Association of LGR5 Expression with Gastric Cancer and Helicobacter pylori CagA Genotype

Background and purpose: Given the role of cancer stem cells in cancer, the aim of this study was to determine the expression of LGR5 marker in gastric cancer and its association with cagA genotype of Helicobacter pylori infection. Materials and methods: A case-control study was performed in gastric biopsy specimens from antrum and body during endoscopic examination of patients attending Sari Touba Clinic, 2017-2018. After reviewing the patient records, the samples from those aged 50 and higher were studied. Case group included gastric cancer specimens with H. pylori infection (n=30) and control group included non-cancerous samples with H. pylori infection (n=30). LGR5 expression and presence of cagA were evaluated by IHC and PCR methods, respectively. Results: The mean ages of gastric cancer and control group were 69.5±10.1 and 62.3±7.8, respectively (P= 0.003). Twenty three patients (76.7%) in cancer group and 24 patients (80%) in control group were positive for cagA genotype. Overexpression of LGR5 was observed in 15 patients (51.7%) with gastric cancer and 11 patients (39.3%) in control group (P= 0.429). LGR5 was also overexpressed in 18 cases (40.9%) with cagA positive genotype and 8 cases (61.5%) with negative cagA genotype (P=0.22). Conclusion: High expression of LGR5 was observed in half of patients with gastric cancer but it was not significantly associated with cagA H.pylori genotype.