P-101 Epidemiology of gastric cancer in Georgia addressing sex differences – 5-year analyses of cancer registry

Gastric cancer remains one of the major global health problems in the world, especially in developing countries. The lifetime risk of developing stomach cancer is higher in men (about 1 in 96) than in women (about 1 in 152). There is data suggesting high rates of undifferentiated cancer and poor survival outcomes in females with gastric cancer, although very few studies have been conducted to investigate sex differences in gastric cancer characteristics. Therefore, we investigated sex differences of gastric cancer in Georgia. In this study was analyzed data from national cancer registry of Gerogia from 2015 to 2021. The data included the number of cases, age, sex, anatomic location, stage, pathologic type and grade of gastric cancer. The aim of the study was to reveal differences between male and female patients. A total of 1824 patients with gastric cancer were evaluated during the period of 2015-2021 years. 49 patients were excluded from the analyses, because of having diagnosis of GIST or other types of sarcoma. From 1775 patients included in analyses 62% were male and 38% were female. The mean age was 64 (35-83) in males and 65 (26-94) in females. No differences were found regarding the anatomic location. Stage distribution among both sexes were relatively same and stage III and IV were most common - stage III 28 % in females and 30% in males, stage IV 45% in females and 43% in males respectively. Differences were observed in pathologic types of gastric cancer – in males were seen not classified adenocarcinomas 40%, undifferentiated carcinomas 29%, intestinal type carcinomas 9%, signet ring carcinomas 4%, mucinous adenocarcinomas 3%, mixed type adenocarcinomas 1% and in females tubular adenocarcinomas 39%, undifferentiated carcinomas 32%, signet ring carcinomas 9%, mixed type adenocarcinomas 2%, mucinous adenocarcinomas 2%, not classified adenocarcinomas 0.5%. There were single cases of rare pathologic entities like gastric carcinoma with osteoclast-like giant cells (OGCs), small cell carcinoma or squamous cell carcinoma in both sexes. No differences were seen regarding grading of tumor, grade 3 being most common (36% and 36%) for both sexes. The study showed no differences in women and man regarding age, tumor location, staging and grading of gastric cancer. There were seen differences in pathologic types - in male patients most commonly was seen not classified adenocarcinoma, although these results could be related to the reporting errors. The rates of signet ring carcinomas are relatively low in Georgia, and more common in female patients. Further studies are required to understand whether there are underling different risk factors for men and women for gastric cancer in Georgia, and to better understand gastric cancer biology differences in this population.