Low yield of gastroscopy in patients with Lynch syndrome
The Turkish Journal of Gastroenterology
Lynch syndrome (LS) is the most common hereditary colorectal cancer (CRC) syndrome, accounting for 1%-4% of all CRCs and 10% of CRCs under the age of 50 years (1). It is an autosomal dominant condition caused by germline mutations in one of four DNA mismatchrepair (MMR) genes, namely MLH1, MSH2, MSH6, and PMS2, as well as mutations in the EPCAM gene, which inactivates MSH2 via promoter hypermethylation. Besides a lifetime risk of CRC averaging 70%-80%, there is also an increased risk of
... sed risk of extracolonic tumors, including carcinoma of the endometrium (40%-60% lifetime risk), ovary, stomach, small bowel, pancreas, hepatobiliary tree, brain, and urinary tract (2). The Amsterdam II criteria are a clinical tool used to help identify LS mutation carriers ( Figure 1 ). The utility of routine surveillance gastroscopy in LS has been a topic of debate for several years. While gastric cancer (GC) was a predominant feature of LS a century ago, it is much less common now, indicating the significant decline in GC incidence in the Western world over the last few decades (3). Until recently, screening gastroscopies were periodically performed for LS patients followed in the Genetics clinic or Hereditary Gastrointestinal Cancer Clinic (GENGI) of our institution. ABSTRACT Background/Aims: Lynch syndrome (LS) is the most common hereditary colorectal cancer syndrome, caused by germline mutations in mismatch-repair genes. Besides a lifetime risk of colorectal cancer averaging 70%-80%, there is an increased risk of extracolonic tumors including gastric cancer. The utility of screening gastroscopy in Lynch syndrome has long been debated. This study aimed to determine the proportion of abnormal gastroscopies among patients screened, including the incidence of gastric cancer and prevalence of precursor lesions. Materials and Methods: Charts of patients with mutation-proven Lynch syndrome between January 1, 2004, and December 31, 2014, from the Genetics clinic and Hereditary Gastrointestinal Cancer Clinic of our institution were retrospectively reviewed. Results: A total of 66 Lynch syndrome patients were identified. Thirty-two gastroscopies were performed in 21 (32%) of them. No gastric cancers were found. The prevalence of precursor lesions (Helicobacter pylori gastritis, atrophic gastritis, and gastric intestinal metaplasia) was 19.05%. A family history of gastric cancer was associated with a non-significant increased risk of abnormal gastroscopy, while sex and specific gene involved did not affect the abnormality rate. Conclusion: Gastric screening in asymptomatic individuals with Lynch syndrome is probably best reserved for high-risk individuals, based on the family history and perhaps ethnicity as suggested by several governing bodies. Larger studies are required to achieve the statistical power necessary to address this controversial issue.