Anaplastic Thyroid Cancer Overview
Fortunately, anaplastic thyroid cancer is, by far, the least common of all thyroid cancers. It can also be called “anaplastic thyroid carcinoma” since carcinoma implies a certain type of cancer. Since thyroid cancer is relatively common, it is very likely that you will know somebody that had or has a form of thyroid cancer. However, anaplastic thyroid cancer is a very uncommon type of thyroid cancer. Most patients and even thyroid specialists have had very little to no experience with this type of rare thyroid cancer. Try not to think about anaplastic thyroid cancer as you would other thyroid cancers, since this assumption will likely lead you to decisions that are not necessarily justified or right for you.
Anaplastic thyroid cancer starts within the thyroid as a growth, or bump (nodule) in the thyroid that quickly grows out of the otherwise normal thyroid tissue. Anaplastic thyroid cancer can grow alarmingly fast and spread very rapidly. Thryoid cancer patients rarely present with symptoms but anaplastic thyroid cancer is an exception to that observation in that most patients actually present with symptoms. Anaplastic thyroid cancer patients often present with a rapidly progressing neck mass. Patients can also often present with hoarseness (vocal cord paralysis), difficulty swallowing or a mass in the neck which does not move. Unlike other more common types of thyroid cancer, prompt evaluation and treatment is critical to successful management of this most aggressive thyroid cancer.
Anaplastic thyroid cancers almost always spread to neck lymph nodes. When anaplastic thyroid cancer has spread to neck lymph nodes, they may not cause any symptoms and may be found easily by the examination of the neck by a skilled doctor’s hands or conversely only detected by examination with high resolution ultrasound of the neck with fine needle aspiration analysis of the cells under a microscope. The determination of the anaplastic thyroid cancer’s extent of disease is critical in planning treatment including the feasibility of complete removal of the neck disease if there is no evidence of the distant spread of the cancer.
Although thyroid cancer is clearly increasing in its incidence both in the United States and globally, the increasing numbers of thyroid cancers does not appear to be due to anaplastic thyroid cancers, rather more that of the most common papillary thyroid cancers. The microscopic description of anaplastic thyroid cancer dates back more than 100 years now. How anaplastic thyroid cancers develop still requires greater investigations. Some anaplastic thyroid cancers clear develop within papillary thyroid cancers that have been present for very long periods of time. In contrast, other anaplastic thyroid cancers appear to develop within the thyroid gland without pre-existing long standing masses or lumps. One thing we have discovered about anaplastic thyroid cancers is that their genetic appearance (the amount mutated events in their genetic makeup) is far more than the other more common thyroid cancers. Early on, most anaplastic thyroid cancers were probably lumped under the diagnosis of poorly differentiated thyroid cancer. Even among thyroid cancer pathology experts today, the line between these two very aggressive forms of thyroid cancer can be quite grey.
Anaplastic thyroid cancer effects men more commonly than women and has a peek incidence at an older age than all other thyroid cancers around 65 years of age. Thyroid cancer is now the fifth most common malignancy among women (and seventeenth among men) in the United States. If you have recently undergone a needle biopsy suggesting an anaplastic thyroid cancer (or poorly differentiated thyroid cancer [sometimes you cannot tell the difference between anaplastic thyroid cancer and poorly differentiated thyroid cancer on a FNA]), there is no time to delay. You need to get into the most expert hands of a thyroid cancer surgeon, be promptly and expertly evaluated, and if feasible and meaningful, have a surgery that effectively removes all of your anaplastic thyroid cancer. If you have already underwent surgery and you have been diagnosed with an anaplastic thyroid cancer), the following pages have been created just for you.
Our Introduction to Thyroid Cancer page has a great general overview of all types of thyroid cancer--read it if you haven't already!
Anaplastic thyroid cancer: Who Gets It?
Anaplastic thyroid cancer (carcinoma) tends to occur later in life than the more common thyroid cancers and is very uncommonly diagnosed in younger adults. In fact, I have never seen one in a child. The peak age of discovery of anaplastic thyroid cancer is most common in individuals above 65 years of age. Anaplastic thyroid cancer affects men more commonly than women. Thyroid cancer is now the fifth most common malignancy among women (and 17th among men) in the United States. Since thyroid cancer can occur at any age, everybody should be aware of any changes in their thyroid gland and make sure their doctor feels the thyroid gland when getting a routine check up. For more details on who gets anaplastic thyroid cancer, the incidence, and ages of patients affected, go to our page on the Diagnosis of anaplastic thyroid cancer.
Anaplastic thyroid cancer: How is it Diagnosed?
Anaplastic thyroid cancer starts as a growth of abnormal cancer cells within the thyroid. As these cells multiply they form a bump or "nodule" within the thyroid that often sticks out of the side or front of the thyroid gland. Unfortunately, since anaplastic thyroid cancers grow at such a rapid pace, rarely are they found early in their formation or incidentally noted on a routine physical examination. Most commonly, anaplastic thyroid cancers are diagnosed by the patient noticing the rapid development of a neck mass or symptoms caused by direct invasion of the anaplastic thyroid cancer causing a change in voice or swallowing. In fact, anaplastic thyroid cancers may grow so quickly, that other family members or observers may comment upon the rapid development of a lump within an individual’s neck. However the mass is discovered, your physician feeling this mass or seeing it as a surprise on some other scan will typically order a thyroid ultrasound to look at the thyroid closely and take pictures of the mass or nodule.
An ultrasound is a way to use sound waves to look underneath the skin. It exposes the patient to absolutely no radiation. Ultrasound for anaplastic thyroid cancer is far more sensitive than any of the most experience of hands. It is critically important in determining the extent of the anaplastic thyroid cancer especially examining the lymph nodes of the neck. The next step is almost always a needle biopsy. We have a pages on needle biopsies of thyroid nodules. Sometimes anaplastic thyroid cancer may not be diagnosed on fine needle aspiration of the thyroid. The thyroid cytologist (doctor that looks at the cells under a microscope) may actual diagnose an anaplastic thyroid cancer as a poorly differentiated thyroid cancer. This really should not impact any of the decision making. Certainly a comprehensive evaluation of the extent of disease is warranted for an anaplastic thyroid cancer or even a poorly differentiated thyroid cancer. Either and both of these diagnoses need to be taken very seriously and analyzed in the same fashion. In fact, the treatment decision making varies little between these two diagnoses. Only when a pathologist can look under the microscope at the thyroid gland itself, and not just the cells, can they tell the difference between a anaplastic thyroid cancer and a poorly differentiated thyroid cancer. There are more pages about ultrasound and the evaluation of anaplastic thyroid cancer. If you have recently undergone a thyroid needle biopsy or are scheduled to have a needle biopsy, these pages are for you.
What Are The Symptoms of a Anaplastic Thyroid Cancer?
Unlike almost all other thyroid cancers, anaplastic thyroid cancer usually has symptoms. Although it almost never causes hyperthyroidism (increased thyroid function) or hypothyroidism (decreased thyroid function), it usually grows so fast and grows locally invasive into surrounding tissues that either its rapid growth rate or local invasion produces its first symptoms. The most common symptoms of anaplastic thyroid cancer are the rapid growth of a neck mass and changes to voice and and swallowing. However, rarely does it make people feel bad. Most importantly, anaplastic thyroid cancer is most commonly diagnosed by expert cytologists (doctors that look at cells under a microscope) following fine needle aspiration analysis of cells obtained from the thyroid gland itself or neck lymph nodes containing metastatic anaplastic thyroid cancer!
Anaplastic Thyroid Cancer: What About Lymph Nodes?
We have lymph nodes all over our body that are made up of groups of infection-fighting and cancer fighting immune cells. We all have had "swollen glands" in our neck when we had a sore throat or tonsils. These same glands that get swollen when we have a neck infection can help fight cancer by preventing the cancer cells from spreading from the thyroid to the rest of the body. Anaplastic thyroid cancer certainly can spread into the lymph nodes of the neck. In fact, at least 90% of anaplastic thyroid cancers will have spread to neck lymph nodes on their initial presentation. Failure to recognize that your anaplastic thyroid cancer has spread to neck lymph nodes is one common cause of persistent anaplastic thyroid cancer. Failure to appreciate the invasive extent of the anaplastic thyroid cancer and remove all of the invasive disease is the other common and critical inadequate surgical management of this disease. These are common oversights of inexperienced thyroid cancer surgeons and has a major impact on the ability to control your anaplastic thyroid cancer. Make sure you have identified the most experienced thyroid cancer surgery expert if you are preparing for surgery of any type of poorly differentiated thyroid cancer. If you underwent surgery and have persistent disease, this may not be correctable but don’t make the same decision again which brought you to your current circumstance.
Because anaplastic thyroid cancer grows so quickly and spreads to neck lymph nodes so routinely, this rapidly growing cancers is commonly self discovered by the patient themselves. Once the anaplastic thyroid cancer has spread into the lymph nodes which are doing their job of capturing the cancerous cells before they can spread further. The anaplastic thyroid cancer basically gets “stuck” in the lymph node something like a filter. Our bodies don’t have any ability to remove the cancer from this filter system and therefore the cancer cells begin growing within the lymph nodes.
Anaplastic thyroid cancer has a great risk of growing into blood vessels in and around the thyroid gland and directly invading the tissues that lay along side the thyroid gland. This is called angioinvasion and soft tissue invasion, respectively. These are microscopic findings of the pathologist following surgery of anaplastic thyroid cancers. These microscopic observations tell the anaplastic thyroid cancer experts exactly how aggressive this cancer is to the patient and the very high risk of these cancers spreading to distant sites of the body.
Anaplastic thyroid cancer almost routinely will spread to lymph nodes of the neck. But independent of this observation, all anaplastic thyroid cancers have a very high risk of recurrence and distant spread of disease essentially within one year of their diagnosis. Most importantly, there is no such thing as a favorable or in fact, early stage anaplastic thyroid cancer. The overview of the importance of lymph nodes in anaplastic thyroid cancer ends here, but if you have this problem, then please continue reading our page on anaplastic thyroid cancer staging.
The Best Cure Rates Come From The Most Experienced Doctors!
What is critically important to you is that you are evaluated and managed by a highly experienced thyroid cancer team whom are experts in the imaging (ultrasound and Xrays), staging, pathologic analysis (the way individual cells look under a microscope) and surgery management of anaplastic thyroid cancer.
How Is Anaplastic Thyroid Cancer Staged?
Anaplastic thyroid cancers are not all alike. Nevertheless, I don’t believe I have ever encountered an anaplastic thyroid cancer that I didn’t have grave concerns over its potential to harm the patient. Almost all anaplastic thyroid cancers are big, spread into local surrounding tissues, have spread to neck lymph nodes and may have grown into blood vessels as well. To separate out the cancers that are easy to cure from those that are more difficult to cure, doctors have come up with a grading or "staging" system. All cancers have their own staging system, but anaplastic thyroid cancer has a staging system that is not like most other cancers. The staging system for anaplastic thyroid cancer does not take into account the size of the thyroid cancer or whether it has spread to lymph nodes or not. Importantly, all anaplastic thyroid cancers are considered stage IV, reflecting the poor prognosis of this type of cancer. The last component of Anaplastic thyroid cancer staging is the presence of distant metastases, which means whether the cancer has spread to distant (far away) areas like the lungs, liver or bones. If you or someone you know has anaplastic thyroid cancer, then please read our more detailed page on anaplastic thyroid cancer staging. Only the earliest stage of anaplastic thyroid cancers should be considered for surgical therapy. Any evidence of distant spread of anaplastic thyroid cancer makes anaplastic thyroid cancer a non-surgical disease. As with any valid staging system, accurate staging predicts chance of cure.
What Surgery May Be Indicated for Anaplastic Thyroid Cancer?
Anaplastic thyroid cancer is very rarely treated with surgery. As stated above, only the earliest stage of anaplastic thyroid cancer should even be considered for surgery. Any evidence of distant spread of anaplastic thyroid cancer makes anaplastic thyroid cancer a non-surgical disease. It is important to understand that the only chance of cure is to have a very expert thyroid cancer surgeon from the beginning. Only the most highly experienced thyroid cancer surgeons will have ever operated on an anaplastic thyroid cancer patient and even fewer will have ever cured an anaplastic thyroid cancer patient. There is no question, the occasional surgeon should not operate on an anaplastic thyroid cancer patient or even a patient with a presumed diagnosis of poorly differentiated thyroid cancer. There is no second chance or opportunity in anaplastic thyroid cancer surgery. Surgery for anaplastic thyroid cancer is filled with a number of choices. Some of these choices in anaplastic thyroid cancer surgery can be made prior to surgery but others may depend upon the thyroid cancer surgery experts experience and thoughts during the actual surgical procedure. The anaplastic thyroid cancer patient will usually require a total thyroidectomy or subtotal thyroidectomy in most circumstances. Frequently anaplastic thyroid surgery may be a complicated thyroidectomy.
Since anaplastic thyroid cancer almost always spreads to neck lymph nodes and local extension of the thyroid cancer must be adequately removed as well, central compartment dissection (removal of the lymph nodes around the thyroid gland) and modified anterolateral neck dissection (removal of the lymph nodes of the side of the neck) are almost always performed in the management of patients with anaplastic thyroid cancer. Because there is only one opportunity to cure anaplastic thyroid cancer and surgery is it!, it is important that you have a surgeon that understands every aspect of anaplastic thyroid cancer surgery and the disease itself. Get the best thyroid cancer surgeon that you can!
What About Thyroid Hormone Pills After Anaplastic thyroid cancer Surgery?
Regardless of whether a patient has most, or the entire thyroid gland removed, all experts agree they should be placed on a thyroid hormone pill for the rest of their lives. This is to replace the hormone in those who have no thyroid gland remaining, and to suppress further growth of thyroid cells in those with some thyroid tissue left in the neck. There is good evidence that anaplastic thyroid cancer rarely responds to thyroid stimulating hormone (TSH) secreted by the pituitary, therefore, a thyroid hormone pill is given largely to replace thyroid hormone to the patient’s hormonal needs but not in a fashion to suppress TSH hormone like in the other more common thyroid cancers like papillary and follicular thyroid cancer. Much more is written for you in sections of Diagnosis of Anaplastic Thyroid Cancer and determining what extent of surgery is right for you.
After Surgery: Radioactive Iodine and Long-Term Follow-up
All patients who had surgery (and chemotherapy and radiation therapy) for anaplastic thyroid cancer will need to see a doctor for many years to have periodic examinations, certain blood tests, and X-ray studies to monitor them, and to detect any return of the cancer as soon as possible should it return. Although there is no clear benefit, some patients with anaplastic thyroid cancer may be evaluated following their surgery (and chemotherapy and radiation therapy) to determine whether radioactive iodine may be a benefit in their disease. This evaluation of radioactive iodine is not urgent and should be delayed until all other definitive treatment has been prescribed or expired. The potential benefit of radioactive iodine may be most appropriate in anaplastic thyroid cancer patients where the cancer may have arisen in a long standing papillary thyroid cancer. More is written about long term follow-up of anaplastic thyroid cancer.