Thyroid cancer: Anaplastic Thyroid Cancer (ATC)
Anaplastic thyroid cancer (ATC) is a rare, but very aggressive cancer, representing only 1-2% of all thyroid cancers. People with anaplastic cancer are usually older with an average age at diagnosis of 65 to 75 years. It is rare to see ATC before the age of 40. Women are twice as likely as men to have anaplastic cancer.
2. Symptoms and signs
Patients will often have a rapidly growing neck mass that is usually associated with voice changes and hoarseness. Breathing difficulties, with a sense of choking or pressure on the neck is common, as well as swallowing difficulties. These changes can occur quickly over a period of weeks.
3. Risk factors
Patients with anaplastic thyroid cancer usually present after age 65 years. Many patients will have a history of thyroid cancer in the past or a longstanding goiterGoiter - enlarged thyroid. A history of head and neck radiation or exposure to radioactive materials in one's past may increase the risk for ATC.
A classic history of very rapidly growing thyroid mass is often enough to warrant treatment. FNAFNA - fine needle aspiration biopsy biopsy usually makes the diagnosis, but sometimes a core biopsy (i.e. larger sample) or open biopsy may be required. Lymphoma and metastatic cancer to the thyroid can look like ATC.
Surgery to remove all of the disease possible is the best treatment for ATC. Unfortunately, most patients have very advanced and large disease by the time they present. For this reason, few patients have surgical cures. Even if the surgery is not curative, patients will likely do better overall if as much neck disease is removed as possible. For patients who are not candidates for an attempt at curative resection, trying to relieve their symptoms (i.e. palliation) is an important consideration. Palliative surgery may include a tracheostomy tube (a tube placed through the skin in the neck into the trachea) for breathing, or a gastrostomy/feeding tube (i.e. stomach tube) if eating/swallowing becomes too difficult. As in all other thyroid surgeries, having a very experienced surgeon is extremely important for patients with ATC.
RAI ablationRAI ablation - the use of radioactive iodine to destroy thyroid cells (either benign or cancer) does not work for ATC. Unlike most thyroid cancer, chemotherapy and external beam radiation therapy are standard treatments. Clinical trials are available, and all patients diagnosed with ATC should see if they qualify. (See Advanced and metastatic thyroid disease)
Unfortunately, ATC is one of the most aggressive cancers in humans. Most patients will present with metastatic disease. Living longer than two years is uncommon if the cancer has spread at the time of diagnosis. Some patients who are not resectable will not live longer than a few weeks, while other patients who can undergo surgery and additional treatments, can survive for a number of years. Patients who respond to chemotherapy may be eligible for subsequent resection.