Page 110 - Helicobacter pylori and Gastric Cancer: From Tumor microenvironment to Immunotherapy

and systemic map biopsies were taken. In total, 131 men and 117 women; mean age, 46 years; range, 20–80 years were studied.
Histological examination
Records of biopsy sampling and the subsequent histological analysis by the gastroenterological pathologist were retrieved and reviewed. Biopsy samples used for the analysis were those obtained using standard biopsy forceps from the five sites specified in the updated Sydney system (Figure 1) and had to be processed according to convention procedures. With respect to the latter, each tissue sample included was placed in a separate bottle of 10% formalin and embedded in paraffin for sectioning. Sections were stained with hematoxylin and eosin (HE) and evaluated according to established procedures. All the specimens were scored by expert gastrointestinal pathologists. For analysis of specimens with IM, PAS and Alcian blue 2.5 staining had to be used to identify the IM subtypes. Gastric atrophy was defined as apparent chronic inflammation of the gastric mucosa with concomitant loss of the gastric glandular cells and their replacement by intestinal- like epithelium, pyloric-like glands, and fibrous tissue. In each single biopsy, atrophy was scored as a percentage of atrophic glands. Non-metaplastic and metaplastic atrophy were considered together. For each biopsy sample, atrophy was scored on a four-tiered scale (no atrophy = 0%, score = 0; mild atrophy = 1–30%, score = 1; moderate atrophy = 31–60%, score = 2; and severe atrophy >60%, score = 3). The OLGA stage resulted from the combination of the overall “antrum score” with the overall “corpus score” [20]. In each specimen, IM was subject to Markov classification (absent or present), and “extensive intestinal metaplasia” was deemed present if IM appeared in two or more specimens of the same patient. A patient was considered to have incomplete IM subtype if the incomplete subtype appeared in at least one specimen. Gastric dysplasia was assessed according the revised Vienna classification[21]. In this study, the expert gastrointestinal pathologists were blinded to the age and sex of the subjects. The graded features were scored according to the updated Sydney system for atrophy[22]. Patients were considered positive for histological atrophy if the score was mild, moderate or marked in each location.
Chapter 5
Chapter 5
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