What is Esophageal Cancer?
Esophageal cancer is a disease in which malignant cells form
in the tissues lining the esophagus (the hollow, muscular tube that connects
the throat and stomach). Part of the upper gastrointestinal (GI) tract, the
esophagus carries food and liquids from the mouth to the stomach.
The wall of the esophagus is made up of several layers of
tissue, including mucous membrane, muscle, and connective tissue. Cancer that
forms in the esophagus beings in the innermost layer of tissue and spreads
outward through the other layers as it grows.
Esophageal cancer is rare. The National Cancer Institute
estimates that 16,470 Americans will be diagnosed with esophageal cancer in
2008.
Types of Esophageal Cancer?
The two most common forms of esophageal cancer, named for
the type of cells that become cancerous, are as follows:
1-Squamous cell carcinoma usually begins in the squamous
cells (the thin, flat cells that line the esophagus and look like fish scales
under a microscope) in the top layer of the esophageal lining, most often in
the upper or middle part of the esophagus.
2-Adenocarcinoma usually begins in glandular cells (the
secretory cells that produce and release fluids like mucus) in the lining of
the esophagus, most often in the lower part of the esophagus near the stomach.
While squamous cell cancers previously comprised the
majority of esophageal tumors in the United States, the incidence of esophageal
adenocarcinomas has risen considerably, making it the most common type of
esophageal cancer.
Another, more rare form of esophageal cancer is small cell
carcinoma, which is an aggressive tumor similar in appearance and behavior to
its lung counterpart. In addition, cancers that start in the breast or lung can
sometimes spread to the esophagus.
Esophageal Cancer Risk
Factors
Anything that increases your risk of developing a disease is
called a risk factor. One condition that can increase the risk of esophageal
cancer is Barrett's esophagus. Barrett's esophagus is caused by long-term
reflux of acid from the stomach into the esophagus (known as gastroesophageal
reflux disease, or GERD). Over time, this chronic acid reflux causes changes in
the cells lining the lower portion of the esophagus near the opening of the
stomach.
In addition, according to the American Cancer Society,
squamous cell carcinoma is more likely among African Americans, while
esophageal adenocarcinoma is more likely among whites.
Some other potential esophageal cancer risk factors are as
follows:
1-Being over age 60
2-Being male
3-Long-term tobacco use and/or heavy alcohol consumption
A diet low in fruits, vegetables, and certain vitamins and
minerals
4-Being overweight
5-Frequent consumption of hot liquids
6-Previous radiation treatment near the esophagus
7-Occupational exposure to dry cleaning solvents or silica
dust
8-Ingestion of lye or other caustic substances that damage
the lining of the esophagus
In addition, sometimes esophageal cancer is associated with
the following medical conditions:
1-Achalasia - a condition in which the esophagus fails to
move food into the stomach properly
2-Tylosis - a rare, inherited disease that causes excess
skin growth on the palms of the hands and soles of the feet
3-Esophageal webs - abnormal bands of tissue that protrude
into the esophagus and make it difficult to swallow
4-A history of head and neck cancer
NOTE: Having a risk factor does not necessarily mean that
you will get cancer. Not having risk factors doesn't mean that you will not get
cancer. If you think you may be at risk for esophageal cancer, you should
consult your doctor.
Esophageal Cancer Symptoms
Esophageal cancer symptoms vary from person to person.
Unfortunately, esophageal cancer often does not present symptoms in the early
stages of the disease.
The most common symptom of esophageal cancer is dysphagia,
or difficulty swallowing.
This symptom usually doesn't appear until the disease is
more advanced, when a tumor has grown large enough to narrow the esophagus to
about half of its normal width. Pain when swallowing and a sensation of food
getting stuck in the throat or chest may also occur.
Other potential esophageal cancer symptoms include the following:
1-Unintentional weight loss
2-Pain in the throat, behind the breastbone, or between the
shoulder blades
3-Pressure or burning in the chest
4-Hoarseness, chronic cough, hiccups
5-Indigestion, heartburn, acid indigestion (caused by
chronic acid reflux, or GERD)
6-Coughing up blood (in more severe cases)
NOTE: These and other symptoms may be caused by conditions
other than esophageal cancer. If you are experiencing any of these symptoms,
you should see your doctor.
Esophageal Cancer Staging
If tests show that esophageal cancer is present, your doctor
will need to know the stage (extent) of the cancer to best plan treatment.
Staging helps determine how much of the esophagus is affected and if cancer
cells have spread outside the esophagus to nearby lymph nodes or other parts of
the body (e.g., liver, lungs, brain, bones).
The stages of esophageal cancer can range from 0 through IV.
In general, the higher the number the more advanced the cancer.
1-Stage 0 (carcinoma in situ) - Abnormal cells are found in
the part of the mucosa forming the innermost lining of the esophagus
2-Stage I - Cancer is found in the top layer of cells lining
the esophagus
3-Stage IIA - Cancer has spread into deeper layers of the
esophagus lining
4-Stage IIB - Cancer has spread to any of the first three
layers of the esophagus lining and to nearby lymph nodes
5-Stage III - Cancer has spread even more deeply to the
outer wall of the esophagus and to nearby tissues or lymph nodes
6-Stage IVA - Cancer has spread to nearby or distant lymph
nodes.
7-Stage IVB - Cancer has spread to distant lymph nodes
and/or organs in other parts of the body.
Esophageal Cancer
Diagnosis
In addition to a complete medical history, physical
examination and blood tests (e.g., CBC), your doctor may use some of the
following tests to diagnose and stage esophageal cancer:
1-Imaging tests
(e.g., upper GI X-rays, chest X-ray, CT scan) create detailed images of areas
inside the esophagus to confirm the location of a tumor and detect whether
cancer has spread.
2-Barium swallow test (upper GI series) uses a liquid that, when swallowed, temporarily coats the
esophagus so the lining shows up clearly on X-rays to reveal any
irregularities.
3-Upper Endoscopy
uses an endoscope (a thin, lighted tube with a tiny camera on the end) to
examine the interior lining of the esophagus. If the tumor is blocking the
opening of the esophagus, certain instruments may be used to enlarge the
opening to help food and liquid pass.
4-Biopsy uses an
endoscope to remove cells or small tissue samples for examination under a
microscope.
5-Endoscopic ultrasound (EUS) uses an endoscope with a small ultrasound probe on its tip
to evaluate how deeply the cancer is in the wall of the esophagus and how far
the cancer has spread into nearby tissues or lymph nodes.
6-Bronchoscopy
uses a bronchoscope (a thin, lighted tube) to look inside the trachea
(windpipe) and bronchi (air passages leading to the lungs) to determine whether
esophageal cancer has spread to these structures.
7-Thoracoscopy and laparoscopy uses a hollow, lighted tube to examine the lymph nodes
inside the chest (thoracoscopy) or abdomen (laparoscopy) and/or to remove the
nodes for further testing.