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BACKGROUND
Anatomy:
The esophagus is
the medical term for the “food pipe.” It connects the lower
part of the throat (pharynx) with the stomach. The esophagus
begins in the lower neck and ends in the lower abdomen. It
lies in the chest just in front of the vertebral column and
just behind the trachea (wind pipe). The esophagus has a
thin muscular wall and a mucosal lining. In the upper three-fourths
of the esophagus this epithelial lining comprises squamous
cells. In the lower one-fourth the lining comprises columnar
cells forming a glandular lining.
It is noteworthy
that the esophagus has no outer coat or serosa. Thus, there
is relatively little barrier to prevent cancer cells from
spreading into surrounding tissues. Immediately adjacent
to the esophagus are the other structures in the mediastinum,
including the windpipe, lymph nodes, heart, and major blood
vessels.
Epidemiology:
Cancer of the esophagus
represents about 1% of about all cancers in the United States.
There are about 12,000 newly diagnosed cases per year in this
country. Cancer of the esophagus is more common in people
who use tobacco products and in people who drink alcoholic
beverages to excess.
Another factor
associated with esophageal cancer is esophageal reflux. People
who have severe esophageal reflux for many years can experience
changes in their lower esophagus called “Barrett’s esophagus.”
A small percentage of people with Barrett’s esophagus will
develop esophageal cancer.
Most cancers of
the upper esophagus are squamous cell carcinoma. Most cancers
of the lower esophagus and gastroesophageal junction are adenocarcinoma.
STAGING:
Esophageal carcinoma
occurs in the cells that line the inside of the esophagus.
Stage I disease means that the cancer is still confined to
just this inner lining and has not started to spread into
the muscular wall of the esophagus. Stage II disease is disease
growing into the muscular walls, but not into adjacent structures
in the neck or chest. Stage III disease means that the cancer
has spread into adjacent tissue, such as the trachea or lymph
nodes. Stage IV disease has spread distantly to organs well
away from the esophagus, such as the liver or lung tissue.
TREATMENT
OPTIONS:
Surgery:
Surgical resection
for esophageal cancer is only practical in early stage disease
(I or II). Surgical resection involves major surgery. In
general, the entire esophagus is removed. The stomach is
then freed up from it abdominal location and brought up into
the chest and connected with the lower throat.
Radiation therapy:
Radiation therapy
is used both as an alternative to surgery for early stage
disease and as an adjunct to surgery in more advanced cases.
When radiation is used instead of surgery, relatively high
doses are administered with the goal of eliminating the cancer,
if possible. When radiation is used as an adjunct to surgery,
it can be given either before the major operation or after.
Radiation in these cases is generally confined to a more moderate
dose.
Chemotherapy:
Chemotherapy is
often beneficial in providing results along with both surgery
and radiation. Drugs used include 5-Fluorouracil and Cisplatin.
RADIATION
THERAPY:
Typical course:
Some patients receive
radiation therapy as the primary mode of treatment. In this
case, relatively high doses of radiation are given. A typical
course of treatment will consist of approximately 65-70 gray
administered in approximately 40 individual treatments, five
days a week over an eight-week period. Radiation treatment
usually is given from several different directions, front
and back as well as sides. The treatment is directed at the
visible tumor as well as adjacent tissue where microscopic
cancerous deposits may be hiding.
In patients who
receive radiation in conjunction with surgery, treatment can
be given either before or after the major radiation. Preoperative
radiation therapy offers the advantage that the tumor may
shrink and make the surgery easier. Postoperative radiation
therapy offers the advantage that the radiation fields can
be constructed more carefully, based on the knowledge obtained
by the surgeon. Thus, the pluses and minuses of the two approaches
have to be considered for each individual patient.
Radiation given
adjuvant to surgery is typically in a lower dose, 50 to 55
gray in 30 treatments over six weeks.
Chemotherapy is
frequently administered in conjunction with radiation therapy.
Studies have suggested a synergistic effect whereby chemotherapy
enhances the effect of radiation on cancer cells without unduly
sensitizing normal cells. Chemotherapy has the additional
advantage in that it may be able to eliminate small cancerous
deposits located outside the radiation field.
Side-effects:
Side effects of
radiation therapy for esophageal cancer include esophageal
irritation and fatigue. The esophageal irritation is a moderately
severe difficulty which typically develops two to three weeks
after the radiation initially begins. There are medications
that help control the sore throat, but it is not possible
to prevent the it entirely. Medications include soothing
medicines such as Carafate and numbing medicines such as Ron’s
Rum. Another important class of medications that is helpful
in these situations is antifungal treatment. Patients receiving
radiation therapy and chemotherapy for esophageal cancer are
prone to develop a yeast infection (monilia). Medicines such
as Diflucan or Nystatin can be quite beneficial.
Of course, patients
with esophageal cancer are also at risk for inadequate nutrition.
Nutritional support can include counseling, as certain foods
are much easier to swallow. Nutritional support can also
be administered mechanically by the placement of a rubber
tube directly through the skin of the abdomen into the stomach
(a PEG tube). Please refer to the separate section in nutrition
for more details regarding nutritional support.
A final side effect
of radiation therapy is fatigue. Patients receiving radiation
often complain that they just don't have quite the energy
that they did before the radiation started. Some of this
may be due to the underlying cancer itself. The radiation,
however, does tend to make people feel tired. There is no
cure for this symptom, but a program of extra naps and mild
exercise can be helpful.
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