have symptoms caused by the ectopic production of other hormones or peptides (ACTH, vasoactive intestinal polypeptide, prostaglandins, kallikreins, serotonin).

Diagnosis of medullary carcinoma

• measurement of serum calcitonin.

The best diagnostic marker is a marked rise in serum calcitonin. To detect excessive calcitonin secretion, a calcium challenge test is performed (15 mg/kg IV over 4 h), which provokes the release of this hormone. X-ray imaging can reveal dense homogeneous conglomerates of calcification in the region of the thyroid gland.

All patients with medullary carcinoma should undergo genetic testing. If mutations are found, the patient's relatives must also be tested, and their basal and stimulated calcitonin levels measured as well.

Treatment of medullary carcinoma

• resection

Total thyroidectomy is indicated even when bilateral involvement is not obvious. The cervical lymph nodes are also removed. If hyperparathyroidism is present, the hyperplastic or adenomatous parathyroid glands must be removed. If a phaeochromocytoma is present, it is usually bilateral. It should be identified and removed before thyroidectomy, otherwise the patient may develop a hypertensive crisis during the operation. Life expectancy in patients with medullary carcinoma and MEN 2A is relatively long; more than 60% of such patients live longer than 10 years. In sporadic medullary carcinoma the prognosis is worse.

Relatives of patients with medullary carcinoma who have raised calcitonin levels but no palpable thyroid abnormality should undergo thyroidectomy, because at this stage the chances of a cure are higher. Some specialists recommend surgery in relatives who have normal basal and stimulated serum calcitonin levels but nevertheless carry a mutation of the ret proto-oncogene.

Anaplastic carcinoma is an undifferentiated malignant tumour that accounts for less than 2% of thyroid cancers. Anaplastic carcinoma occurs mainly in elderly people and is somewhat more common in women. The tumour is painful and grows rapidly. Rapid enlargement of the thyroid gland may also indicate thyroid lymphoma, particularly if it occurs against a background of Hashimoto's thyroiditis.

There is no effective therapy and the disease is usually fatal. About 80% of patients die within the first year after diagnosis. In selected cases with small tumours, thyroidectomy followed by external beam radiotherapy may help. To date, chemotherapy remains largely experimental.

Thyroid tumours of this type may develop after massive external irradiation of the gland, as was seen after the explosion of atomic bombs, nuclear reactor accidents or incidental irradiation of the gland during radiotherapy. Such tumours are sometimes found 10 years or more after the radiation exposure, but the increased risk persists for 30—40 years. The tumours are usually benign; however, papillary carcinoma is found in about 10% of cases. The tumours are often polycentric or diffuse.

Patients who have been exposed to radiation should be examined annually by palpation of the thyroid gland, ultrasound and measurement of thyroid autoantibodies (to rule out Hashimoto's thyroiditis). Scanning of the gland does not always reveal the lesions.

If a nodule is found on ultrasound, fine-needle aspiration biopsy is required. In the absence of suspicious or malignant lesions, many physicians recommend lifelong administration of TSH-lowering doses of thyroid hormone in order to suppress thyroid function and thyrotropin secretion, which may potentially reduce the likelihood of thyroid cancer developing.

Where the results of fine-needle aspiration biopsy raise a suspicion of cancer, surgery is required. Total thyroidectomy is the method of choice, and if cancer is confirmed, radioactive iodine is prescribed after the operation (depending on the size, histology and invasiveness of the tumour) to destroy the residual thyroid tissue.

• innovative diagnostic techniques;
• histopathological analysis of the removed tissue at certified institutes of pathology;
• selection of the optimal individual therapy by a multidisciplinary tumour board (surgeons, oncologists, radiologists, chemotherapists, pathologists, nuclear medicine specialists);
• treatment starts immediately once the diagnostic work-up is complete;
• adherence to international treatment protocols;
• the highest quality standards in medical care;
• early postoperative rehabilitation of patients;
• the option of endoscopic thyroidectomy;
• the option of robotic thyroidectomy;
• supportive therapy to minimise the side effects of chemotherapy and
• radiotherapy in certain types of thyroid cancer;
• an individually tailored radiotherapy plan for certain types of thyroid cancer;
• treatment with authentic latest-generation cytostatic drugs for certain types of thyroid cancer.