larynx cancer

The larynx (larynx) is formed from cartilage, muscle and mucosal tissue. It is located below the pharynx and forms the entrance to the trachea. At the top (at the base of the tongue) is the larynx. Behind the larynx is the entrance to the esophagus. When you swallow, the larynx closes off the windpipe. This prevents food from entering the trachea, but slides into the esophagus.

Your vocal cords (glottis) are also located in the larynx. When air flows through the larynx, it causes the vocal cords to vibrate at the desired height. The height of the vibration determines the pitch of the sound that is produced in this way. The larynx thus plays an essential role in speaking and singing.

What is larynx cancer?

All forms of cancer have one thing in common: in body cells, errors have arisen in the genes (the genetic material) that regulate their division, growth and development. This makes them behave very differently. These derailed cells are cancer cells. They are characterized by their unrestrained division, which causes them to grow into growths, or tumors. In addition, unlike benign growths (eg warts), these malignant tumors can invade surrounding tissues and organs. Cancer cells can also become detached from it. These can spread through the blood and/or lymph nodes to other places in the body to form new tumors there.

Laryngeal cancer usually develops in the lining of the larynx. There are different forms:

• Glottic tumor. The tumor forms on or near the vocal cords (the glottis). A glottic tumor is usually discovered quickly because it causes voice change or hoarseness.
• Supraglottic tumor. The tumor starts in the upper part of the esophagus, which also contains the larynx (the supraglottis). A supraglottic tumor does not cause symptoms until late, such as pain in the throat and swallowing difficulties. Usually the tumor is already large by then.
• Subglottic tumor. The tumor grows in the piece of esophagus that is located under the vocal cords (subglottis).

By the precancerous stages of laryngeal cancer we mean changes in the larynx tissue that, without treatment, can degenerate into malignant tumors. This can manifest itself in a chronic irritation of the vocal cords. The symptoms of this are the same as with larynx cancer, such as persistent hoarseness.

If laryngeal cancer is not detected in time, the tumor can metastasize. In the first instance, this concerns metastases in the lymph nodes in the neck. The risk of metastasis is greatest in supraglottic tumors because there are more lymphatic vessels here than in the rest of the larynx. When the disease has reached an advanced stage, cancer cells can lodge in other organs, such as the lungs, via the blood.

Numbers

It is estimated that every year about 700 Dutch people are told that they have larynx cancer. This is about five in every 100,000 people. About two-thirds of them are glottic tumors. Nearly one third of patients have the supraglottic form. A subglottic tumor is rare.

Men get laryngeal cancer much more often (4.5-6 times) than women. However, the number of female patients has clearly increased in recent years. This is probably related to the fact that women have started smoking and drinking (alcohol) more in recent decades.

The disease mainly occurs between the ages of 55-74.

Causes and risk factors

It is unknown exactly how laryngeal cancer develops. However, a link has been discovered between the disease, smoking and excessive alcohol consumption. Other risk factors include:

• Prolonged inhalation of irritants, such as asbestos and some chemical and metal fumes.
• Frequent exposure to radioactive radiation.
• A chronic infection by the Human Papillomavirus (HPV). This sexually transmitted virus can cause cancer in the pharynx, oral cavity and larynx during oral sex. You can get genital warts and cervical cancer through vaginal sex.
• Hereditary predisposition may also play a role. Some people seem to be more susceptible to the effects of carcinogens, such as cigarette smoke.

The symptoms

The symptoms of larynx cancer depend on where the tumor grows in the larynx.

On/near the vocal cords (glottis):

• Hoarseness that does not go away.

Above the vocal cords (supraglottis):

• A sore throat.
• A dry or sore throat.
• The feeling of having a lump in the throat.
• Often choke.
• Increased mucus production.
• Coughing up bloody mucus.
• Bad breath.

Below the vocal cords (subglottis):

• Vague cough symptoms.

Regardless of location, a large tumor in the larynx can cause shortness of breath, a lot of mucus in the throat, difficulty swallowing and pain radiating to the ear.

The diagnosis of larynx cancer

Do you have complaints that may indicate laryngeal cancer? Make an appointment with your doctor. He will first examine you physically and then may prescribe medication. Think, for example, of a cough syrup, an expectorant or antibiotics. If this does not improve after a week, it is very important that you raise the alarm again. If necessary, the GP will refer you to an ear, nose and throat specialist (ENT specialist).

Various studies

An ENT specialist will perform various tests to determine whether your symptoms are the result of laryngeal cancer, including:

• mirror. The doctor uses a mirror on a long handle to inspect the entrance to your larynx and vocal cords.
• Flexible laryngoscopy. The doctor will insert a thin flexible tube through your nose. At the end is a camera, with which he can see your pharynx.
• Stroboscopy. A strobe is a thin tube that houses a camera. This allows the doctor to make a video recording of the vocal cords and assess their vibration function. He inserts this instrument through the mouth.

If the doctor sees something abnormal during these examinations, further investigation will follow to determine whether or not it is cancer and, if so, how far the tumor has spread and/or whether there are metastases. The latter determines the stage of the disease. You can get the following exams:

• CT scan/ MRI scan. A CT scan is a device that uses X-rays to create very detailed images of the inside of your body. An MRI scan does this using a magnetic field in combination with radio waves and a computer.

• Ultrasound with puncture of the neck glands. The neck glands are made visible with sound waves. If the images show possible metastases, the doctor will aspirate some tissue from suspicious glands with a needle. This is examined under the microscope. The results indicate whether there are metastases in the lymph nodes.
• PET scan (Positron Emission Tomography). The doctor gives the patient a small amount of radioactive sugar molecules. Because cancer cells use a lot of energy (in the form of sugar), the radioactive sugar accumulates in it. They can be made visible with a scanning device.

The treatment

The treatment of laryngeal cancer depends on the size and location of the tumor, how far it has grown into surrounding tissue and/or has spread. The age and condition of the patient also play a role.
The most common forms of treatment are:

• laser therapy. A certain type of light rays kill tumor tissue. This form of treatment is used if the tumor is small or threatens to close the trachea due to its size.
• Radiation (radiation therapy). Ionizing radiation destroys cancer cells. The duration and extent of radiotherapy depends on the stage of the disease.

• Chemotherapy. The doctor administers medication that inhibits the cell division of cancer cells. In laryngeal cancer, this form of treatment is often only applied palliatively. This means that the treatment is no longer aimed at a cure, but at alleviating the symptoms for as long as possible.

• Operation. The doctor removes all or part of the larynx (total laryngectomy). In addition, it may be necessary to (partially) remove the thyroid gland. Due to a total laryngectomy, the patient no longer has vocal cords. In addition, the larynx is gone, so that there is a direct connection between the throat and a trachea. To prevent food from entering the windpipe, a so-called tracheostomy is performed. As a result, there is no longer a connection between the mouth, pharynx and the trachea. An opening is made at the bottom of the neck for breathing.

Outlook

Larynx cancer is often detected at an early stage in the Netherlands. The prospects are then favourable.

The average five-year survival rate of larynx cancer is 70 percent. The prognosis in women is slightly better than in men. The chance that patients with a small glottic tumor are still alive after 5 years is 80-92 percent. In about 60 percent of patients who had a total laryngectomy, the disease does not recur within 5 years.

Patients with late stage (IV) larynx cancer have a five-year survival rate of less than 3 percent.