Barrett’s
esophagus, a condition that affects the esophagus or food pipe, has been linked
to cancer.
Barrett’s esophagus occurs as a consequence of damage to the inner lining of
the esophagus by acid regurgitating upward from the stomach. The cells of the
esophagus change their appearance and resemble the intestinal lining.
Barrett’s esophagus is a premalignant condition,
that is, it predisposes a person to esophageal cancer. The patient may
initially show some cellular changes called low-grade dysplasia. Low-grade
dysplasia may further progress to high-grade dysplasia and then to a type of
cancer called adenocarcinoma.
It is for
this reason that people with Barrett’s esophagus are recommended periodic
surveillance with repeated endoscopies and biopsies at regular intervals.
However,
recent statistics indicate that most cases of adenocarcinoma in the general
population do not have a previous diagnosis of Barrett’s esophagus. Also, regular surveillance
of cases of Barrett’s esophagus has not shown any benefit in terms of survival.
A large study
was carried out to estimate the risk of developing adenocarcinoma and
high-grade dysplasia in patients with Barrett’s esophagus in Denmark. Data for the study was
obtained from the Danish Pathology Registry and the Danish Cancer Registry.
In addition, the researchers also aimed to
compare the incidence of adenocarcinoma in patients with Barrett’s esophagus
with that of the general population. They also tried to find out whether the
presence of low-grade dysplasia at the time of diagnosis of Barrett’s esophagus
could influence the development of adenocarcinoma or high-grade dysplasia.
According to the data, 11,028 patients in Denmark
were diagnosed as suffering from Barrett’s esophagus based on endoscopic biopsy
between the years 1992 to 2009. These included 7366 men and 3662 women. During
the follow-up period of a median of 5.2 years, 197 new cases of adenocarcinoma
were diagnosed. Of these, 131 cases were diagnosed in the first year of follow
up following diagnosis and 66 or 33.5% cases were diagnosed after the first
year.
During this same period, 2602 new cases of adenocarcinoma
were diagnosed in the general population.
Thus,
only 7.6% of all cases of adenocarcinoma occurred in patients with pre-existing
Barrett’s esophagus.
The study thus
showed that though patients with Barrett’s esophagus are at a risk of developing
high-grade dysplasia and adenocarcinoma, the risk is relatively lower that what
was previously reported. In fact, it states that the incidence was 4 to 5 times lower than
what was previously reported.
Among the
patients diagnosed with Barrett’s esophagus, 621 patients or 5.6% patients were
also diagnosed with low-grade dysplasia. 2.3% patients with low-grade dysplasia and 0.5%
patients without low-grade dysplasia developed adenocarcinoma at the end of one
year.
Thus patients with low-grade
dysplasia at the time of diagnosis of Barrett’s esophagus were at a higher risk
for developing adenocarcinoma compared to those without low-grade dysplasia.
Low-grade dysplasia also increased the changes of
patients suffering from high-grade dysplasia in the later years.
Most of the cancers were diagnosed within the first
year of diagnosis of Barrett’s esophagus. This could have been because the
cancer was overlooked at the time of diagnosis of Barrett’s esophagus or
because of biopsy sampling error on the initial endoscopy.
The study thus concludes that the risk for
developing esophageal adenocarcinoma is small in the absence of dysplasia.
Thus, subjecting these patients to routine
surveillance may not be necessary. This approach could reduce the cost of
treatment as well as inconvenience to the patient. In fact, the American
Gastroenterology Association has recently recommended considering removal of
dysplastic cells through endoscopic eradication rather than surveillance
especially in cases of high-grade dysplasia.
Reference:
1. Hvid-Jensen F, Pedersen L, Drewes AM, Sørensen HT, and Funch-Jensen
P. Incidence of Adenocarcinoma among Patients with Barrett's Esophagus. N Engl
J Med 2011; 365:1375-1383
Source-Medindia