What Is Laryngeal Cancer (Cancer Of The Larynx)? What Causes Laryngeal Cancer?

Editor's Choice
Main Category: Cancer / Oncology
Also Included In: Ear, Nose and Throat
Article Date: 20 Nov 2009 - 0:00 PST

email to a friend   printer friendly   view / write opinions

Laryngeal cancer (cancer of the larynx) is a rare type of cancer. It can cause hoarseness of the voice and swelling of the throat.

The larynx, also known as the voice box, is a tube-like structure found at the entrance of the trachea (windpipe). The lump at the front of the throat, commonly known as the Adam's apple, is the larynx.

The larynx has three main functions:

• Helping to channel oxygen into the trachea when breathing
  
  
• Acting like a valve, closing off the trachea when swallowing to prevent food or liquid from entering the airways
  
  
• It has two membranes (the vocal cords) which vibrate as air passes through them, producing the sound of the voice

Laryngeal cancer is rare and approximately four out of five cases are in men. The condition mostly affects older people. The average age for the onset of symptoms is 60.

The two biggest contributing factors to getting laryngeal cancer are alcohol and tobacco use. It is estimated that 75 percent of all cases are caused by alcohol or tobacco use.

Recent evidence indicates that the human papilloma virus (HPV) may also be responsible for some cases of laryngeal cancer, particularly in younger people.

As with most cancers, the outlook for laryngeal cancer is mainly determined by what stage the cancer has reached when it is diagnosed.

If the cancer is in its early stages and has not spread outside the larynx, the chance of being completely cured is relatively high. Laryngeal cancer can be treated with a combination of surgery, radiotherapy, chemotherapy and a medicine called cetuximab.

Different types of laryngeal cancer:

• Nasopharyngeal cancer begins in the nasopharynx which is the part of the throat just behind the nose.
  
  
• Oropharyngeal cancer begins in the oropharynx which is the part of the throat that is right behind the mouth.
  
  
• Hypopharyngeal cancer (laryngopharyngeal cancer) begins in the hypopharynx (laryngopharynx) which is the lower part of the throat, just above the esophagus and windpipe.
  
  
• Glottic cancer begins in the vocal cords.
  
  
• Supraglottic cancer begins in the upper portion of the larynx and includes cancer that affects the epiglottis, which is a piece of cartilage that blocks food from going into the windpipe.
  
  
• Subglottic cancer begins in the lower portion of the voice box, below the vocal cords.

What are the signs and symptoms of laryngeal cancer?

A symptom is something the patient feels and reports, while a sign is something other people, such as the doctor notice. For example, pain may be a symptom while a rash may be a sign.

Most cases of laryngeal cancer develop near the vocal cords; therefore the initial symptom is often a noticeable change in the sound of the voice. In many cases, the voice may be unusually hoarse or husky.

Other symptoms include:

• a lump in the neck
• difficulty breathing
• ear pain
• pain when swallowing
• difficulty swallowing
• persistent coughing
• sore throat
• unexplained weight loss

If any of those symptoms last for more than three weeks, it is recommended to seek medical advice. These symptoms are similar to those for many other conditions. It is unlikely that they are caused by cancer. It is a good idea to rule out more serious causes of the symptoms.

What causes laryngeal cancer?

Cancer begins with a change in the structure of DNA which provides cells with a basic set of instructions (such as when to grow and reproduce). A change in its structure is called a genetic mutation. It can alter these instructions and cause the cells to reproduce uncontrollably. As a result, this produces a lump of tissue known as a tumor.

If left untreated, cancer can quickly grow and spread to other parts of the body. Cancer usually spreads through the lymphatic system (a series of glands or nodes located throughout the body). Once the cancer reaches the lymphatic system, it can spread to any other part of the body.

Alcohol and tobacco

Evidence shows that alcohol and tobacco are the two biggest risk factors for laryngeal cancer.

There is indication that alcohol and tobacco contain chemicals which affect the normal functioning of the cells of the larynx. This triggers mutations which can lead to cancer. Drinking alcohol and smoking carry individual risks. However, the association of both greatly increases the risks.

Research has shown that smoking 40 cigarettes a day without drinking alcohol increases the risk of developing laryngeal cancer by five times. In addition, drinking the equivalent of 30 pints of beer a week without smoking also increases the risk of getting laryngeal cancer by five times. However, smoking more than 40 cigarettes a day and drinking an average of 30 pints a week, increases the risk of developing laryngeal cancer by 38 times.

Human papilloma virus (HPV)

The human papilloma virus (HPV) is a family of viruses which affect the skin and moist membranes that line the body (cervix, anus, mouth and throat).

Research has revealed that HPV may increase the risk of getting laryngeal cancer. HPV is known to cause changes in the cells of the cervix, leading to cervical cancer. It is thought that it may have a similar effect on the cells of the larynx. HPV is spread during sexual intercourse (including anal and oral sex).

Diet

Evidence suggests that a diet high in red meat, processed food and fried food can increase the risk of developing laryngeal cancer.

Occupational exposure

Exposure to high levels of certain substances may increase the risk of developing laryngeal cancer. These substances include:

• coal dust
• diesel fumes
• formaldehyde (a chemical used in a wide range of industrial processes, such as paint manufacturing and cosmetics)
• isopropyl alcohol (often used as a cleaning solvent)
• nickel
• paint fumes
• wood dust

How is laryngeal cancer diagnosed?

During medical evaluation the inside and outside of the throat are checked for any abnormalities, such as lumps and swellings, as well as a review of symptoms and recent medical history.

A blood test may be required to rule out other possible causes of the symptoms, such as infection.

Nasoendoscope

A nasoendoscope is a medical instrument which consists of a small tube with a light. The tube can be threaded through one of the nostrils and passed into the back of the throat, allowing a clearer view of the larynx. The procedure is not painful but can sometimes feel a little uncomfortable; therefore an anesthetic spray is often used to numb the nose and throat.

Panendoscope

A panendoscope is similar to a nasoendoscope but is longer and contains a camera as well as a light. It is often used when the results of earlier tests are inconclusive or detected a possible problem. The panendoscope can show much more of the larynx in greater detail. This procedure can be painful so is usually performed under general anesthetic.

Biopsy

A small sample of suspected cancerous tissue is removed and sent to a laboratory to check for cancerous cells. It is often performed at the same time as using the nasoendoscope or panendoscope. Small instruments are passed down the tube and used to remove a tissue sample.

When there is a noticeable lump in the neck, a needle can be used to draw out a sample of tissue. This is known as fine needle aspiration (FNA).

Further testing

If the biopsy results show that there is cancer and there is a risk it may have spread, further testing will assess how widespread the cancer is. These tests may include X-rays, computerized tomography (CT) scans and magnetic resonance imaging (MRI) scans.

What is the treatment for laryngeal cancer?

It can be difficult to decide which treatment is best, the cancer team will make recommendations, but the final decision will be the patient´s.

Staging

Health professionals use a four-stage system to describe how far laryngeal cancer has advanced. The four stages are:

• Stage 1. The cancer is contained in the top layers of tissue that cover the larynx. The vocal cords are usually unaffected.
  
  
• Stage 2. The cancer has spread deeper into the larynx, affecting the normal working of the vocal cords and making the voice hoarse. Nearby lymph nodes are unaffected.
  
  
• Stage 3. The cancer has spread throughout the larynx and one of the vocal cords is no longer able to move. It results in loss of voice. Small lymph nodes near the larynx may also contain cancerous cells.
  
  
• Stage 4. The cancer has spread beyond the larynx and into the larger lymph nodes. In very advanced cases, the cancer can also spread to another part of the body, usually the lungs.

In early stage-one laryngeal cancer, it may be possible to remove the cancer using radiotherapy alone. Later stage-one and stage-two cancer will probably require a combination of surgery and radiotherapy.

In stages three and four, more extensive surgery may be required as well as radiotherapy and chemotherapy. In particularly severe cases, the entire larynx may have to be removed.

Radiotherapy

It uses controlled doses of high-energy radiation to destroy cancerous cells and can be used as a primary treatment in early-stage laryngeal cancer. It is also often used as a secondary treatment before or after surgery to stop cancerous cells from returning.

The energy beams used during radiotherapy have to be precisely targeted on to the larynx. A special plastic mask is made to hold the head in the right position. During the first visit to the radiotherapist, a mould of the patient´s face is taken to make the mask.

Radiotherapy is usually given in short daily sessions during the week, with a break from treatment at the weekend. As well as killing cancerous cells, radiotherapy can affect healthy tissue and has a number of side effects, including:

• dry mouth
• loss of appetite
• loss of taste
• mouth ulcers
• nausea
• sore mouth
• sore throat
• sore, red skin (similar to a sunburn)
• tiredness

Protective gels can be used to treat mouth ulcers and medicines can help to relieve a dry mouth.

Sometimes, radiotherapy can cause the tissues of the throat to become inflamed. If the inflammation is severe, it can cause breathing difficulties that should be reported to a doctor.

Most side effects should pass after radiotherapy has been completed. Symptoms such as tiredness and dry mouth can last for several months after treatment.

Surgery

There are four types of surgery which are used to treat laryngeal cancer:

• laser surgery
• endoscopic resection
• partial laryngectomy
• total laryngectomy

Laser surgery. It is used if the tumor in the larynx is still very small. A fiber optic cable is placed into the larynx and a laser is passed through the cable to destroy cancerous cells.

The operation is carried out under a general anesthetic and usually requires an overnight stay at the hospital.

Endoscopic resection. It can be used to treat stage-one and stage-two laryngeal cancer. An endoscope (a small flexible tube with a light and a camera) is used. Small surgical instruments can also be passed down through the endoscope.

The endoscope is guided into the larynx. The camera relays images to a screen to view the larynx in detail. The surgeon will remove any cancerous cells, using either a laser or surgical instruments.

An endoscopic resection is carried out under general anesthetic and does not cause any long-lasting side effects. Some soreness in the mouth and throat may be experienced for a few weeks afterwards.

Partial laryngectomy. It is usually used to treat stage-three laryngeal cancer. The operation involves surgically removing the affected part of the larynx. Some of the vocal cords will be retained. As a result, the voice may be quite hoarse or weakened.

While the larynx is healing it may not be able to function in helping to breathe. If this is the case, the surgeon will create a temporary hole in the neck which is attached to a tube to help breathing. This is known as a temporary tracheotomy. Once the larynx has healed, the tube can be removed and the hole will heal. There may be a small amount of scarring.

Total laryngectomy. It is usually used to treat advanced stage-three or stage-four laryngeal cancer. The operation involves removing the entire larynx. Nearby lymph nodes may also need to be removed if the cancer has spread to them.

As vocal cords will be removed, the patient will not be able to speak in the usual way. There are several ways to help restore speech. A total laryngectomy requires a permanent tracheotomy. The tube will usually be removed after a few weeks, leaving the hole (stoma).

Having a permanent tracheotomy can seem disturbing and frightening at first, but most people get used to the stoma after a few months.

Chemotherapy. It is often used in combination with radiotherapy before surgery to treat advanced laryngeal cancer. Chemotherapy uses powerful cancer-killing medicines to damage the DNA of the cancerous cells and stop them from reproducing.

Chemotherapy can often be used to shrink a tumor, which means it is not necessary to remove the entire larynx during surgery.

The medicines used in chemotherapy can sometimes damage healthy tissue as well as the cancerous tissue. Unfortunately, side effects are common. They can include:

• hair loss
• mouth ulcers
• nausea
• sore mouth
• tiredness
• vomiting

Once the treatment has finished, these side effects should stop.

Monoclonal antibody therapy. It can be used to treat stage-three or stage-four laryngeal cancer and is also used when chemotherapy is not possible. It uses a medicine called cetuximab.

Cetuximab targets special proteins called epidermal growth factor receptors (EGFRs), which are found on the surface of cancer cells. EGFRs help the cancer to grow, so by targeting these proteins cetuximab can prevent the cancer from spreading. The medicine is given intravenously.

The side effects are usually mild and include:

• breathlessness
• conjunctivitis (inflammation of the eyes)
• diarrhea
• nausea
• skin rashes

In some people, cetuximab can trigger allergic reactions, such as a swollen tongue or throat. Occasionally, the allergic reaction can be severe and life threatening and is known as an infusion reaction. Infusion reactions occur in around 3 percent of people who take cetuximab. Most infusion reactions occur within 24 hours of the start of the treatment. Therefore there is close monitoring once treatment begins. Infusion reaction can be relieved with anti-allergy medicines (such as corticosteroids).

What are the complications of laryngeal cancer?

Vocal restoration

If the larynx has been completely removed as part of the treatment for laryngeal cancer, additional treatment may be needed to restore the voice. A speech and language therapist (SLT) will work with the patient after the operation.

There are several treatment options available:

• Electropharynx. It is a small electrical device that vibrates, producing sound. By holding the device under the chin and moving the mouth and lips, the vibrations translate into spoken words.
  
  
• Oesophageal speech. It is a technique for speaking that can be taught by SLTs. It involves learning to push through the esophagus. As the air moves through the esophagus, it vibrates and makes a noise. Some people find it easy to learn esophageal speech but some find it more difficult.
  
  
• Voice prosthesis. It is an artificial valve which can be implanted into the neck. The voice produced by the valve sounds natural, although it may be lower pitched than before.

How can laryngeal cancer be prevented?

There is no confirmed method to prevent throat cancer from occurring. But in order to reduce the risk of throat cancer some recommendations can be followed:

• Drink alcohol only in moderation. For women and older adults, this means no more than one drink a day. For men, moderate drinking means no more than two drinks a day.
  
  
• Opt for a healthy diet full of fruits and vegetables. The vitamins and antioxidants in fruits and vegetables may reduce the risk of throat cancer. Eat a variety of colorful fruits and vegetables. Research shows that eating a diet high in fresh vegetables (particularly tomatoes), citrus fruits (oranges, grapefruits and lemons), olive oil and fish oil can help reduce the risk of getting laryngeal cancer. This is often called a 'Mediterranean-style' diet.
  
  
• Stop smoking or do not start smoking. Do not smoke. Smoking makes treatment less effective, it makes it harder for the body to heal after surgery and increases the risk of getting another cancer in the future. Get medical advice on the benefits and risks of the many stop smoking strategies, such as medication, nicotine replacement products and counseling.
  
  
• Use caution around chemicals. When working with chemicals, whether on the job or around the house, carefully follow the directions. Avoid breathing hazardous chemical fumes. Properly ventilate the room and wear a mask over nose and mouth.

Alternative medicine

No alternative treatments have proved helpful. However, some complementary and alternative treatments may help cope with the diagnosis and with the side effects of cancer treatment. Alternative treatments that may be helpful include:

• Acupuncture
• Massage therapy
• Meditation
• Relaxation techniques

You can take steps to help you feel more in control and to help you cope with your cancer diagnosis. To cope, try to:

• Find out all the information about your laryngeal cancer. Write down a list of questions to ask your doctor. Ask your doctor about further sources of information about your cancer. The more you know about your specific condition, the more comfortable you will feel in making treatment decisions.
  
  
• Find someone to talk with. Seek out sources of support that can help you deal with the emotions you are feeling. Close friends or family members can be good listeners. Clergy members and counselors are other options. Consider joining a support group for people with cancer.
  
  
• Taking care of yourself during cancer treatment. Make keeping your body healthy during treatment a priority. Avoid extra stress. Get enough sleep each night. Take a walk or find time to exercise. Make time for relaxing, such as listening to music or reading a book.
  
  
• Go to all of your follow-up appointments. Unfortunately, cancer can recur after treatment. Your doctor will schedule follow-up exams every month or two during the first two years after treatment, and then less frequently after that. Follow-up exams can be stressful. They can remind you of your initial diagnosis and treatment. Expect some anxiety around the time of each follow-up appointment. Plan ahead by finding relaxing activities that can help redirect your mind away from your fears.

Written by Stephanie Brunner B.A.
Copyright: Medical News Today
Not to be reproduced without permission of Medical News Today