Larynx cancer is a type of head and neck cancers. It is the 9th most common type of cancer in India. In 2018, 28,721 new cases of larynx cancer were reported in India.
Larynx is the part between the base of the tongue and the trachea, which is made up of cartilages. It contains the vocal cords, which vibrate and produce sounds and help to speak. The larynx also helps to breathe and swallow. There are three parts of the larynx- the upper part or the supraglottis, the middle part or the glottis, and the lower part or the subglottis.
Approximately 35% of laryngeal cancers begin in the supraglottis, 60% in the glottis, and only 5% in the subglottis.
About larynx cancer
Larynx cancer is a rare type of head and neck cancer, which occurs in the larynx or the voice box. Cancer is a rapid, uncontrollable growth of cells that cause damage to the body. Usually, the laryngeal cancers occur in the squamous cells, the cells that line the inside of larynx. In the later stages the cancer may spread to nearby tissues or organs such as the trachea, thyroid, esophagus, lymph nodes in the neck, upper part of the spinal column, and other parts of the body.
The exact cause of larynx cancer is not known. However, there are several factors that increase the risk of larynx cancer. These factors include:
- Age over 55 years old
- Male gender (they have five times more risk than women)
- Personal or family history of head and neck cancer
- Smoking tobacco and other products
- Having large amounts of alcohol
- Following an unhealthy diet
- Exposure to substances like asbestos, coal dust, wood dust, sulfuric acid mist, nickel, etc.
Signs and symptoms
Some of the signs and symptoms of larynx cancer are listed below:
- A sore throat or cough for a long period
- Change in voice, such as hoarseness for more than two weeks
- Ear pain
- Pain or trouble when swallowing
- A lump in the neck or throat
- Problems producing voice (dysphonia)
Reach out for medical help in case of the following symptoms:
- High-pitched and noisy breathing (stridor)
- Trouble breathing (dyspnea)
- Feeling like there is something in the throat (globus sensation)
- Coughing blood (hemoptysis)
The tests discussed below can help diagnose larynx cancer:
Physical exam: The neck is examined to check for any abnormal signs of larynx cancer. A gloved finger can be used to examine the insides of the mouth and throat.
Laryngoscopy: It is a procedure in which a thin, tube-like instrument with a light and a lens (laryngoscope) is inserted into the throat via mouth. A tool may be used to remove the sample tissue, which is then examined under the microscope.
Biopsy: A small piece of the larynx is removed to be examined under the microscope.
Computed tomography (CT) scan: In this procedure, a series of cross-sectional images of the areas inside the body are produced using X-rays. In larynx cancer, it is done to determine the extent of the cancer.
Magnetic resonance imaging (MRI): In this test, clear images of various parts of the body are obtained using radio waves, a large magnet, and a computer. MRI scan is recommended when CT scan is not able to provide all the necessary information about the larynx cancer.
PET scan: In this method, a very small dose of a radioactive chemical is injected into a vein, which is absorbed by the organs and tissues. A scanner produces three-dimensional images from the energy released by the radioactive substance. This scan is recommended to get a detailed information about the cancer.
Bone scan: This scan is recommended when any signs that cancer have spread to bones are noticed. In this procedure, a very small amount of a radioactive chemical is injected into a vein, which gets collected in the bones with cancer and can be detected by a scanner.
Barium swallow: This test is recommended to examine irregularities in different regions of the throat.
Stages of Larynx Cancer:
The following are the stages of larynx cancer:
- Stage I: Cancer is formed in the supraglottis, glottis, or subglottis of the larynx and the vocal cords work normally.
- Stage II:
Supraglottis: Cancer is formed in one or more areas of supraglottis or has spread to the tissues near the vocal cords or the base of the tongue. The vocal cords function normally.
Glottis: Cancer has spread to the subglottis, supraglottis, or both, and/or vocal cords do not function normally.
Subglottis: Cancer has spread to one or both vocal cords; vocal cords may not function normally.
- Stage III: Cancer may be formed in more than one area, or may have spread through the thyroid cartilage, or may have spread to one or both vocal cords, may have spread to one lymph node (<3cm in size) on the same side of the neck as the primary tumor, vocal cords may or may not work normally.
- Stage IV: This stage is categorised into three substages based on whether the cancer has spread to nearby tissues such as the trachea, thyroid, esophagus or neck; cancer has spread to lymph node (<3c cancer m or >3cm and <6cm or >6cm in size) on the same side of the neck as the primary tumor; they has spread through the outside covering of the lymph node; the vocal cords may not work normally, and whether cancer has spread to other parts of the body, such as the bones, lungs, or liver.
There are different types of treatment available for patients with larynx cancer. These include radiation therapy, chemotherapy, or surgery. A combination of these methods can be used for appropriate patients. Doctors may suggest any clinical trial if it appears to be more promising than the beforementioned methods.
During radiation therapy, high energy X-rays are delivered to kill the cancer cells. To treat larynx cancer, hyperfractionated radiation may be used. In this type of radiation treatment, less than usual total daily dose of radiation is divided into two doses and given two times a day. This radiation is given at the same time as the standard radiation therapy.
Chemotherapy involves the use of drugs to kill or to slow the growth of cancer cells. When the drugs are given, they enter the bloodstream and reach the cancer cells throughout the body. These drugs are usually given intravenously.
Surgery can be recommended for all stages of larynx cancer. When performed in the early stage of cancer, surgery aims to take out the cancer without removing the entire larynx and protect the major functions of larynx. For advanced stage cancers, the larynx is removed completely (laryngectomy).
Below are some of the surgical procedures used to treat larynx cancer. The most appropriate approach will be selected for each patient.
- Cordectomy: Only the vocal cords are removed.
- Supraglottic laryngectomy: Only the supraglottis is removed.
- Hemilaryngectomy: The half of the larynx is removed and saves the voice.
- Partial laryngectomy: A part of the larynx is removed and saves the ability to talk.
- Total laryngectomy: The whole larynx is removed. A hole is made in the front of the neck for easy breathing (tracheostomy).
- Thyroidectomy: All or a part of the thyroid gland is removed.
- Laser surgery: A narrow laser beam is used as a knife to make bloodless cuts in tissue or surface.
After the cancer is removed, some patients may be given radiation or chemotherapy to kill the remaining cancer cells (if any). These treatments can also be given to reduce the recurrence of cancer; it is called adjuvant therapy.
Immunotherapy involves using the patient's immune system to fight cancer. The substances produced by the body or made in the laboratory can direct, boost or restore the natural defence against cancer. For treating larynx cancer, immune checkpoint inhibitors such as nivolumab and pembrolizumab can be used.
The prognosis of a patient depends on the stage, location, size and grade of the tumor, the patient’s age, gender, and general health. Cancers found in the early stage have a greater cure rate than those found in the late stage. Cancers that have invaded other areas of the body have a poor survival rate. After being diagnosed with larynx cancer, one must stop smoking, as it can improve the prognosis. Continuing to smoke after treatment can increase the risk of cancer recurrence, delay the healing process, worsen the side effects of the treatment, and prevent the patient’s voice from recovering completely.
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