Gastric cancer ranks fourth in incidence and second in
mortality among all cancers worldwide. Despite the decrease
in incidence in some regions of the world, gastric cancer
continues to present a major clinical challenge due to
most cases being diagnosed in advanced stages with poor
prognosis and limited treatment options. The development
of gastric cancer is a complex and multifactorial process involving
a number of etiological factors and multiple genetic
and epigenetic alterations. Among the predisposing factors
are:
Helicobacter pylori
infection, high salt intake, smoking,
and in a small percentage of patients, a familial genetic component.
More than 95% of stomach cancer cases are adenocarcinomas,
which are classified into two major histologic
types: intestinal and diffuse. Intestinal type adenocarcinoma
is preceded by a sequence of gastric lesions known as
Correa´s cascade and is the histologic type associated with
the global decrease in gastric cancer rates. Diffuse type adenocarcinomas
have a more aggressive behavior and worse
prognosis than those of the intestinal type. According to
the anatomical location, adenocarcinomas are classified as
proximal (originating in the cardia) and distal (originating
in the body and antrum). This classification seems to recognize
two different clinical entities. Surgical resection of
the tumor at an early stage is the only effective treatment
method. Therefore, the identification and surveillance of
patients at risk may play a significant role in survival rates.
Anti-
Helicobacter pylori therapy has been shown to be an
effective measure in the prevention of gastric cancer.
