Assessment of the prognostic significance of clinical and morphological factors on the survival of patients with locally advanced gastric cancer after radical surgical treatment: The experience of the Russian Center.

e16062 Background: Various staging systems are used to form a prognosis and determine an effective treatment strategy in patients with locally advanced gastric cancer (GC). Among these, the most widely used is the TNM UICC/AJCC staging system. However, even within the same stage, GC can vary significantly in terms of prognosis after surgery. The aim of our study was to assess the influence of clinical and pathomorphological biomarkers on the survival rate of patients with locally advanced GC after radical surgical treatment. Methods: For retrospective analysis, 124 patients were selected at the age from 29 to 86 years (mean age 65.69±10.09; 95% CI 63.90-67.49) with a diagnosis of stage I-III of GC who received only surgical treatment from 2015 to 2018. In 32 (26.1%) patients, the primary tumor was localized in the region of the cardioesophageal junction, in 61 (48.9%) - in the region of the stomach body, in 31 (25.0%) - in the pylorus. All patients underwent radical surgical treatment with subsequent staging of the disease according to the TNM system (6th edition), additional assessment of the lesion of the greater/lesser omentum. In 18 (14.5%) patients, stage IA was registered, in 10 (8.1%) - IB, in 23 (18.5%) - IIA, in 15 (12.1%) - IIB, 27 (21.8%) - IIIA, 26 (21.0%) - IIIB and 5 (4.0%) - IIIC. Results: We had a significant predictive value of the degree of metastatic lesions of the lesser and greater omentum (p <0.0001). The median OS in patients without omentum lesions at the time of assessment was not reached (follow-up period 42.0-54.0 months). The median OS in patients with only the greater omentum was 55.0 months (95% CI 6.5-55.0), which was 21.0 months higher than the median OS in patients with isolated lesions of the lesser omentum (24.0 months, 95% CI 19.0-57.0) and by 41.0 months exceeded the median OS of patients with combined lesions of the lesser and greater omentum (14.0 months, 95% CI 25.5-57). All factors that showed a significant effect on OS in the course of univariate analysis were included in the Cox proportional hazards model: the size of the primary tumor (T), the level of lesion of the regional lymphatic system (N), and the presence of lesions of the greater or lesser omentum. In general, the significance of the entire model was undeniable: p <0.0001. Significant prognostic influence was exerted by indicators characterizing the prevalence of the tumor process: T criterion (p=0.0090) and N criterion (p=0.0016). Conclusions: Despite the fact that, in multivariate analysis, the lesion of the greater and lesser omentum did not show a significant effect on OS in patients with locally advanced GC, this issue requires further study, since in the Cox model, the lesion of the lesser omentum, rather than the greater omentum, had a more favorable effect on the OS index. which allows you to increase RH by 12-60% (p=0.4046).