Laryngeal Carcinoma

Laryngeal Carcinoma

The larynx is an organ which participates in breathing, swallowing and sound production. It also prevents food from entering the windpipe. The larynx has three main parts: the supraglottis (back of the throat that closes the windpipe when you swallow, the glottis (the area of the vocal cords) and subglottis which is below the vocal cords. Cancer or carcinoma of the larynx is called laryngeal cancer or carcinoma. Any part of the larynx may be the site of carcinoma. The most prevalent type of laryngeal cancer is squamous cell carcinoma. The glottis is the most affected part followed by supraglottis and subglottis.

Types of carcinoma in larynx

There can be several types of cancer in larynx like carcinoma, sarcoma and myeloma. But, the carcinomas are predominant in most cases. There are two kinds of laryngeal carcinoma. These are:

Squamous cell carcinoma: It occurs in 95 % cases of larynx cancer. Cancer originates from the squamous cells of the larynx.

Adenocarcinoma: It is rare in comparison to squamous cell carcinoma. It originates from the adenomatous cells of the larynx, which produces mucous.

Symptoms of laryngeal carcinoma

  • Symptoms vary with the exact site of cancer (glottis, supraglottis and subglottis). In general, the symptoms may include the following:
  • Pain while swallowing
  • Hoarse voice which persists for more than two weeks (this eliminates the chances of having laryngitis, which does not persist so long)
  • Lump in the throat
  • Breathing problems
  • Pain in the ear
  • Coughing without any proper reasons

Causes of laryngeal carcinoma

Long term smoking: Smoking is the major cause of laryngeal cancer. A smoker has three times the risk of developing laryngeal cancer than a non-smoker.

Excessive consumption of alcohol: Heavy drinking has been associated with laryngeal carcinoma.

Age: Risk of laryngeal carcinoma increases with age. People over 50 years are more prone to getting affected.

Inadequate nutrition and weak immune system: The disease is more common in people who do not get proper vitamins and nutrients in their diet. Their immune system becomes weak and contributes to the risk of developing laryngeal carcinoma.

Exposure to asbestos and other toxic chemicals: Toxic chemicals and asbestos at the place of work can lead to higher risk of developing laryngeal carcinoma.

HPV infection: Infection of larynx by human papillovirus (HPV) may be a cause of laryngeal cancer. It is thought to be causing an increase in some of these cancers.

Gastroesophageal reflux disease (GERD): Gastroesophageal reflux disease (GERD) results in regurgitation of gastric acids and digestive juices into the esophagus after food has been swallowed. It may contribute to the development of laryngeal cancer but is more definitely associated with esophageal cancer.

Diagnosis

Physical exam of the throat and neck: This is initially done by the doctor to feel for swollen lymph nodes in the neck.

Laryngoscopy: A laryngoscope, which is a narrow tube like instrument with a light at its end, is used by specialist in ears, nose and throat to view the larynx. Doctors can also  look at the area using small mirrors similar to those used by dentists.

Endoscopy: This procedure requires a narrow tube like instrument called endoscope. The doctor inserts it through the mouth to have a view of the larynx. Abnormal growths like tumor can be detected using an endoscope. This procedure also helps to perform a biopsy.

There are two kinds of endoscopes which are used for the purpose of detecting laryngeal cancer: Nasoendoscope and Panendoscope.

The nasoendoscope is inserted through the nostrils which finally reach the larynx and gives a prominent view of the affected region. If the results of nasoendoscopy are not conclusive, then doctors use a panendoscope to get a better view of the region. The panendoscope is longer than the nasoendoscope. Both are performed under general anesthesia and used to take biopsies of suspicious areas.

Biopsy: Cells or tissues removed from the affected tissue are examined under a microscope in the laboratory to check for signs of cancer. It can be done while performing an endoscopy.

CT scan (CAT scan): The CT scan is a procedure by which images of the internal organs of the body can be obtained with a help of x-rays. A contrasting dye is sometimes injected in the veins so that the images are clearly understood. Sometimes contrast fluid is also given by mouth. The images can be viewed with the help of a computer.

MRI (magnetic resonance imaging): This imaging procedure is based on the use of radiowaves in the presence of a magnet. The images produced can be viewed with the help of a computer attached to the machine.

Imaging techniques are usual used to look for cancer and/or see how far it has spread.

Treatment

Radiation therapy

Radiation therapy is preferred if the cancer is diagnosed at an early stage. High energy x-rays are used to kill the cancer cells in the larynx. This can be done in two ways:

  • External radiation therapy: Radiation is given by a machine from outside the body at the affected region.
  • Internal radiation therapy: Radioactive substance sealed in a needle or wire is placed near the larynx. Radiation emitted from this radioactive substance kills the cancer cells.

Radiation therapy alone may be enough to cure the cancer at an early stage. But, if the cancer has spread, then radiation can be used to reduce the size of the tumor so that surgery can be performed easily. It may also be used as an adjuvant therapy after surgery to remove the cancer cells which could not be removed. This reduces the chances of recurrence of laryngeal cancer.

Surgery

Surgery is frequently used for all stages of laryngeal cancer. The following surgical procedures may be used:

  • Cordectomy: Removal of vocal cords only.
  • Supraglottic laryngectomy: Removal of supraglottis only.
  • Hemilaryngectomy: Removal of half of the larynx (voice box) to prevent loss of voice.
  • Partial laryngectomy: Removal of part of the larynx (voice box) to avoid loss of a person’s ability to talk.
  • Total laryngectomy: Removal of the whole larynx.

 

Surgical resection of the larynx is required mainly when the tumor has grown large enough and radiation therapy alone cannot cure the cancer. If the disease has spread outside the larynx, then surgery can be done only for palliation, which improves the survival time of the patient.

Laser surgery can also be done. A beam of laser is used to cut off the affected area and tumor on the larynx.

 

Chemotherapy

Chemotherapy is the use of drugs to treat cancer. They can be swallowed or administered through veins. It can also be specifically directed at the cancer-affected region. In most cases of laryngeal carcinoma, chemotherapy is given to patients in combination with radiation therapy. This combination is used so that the patient’s ability to talk can be saved. It may also be used when the disease has spread to other organs and surgical resection cannot cure the cancer alone.

Biological treatment with antibodies

Cetuxinab, is a monoclonal antibody based drug that targets epidermal growth factor receptors (EGFR) in the cell membrane. The growth factors are required for the cancer cells to divide and proliferate. They do this by binding to these receptors and initiating a signaling pathway. The antibody prevents the growth factors from binding to these receptors.

Staging

Like other cancers, laryngeal cancer is staged from I to IV based on how localized it is. In Stage I, cancer remains localized in the upper layers of larynx without affecting the vocal cords. By stage IV, cancer spreads from the larynx into the larger lymph nodes and may also reach the nearby organs like lungs.

Prognosis

A number of factors influence prognosis. The stage at which the cancer is diagnosed, as well as which part of the larynx is involve, are both important factors. Laryngeal cancer can be cured if detected at an early stage when the disease has not spread. 90 % of patients who are diagnosed early with laryngeal cancer in the glottis survive for five years. Therefore, the prognosis is good at this stage of the disease. But, once it spreads to nearby regions the prognosis worsens drastically. The size of the tumor, its location and its grade are also important factors that influence prognosis. Stage IV cancer of the area below the voice box has a survival rate of only 24%. Continuation of smoking during treatment reduces the chances of survival even more. The general health of the patient should also be taken into consideration to predict his/her chances of survival.

References

  1. Silver CE, Beitler JJ, Shaha AR, Rinaldo A, Ferlito A. (2009) Current trends in initial management of laryngeal cancer: the declining use of open surgery. Eur Arch Otorhinolaryngol.;266(9):1333-52.
  2. Chu EA, Kim YJ. (2008) Laryngeal cancer: diagnosis and preoperative work-up. Otolaryngol Clin North Am.;41(4):673-95
  3. Back G, Sood S. (2005) The management of early laryngeal cancer: options for patients and therapists. Curr Opin Otolaryngol Head Neck Surg.;13(2):85-91.
  4. Cattaruzza MS, Maisonneuve P, Boyle P. (1996) Epidemiology of laryngeal cancer. Eur J Cancer B Oral Oncol.;32B(5):293-305.
  5. Cowles SR. (1983) Cancer of the larynx: occupational and environmental associations.
    South Med J. ;76(7):894-8.
  6. www.cancer.org/Cancer/LaryngealandHypopharyngealCancer/DetailedGuide/laryngeal-and-hypopharyngeal-cancer-survival-rates
  7. This article was originally published on September 3, 2012 and last revision and update was 9/4/2015.