The trachea, commonly known as windpipe, is a tube like structure which connects our mouth and nose to our lungs. It further divides into a right and left bronchus, (plural bronchi), which are the two airways supplying air to both the lungs. The trachea is located within the neck and is present anterior to the esophagus. The length of trachea is around 5-7 inches (10-16 cm) and is composed of rings made of cartilage or fibrous tissue, which can be felt upon touching the front side of the neck.
Tracheal cancer is quite rare and constitutes about 0.1% of all the cancers. Squamous cell carcinoma and adenoid cystic carcinoma are the most common types of tracheal cancer. Squamous cell cancers begin in the cells which line various parts of the body, e.g. mouth, airways and esophagus. Adenoid cystic cancers are rarer and start from the glandular tissue. They commonly develop in the head and neck region, but can also form in other parts of the body.
Surgery and radiation therapy are the commonly used treatments for tracheal cancer. They can be done individually or in combination. Chemotherapy is commonly given for alleviating symptoms and is called palliative chemotherapy.
Causes of Tracheal Cancer
The exact cause of tracheal cancer is not known. There are some risk factors for tracheal squamous cell cancer, such as smoking. Tracheal squamous cell cancer is seen commonly in males who are aged above 60.
However, there is no confirmation that smoking is linked to adenoid cystic carcinoma of the trachea. This type of cancer affects both male and female equally.
Signs and Symptoms of Tracheal Cancer
- Patient has a dry cough.
- Voice hoarseness.
- Difficulty in swallowing.
- Fevers and chills.
- Recurrent chest infections.
- Patient coughs up blood.
- Patient experiences wheezing during breathing.
Investigations for Tracheal Cancer
It is difficult to diagnose tracheal cancer, as it occurs rarely. It can be mistaken for other medical conditions, such as bronchitis or asthma. The following investigations help in confirming the diagnosis and in finding out the extent of the cancer.
- Medical history and physical examination.
- CT scan is a test which gives a three-dimensional picture of what is happening in the body. Patient may be given a dye via injection or a drink which helps in highlighting specific areas in the body.
- MRI (Magnetic Resonance Imaging) scan is similar to CT scan, but uses magnetism, not x-rays, to generate a detailed picture of areas inside your body.
- Bronchoscopy is a test which uses a thin, flexible tube (bronchoscope) which is passed down your mouth or nose into the trachea to look for any abnormalities. Photographs and a biopsy can be done at the same time.
- Rigid bronchoscopy is also sometimes done to visualize the tumor clearly. It also helps in keeping the trachea stable during the procedure.
Stages of Tracheal Cancer
TNM Staging for Tracheal Cancer
This is the most common staging system used for cancer and is known as TNM system:
- T stands for size or location of the primary tumor, i.e. where the cancer first developed in the body.
- N stands for the affected lymph nodes.
- M stands for metastases, i.e. spreading of the cancer to other areas of the body.
This T, N and M system usually has numbers with it to describe the cancer in detail, such as a T1 tumor is very small and is present only in a single layer of the tissue; whereas a T4 tumor can be larger and has spread into many layers of the tissue.
Number Staging System for Tracheal Cancer
Doctors also use a number staging system and it commonly consists of three or four numbers to describe the cancer stage.
- Stage 1 is cancer in the initial stage where it is often small in size and hasn't metastasized.
- Stage 4 is referred to an advanced stage cancer, which has usually metastasized or spread to other areas of the body.
- Stages 2 and 3 are the stages which are present in between the stage 1 and stage 2.
The number stages are used with various combinations of the TNM stages such as T1, N0, M0 or T2, N0, M0.
The number stages can also be subdivided for more detailed description about the size and extent of the tumor, such as a stage 4 cancer can be subdivided into stage 4a, 4b and 4c…
Grading of the Cancer
Grading denotes the appearance of the cancer cells when seen microscopically. Grading gives the doctor an idea about how the cancer may act or behave in the future.
Low-grade cancer means that the cancer cells resemble the normal cells. High-grade cancer means that the cancer cells look distinctly abnormal. A low-grade tumor grows slowly and is less likely to metastasize when compared to a high-grade tumor.
Treatment for Tracheal Cancer
Treatment depends on the stage of the cancer, its location, patient's general health and treatment preference. Surgery and radiation therapy are the commonly done treatments for tracheal cancer. They can be done individually or in combination. Chemotherapy is commonly given for alleviating symptoms and is called as palliative chemotherapy.
Surgery for Tracheal Cancer
In early stage, where the cancer is small, surgery is done to completely remove the tumor along with a margin of healthy tissue. This type of surgery is known as specialized surgery and can be done only in specialist centers. In cases where the cancer has affected most of the trachea, the affected part is removed and the cut ends of the trachea are re-joined.
The trachea will be somewhat shorter after the surgery, so the patient is advised to avoid stretching his/her head back for sometime after the surgery. Patient then should follow up with a physiotherapist who will teach breathing exercises. Patient may cough up blood stained phlegm (sputum) for some days after the surgery.
Radiation Therapy for Tracheal Cancer
Radiation therapy uses high energy beams, such as x-rays to kill cancer cells. Radiation therapy can be given after the surgery to kill any remaining cancer cells and to decrease the chances of recurrence and this is known as adjuvant radiation therapy. Radiation therapy can be done in individuals for early stage, low-grade tracheal cancer, especially in those patients who are not able to withstand surgery. Radiation therapy done for relieving symptoms is known as palliative radiation therapy. Radiation therapy can be given externally (external beam radiation therapy) or internally (brachytherapy). Side effects of radiation therapy include:
- Difficulty in swallowing.
- Changes in the skin, such as redness, itchiness, changes in skin color.
- Hair loss.
Chemotherapy for Tracheal Cancer
Chemotherapy uses chemicals or drugs to destroy cancer cells. Drugs used are known as anti-cancer or cytotoxic drugs. They work by hindering the growth of cancer cells. Chemotherapy given for controlling the cancer or relieving the symptoms is known as palliative chemotherapy. Drugs commonly used are carboplatinor or cisplatin. Chemotherapy is rarely utilized for tracheal adenoid cystic cancer.
Treatment for Controlling the Symptoms of Tracheal Cancer
Laser Therapy Treatment for Controlling the Symptoms of Tracheal Cancer
Laser therapy burns the tumor using a laser light. This treatment is done under general anesthesia. Using a bronchoscope, a flexible fibre is passed down and the laser beam is aimed at the tumor to destroy as much of the tumor as possible. This treatment doesn't carry much side effects and patient can go home the same day or the next day. Sometimes laser therapy is also combined with radiation therapy to make the treatment more effective.
Brachytherapy or Internal Radiation Therapy Treatment for Controlling the Symptoms of Tracheal Cancer
Brachytherapy is done to open up the airway thereby relieving some symptoms. The source of the radiation such as seeds or wire is placed inside the trachea near the tumor via a tube passed through bronchoscope. After some time it is removed.
Cryotherapy Treatment for Controlling the Symptoms of Tracheal Cancer
Cryotherapy involves the use of liquid nitrogen, to freeze and kill the cancer cells. It is done under general anesthesia. Cryoprobe is an instrument which is placed near the tumor via bronchoscope. Liquid nitrogen is then passed through the probe to destroy as much tumor as is possible. Cryotherapy generally doesn't have many side effects. Patient may cough up additional phlegm for some days after the treatment.
Diathermy Treatment for Controlling the Symptoms of Tracheal Cancer
This treatment is also known as electrocautery and helps in relieving cancer symptoms. A probe is passed via a bronchoscope and is heated with electrical current to kill cancer cells. This treatment doesn't have that many side effects.
Photodynamic Therapy (PDT) Treatment for Controlling the Symptoms of Tracheal Cancer
Photodynamic therapy involves the use of laser or other sources of light along with a light-sensitive drug to kill cancer cells. This light-sensitive medicine is given via vein in a liquid form. After the medicine is given, with the help of a bronchoscope, the laser light is targeted at the tumor to destroy cancer cells.
Patient may feel some sensitivity to light after the treatment for some weeks; however, this is temporary. Other side effects are breathlessness, cough, swelling and inflammation.
Photodynamic therapy is a new treatment and is suitable for some individuals only. It is available at specialized centers.
Airway Stents Treatment for Controlling the Symptoms of Tracheal Cancer
A stent is placed inside the airway to keep it open. This stent is passed via bronchoscope and is placed under general anesthesia. This treatment helps the patient in breathing more easily and the stent can remain in the trachea permanently. Side effects include blockage from mucus, infection, cough, and irritation of the air passage.
Post Treatment Follow-Up for Tracheal Cancer
Patient should go for regular check-ups after the cancer treatment is done. If patient is experiencing any problems or other symptoms, then he/she should contact doctor immediately.