Q&A: What to Know About Tracheal Cancer

Cancer of the trachea is a rare, complicated disease that requires highly specialized care.

Answering common questions about tracheal cancer is Garrett Walsh, M.D., a professor in M. D. Anderson's Department of Thoracic & Cardiovascular Surgery and associate medical director of the institution's Thoracic Center.

What is the trachea?

The trachea, or windpipe, is a very specialized organ, about 12 centimeters in length, that stretches from the lower part of the larynx (voice box) to where the main airways divide into the right and left lungs.

The cells lining the trachea include mucous-producing cells that help protect the lungs. They also contain microscopic hairs that help clean the lungs by moving this mucus and trapped particulate matter that we breathe away from the delicate lung tissues.

What is tracheal cancer?

Because its structure is complex, a variety of benign and malignant tumors can develop in the tracheal mucosal lining, the tracheal wall itself, or both. These would be described as primary tracheal tumors. Because of the close relationship of the trachea with a variety of other organs as it goes from the neck down in the chest cavity, it can be invaded secondarily by tumors that develop in neighboring organs such as the thyroid or esophagus.

How many cases are treated at M. D. Anderson?

As a major referral center for complex tracheal tumors, M. D. Anderson sees approximately five to 10 patients with primary tracheal malignancies each year. Secondary tumors would be much more common.

Tracheal tumors are exceedingly rare in comparison to other malignancies of the aerodigestive tract including the larynx, lung and esophagus, of which we see several thousand new cases per year in our institution. In one large autopsy series completed outside of M. D. Anderson, only four patients with primary tracheal tumors were identified in 89,600 autopsies.

Secondary tumors which involve the trachea by direct extension or metastasize from another site are much more common.

What causes tracheal cancer?

Specific types of tracheal cancer are related to smoking. Others have no known cause.
Tracheal tumors can involve virtually all age groups, from pediatric patients to people in their 80s.

The two most common types of tracheal cancer include:

Adenocystic carcinoma- a cancer of a subgroup of salivary gland tumors involving the trachea. There is no known association of cigarette smoking with this type of cancer and no other relationship with any known carcinogens.

Squamous cell carcinoma- a cancer that begins in the squamous cells, the thin, scaly cells that make up the passages of the respiratory and digestive tracts, the outer layer of the skin and the lining of the hollow organs of the body.

Squamous cell carcinoma, like other squamous cell carcinomas in the aerodigestive tract, is clearly associated with smoking. In fact, up to 40% of patients with this cancer have had other smoking-related cancers at other sites, which might include the tongue, tonsils, larynx or lungs.

Squamous cell carcinoma occasionally can develop from a condition called squamous papillomatosis, which is associated with the human papilloma virus. The degeneration into squamous cell carcinoma usually occurs 15 to 20 years after the diagnosis of papillomatosis, and usually in patients who are also smokers. Squamous papillomatosis can often involve children and adolescents.

What are symptoms of tracheal cancer?

Symptoms are often overlooked and difficult to diagnose, and it may be several months and often years before a final diagnosis is made.

Symptoms could include any of the following:

• Dry, non-productive cough
• Coughing up blood (occasionally)
• Shortness of breath after exertion
• Voice hoarseness
• Uncoordinated swallowing attempts
• Fevers, chills and pneumonia (may be recurrent problems over many months to years)
• Wheezing (occasionally as the tumor progresses and restricts air flow into the lungs)

Wheezing is often misdiagnosed as adult-onset asthma and can be treated as such for several months to years. Patients are often placed on a variety of bronchodilators and steroids before a diagnosis is made. The imaging techniques of the trachea are such that it can often be recognized on a plain chest radiograph by an astute radiologist.

Any symptoms of adult-onset asthma or progressive shortness of breath, cough or coughing up blood should be evaluated by a bronchoscopy. A bronchoscopy involves placing a flexible tube with a camera at the end down the nose or throat to visualize and often take tissue specimens of the larynx, trachea, bronchus and lungs.

Is there a way to prevent tracheal cancer?

Clearly, squamous cell carcinoma of the trachea is associated with continued and prolonged cigarette smoking. This cancer can likely be reduced or prevented by ensuring that young adolescents and teenagers never become addicted to nicotine and cigarette smoking.

How is tracheal cancer diagnosed?

A recommended medical workup could include:

Accurate diagnostic imaging- this includes chest radiographs and computed tomography (CT) scans of the head and neck and chest. This must be followed by a rigid bronchoscopic evaluation of the larynx, trachea and both right and left mainstem airways to assess precisely the location of the tumor and its extent of involvement of the tracheal wall.

Bronchoscopic evaluation- during the bronchoscopy, portions of the tumor are sampled and analyzed by a pulmonary pathologist to assess the origin of these malignancies, and help in the diagnosis of either a primary tumor of the trachea or one that is secondary. If it would appear that there is metastasis, then a concerted search is made to locate the primary tumor at another site in the body.

As curative therapy is our hope, a patient's best shot is their first shot!

It is crucial that specialists address this very rare cancer. It is necessary to have a collective effort by several physicians with expertise in the pathologic assessment and surgical management as well as radiation therapy and chemotherapy.

The evaluation or surgical resection could be compromised if the patient undergoes inappropriate interventions such as repeated laser fulgurations (burning or vaporizing a tumor using lasers) or stent placement (inserting an expandable device (stent) made of metal or silicone into the airway to allow it to be opened).

How is tracheal cancer treated?

The best treatment involves complete surgical removal of the entire tumor. Virtually all benign and low-grade malignancies of the trachea should be resected if technically feasible. Up to half of the trachea can be removed and reattached, if necessary, to obtain clear margins above and below the tumor.

Treatments may require extended resections that involve the larynx with reimplantation of the trachea just below the vocal cords. Complicated resections of the lower trachea and either right or left lung and their mainstem airways are also possible.

If patients are initially seen in a center that is unfamiliar with these techniques or treatment options, they should be immediately transferred to a specialized referral center once they have been stabilized.

What is the five-year survival rate after surgery?

Survival statistics have significantly improved over the last 40 years since tracheal surgery has been perfected. Surgical outcomes are very important predictors of overall survival from tracheal cancer.

Survival rates for surgically removed tracheal cancers:

• Adenocystic carcinomas - 70%
• Squamous cell carcinomas - 50%