Esophageal
cancer is the eighth most frequently diagnosed cancer worldwide, and because of
its poor prognosis it is the sixth most common cause of cancer-related death. It caused about 400,000 deaths in 2012, accounting for about 5% of all
cancer deaths (about 456,000 new cases were diagnosed, representing about 3% of
all cancers). Rates vary widely between countries, with about half of all
cases occurring in China. It is around three times more common in men
than in women.
In the United States, esophageal cancer is the
seventh-leading cause of cancer death among males (making up 4% of the total). The National Cancer Institute estimated there were about 18,000 new cases
and more than 15,000 deaths from esophageal cancer in 2013 (the American Cancer
Society estimated that during 2014, about 18,170 new esophageal cancer cases
will be diagnosed, resulting in 15,450 deaths).
Esophageal
cancer (or oesophageal cancer) is cancer arising from the foodpipe known as the
esophagus that runs between the throat and the stomach. Symptoms often
include difficulty in swallowing and weight loss. Other symptoms may include pain when
swallowing, a hoarse voice, enlarged lymph nodes (glands) around the
collarbone, a dry cough, and possibly coughing up or vomiting blood.
The
two main
sub-types of
the disease are esophageal squamous-cell carcinoma (often abbreviated to ESCC),
which is more common in the developing world, and esophageal adenocarcinoma
(EAC), which is more common in the developed world. A number of less
common types also occur. Squamous-cell
carcinoma arises from the epithelial cells that line the esophagus.
Adenocarcinoma arises from glandular cells present in the lower third of
the esophagus, often where they have already transformed to intestinal cell
type.
The
most common causes of the
squamous-cell type are: tobacco, alcohol, very hot drinks, and a poor diet.
The most common causes of the adenocarcinoma type are smoking tobacco,
obesity, and acid reflux. The two main types (i.e. squamous-cell
carcinoma and adenocarcinoma) have distinct sets of risk factors.
Squamous-cell carcinoma is linked to lifestyle factors such as smoking
and alcohol. Adenocarcinoma has been
linked to effects of long-term acid reflux. Tobacco is a risk factor for
both types. Both types are more common in men and in the over-60s.
Prominent symptoms usually do not
appear until the cancer has infiltrated over 60% of the circumference of the
esophageal tube, by which time the tumor is already in an advanced stage. Onset of symptoms is usually caused by
narrowing of the tube due to the physical presence of the tumor.
The diagnosis is best made with
esophagogastroduodenoscopy (endoscopy); this involves the passing of a flexible
tube with a light and camera down the esophagus and examining the wall.
Biopsies taken of suspicious lesions are then examined histologically for
signs of malignancy. Additional testing is needed to assess how much the
cancer has spread. The Computed tomography (CT) of the chest, abdomen and
pelvis can evaluate whether the cancer has spread to adjacent tissues or
distant organs. Esophageal endoscopic ultrasound can provide staging
information regarding the level of tumor invasion, and possible spread to
regional lymph nodes. Staging is based on the TNM staging system, which
classifies the amount of tumor invasion (T), involvement of lymph nodes (N),
and distant metastasis (M).
Prevention includes stopping
smoking or chewing tobacco. According to the US National
Treatment involves a set of
options. Early-stage EAC may be treated by surgical removal of all or
part of the esophagus (esophagectomy), although this is a difficult operation
with a relatively high risk of mortality or post-operative difficulties.
Esophagectomy is the removal of a segment of the esophagus; as this shortens
the length of the remaining esophagus, some other segment of the digestive
tract is pulled up through the chest cavity and interposed. This is usually the stomach or part of the
large intestine (colon) or jejunum. Reconnection
of the stomach to a shortened esophagus is called an esophagogastric
anastomosis.
If
the person cannot swallow at all, an esophageal stent may be inserted to keep
the esophagus open. A nasogastric tube
may be necessary to continue feeding while treatment for the tumor is given,
and some patients require a gastrostomy (feeding hole in the skin that gives direct
access to the stomach).
Chemotherapy
and radiotherapy are also solutions. Chemotherapy depends on the tumor
type, and may be given after surgery, before surgery or if surgery is not
possible. Radiotherapy is given before,
during, or after chemotherapy or surgery, and sometimes on its own to control
symptoms.
Laser
therapy is the use of high-intensity light to destroy tumor cells while
affecting only the treated area. This is typically done if the cancer cannot be
removed by surgery. Photodynamic
therapy, a type of laser therapy, involves the use of drugs that are absorbed by
cancer cells; when exposed to a special light, the drugs become active and
destroy the cancer cells.
Patients
are followed closely after a treatment regimen has been completed.
Frequently, other treatments are used to improve symptoms and maximize
nutrition.
In
general, the prognosis of esophageal
cancer is quite poor, because most patients present with advanced
disease. By the time the first symptoms (such as difficulty swallowing)
appear, the cancer has already well progressed. The overall five-year survival
rate (5YSR) in the United States is around 15%, with most people dying within
the first year of diagnosis.
The good news is that listening to stories of cancer
survivors (Bart Frazzitta and Jerry Poisson) gives hope that cancer in general,
and esophageal cancer in particular, will be defeated. For good! With God’s blessings.
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