Introduction
Gastric cancer, which has a gradually decreasing incidence in many
industrialized countries, still remains the second leading cause of
cancer related deaths around the world. (1). Gastric cancer is
classified into two main types: intestinal and diffuse. Intestinal type
gastric cancer is related to premalignant lesions such as chronic
atrophic gastritis (AG) and intestinal metaplasia (IM) (2,3). IM,
defined as gastric mucosa changing into epithelium with intestinal
morphology, is associated with Helicobacter pylori (H. pylori)
infection, and during this infection, gastric mucosa progresses into
many stages of chronic gastritis, AG and IM (4,5).
Colorectal cancers (CRC) are one of the most common cancers worldwide.
Colorectal carcinogenesis usually originates from colorectal adenomas
that develop from normal mucosa and the adenoma – carcinoma sequence
(6,7). This process gives us a chance to early diagnose and intervene
before the development of cancer. Colorectal adenomas are considered the
most important precancerous lesions for CRC. These two diseases,
colorectal adenomas and CRC, are collectively referred to as colorectal
neoplasia.
Clarifying the pathogenesis and the risk factors of colorectal cancers
is of great importance in the early diagnosis and treatment of this
cancer (7). Various previous studies were conducted on this matter after
H. pylori infection was accepted as a risk factor for colorectal cancer
in the 1990s (9). While some studies determined a positive association
between H. pylori infection and colorectal cancers (10-15), there were
studies stating that this was controversial as well (16-18). In
addition, studies investigating the association between gastric IM and
colorectal adenomas were also conducted (7,13,19). In a recent study, a
significant association between gastric IM and colorectal adenoma
prevalence was reported (13). The aim of this study was to evaluate the
relationship between H. pylori infection and IM, which is considered a
premalignant lesion for gastric cancer, with colon neoplasia.