This is a relatively rare condition, to which only about 0.5 per cent of cancer deaths are being attributed. It is significant that children are very prone to it if there has been previous history of X-ray therapy to the head or neck regions. Even small doses of X-ray therapy seem capable of initiating thyroid cancer.
More is being learned about the relationship between X-ray therapy and this form of cancer and it seems that even after periods of twenty or thirty years (a very long latent period) cancer can still take place as a result of irradiation. In recent years Pacific Ocean nuclear tests have aroused public outcries because of the possibility of fallout producing cancer in people living in the general vicinity, and Australia and New Zealand have been no exception for these fears.
There are various types of cancer, and these vary according to the patient’s age. In young people, a slow-growing type is more common. In older persons, a very rapidly growing and highly lethal one called Anaplastic Carcinoma is more likely, and this can quickly prove fatal.
Thyroid Cancer Symptoms
The majority of patients will present with either a diffuse swelling of the thyroid or a single firm feeling nodule. Often this has developed suddenly, and the patient may complain of general discomforts, such as a choking sensation in the neck or a tight feeling.
Sometimes symptoms due to pressure may take place, such as noisy breathing, breathlessness or difficulty in swallowing. Less commonly the recurrent laryngeal nerve that supplies the voice box may be affected, producing a hoarse voice.
The most common type is called a Papillary Carcinoma (cancer) that may affect all age groups, but especially younger patients. It comes on as a hard, single nodule in a previously normal gland, and it may spread to lymph glands in the neck close by, and sometimes to the bones and lungs. It grows very slowly, and about fifty per cent of patients survive for ten years or more.
Middle aged patients tend to suffer from a so called follicular carcinoma, this being pathologically different from the one already mentioned. The patient may first complain of a single nodule occurring in the thyroid, or initially there may be nerve involvement producing a hoarse voice. Sometimes the patient will come with a fracture resulting from a spread of the cancer to a bone that has subsequently fractured of its own accord.
Older patients and the aged more often suffer from a serious, rapidly growing type called Anaplastic Carcinoma. Very quickly these advance to involve the overlying skin and surrounding structures. Pain, swelling and redness are typical symptoms. The majority of cases are quite inoperable by the time they request treatment and most are fatal within a few months.
Fortunately, most of these cancers are relatively rare, but any single thyroid nodule must receive immediate investigation by the doctor, or at an endocrine clinic at a major hospital where they are geared to diagnose promptly and treat such cases. The sooner this is carried out the better. Malignant changes seldom arise in a gland that contains multiple nodules, and less than 5 percent of solitary nodules prove to be cancerous on microscopic examination after they have been removed.
Thyroid Cancer Treatment
Total thyroidectomy is essential, with removal of the lymph glands in the vicinity as early as possible. In some cases only part of the gland may be removed. It depends on the situation at the time and the opinion of the operating surgeon.
Afterwards, replacement therapy with thyroxin is essential, and this may have to be continued for life. if metastases (spread of cancer cells to other regions of the body) have occurred, deep X-ray therapy may be given, or else radioactive iodine may be used if tests indicate it may he useful. With the anaplastic type of cancer, almost invariably the illness has advanced too far for surgery to be of any benefit, and the patient is probably best treated with radiotherapy.
The outlook for patients who are younger, and with the slower growing cancers, is good and progression of the disease (even without treatment) is slow. Nevertheless, the sooner treatment can be initiated the better. Aged persons with the more severe forms do not do nearly so favorably and often die within months.