Laryngeal Cancer

Laryngeal cancer, or voice box cancer, is a cancer that develops in the lower portion of the throat. In adults, the most common form of laryngeal cancer is squamous cell carcinoma, which is a cancer arising from the squamous cells that line the larynx. In children, the most common form of laryngeal cancer is a rhabdomyosarcoma, which is a type of sarcoma that develops in muscles that are attached to bones.

The larynx/voice box is the entry point to the trachea, and contains the vocal cords that allow us to speak. It consists of three main sections: the supraglottis, glottis and subglottis. The supraglottis is the top portion of the larynx, and provides a protective flap over the trachea that prevents foreign material, such as food, from entering the lungs. The middle portion, the glottis, contains the vocal cords that vibrate when air passes through and produces the voice. The bottom portion of the larynx is the subglottis, which provides passage to the trachea.

Laryngeal cancer is most commonly diagnosed in males, and is often diagnosed after the age of 55. However, anyone can get this disease.

Types of Laryngeal Cancer

There are several types of laryngeal cancer, which are categorised by the types of cells the cancer develops from.

Squamous Cell Carcinoma (SCC)

Squamous cell carcinomas (SCCs) are the most common form of laryngeal cancer in adults, and develops from the squamous cells that line the larynx. SCCs of the larynx can be aggressive, but can have a good prognosis. These tumours can be subcategorised into the part of the larynx they develop in.

Supraglottic Squamous Cell Carcinoma

Supraglottic SCCs are a less common subtype of laryngeal SCCs, and develop in the top portion of the larynx (supraglottis). Tumours that develop here (as well as their treatment) can adversely affect speech, swallowing, and/or breathing abilities. These cancers can be aggressive, are likely to metastasise early (notably to lymph nodes in the cervical spine), and may not have as good of a prognosis as other types of laryngeal SCCs.

A very rare variant of SCC, called basaloid SCC (BSCC), has a predilection to develop in the supraglottis. BSCC is very aggressive, and is often associated with a less favourable prognosis than other subtypes.

Glottic Squamous Cell Carcinoma

Glottic SCCs are the most common subtype of laryngeal SCCs that develop in the middle portion of the larynx (glottis). Tumours that develop here (as well as their treatment) can adversely affect speech, swallowing, and/or breathing abilities. Unlike supraglottic SCCs, glottic SCCs rarely metastasise due to the poor lymphatic drainage in this area. Glottic SCCs can be less aggressive, and can have a good prognosis.

Subglottic Squamous Cell Carcinoma

Subglottic SCCs are the rarest subtype of laryngeal SCCs that develop in the bottom portion of the larynx (subglottis). Tumours that develop here often produce minimal (if any) symptoms, often leading to a delayed diagnosis and an advanced stage of disease at diagnosis. These cancers can be aggressive, are likely to metastasise early (notably to nearby lymph nodes), and may not have as good of a prognosis as other types of laryngeal SCCs.

Transglottic Squamous Cell Carcinoma

Transglottic SCCs are the rarest subtype of laryngeal cancers, and occur when the tumour is in two portions of the larynx. This type of cancer always involves the glottis, and can also affect either the supraglottis or subglottis. There has been limited research done into the aggressiveness and prognosis of this subtype.

Minor Salivary Gland Cancer

Salivary glands are responsible for the production of saliva, which is a fluid that aids in digestion, prevents your mouth from becoming too dry and supports healthy teeth. Humans have three pairs of major salivary glands behind the jaw, as well as several minor salivary glands found in the lips, cheeks, mouth, and throat. The minor salivary glands in the throat are found under the lining of the larynx and hypopharynx.

For more information on salivary gland cancers, please refer to the Rare Cancers Australia Salivary Gland Cancers page.

Laryngeal Papillomas

Laryngeal papillomas are the most common type of laryngeal tumour in children, and are often benign. They are generally considered low grade tumours, as they often develop slowly and rarely metastasise. Laryngeal papillomas often have a good prognosis.

Sarcomas

Laryngeal sarcomas are a less common type of laryngeal cancer that develops from the soft connective tissues that help give the larynx its shape. These cancers can be aggressive and can metastasise, however they can have a good prognosis. Types of sarcomas associated with laryngeal cancer include:

Rare types of Laryngeal Cancer

These types of laryngeal cancer are very rare:

  • Basloid squamous cell carcinomas (BSCCs) (a rare variant of SCCs).
  • Lymphomas.
  • Melanomas (mucosal).
  • Neuroendocrine tumours.
  • Plasmacytomas.
  • Sarcomatoid carcinoma (a tumour that has parts of both carcinomas and sarcomas).
  • Verrucous carcinomas (a rare variant of SCCs).

Treatment

If laryngeal cancer is detected, it will be staged and graded based on size, metastasis, and how the cancer cells look under the microscope. Staging and grading helps your doctors determine the best treatment for you.

Cancers can be staged using the TNM staging system:

  • T (tumour) indicates the size and depth of the tumour.
  • N (node) indicates whether the cancer has spread to nearby lymph nodes.
  • M (metastasis) indicates whether the cancer has spread to other parts of the body.

This system can also be used in combination with a numerical value, from stage 0-IV:

  • Stage 0: this stage describes cancer cells in the place of origin (or ‘in situ’) that have not spread to nearby tissue.
  • Stage I: cancer cells have begun to spread to nearby tissue. It is not deeply embedded into nearby tissue and had not spread to lymph nodes. This stage is also known as early-stage cancer.
  • Stage II: cancer cells have grown deeper into nearby tissue. Lymph nodes may or may not be affected. This is also known as localised cancer.
  • Stage III: the cancer has become larger and has grown deeper into nearby tissue. Lymph nodes are generally affected at this stage. This is also known as localised cancer.
  • Stage IV: the cancer has spread to other tissues and organs in the body. This is also known as advanced or metastatic cancer.

Cancers can also be graded based on the rate of growth and how likely they are to spread:

  • Grade I: cancer cells present as slightly abnormal and are usually slow growing. This is also known as a low-grade tumour.
  • Grade II: cancer cells present as abnormal and grow faster than grade-I tumours. This is also known as an intermediate-grade tumour.
  • Grade III: cancer cells present as very abnormal and grow quickly. This is also known as a high-grade tumour.

Once your tumour has been staged and graded, your doctor may recommend genetic testing, which analyses your tumour DNA and can help determine which treatment has the greatest chance of success. They will then discuss the most appropriate treatment option for you.

Treatment is dependent on several factors, including location, stage of disease and overall health. In adult patients, your tumour will be staged and graded to help determine the best treatment option for you. There is currently no standard staging system for children with laryngeal cancer.

The treatment options for adults and children with laryngeal cancer are similar. These options may include:

  • Surgery, potentially including:
    • Laser therapy.
    • Laryngectomy.
    • Thyroidectomy.
  • Radiation therapy.
  • Chemotherapy.
  • Targeted therapy.
  • Immunotherapy.
  • Clinical trials.
  • Palliative care.

Risk factors

  • Smoking tobacco.
  • Drinking alcohol.
  • Infection with the human papillomavirus (HPV).
  • Exposure to hazardous chemicals.
  • Having a weakened immune system.
  • Having a family history of laryngeal cancer.

Not everyone with these risk factors will develop the disease, and some people who have the disease may have none of these risk factors. See your general practitioner (GP) if you are concerned.

Symptoms

Potential symptoms of laryngeal cancers include:

  • Changes in the voice, such as an unusual hoarseness.
  • Persistent sore throat.
  • Difficulty and/or painful swallowing.
  • Persistent cough.
  • Dyspnea.
  • Unexplained weight loss.
  • Pain in the ear.

Not everyone with the symptoms above will have cancer, but see your GP if you are concerned.

Diagnosis

If your doctor suspects you have laryngeal cancer, they may order the following tests to confirm the diagnosis and refer you to a specialist for treatment:

  • Physical examination.
  • Imaging tests, potentially including:
    • MRI (magnetic resonance imaging).
    • CT (computed tomography) scan.
    • PET (positron emission tomography) scan.
  • Blood tests.
  • Exploratory surgery, potentially including:
    • Endoscopy.
    • Laryngoscopy/Microlaryngoscopy.
  • Biopsy.

References

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