Anaplastic thyroid cancer | |
---|---|
Other names | Anaplastic thyroid carcinoma, ATC |
Microscopic image of anaplastic thyroid carcinoma. H&E stain. | |
Specialty | ENT surgery, oncology, endocrinology |
Prevention | Use a thyroid guard when having any type of radiation, like X-rays or certain scans - even dental X-rays. |
Treatment | Chemotherapy, radiation therapy |
Anaplastic thyroid cancer (ATC), also known as anaplastic thyroid carcinoma, is an aggressive form of thyroid cancer characterized by uncontrolled growth of cells in the thyroid gland. This form of cancer generally carries a very poor prognosis due to its aggressive behavior and resistance to cancer treatments. [1] The cells of anaplastic thyroid cancer are highly abnormal and usually no longer resemble the original thyroid cells and have poor differentiation.
ATC is an uncommon form of thyroid cancer only accounting for 1-2% of cases, but due to its high mortality, is responsible for 20-50% of deaths from thyroid cancer. [2] The median survival time after diagnosis is three to six months. [2] Some studies report that 10% to 15% survive more than 1 year; 3-year and 5-year survival is very rare. [3] [4] It occurs more commonly in women than in men and is seen most commonly in people ages 40 to 70. [2]
Anaplastic thyroid cancer typically manifests as a rapidly enlarging neck mass. [2] Associated redness and swelling of the overlying skin sometimes occur. ATC commonly causes symptoms by compressing local structures, such as the esophagus, carotid arteries, recurrent laryngeal nerve and trachea. This compression of local anatomic structures may cause symptoms such as difficulty controlling the voice, hoarseness, difficulty swallowing, or trouble breathing. [2] Other symptoms include cough, neck pain, or symptoms from the spread of cancer to distant sites in the body, such as the brain. ATC may rarely present with coughing up blood. [2]
Risk factors include being over the age of sixty, a long-standing goiter, and repeated radiation exposure to the chest or neck.
Nearly half of ATC cases occur in the setting of coexisting differentiated thyroid cancer. This suggests that many ATC cases have dedifferentiated from differentiated thyroid cancer and, as a result, become more aggressive and difficult to treat. Differentiated thyroid cancer is seen coexisting with ATC on fine-needle aspiration biopsies in 20-50% of cases. [2]
Anaplastic tumors have a high mitotic rate and frequently invades the local blood and lymphatic vessels. [5] Cellular death is frequently visualized on microscopic images. [2] The presence of regionally swollen lymph nodes in older patients in whom needle aspiration biopsy reveals characteristic vesicular appearance of the nuclei supports a diagnosis of anaplastic carcinoma. Microscopic images of ATC usually show inflammatory cells from the immune system such as T cells and macrophages. [2]
On immunohistochemistry testing, ATC is usually positive for the keratin, p53, and PAX8 proteins and is negative for thyroid transcription factor-1, thyroglobulin, and calcitonin. [2] ATC cells demonstrate high levels of PD-L1 expression. [2] BRAF and TERT mutations are seen more commonly in ATC than in differentiated thyroid cancer. [2]
Fine-needle aspiration is essential in order to obtain a sample of the thyroid tissue to allow for microscopic examination. This allows an experienced pathologist to differentiate ATC from other diseases, such as other forms of thyroid cancer. [2] It is very important to distinguish between ATC and poorly-differentiated thyroid cancer and this distinction can be difficult to make. [2] The presence of PAX-8 positive staining and association with a different thyroid cancer that is adjacent to the ATC support the diagnosis. [2]
ATC is divided into several different subclasses based on its microscopic characteristics. These include sarcomatoid, squamoid, osteoclastic, paucicellular, rhabdoid, and carcinomasarcoid variants. [2] As of 2019, despite the fact that these ATC subtypes are recognized, this classification has not led to differences in management. [2] ATC is always considered to be stage IV when it is diagnosed. [6]
There are no reliable laboratory tests for ATC. [2] Ultrasound imaging of ATC lesions reveals a hypoechoic mass (appears dark on ultrasound) with invasion of the local structures and may help to better characterize the presence or absence of neck lymph node metastases. [2] If surgery is planned, however, then a contrast-enhanced computed tomography (CT) scan of the neck must be performed. [2] A PET scan is preferred for staging ATC but a CT scan of the neck, chest, abdomen, and pelvis can be substituted if the former is unavailable. [2] Magnetic resonance imaging (MRI) of the brain is also recommended to assess for distant metastases. [2]
In addition to ATC, a rapidly enlarging neck mass prompts consideration of several other important diagnoses. These include other cancers such as primary thyroid lymphoma, poorly differentiated thyroid cancer, sarcomas, and metastases from cancers of the upper digestive tract and respiratory tract. [2] Squamous cell carcinoma of the thyroid gland is a rare cause of this presentation. [2]
This section is empty. You can help by adding to it. (June 2022) |
ATC is considered an emergency cancer diagnosis since it poses a high risk of blocking the airway and/or esophagus due to its rapid growth in the neck, either of which can quickly cause a person's death by asphyxiation, if not immediately corrected. [2]
Unlike its differentiated counterparts, anaplastic thyroid cancer is highly unlikely to be curable either by surgery or by any other treatment modality, and is in fact usually unresectable due to its high propensity for invading surrounding tissues. [7] A multidisciplinary team including an endocrine pathologist, head and neck surgeon, medical oncologist, radiation oncologist, endocrinologist, and a palliative care physician is essential for optimal management. [2] Palliative treatment consists of radiation therapy usually combined with chemotherapy.
The use of tracheostomy as part of supportive care for ATC is controversial. [2]
Medications, such as fosbretabulin (a type of combretastatin), bortezomib and TNF-Related Apoptosis Induced Ligand (TRAIL), are, however, under investigation in vitro and in human clinical studies. Based on encouraging Phase I and II clinical trial results with fosbretabulin, [8] a type of medication that selectively destroys tumor blood vessels, clinical trials have been evaluating whether the medication can extend the survival of patients with ATC. [9]
With the advent of molecular testing and next-generation sequencing, BRAF and MEK inhibitors are playing an increasing role in the management of patients with anaplastic thyroid cancer harboring such mutations. The combination of dabrafenib and trametinib has shown significant increases in overall survival and has been approved by the FDA. Another similar combination is vemurafenib and cobimetinib.
Immunotherapy is also starting to play an important role in anaplastic thyroid cancer management with several ongoing clinical trials demonstrating promising effects. Specific drugs being tested are atezolizumab, pembrolizumab, and spartalizumab, amongst others.
Combinatorial therapy that is molecular-based may lead to significant tumor regression, potentially making patients amenable to curative surgery. [10]
The role of external beam radiotherapy (EBRT) in thyroid cancer remains controversial and there is no level I evidence to recommend its use in the setting of differentiated thyroid cancers such as papillary and follicular carcinomas. Anaplastic thyroid carcinomas, however, are histologically distinct from differentiated thyroid cancers and due to the highly aggressive nature of ATC aggressive postoperative radiation and chemotherapy are typically recommended.
The National Comprehensive Cancer Network Clinical Practice Guidelines currently recommend that postoperative radiation and chemotherapy be strongly considered. No published randomized controlled trials have examined the addition of EBRT to standard treatment, namely surgery. Radioactive iodine is typically ineffective in the management of ATC as it is not an iodine-avid cancer. [11]
Imbalances in age, sex, completeness of surgical excision, histological type and stage, between patients receiving and not receiving EBRT, confound retrospective studies. Variability also exists between treatment and non-treatment groups in the use of radio-iodine and post-treatment thyroid stimulating hormone (TSH) suppression and treatment techniques between and within retrospective studies.
Some recent studies have indicated that EBRT may be promising, though the number of patients studies has been small. [12]
Clinical trials for investigational treatments are often considered by healthcare professionals and patients as first-line treatment.
In the absence of extracervical or unresectable disease, surgical excision should be followed by adjuvant radiotherapy. In the 18–24% of patients whose tumour seems both confined to the neck and grossly resectable, complete surgical resection followed by adjuvant radiotherapy and chemotherapy could yield a 75–80% survival at 2 years.
There are a number of clinical trials for anaplastic thyroid carcinoma underway or being planned. [13]
The overall 5-year survival rate of anaplastic thyroid cancer has been given as 7% [14] or 14%, [15] although the latter has been criticized as being overestimated. [15] Additional factors that affect prognosis include the person's age, the presence of distant metastases, the dose of radiation administered to the primary tumor and regional lymph nodes, and if combined modality treatment is used. [2]
Treatment of anaplastic thyroid cancer is generally palliative in its intent due to its highly aggressive nature and nearly universal mortality. Larger tumors, distant metastases, acute obstructive symptoms, and leukocytosis portend a poorer prognosis. Death is attributable to upper airway obstruction and suffocation in half of patients, and to a combination of complications of local and distant disease, or therapy, or both in the remainder.
Anaplastic thyroid cancer is extremely aggressive; historically, in most cases death occurs in less than 1 year as a result of aggressive local growth and compromise of vital structures in the neck. ATC in most series has a median survival of 4 to 5 months from the time of diagnosis, with rare long-term survivors. [16]
Recent data however suggests that patients with BRAFV600E mutated disease, even if in an advanced stage, may have significantly better prognosis, as novel targeted therapies can extend tumor control considerably, while also leading to tumor burden decrease and potentially make patients candidates for surgery. [10] Recent advances show that using a combination of novel targeted therapies, immunotherapy, and surgery, 1 year and 2 year survival for anaplastic thyroid cancer patients have increased to 59% and 42%, respectively. [10]
This section is empty. You can help by adding to it. (June 2022) |
This section is empty. You can help by adding to it. (June 2022) |
This section is empty. You can help by adding to it. (June 2022) |
A brain tumor occurs when a group of cells within the brain turn cancerous and grow out of control, creating a mass. There are two main types of tumors: malignant (cancerous) tumors and benign (non-cancerous) tumors. These can be further classified as primary tumors, which start within the brain, and secondary tumors, which most commonly have spread from tumors located outside the brain, known as brain metastasis tumors. All types of brain tumors may produce symptoms that vary depending on the size of the tumor and the part of the brain that is involved. Where symptoms exist, they may include headaches, seizures, problems with vision, vomiting and mental changes. Other symptoms may include difficulty walking, speaking, with sensations, or unconsciousness.
A sarcoma is a malignant tumor, a type of cancer that arises from cells of mesenchymal origin. Connective tissue is a broad term that includes bone, cartilage, muscle, fat, vascular, or other structural tissues, and sarcomas can arise in any of these types of tissues. As a result, there are many subtypes of sarcoma, which are classified based on the specific tissue and type of cell from which the tumor originates.
Endometrial cancer is a cancer that arises from the endometrium. It is the result of the abnormal growth of cells that have the ability to invade or spread to other parts of the body. The first sign is most often vaginal bleeding not associated with a menstrual period. Other symptoms include pain with urination, pain during sexual intercourse, or pelvic pain. Endometrial cancer occurs most commonly after menopause.
Ovarian cancer is a cancerous tumor of an ovary. It may originate from the ovary itself or more commonly from communicating nearby structures such as fallopian tubes or the inner lining of the abdomen. The ovary is made up of three different cell types including epithelial cells, germ cells, and stromal cells. When these cells become abnormal, they have the ability to divide and form tumors. These cells can also invade or spread to other parts of the body. When this process begins, there may be no or only vague symptoms. Symptoms become more noticeable as the cancer progresses. These symptoms may include bloating, vaginal bleeding, pelvic pain, abdominal swelling, constipation, and loss of appetite, among others. Common areas to which the cancer may spread include the lining of the abdomen, lymph nodes, lungs, and liver.
Head and neck cancer is a general term encompassing multiple cancers that can develop in the head and neck region. These include cancers of the mouth, tongue, gums and lips, voice box (laryngeal), throat, salivary glands, nose and sinuses.
Oligodendrogliomas are a type of glioma that are believed to originate from the oligodendrocytes of the brain or from a glial precursor cell. They occur primarily in adults but are also found in children.
Small-cell carcinoma is a type of highly malignant cancer that most commonly arises within the lung, although it can occasionally arise in other body sites, such as the cervix, prostate, and gastrointestinal tract. Compared to non-small cell carcinoma, small cell carcinoma is more aggressive, with a shorter doubling time, higher growth fraction, and earlier development of metastases.
Invasive carcinoma of no special type, invasive breast carcinoma of no special type (IBC-NST), invasive ductal carcinoma (IDC), infiltrating ductal carcinoma (IDC) or invasive ductal carcinoma, not otherwise specified (NOS) is a disease. For international audiences this article will use "invasive carcinoma NST" because it is the preferred term of the World Health Organization (WHO).
A hemangiopericytoma is a type of soft-tissue sarcoma that originates in the pericytes in the walls of capillaries. When inside the nervous system, although not strictly a meningioma tumor, it is a meningeal tumor with a special aggressive behavior. It was first characterized in 1942.
Papillary thyroid cancer is the most common type of thyroid cancer, representing 75 percent to 85 percent of all thyroid cancer cases. It occurs more frequently in women and presents in the 20–55 year age group. It is also the predominant cancer type in children with thyroid cancer, and in patients with thyroid cancer who have had previous radiation to the head and neck. It is often well-differentiated, slow-growing, and localized, although it can metastasize.
Vulvar cancer is a cancer of the vulva, the outer portion of the female genitals. It most commonly affects the labia majora. Less often, the labia minora, clitoris, or Bartholin's glands are affected. Symptoms include a lump, itchiness, changes in the skin, or bleeding from the vulva.
Signet ring cell carcinoma (SRCC) is a rare form of highly malignant adenocarcinoma that produces mucin. It is an epithelial malignancy characterized by the histologic appearance of signet ring cells.
Cancer of unknown primary origin (CUP) is a cancer that is determined to be at the metastatic stage at the time of diagnosis, but a primary tumor cannot be identified. A diagnosis of CUP requires a clinical picture consistent with metastatic disease and one or more biopsy results inconsistent with a tumor cancer.
Medullary thyroid cancer is a form of thyroid carcinoma which originates from the parafollicular cells, which produce the hormone calcitonin. Medullary tumors are the third most common of all thyroid cancers and together make up about 3% of all thyroid cancer cases. MTC was first characterized in 1959.
Esthesioneuroblastoma is a rare cancer of the nasal cavity. Arising from the upper nasal tract, esthesioneuroblastoma is believed to originate from sensory neuroepithelial cells, also known as neuroectodermal olfactory cells.
Thyroid cancer is cancer that develops from the tissues of the thyroid gland. It is a disease in which cells grow abnormally and have the potential to spread to other parts of the body. Symptoms can include swelling or a lump in the neck, difficulty swallowing or voice changes including hoarseness, or a feeling of something being in the throat due to mass effect from the tumor. However, most cases are asymptomatic. Cancer can also occur in the thyroid after spread from other locations, in which case it is not classified as thyroid cancer.
Human papillomavirus-positive oropharyngeal cancer, is a cancer of the throat caused by the human papillomavirus type 16 virus (HPV16). In the past, cancer of the oropharynx (throat) was associated with the use of alcohol or tobacco or both, but the majority of cases are now associated with the HPV virus, acquired by having oral contact with the genitals of a person who has a genital HPV infection. Risk factors include having a large number of sexual partners, a history of oral-genital sex or anal–oral sex, having a female partner with a history of either an abnormal Pap smear or cervical dysplasia, having chronic periodontitis, and, among men, younger age at first intercourse and a history of genital warts. HPV-positive OPC is considered a separate disease from HPV-negative oropharyngeal cancer.
A brain metastasis is a cancer that has metastasized (spread) to the brain from another location in the body and is therefore considered a secondary brain tumor. The metastasis typically shares a cancer cell type with the original site of the cancer. Metastasis is the most common cause of brain cancer, as primary tumors that originate in the brain are less common. The most common sites of primary cancer which metastasize to the brain are lung, breast, colon, kidney, and skin cancer. Brain metastases can occur months or even years after the original or primary cancer is treated. Brain metastases have a poor prognosis for cure, but modern treatments allow patients to live months and sometimes years after the diagnosis.
Carcinoma of the tonsil is a type of squamous cell carcinoma. The tonsil is the most common site of squamous cell carcinoma in the oropharynx. It comprises 23.1% of all malignancies of the oropharynx. The tumors frequently present at advanced stages, and around 70% of patients present with metastasis to the cervical lymph nodes. . The most reported complaints include sore throat, otalgia or dysphagia. Some patients may complain of feeling the presence of a lump in the throat. Approximately 20% patients present with a node in the neck as the only symptom.
Ovarian squamous cell carcinoma (oSCC) or squamous ovarian carcinoma (SOC) is a rare tumor that accounts for 1% of ovarian cancers. Included in the World Health Organization's classification of ovarian cancer, it mainly affects women above 45 years of age. Survival depends on how advanced the disease is and how different or similar the individual cancer cells are.