This booklet was first written by thyroid cancer patients and then reviewed by members of the Canadian Thyroid Cancer Association’s Medical Advisory Board for publication. This booklet is based on the experiences of thyroid cancer patients and is dedicated to answering your questions. If you need more detailed information on medical aspects of thyroid function, diagnosis, surgery and treatment, we recommend consulting your primary care physician or an authoritative website – some references are given at the end of this booklet.
In our work with thyroid cancer patients, we find it helpful to remind them that thyroid cancer is almost always curable (97% survival rate). The vast majority of patients believe that once the surgery and initial treatment is completed, the hardest part is over. However, there are still a small number of patients who have more complicated cases or who have not recovered for more than a year. Patients with thyroid cancer tell us they want to know in advance what they are going to experience, including the less likely and less common after-effects.
There are five main types of thyroid cancer: papillary, follicular, insular, undifferentiated, and medullary. The first two types account for the majority of cases (more than 85%) and share a similar treatment approach, often collectively referred to as well-differentiated thyroid cancer. This brochure is based on the experience of patients with well-differentiated thyroid cancer. In the following, thyroid cancer is referred to as well-differentiated thyroid cancer.
The thyroid gland and thyroid hormones
The thyroid gland is located in the front of the neck and is shaped like a butterfly, acting like a “fireplace”. For example, in a building, there is a thermostat that monitors the room temperature and if it is too low, it gives the order to heat the room. Then, the furnace will receive the heating signal and start heating. There is a similar circulatory pathway in the human body. The relationship between the thermostat and the “furnace” is the same as the relationship between the pituitary gland (located in the brain) and the thyroid gland. The pituitary gland sends signals called thyroid stimulating hormones (TSH), which are released when the thyroid gland is needed to produce and release thyroid hormones (usually T4 and T3). These hormones are essential for organs such as the brain and heart and lungs.
If your thyroid gland has been removed due to thyroid cancer, you will need to take LT4 pills to replace the hormones previously produced by the thyroid gland. Chemically, LT4 is the same as the hormone produced by the thyroid gland itself and will be used by your body in the same way. This allows your body to convert the LT4 taken into LT3 (LT4 is the inactive precursor of LT3). Sometimes LT3 preparations can also be taken directly.
How thyroid cancer is diagnosed
The diagnosis of thyroid cancer usually begins with the discovery of a thyroid nodule. Either they are found accidentally by imaging scans (e.g. ultrasound, CT, MRI); or they are so large that the lump can be detected by the naked eye; or they are palpated through a physical examination of the neck. Up to 95% of nodules are benign, although any nodule larger than 25px or progressively larger should be further examined by an endocrine surgeon or ENT or other endocrinologist in thyroid cancer. A number of special tests can help distinguish between a nodule and a tumor.
The best way to make a definitive diagnosis is by fine needle aspiration (FNA), where a specimen is taken and tested by someone who specializes in specimens. Also, thyroid ultrasound can help clarify the nature of the nodule, as cancerous masses have a specific presentation. The two techniques are often combined to perform ultrasound-guided fine-needle aspiration. Other tests such as radioactive iodine scans, CT, MRI and PET are generally difficult to conclude if they are malignant and are often used to monitor disease recurrence and progression. Blood tests (including TSH) cannot be used as indicators of malignancy.
Sometimes FNA results show “inconclusive” or “undiagnostic”, suggesting that the specimen was taken from outside the central area of the nodule, or that the number of specimens is insufficient, or that the specimen does not show enough to make a diagnosis. In this case, it is usually recommended that the test be repeated in a few months at a higher level of care.
It is important to see a specialist, as this increases the chances of a definitive diagnosis. That said, sometimes the nodules are so small that it requires a high level of skill to obtain a suitable specimen through a fine needle. Large consultation centers have experienced cytopathologists who can better visualize the cells under a microscope. However, even in these ideal circumstances, your doctor may still not be able to determine if you have thyroid cancer.
What is the FNA experience like?
A doctor who specializes in this test (usually a surgeon or sonographer) will use a needle to penetrate one or more nodes in your neck and then remove the cells and place them on a small glass plate. He may put the needle into the same node several times to obtain different specimens to make sure he gets the right one in the right place. The doctor will ask you to tilt your head back, and then you will experience a piercing and pulling sensation. Most people find this procedure uncomfortable and unsettling, but it is a very brief procedure. You may feel pain for a few days afterwards, a bit like a bruise. The whole procedure is very safe and does not cause the cancer to spread.
Surgery
Normally, if a patient tests positive for thyroid cancer, the doctor will recommend surgery to remove all or part of the thyroid gland. Surgeons call this a partial thyroidectomy (PT) or a total thyroidectomy (TT). The extent of surgery depends on several factors, including the patient’s age, gender, size and number of nodules, and FNA cytology results.
In less common cases (5%), some patients diagnosed with differentiated thyroid cancer (papillary or follicular) present with a more aggressive – more likely to spread – or rare subtype. High aggressiveness is more often seen in patients over 60 years of age or in men. That is, FNA cytology and/or post-operative pathology suggests that the thyroid cancer has lost its well-differentiated features (e.g., high-cell or island cancer) or that the cancer has spread to surrounding tissues or lymph nodes. Having distant metastases at the time of diagnosis is very rare in thyroid cancer.
If there is a confirmed or suspected metastasis in the cervical lymph nodes, not only the entire thyroid is removed during surgery, but also the cervical lymph nodes are dissected. If thyroid cancer cells are found in the lymph nodes of the neck, local metastasis has occurred. Sometimes one or more lymph nodes are removed intraoperatively and sent to the pathology lab. If the results suggest that cancer cells are found, the surgeon continues the surgery and clears all the lymph nodes in the area.
Lymph node dissection in the neck is referred to as cervical dissection, and in most cases refers to lymph node dissection in the central region alone. In this case, the body surgical incision is usually as large as a simple thyroidectomy (a horizontal incision about a few centimeters long). If metastases are found in the lateral lymph nodes of the neck, a lymph node dissection of the lateral cervical region is performed. If both sides are present, bilateral lateral cervical zone lymph node dissection is required. When lateral lymph node dissection is performed, the neck incision is often extended unilaterally or bilaterally under the ear.
Why do you get thyroid cancer?
The answer is: the cause is unknown. There is a relationship between thyroid cancer and a history of high-dose radiation exposure to the neck, such as those who lived near the site of the Chernobyl accident in Ukraine. It has also been shown that some populations have a genetic susceptibility to thyroid cancer, and this has been precisely described in much of the literature. The relationship between exposure or incidental exposure (e.g., dental or mammography) to low doses of radiation and chemicals in the environment (e.g., BPA) is being studied, but no definitive conclusions have been reached.
Recent studies suggest that some people may have a genetic susceptibility to thyroid. Therefore, if thyroid nodules are found in the offspring of a patient with thyroid cancer, it is best to see a thyroid specialist because of the higher than average likelihood that their nodules will be malignant.
What should I prepare before having the surgery?
1. Be prepared. Have some easy to prepare and delicious food at home after surgery.
2. Find a good driver. Arrange for a driver to escort you home.
3.Ease the workload. Arrange for babysitting, dog walking, etc. Remember to take a few weeks off before you can return to work.
4.Use a special pillow. A dog bone shaped or curved pillow is helpful. Many people find these pillows very comfortable and help give the neck a support during the recovery period. Others use hot or cold water packs to reduce swelling.
5. Pack items for your hospital stay. You may need: medications, curved pillows or general pillows, toiletries, slippers, robes or pajamas.
6.After discharge from the hospital, follow the medical advice and prescriptions given to you. Eat plenty of soft, high-fiber foods and do not sit with your back hunched over.
7. Minimize scars. Follow your doctor’s instructions and keep the scars always covered with ointment.
8. Rest. Recovery requires several weeks of rest.
Post-operative recovery
Although the specifics can vary from person to person, patients who have thyroidectomy alone or combined with neck lymph node dissection often recover well in a relatively short period of time. In just a few weeks, they can have a return to the preoperative feeling. The incisions may remain red for 6 months and beyond, and then fade in the following months until they almost disappear. The entire process varies depending on the body type of the individual. Sometimes, the patient’s scar may bulge (keloid).
Patients with unilateral or bilateral neck lymph node dissection will take longer to recover. In general, movement and rotation of the head and neck are temporarily affected during the healing period. Sometimes the neck and shoulders may feel numb and weak. For most patients, these symptoms will improve over several months, while a small percentage of patients will experience permanent numbness, decreased mobility or other sequelae. Physical therapy can help improve the mobility of the neck and shoulder.
Post-operative sequelae
Most patients have no significant or lasting postoperative sequelae. In a small percentage of cases (10% of patients), the parathyroid glands are incorrectly cut or “stented” during surgery. The parathyroid glands are four wheat-grain sized glands located adjacent to or behind the thyroid gland. Their function is to regulate the amount of calcium in the body’s bones and blood. If the parathyroid glands are removed intraoperatively (or temporarily damaged), they will enter a state of hypoparathyroidism (low blood calcium), a condition that requires daily treatment with high doses of calcium and active vitamin D. The hypocalcemic state can be quickly obtained by postoperative monitoring of blood calcium and observation of physical signs (e.g., tapping the patient’s cheek and observing reflexes). Sometimes, despite the preservation of 1 or more intact parathyroid glands, patients may still have hypocalcemia. In such cases, the dose of calcium tablets and vitamin D is gradually reduced over the months following surgery to stimulate the parathyroid glands to restore their own function. More rarely, the stimulation of these glands is ineffective and the patient has to take calcium tablets and vitamin D for life.
Another risk of the procedure is varying degrees of voice loss or hoarseness (2-5% of patients). A small number of patients will feel that their vocal range has narrowed. It usually gets better after a few weeks, but occasionally it is necessary to see a voice rehabilitator or articulation specialist to learn to pronounce the voice differently.
Treatment of thyroid cancer
Surgery is the first step in the treatment of thyroid cancer.
Hormone therapy is the second step. All thyroid cancer patients need to take a daily dose of thyroxine tablets. Maintaining a certain dose not only helps the patient feel good and supports the function of the heart, brain, lungs and other organs, but also reduces the rate of thyroid cancer recurrence. The target range of TSH is related to the extent and type of the primary site, recurrence or persistence. The American Thyroid Association recommends maintaining TSH at 0.3-2.0 mIU/L for low-risk patients, 0.1 mIU/L or less for high-risk patients, and anything in between for other patients. Sometimes patients are maintained at a very low TSH level for the first few years after surgery and then allowed a slight increase in TSH in subsequent years if there is no recurrence or persistent status. the benefit of having a TSH near the upper limit is that it can mitigate side effects such as bone loss and arrhythmias caused by too low a TSH.
Radioactive iodine therapy (RAI) is the third step of treatment, using radioactive iodine to ablate (kill) residual thyroid cells (normal residual thyroid cells) and/or residual thyroid cancer cells. This treatment is now less commonly used than in years past. The indications are threefold: 1. ablation of normal residual cells to facilitate follow-up; 2. adjuvant therapy for people at intermediate/high risk of recurrence; and 3. treatment of known metastases (sometimes cancer spread or recurrence). There are also cases where only a lower dose is used for scanning. Scholars and thyroid specialists are currently exploring the best patients and indications to benefit from this protocol. It is not as frequently used today as it was during the period 1995-2005, when RAI was routinely performed in 80% of patients postoperatively. more on RAI in the next section.
In a few cases, external radiation (EBR) may be used against metastatic thyroid cancer that is difficult to remove surgically or that does not respond to RAI. If your doctor recommends external irradiation, it is important that you understand the reasons for your doctor’s recommendation and the side effects of this treatment. The treatment process and recovery from external irradiation can be arduous.
Preparation for RAI
If you need to receive a treatment or scan dose of RAI, there are two things to do to prepare for efficiency. One is to get your TSH levels up and the other is to prepare a special low iodine diet (LID).
In order for RAI to be absorbed more effectively by thyroid cells, TSH needs to be at least 30 mIU/L. Some hospitals test patients’ TSH several days in advance to ensure adequate levels are achieved. Others will give a small RAI scan in advance as an uptake criterion to calculate and customize the treatment dose (also called a dosimetry). Most hospitals have a set of treatment criteria for patients with similar conditions.
TSH can be raised in two ways (only one is applied at a time). There are advantages and disadvantages to each method, and your doctor may advise you, or you may choose your own. It is important to note that there are no direct costs involved in having hypothyroidism treatment (although there may be non-direct costs associated with health maintenance and reduced work hours), but there may be a $1,800 cost for thyrotropin injections in some states.
The following are brief descriptions of the two preparation options.
1. “Entering a hypothyroid state” (withdrawal)
Although the specifics of withdrawal vary, most doctors will recommend that you
Stop taking your LT4 replacement medication for at least 6 weeks. You can take LT3 for the first 4 weeks because it is quickly metabolized by the body. 24-48 hours after the RAI treatment or scan you can continue taking the medication.
Many patients undergoing hypothyroidism preparation will have side effects, including many symptoms and a range of intolerances:.
Fatigue; weakness; mild headache; sleep problems; edema; memory loss; inattention; irritability; depression; dry eyes, skin, hair; muscle pain, cold intolerance; constipation; numbness; itching; ringing in the ears; and/or vision changes.
Most patients feel progressive symptoms worsen within 2 weeks of stopping the medication, meaning that each day you feel worse than the day before. These symptoms will gradually disappear once you continue taking thyroxine.
2. Thyrotropin injections (elevated TSH)
Thyrotropin injection means that the patient does not need to stop taking thyroxine tablets and therefore does not go into hypothyroidism. Thyrotropin injections are given by a health care provider (e.g. nurse) over 2 days (once a day) prior to RAI treatment.
The injections cause an increase in TSH, but the patient will not have the symptoms of hypothyroidism described above. Occasionally, some patients may experience mild headache and nausea after the injection.
Regardless of the RAI preparation regimen and RAI dose described above, all patients receiving RAI are placed on a special low iodine diet that is maintained for 2 weeks until 24-48 hours after the RAI is administered.
The low iodine diet is a very specific diet. In order to better guide patients, the Thyroid Cancer Council of Canada (TCC) has prepared a very detailed list that is available for free review. To obtain a copy, you can fill out the “Get Connect” request form on the TCC website.
Radioactive Iodine Therapy
Patients swallow RAI as if they were taking a pill or drinking a small amount of liquid with water through a straw, which has a bitter metallic taste. Most patients do not experience immediate side effects, but if they are preparing for withdrawal, they may still experience side effects during the recovery period after the RAI ends. Patients will not experience pain or hair loss.
Immediately after receiving RAI, you will be placed in isolation for at least 2 days, either in the hospital or at home (the hospital will inform you of their recommendations in advance). The duration of isolation is related to the RAI dose. Patients with normal kidney function will metabolize the vast majority after 2 to 3 days, and if there are no symptoms of hypothyroidism, you can usually go home in 4 or 5 days. The nuclear medicine department will give you a guideline, including a request that you have access to a separate bedroom and bathroom for at least the first 3 to 7 days after you go home. You will also be asked to stay away from small children, pregnant women and pets (for more than a few minutes) for the first few days.
Most of the RAI that is metabolized in the first few days is through urine, saliva, tears and sweat. Patients will generally be told to wash bathrooms, bedding, kitchenware and clothing once the first week is over, and to wash them separately, and then they can return to their normal lives. It is not necessary to use special cleaning agents to clean them, because the residual RAI can be washed off normally by ordinary procedures. Eventually any residual RAI on the object will dissipate (meaning it will disappear slowly over time). Therefore, it is better to use washable clothes and kitchenware and then wash them all on the last day. It is also best to use reusable items, not discardable ones such as paper plates, as this can cause your waste to become temporarily radioactive.
All RAI patients return to the hospital after 1 week of treatment for a full body scan. the WBS machine looks like a box-like object, you lie on a narrow flat bed and the machine moves parts of your body at once or continuously to perform the scan. Usually you just need to take off your glasses and jewelry. The whole process takes about 45 minutes. When the machine reaches the area above your head, it will be very close to your face, so you can close your eyes and relax for a moment. The scan is quiet and you won’t feel pain or discomfort. However, you must remain still in order to get a clearer image. Some hospitals tie patients down to keep them still, and some will provide a blanket to cover you. wbs does not expose you to radiation, but rather to the RAI you swallowed earlier to visualize. While scanning, your full body scan will be displayed on the monitor next to you. In some hospitals, the imaging doctor will give the report to the patient immediately, but most hospitals give the report to your doctor, who will then give it to you several days later. If the images are not quite clear (mostly caused by differences in the timing of the WBS after the RAI), your doctor will ask you to go back a few days later and have it done again.
Follow-up visit
Although very rare, thyroid cancer has a 10-15% chance of recurrence. Therefore, all thyroid cancer patients should have lifelong follow-up with a specialist. Follow-up visits are usually performed by an endocrinologist, but can sometimes be performed by a surgeon, nuclear medicine doctor or family doctor.
Patients should consider which follow-up procedure is best for their situation, as it may change if they remain recurrence-free for many years. Most patients need a neck scan and TSH blood test at least every year or whenever symptoms of hypo- or hyperthyroidism occur. For the patient’s health and to keep relapses at bay, regular TSH reviews will ensure that hormone levels are within the target range.
Patients should also undergo other tests. Even in the absence of significant relapse symptoms, patients should have regular neck ultrasounds and thyroglobulin (Tg) tests. Typically Tg and anti-Tg antibodies will be performed at the same time. If anti-Tg antibodies are detected in a patient’s blood sample, this is an important indication.
Tg is only secreted by thyroid cells into the circulation and therefore can be used as an indicator of thyroid cancer recurrence. It is best to prepare before doing Tg testing as if it were RAI treatment. That is, Tg is most valuable as a cancer indicator when thyroid tissue is in a stimulated state to release Tg. And when the patient has elevated TSH, it stimulates the thyroid tissue. Because Tg testing is the same as preparation prior to RAI, patients can have Tg testing during the week of RAI treatment. If Tg is not performed together with RAI, it is still best to prepare for RAI as described previously in addition to a low iodine diet.
Recurrence
Recurrence does not occur in 80-95 % of patients. The cure rate of thyroid cancer remains high even in patients who have developed focal metastases.
Patients who show signs of recurrence should have several specific follow-up tests, including: ultrasound, WBS, CT, PET-CT or MRI. if the patient is known to have a neck node (often one or more lymph nodes) and is large, an FNA is usually indicated. In cases of recurrence that have been diagnosed or are highly suspected, reoperation or continued close observation is recommended. RAI or EBR may also be recommended in some cases.
Thyroid hormone balance
Taking LT4 daily can make you feel good, give your body the vital hormones it needs to function properly, and inhibit thyroid cancer recurrence.
It is important to take LT4 the right way, it must be taken at the same time each day on an empty stomach and only orally with water, not with food, other nutrients or medications. To learn more about thyroxine replacement therapy, please go to our website.
The dose of LT4 should be enough to inhibit the TSH from falling into the target range. Too much hormone (too high a dose) can cause hyperthyroidism. And too low can cause hypothyroidism and sometimes weight gain.
LT4 is slow acting and each dose change requires a 6-week wait to achieve maximum effectiveness and to observe changes in TSH. Some patients require multiple dose adjustments (especially in the first few months after surgery) to reach the target range. Your doctor will give you the appropriate TSH range and LT4 dose.
In most cases, patients can take LT4 daily without stress and feel good. This is the segment of the population that will remain on this medication for many years or even for the rest of their lives.
Occasionally, however, patients who have adjusted their TSH to the target range do not feel as well as they used to. It is usually recommended to wait a few weeks or months for the body to adjust to the dose change. If after a long time the patient still feels unwell, a very small dose adjustment can be made. Small dose adjustments can keep the patient’s TSH from deviating from the target while reducing the symptoms or side effects of the discomfort they are experiencing. This can sometimes be accomplished by adjusting to a variable dose (i.e., one dose on some days of the week and another dose on other days).
Changing the brand of LT4 you are taking is not recommended; the pharmacology varies from brand to brand. Many patients prefer brands that offer multiple doses so that they can have more different options when adjusting the dose later (e.g., levothyroxine sodium).
A small number of patients may find that one brand of LT4 is better suited to their body than others, or some patients may also need to add LT3.
It is best to have blood tests done in the same place each time.
Patients should never change their LT4 dose, brand or add LT3 without consulting their doctor.
Emotional changes
Patients experience a range of mood changes after treatment for thyroid cancer, and they may last for months or years. These changes include.
1. Fear, worry and doubt about the cancer diagnosis, especially if you have waited a long, long time for diagnosis and treatment.
2.Mood changes with great ups and downs.
3.Loss of confidence in your health often makes you feel sad.
4.The possible relapse after treatment makes you feel afraid. Pain is more painful in the imagination of many patients than it actually is. It takes a lot of time to adjust to these emotions.
5. Social limitations: Children sometimes express emotional turmoil in the opposite way. You may lose friends and have limited relationships with loved ones. You may feel depressed or moody, especially during the adjustment of the LT4 dose.
All of these changes may bring pain, sadness and stress in the short term. Feeling isolated and afraid to take on family and friend responsibilities are more common. Don’t be afraid to ask for help if you need it.
Communicate well with the people you love and care for and let them know how they can help. Healing takes time – physical and mental – to build, so be patient again. In addition to friends and family, support groups such as the Canadian Thyroid Cancer Association, community or church can help. Professional psychologists and social workers are also available through cancer clinics.
Effects of thyroid cancer on the fetus and the mother
There are no long-term effects of thyroid cancer on either male or female fetuses. However, patients undergoing RAI treatment who wish to become pregnant or prepare for pregnancy should wait at least 6 months to a year after treatment, mainly to ensure that they do not require further treatment.
Women’s post-operative rehabilitation or low thyroxine preparation prior to RAI treatment may cause menopause. high or low TSH levels may also cause menopause. Once you have recovered, these will return to normal.
Pregnant women taking LT4 should consult with their thyroid specialist for dosing. In order to maintain TSH at a dose that is good for both the fetus and the mother, the dose of LT4 needs to be raised during pregnancy and lactation.
In addition to the possible shortening of life expectancy, thyroid cancer, like other cancers, can cause mental changes. Mental changes can also affect a person’s sex drive and fertility. If you have been affected, talking to a trusted partner who has had a similar experience can help you rebuild your confidence and sense of security.
Eighty percent of thyroid cancer patients are women.
Thyroid cancer has a 98% cure rate.
The prognosis for thyroid cancer varies greatly, depending on the type of tumor.
The cure rate is lower for men.
The incidence of thyroid cancer is increasing faster than any other tumor.
Only 0.2% of cancer research funds are devoted to thyroid cancer.