By
Rabiya S. Tuma, PhD
Esophageal cancer is an aggressive form of cancer, and one that
often remains asymptomatic until relatively late in the disease
process. “Before I was diagnosed with this, I had never
heard of it,” says Bart Frazzitta, from Manalapan, New Jersey. “I
didn’t even think you could get esophageal cancer.” In
fact, there were approximately 14,250 new cases of esophageal
cancer diagnosed in 2004 in the United States and 13,300 deaths
from the
disease. Additionally, of all the solid tumors, esophageal cancer
is the one that has been increasing most rapidly in recent years.
The reasons for the increase may be related to an increase in
gastroesophageal reflux disease and other lifestyle factors.
Esophageal cancer initially develops in the esophagus, which
is the smooth muscular tube that carries food and liquids from
the
throat
to
the stomach.
There are two types of esophageal cancer: squamous cell carcinoma
and adenocarcinoma. Squamous cell carcinoma occurs when the cells
that normally line the inside of the esophagus begin to proliferate
abnormally. Adenocarcinoma develops from abnormal glandular cells
that line the walls of the esophagus that has been damaged by
gastroesophageal reflux disease (GERD).
Previously, squamous
cell carcinoma was the predominant form of the disease. In recent
decades, however, adenocarcinoma has become more prevalent and
now
accounts for more than half of all cases of esophageal cancer in the United States,
says Stuart Spechler, MD, from the University of Texas Southwestern Medical Center
in Dallas.
Unfortunately, the disease does not produce many symptoms in
its early stages and thus goes undetected. Large, advanced tumors
may cause
weight loss, difficulty
swallowing, or evidence of blood in stool or vomit.
With no early warning symptoms,
individuals often don’t realize something
serious is going on until they have advanced cancer. Frazzitta’s only symptom
was chronic heartburn a couple of times a week for about a year. Yet when he
was diagnosed in December 1999, he had stage 3 cancer, which means the disease
had already spread from the esophagus to surrounding tissues or lymph nodes.
“A lot of people will go and get an antacid and feel better
and think they have cured the problem,” says Frazzitta, who
subsequently has become a patient advocate and co-founder of the
Esophageal Cancer Education Foundation
(www.fightec.org). In truth, the antacid just masked a symptom of a serious
disease, which is why experts recommend that if heartburn or indigestion
persists, people
should see a doctor.
The Risk Factors
The two types of esophageal cancer occur with
different frequencies in different ethnic groups. Squamous cell
carcinoma is more common
in blacks and Asians,
while white men are at highest risk for adenocarcinoma.
Some of the risk factors
for the two subtypes are the same, but not all of them. For example,
obesity is a risk factor for adenocarcinoma, while malnutrition
puts individuals at increased risk for squamous cell carcinoma.
However, heavy smoking and age over 50 are associated with an increased
risk of both types of disease.
Sometimes, however, even those risk factors don’t
apply. Vickie Powell, a resident of Radcliff, Kentucky, was just 38 when she
developed a case of the
hiccups that she couldn’t keep at bay. Initially her doctor put her on
an antacid, which she took for a week and a half.
“You know your own body,” says Powell. “I went
back to the doctor and said something just is not right.” After
more tests, she was told that she had a golf ball-sized tumor in
her lower esophagus and upper stomach.
She wasn’t overweight, she didn’t drink or smoke, and she doesn’t
ever remember having heartburn.
A major risk factor for
adenocarcinoma of the esophagus is Barrett’s esophagus, which
occurs when the valve that lies between the stomach and the esophagus
doesn’t function properly. Normally, it acts like a one-way
gate, letting food and liquid move from the esophagus into the stomach,
but keeping the acid and digestive enzymes of the stomach in the
stomach. If the valve weakens, then acid will escape into the esophagus,
which is called acid reflux. Repeated exposure to the acid damages
the esophageal cells, causing them to die.
When new cells arise to take their place, a strange thing happens,
says Dr. Spechler, who is an expert on Barrett’s esophagus.
Instead of regenerating new esophageal cells that would continue
to be damaged by the acid escaping
from the stomach,
the esophagus begins to produce cells that resemble those that line the
intestinal tract. Such cells are ready for an acid bath and aren’t damaged
as easily by acid reflux.
Unfortunately, these cells are predisposed
to form cancers when they arise in the esophagus. Thus, patients with
chronic GERD and who develop
Barrett’s
esophagus are at significantly higher risk for esophageal cancer and
should undergo regular cancer surveillance. One common form of surveillance
is called endoscopy,
in which a physician runs a thin tube with a camera and a light at the
end into the esophagus, allowing for a visual of what the tissue looks like.
Screening all GERD patients with endoscopy to look for Barrett’s esophagus
is neither feasible nor practical, however. Approximately 60 million
adults in the United States have regular heartburn, but only a tiny fraction
of those will
develop esophageal cancer. Researchers are trying to identify better
ways to diagnose esophageal cancer earlier.
Treatment of Barrett’s Esophagus
Like many cancers, the
timing of diagnosis is critical in esophageal cancer. “If
we can catch it early, we can cure it,” says Dr. Spechler. With that
in mind, physicians like to closely follow patients who have Barrett’s
esophagus or other high-risk factors for the disease.
If the cells in
the esophagus begin to look abnormal but are not yet cancerous, a stage
called dysplasia, Dr. Spechler and others will often
recommend surgical
treatment to prevent full-blown cancer from developing. If left untreated,
31 to 59 percent of patients with high-grade dysplasia will develop
cancer within five years.
Currently, the standard surgery for high-grade
dysplasia is an esophagectomy, in which the surgeon removes the
unhealthy portion of the esophagus and
possibly some of the neighboring stomach, and then reconnects the remaining
regions
of the tube together. Although this surgery is effective at preventing
the disease and treating some stages of the cancer itself, it is a difficult
surgery and
between 3 and 12 percent of patients may die as a result of the surgery
itself.
Researchers are testing less drastic surgical methods, but these
are still in clinical trials, and it is not yet clear how effective
they
are at preventing
the development of cancer, although early results look promising. One
method involves using an endoscope with a small blade attached to the
end to cut
away
the unhealthy cells. Another method being tested is to use a laser to
burn away the dysplastic cells.
Management of Early-Stage Esophageal
Cancer
For those patients who are diagnosed with esophageal cancer,
esophagectomy is the standard therapy, unless the cancer has
spread beyond the esophagus
and adjacent
tissue. The proportion of esophageal cancer patients alive five years
after diagnosis is between 5 and 30 percent, depending on the stage of
cancer they
have at diagnosis
and how well they respond to treatment.
Most patients with localized esophageal cancer (stage 1 or 2 disease)
used to be treated with surgery alone. In recent years, a combination
of chemotherapy and radiation or chemotherapy and radiation followed
by surgery is being
used
more often to treat esophageal cancer, says David Ilson, MD, from Memorial
Sloan-Kettering Cancer Center in New York. The addition of chemotherapy
to
a radiation treatment
protocol can enhance the effectiveness of radiation and increase the
proportion of patients who achieve a complete remission or a good partial
remission with radiation. Subsequent surgery, done after chemotherapy
and radiation, can then
be used to remove any residual cancer. Combining chemotherapy, radiation
therapy and surgery (called combined modality approaches) are increasing
the cure rate
of this cancer.
The current standard chemotherapy
given with radiation therapy is a combination of 5-FU plus cisplatin,
but this can lead to significant side effects of mouth sores and
esophagitis. “We are trying to identify more effective chemotherapy
regimens that have fewer side effects,” says Dr. Ilson.
Regimens currently being tested use cisplatin in combination with
newer chemotherapy drugs like Camptosar® (irinotecan), Taxotere®
(docetaxel), Taxol® (paclitaxel) and Gemzar® (gemcitabine).
Since cisplatin causes a number of side effects, including nausea,
vomiting, kidney damage and hearing loss, a better-tolerated analogue
of platinum oxaliplatin (Eloxatin™) is being studied in esophageal
cancer.
Options for Advanced Esophageal Cancer
For patients with metastatic
(stage 4) disease, surgery is not recommended. Rather, physicians
treat such advanced disease with
chemotherapy, which
is not likely
to cure the cancer but may slow its progress and make the patient more
comfortable.
Chemotherapy drugs that are used include 5-FU, cisplatin,
Taxol, Taxotere, Camptosar and Eloxatin. Additionally, a phase
III randomized trial in
the United Kingdom
is testing the efficacy of a Xeloda® (capecitabine) combination in esophageal
cancer. But Dr. Ilson says Xeloda is not yet used frequently in the United
States for this disease.
In addition to traditional chemotherapy agents,
physicians are testing the use of newer, less toxic targeted drugs in
esophageal cancer. Unlike
standard chemotherapy
drugs, which kill all dividing cells, targeted therapies block specific
steps
in the cancer cell growth pathway and leave most healthy cells undamaged.
Dr. Ilson’s research group is
setting up trials to test the monoclonal antibody Erbitux™
(cetuximab), which targets the epidermal growth factor receptor
(EGFR), in combination with standard chemotherapy in patients with
locally advanced esophageal cancer. They will also test Avastin®
(bevacizumab), another monoclonal antibody that blocks blood vessel
formation, in combination with chemotherapy and radiation in adenocarcinoma-type
esophageal cancer.
Nutrition and
Swallowing
Patients with advanced esophageal cancer may experience
difficulty swallowing and an inability to take solid food, which
can cause
malnourishment and
an inability to tolerate chemotherapy. In patients who are not candidates
for curative surgery
or radiation-based treatment, the relief of swallowing difficulties is
a
primary goal of palliative or symptom-relieving management. Chemotherapy
alone in advanced
disease may relieve swallowing problems.
Additionally, there are several options
for local therapy, and esophageal stenting is one of the most common.
During the procedure, a physician uses endoscopy to place a stent
in the esophagus, and, because the stent is a semi-rigid tube, it
prevents the tumor from blocking or narrowing the esophagus.
Another option that is
sometimes used is called photodynamic therapy. In photodynamic therapy,
the patient receives an injection of a drug called Photofrin®
(porfimer sodium) that causes cells to be sensitive to light. The
gastroenterologist uses an endoscope to then shine laser light on
the tumor, killing the cancer cells. One problem with this approach
is that the patient has to avoid light for several weeks after treatment,
which can significantly lower his or her quality of life. Also,
the results of this treatment are relatively short-lived.
If a patient has failed
chemotherapy or they have a stent in place but the tumor is overgrowing
the stent, physicians may use radiation to locally control the tumor.
In some cases, the doctor may opt to use laser therapy in which
a laser is attached to an endoscope to kill off parts of the tumor
that are causing swallowing difficulties. In this situation, however,
radiation is used more frequently than lasers, says Dr. Ilson.
For patients who are malnourished and
not able to take in adequate amounts of calories, a feeding tube is placed
in the stomach. This tube (usually
called a PEG tube) allows food to be administered directly into the stomach,
thus
ensuring
the patient receives adequate nutrition.
Looking Ahead
Until less toxic treatments are available, the emotional
and physical cost of therapy can be high. For example, Powell
had an esophagogastrectomy
in
which the surgeons removed one-fifth of her stomach, 8 inches of her
esophagus, the
surrounding lymph nodes and the sphincter muscle that controls flow between
the esophagus and the stomach. Additionally, because she was so young,
her doctor
wanted to use a particularly aggressive therapy to prevent recurrence.
Thus, after surgery, she received two rounds of chemotherapy, with each
round consisting
of five days of continuous intravenous drip of 5-FU and cisplatin. She
also had
30 radiation treatments.
Now, as she has just had her seventh-year CT scan, she remains cancer-free,
though she suffers from surgery complications. Without a sphincter muscle,
she still
has trouble keeping food down and has to eat small meals every couple
of hours rather than three normal-sized ones. And even the small ones
make her
nauseous.
“For a while I was really depressed about it, but I have
learned to deal with it. This is what I have left. But I am cancer-free
and I try to move on
every day,” she says. “Sometimes I don’t realize how lucky
I am until I go to the doctor and I tell my story. Now, I’m just at a
point where I want to help as many people as I can.”
Frazzitta, who participants
can meet at the CURE Patient & Survivor Forum in Washington,
D.C., this July, had six weeks of Taxol and cisplatin chemotherapy
plus radiation to treat his stage 3 disease. After recovering from
this therapy for two months, he underwent an esophagogastrectomy
in which the surgeon removed two-thirds of his esophagus and one-third
of his stomach.
He left
the hospital
10 days later.
That was May 2000. Now,
nearly five years later he won’t say he’s cancer-free,
but his last CT scan six months ago was clear—and he hopes
the next one will be clear as well.
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