P-098 Local advanced gastric cancer: optimization of management

Abstract

Introduction: Search of best treatment plan for local advanced gastric cancer (GC) patients (GCP) (T4bN0-2M0) was realized. Methods: We analyzed data of 144 consecutive GCP (age = 55.7 ± 9.5 years; tumor size = 8 ± 3 cm) radically operated (R0) and monitored in 1975-2015 (m = 95, f = 49; total gastrectomy = 41, distal gastrectomy = 70, proximal gastrectomy = 33, combined gastrectomy with resection of 1-6 adjacent organs (pancreas, liver, diaphragm, colon transversum, splenectomy, small intestine, kidney, adrenal gland, etc.) = 144; T4b = 144; M1 = 0; N0 = 47, N1 = 10, N2 = 87; G1 = 37, G2 = 25, G3 = 82; only surgery-S = 97, adjuvant treatment-AT = 47 (chemoimmunotherapy: 5-FU + thymalin/ taktivin). Survival curves were estimated by the Kaplan-Meier method. Differences in curves between groups of GCP were evaluated using a log-rank test. Cox modeling, clustering, SEPATH, Monte Carlo, bootstrap simulation and neural networks computing were used to determine any significant dependence. Results: For total of 144 GCP overall life span (LS) was 1685.3 ± 2100.3 days, (median = 728 days) and cumulative 5-year survival (5YS) reached 43.9%, 10 years - 36.5%, 20 years - 30.4%. 40 GCP lived more than 5 years without GC progressing. 72 GCP died because of GC during the first 5 years after surgery. 5YS was superior significantly after AT (69.3%) compared with S (35.1%) (P = 0.001 by log-rank test). Cox modeling displayed that 5YS significantly depended on: phase transition (PT) N0-N12 in term of synergetics, tumor growth, histology, localization, age, AT, ESS, color index, residual nitrogen, blood chlorides, hemorrhage time (P = 0.000-0.049). Neural networks computing, genetic algorithm selection and bootstrap simulation revealed relationships between 5YS and PT N0-N12 (rank = 1), color index (rank = 2), eosinophils (3), ESS (4), age (5), thrombocytes/cancer cells - CC (6), eosinophils/CC (7), healthy cells/CC (8), AT (9). Correct prediction of 5YS was 100% by neural networks computing. Conclusion: Optimal management strategies for local advanced GCP are: 1) availability of experienced surgeons because of complexity of radical procedures; 2) aggressive en block surgery and adequate lymph node dissection for completeness; 3) high-precision prediction; 4) adjuvant treatment for GCP with unfavorable prognosis.