Laryngeal cancer | |
---|---|
Other names | Cancer of the larynx, laryngeal carcinoma |
Larynx cancer – endoscopic view | |
Specialty | Oncology, otorhinolaryngology |
Deaths | 94,800 (2018) [1] |
Laryngeal cancer or throat cancer is a kind of cancer that can develop in any part of the larynx (voice box). It is typically a squamous-cell carcinoma, reflecting its origin from the epithelium of the larynx.
The prognosis is affected by the location of the tumour. For the purposes of staging, the larynx is divided into three anatomical regions: the glottis (true vocal cords, anterior and posterior commissures); the supraglottis (epiglottis, arytenoids and aryepiglottic folds, and false cords); and the subglottis. Most laryngeal cancers originate in the glottis, with supraglottic and subglottic tumours being less frequent.
Laryngeal cancer may spread by: direct extension to adjacent structures, metastasis to regional cervical lymph nodes, or via the blood stream. The most common site of distant metastases is the lung. Laryngeal cancer occurred in 177,000 people in 2018, and resulted in 94,800 deaths (an increase from 76,000 deaths in 1990). [1] [2] Five-year survival rates in the United States are 60.3%. [3]
The symptoms of laryngeal cancer depend on the size and location of the tumour. Symptoms may include the following: [4] [5]
Adverse effects of treatment can include changes in appearance, difficulty eating, dry mouth, or loss of voice that may require learning alternate methods of speaking. [6]
The most important risk factor for laryngeal cancer is tobacco smoking. Death from laryngeal cancer is 20 times more likely for the heaviest smokers than for their non-smoking peers. [7] Regular and heavy consumption of alcohol, particularly alcoholic spirits, is also a significant risk factor. Using alcohol and tobacco together is an especially high risk factor and causes 89% of laryngeal cancer cases. [8] [9]
Occupational exposure to environmental factors such as wood dust, paint fumes, and certain chemicals used in the metalworking, petroleum, plastics, and textile industries [10] is also believed to be a risk factor for laryngeal cancers. Infections by some forms of HPV carry some risk of laryngeal carcinoma. [11]
People with a history of head and neck cancer are known to be at higher risk (about 25%) of developing a second, separate cancer of the head, neck, or lung. This is likely due to chronic exposure to the carcinogenic effects of alcohol and tobacco. In this situation, a field change effect may occur, where the epithelial tissues start to become diffusely dysplastic with a reduced threshold for malignant change. This risk may be reduced by quitting alcohol and tobacco.[ citation needed ]
Other reported risk factors include being of low socioeconomic status, male sex, or age greater than 55 years.[ citation needed ]
Diagnosis is made by the doctor on the basis of a medical history, physical examination, and special investigations which may include a chest x-ray, CT or MRI scans, and tissue biopsy. The examination of the larynx requires some expertise, which may require specialist referral.[ citation needed ]
The physical exam includes a systematic examination of the whole patient to assess general health and to look for signs of associated conditions and metastatic disease. The neck and supraclavicular fossa are palpated to feel for cervical adenopathy, other masses, and laryngeal crepitus. The oral cavity and oropharynx are examined under direct vision. The larynx may be examined by indirect laryngoscopy using a small angled mirror with a long handle (akin to a dentist's mirror) and a strong light. Indirect laryngoscopy can be highly effective, but requires skill and practice for consistent results. For this reason, many specialist clinics now use fibre-optic nasal endoscopy where a thin and flexible endoscope, inserted through the nostril, is used to clearly visualise the entire pharynx and larynx. Nasal endoscopy is a quick and easy procedure performed in clinic. Local anaesthetic spray may be used.[ citation needed ]
If there is a suspicion of cancer, biopsy is performed, usually under general anaesthetic. This provides histological proof of cancer type and grade. If the lesion appears to be small and well localised, the surgeon may undertake excision biopsy, where an attempt is made to completely remove the tumour at the time of first biopsy. In this situation, the pathologist will not only be able to confirm the diagnosis, but can also comment on the completeness of excision, i.e., whether the tumour has been completely removed. A full endoscopic examination of the larynx, trachea, and esophagus is often performed at the time of biopsy.[ citation needed ]
For small glottic tumours further imaging may be unnecessary. In most cases, tumour staging is completed by scanning the head and neck region to assess the local extent of the tumour and any pathologically enlarged cervical lymph nodes.
The final management plan will depend on the site, stage (tumour size, nodal spread, distant metastasis), and histological type. The overall health and wishes of the patient must also be taken into account. A prognostic multigene classifier has been shown to be potentially useful for the distinction of laryngeal cancer of low or high risk of recurrence and might influence the treatment choice in future. [12]
Laryngeal tumours are classified according to the guidelines set by academic organisations such as the National Comprehensive Cancer Network (NCCN) . [13] Overall classification, also known as "staging", can help predict treatment options for patients. [14] Staging consists of three separate evaluations. The first is of the tumour/cancer itself ("T"). [14] The second is the extent to which adjacent lymph nodes are involved in the tumour/cancer's spread ("N"). [14] The third is the presence or absence of any distant metastases ("M). [14] The specific “staging” criteria for laryngeal cancer, as utilised in the NCCN’s 2019 Guidelines for Head and Neck Cancers, [15] are:
TX: Unable to assess
Tis: Carcinoma in situ
T1: Tumour present in only one subsite of the supraglottis. Vocal cords have normal mobility.
T2: Tumour invades mucosa. There is no fixation of the larynx.
T3: Tumour causes fixation of the vocal cords, with or without invasion of neighbouring areas.
T4:
T1: Tumour only involves the vocal cords. Vocal cords have normal mobility.
T2: Tumour meets at least one of the following criteria:
T3: Tumour meets at least one of the following criteria:
T4: Same as “Supraglottis”
T1: Tumour is only in the subglottis
T2: Tumour involves both subglottis and vocal cords (regardless of cord mobility)
T3: Same as “Glottis”
T4: Same as “Supraglottis”
If Using Clinical (Non-Pathological) Diagnosis
NX: Unable to assess
N0: No involvement of neighbouring lymph nodes
N1: Tumour meets ALL of the following criteria:
N2: Tumour meets ANY of the following criteria
N3: Tumour meets ANY of the following criteria:
If Using Pathological Diagnosis
NX: Same as “Clinical Diagnosis – NX”
N0: Same as “Clinical Diagnosis – N0”
N1: Same as “Clinical Diagnosis – N1”
N2: Tumour meets ANY of the following criteria
N3: Tumour meets ANY of the following criteria:
M0: No evidence of distant metastasis
M1: Evidence of distant metastasis
Specific treatment depends on the location, type, and stage of the tumour. [16] Treatment may involve surgery, radiotherapy, or chemotherapy, alone or in combination. [16]
Surgical Treatment
Surgical treatment may involve partial or full removal of the tumour. [17] Neighbouring tissues and structures may or may not be removed, depending on their involvement in the tumour’s structure and spread. [18] Full removal of the larynx may be necessary in some cases.
Adjunct Treatment
Adjunct treatment, most commonly the administration of chemotherapy or radiotherapy, may be necessary. [18] Chemotherapy or radiotherapy may be necessary singly, in combination with each other, or in combination with surgery. [15] Adjunct treatment may be necessary prior to surgical treatment, alongside surgical treatment, or after surgical treatment. Clinical decision-making can be difficult in circumstances where the patient is unable to access necessary adjunct treatment.
Multi-Disciplinary Treatment
Often, successful treatment of and recovery from laryngeal cancer will involve expertise outside of the realms of surgery or oncology. Physical therapists, occupational therapists, speech therapists, psychiatrists, psychologists, oral/maxillofacial surgeons, dentists, neurologists, neurosurgeons, and endocrinologists may all become involved in the care of patients with laryngeal cancer.
Incidence is five in 100,000 (12,500 new cases per year) in the US. [19] The American Cancer Society estimated that 9,510 men and women (7,700 men and 1,810 women) would be diagnosed with and 3,740 men and women would die of laryngeal cancer in 2006.[ citation needed ]
According to the GLOBOCAN 2018 estimates of cancer incidence and mortality produced by the International Agency for Research on Cancer, there were 177,422 new cases of laryngeal cancer worldwide in 2018 (1.0% of the global total.) Among worldwide cancer deaths, 94,771 (1.0%) were due to laryngeal cancer. [20]
In 2019, it is estimated that there will be 12,410 new laryngeal cancer cases in the United States, (3.0 per 100,000). [21] The number of new cases decreases every year at a rate of 2.4%, [21] and this is believed to be related to decreased cigarette smoking in the general population. [22]
Laryngeal cancer is listed as a "rare disease" by the Office of Rare Diseases (ORD) of the National Institutes of Health (NIH). This means that laryngeal cancer affects fewer than 200,000 people in the US. [23]
The larynx, commonly called the voice box, is an organ in the top of the neck involved in breathing, producing sound and protecting the trachea against food aspiration. The opening of larynx into pharynx known as the laryngeal inlet is about 4–5 centimeters in diameter. The larynx houses the vocal cords, and manipulates pitch and volume, which is essential for phonation. It is situated just below where the tract of the pharynx splits into the trachea and the esophagus. The word 'larynx' comes from the Ancient Greek word lárunx ʻlarynx, gullet, throatʼ.
A lymph node, or lymph gland, is a kidney-shaped organ of the lymphatic system and the adaptive immune system. A large number of lymph nodes are linked throughout the body by the lymphatic vessels. They are major sites of lymphocytes that include B and T cells. Lymph nodes are important for the proper functioning of the immune system, acting as filters for foreign particles including cancer cells, but have no detoxification function.
Kidney cancer, also known as renal cancer, is a group of cancers that starts in the kidney. Symptoms may include blood in the urine, a lump in the abdomen, or back pain. Fever, weight loss, and tiredness may also occur. Complications can include spread to the lungs or brain.
Oral cancer, also known as oral cavity cancer, tongue cancer or mouth cancer, is a cancer of the lining of the lips, mouth, or upper throat. In the mouth, it most commonly starts as a painless red or white patch, that thickens, gets ulcerated and continues to grow. When on the lips, it commonly looks like a persistent crusting ulcer that does not heal, and slowly grows. Other symptoms may include difficult or painful swallowing, new lumps or bumps in the neck, a swelling in the mouth, or a feeling of numbness in the mouth or lips.
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.
Cancer staging is the process of determining the extent to which a cancer has grown and spread. A number from I to IV is assigned, with I being an isolated cancer and IV being a cancer that has metastasized and spread from its origin. The stage generally takes into account the size of a tumor, whether it has invaded adjacent organs, how many regional (nearby) lymph nodes it has spread to, and whether it has appeared in more distant locations (metastasized).
The recurrent laryngeal nerve (RLN) is a branch of the vagus nerve that supplies all the intrinsic muscles of the larynx, with the exception of the cricothyroid muscles. There are two recurrent laryngeal nerves, right and left. The right and left nerves are not symmetrical, with the left nerve looping under the aortic arch, and the right nerve looping under the right subclavian artery, then traveling upwards. They both travel alongside the trachea. Additionally, the nerves are among the few nerves that follow a recurrent course, moving in the opposite direction to the nerve they branch from, a fact from which they gain their name.
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).
Prostate cancer staging is the process by which physicians categorize the risk of cancer having spread beyond the prostate, or equivalently, the probability of being cured with local therapies such as surgery or radiation. Once patients are placed in prognostic categories, this information can contribute to the selection of an optimal approach to treatment. Prostate cancer stage can be assessed by either clinical or pathological staging methods. Clinical staging usually occurs before the first treatment and tumour presence is determined through imaging and rectal examination, while pathological staging is done after treatment once a biopsy is performed or the prostate is removed by looking at the cell types within the sample.
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. The cells of anaplastic thyroid cancer are highly abnormal and usually no longer resemble the original thyroid cells and have poor differentiation.
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.
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.
Lung cancer staging is the assessment of the extent to which a lung cancer has spread from its original source. As with most cancers, staging is an important determinant of treatment and prognosis. In general, more advanced stages of cancer are less amenable to treatment and have a worse prognosis.
Hypopharyngeal cancer is a disease in which malignant cells grow in the hypopharynx the area where the larynx and esophagus meet.
Lobular carcinoma in situ (LCIS) is an incidental microscopic finding with characteristic cellular morphology and multifocal tissue patterns. The condition is a laboratory diagnosis and refers to unusual cells in the lobules of the breast. The lobules and acini of the terminal duct-lobular unit (TDLU), the basic functional unit of the breast, may become distorted and undergo expansion due to the abnormal proliferation of cells comprising the structure. These changes represent a spectrum of atypical epithelial lesions that are broadly referred to as lobular neoplasia (LN).
Breast cancer classification divides breast cancer into categories according to different schemes criteria and serving a different purpose. The major categories are the histopathological type, the grade of the tumor, the stage of the tumor, and the expression of proteins and genes. As knowledge of cancer cell biology develops these classifications are updated.
Sebaceous carcinoma, also known as sebaceous gland carcinoma (SGc), sebaceous cell carcinoma, and meibomian gland carcinoma, is an uncommon malignant cutaneous (skin) tumor. Most are typically about 1.4 cm at presentation. SGc originates from sebaceous glands in the skin and, therefore, may originate anywhere in the body where these glands are found. SGc can be divided into 2 types: periocular and extraocular. The periocular region is rich in sebaceous glands making it a common site of origin. The cause of these lesions in the vast majority of cases is unknown. Occasional cases may be associated with Muir-Torre syndrome. SGc accounts for approximately 0.7% of all skin cancers, and the incidence of SGc is highest in Caucasian, Asian, and Indian populations. Due to the rarity of this tumor and variability in clinical and histological presentation, SGc is often misdiagnosed as an inflammatory condition or a more common neoplasm. SGc is commonly treated with wide local excision or Mohs micrographic surgery, and the relative survival rates at 5 and 10 years are 92.72 and 86.98%, respectively.
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.
In CT scan of the thyroid, focal and diffuse thyroid abnormalities are commonly encountered. These findings can often lead to a diagnostic dilemma, as the CT reflects nonspecific appearances. Ultrasound (US) examination has a superior spatial resolution and is considered the modality of choice for thyroid evaluation. Nevertheless, CT detects incidental thyroid nodules (ITNs) and plays an important role in the evaluation of thyroid cancer.
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