AWGS2019 vs EWGSOP2 for diagnosing sarcopenia to predict longterm prognosis in Chinese patients with gastric cancer after radical gastrectomy

BACKGROUND Sarcopenia is a nutrition-related disease and has a profound effect on the longterm overall survival(OS)of patients with gastric cancer.Its diagnostic criterion is critical to clinical diagnosis and treatment.However,previous research reported widely differing sarcopenia prevalence due to different criteria.AWGS2019 and EWGSOP2 are the two latest and widely adopted criteria.AIM To compare the effects of AWGS2019 and EWGSOP2 on the long-term OS of Chinese gastric cancer patient after radical gastrectomy.METHODS An observational study was conducted from July 2014 to January 2017,which included 648 consecutive gastric cancer patients who underwent radical gastrectomy.The sarcopenia elements(skeletal muscle index,handgrip strength,and gait speed)were measured within 1 mo or 7 d before surgery.The patients were followed at fixed intervals to gain the outcomes.Multivariate Cox regression analysis was performed to determine the association between sarcopenia and the long-term OS of these patients according to the two criteria separately.The predictive performance of the models with AWGS2019 and EWGSOP2 were evaluated by the concordance index(C-index)and area under the time-dependent receiver operating characteristic curve(AUC).The Akaike information criterion(AIC)was applied to compare model fits.RESULTS The prevalence of sarcopenia was 20.5%and 11.3%according to AWGS2019 and EWGSOP2,respectively.Sarcopenia was an independent risk factor for the longterm OS no matter based on AWGS2019 or EWGSOP2,but AWGS2019-sarcopenia in multivariate model had a higher hazard ratio(HR)[2.150(1.547-2.988)]than EWGSOP2-sarcopenia[HR 1.599(1.092-2.339)].Meanwhile,the model with AWGS2019-sarcopenia[C-index 0.773(0.742-0.804);AIC 2193.7;time-dependent AUC 0.812(0.756-0.867)for 1-year OS,0.815(0.778-0.852)for 3-year OS,and 0.809(0.759-0.859)for 5-year OS]had better predictive power and model fits than the model with EWGSOP2-sarcopenia[C-index 0.762(0.729-0.795);AIC 2215.2;timedependent AUC 0.797(0.741-0.854)for 1-year OS,0.804(0.767-0.842)for 3-year OS,and 0.799(0.748-0.850)for 5-year OS].CONCLUSION Sarcopenia is an independent risk factor for the long-term OS in Chinese gastric cancer patients undergoing radical gastrectomy.The prediction model with AWGS2019-sarcopenia has better predictive power and model fits than the prediction model with EWGSOP2-sarcopenia.AWGS2019 may be more appropriate for diagnosing sarcopenia in these Chinese patients than EWGSOP2.

Soliton molecules and mixed solutions of the(2+1)-dimensional bidirectional Sawada-Kotera equation

In this paper,we investigate some new interesting solution structures of the(2+1)-dimensional bidirectional Sawada–Kotera(bSK)equation.We obtain soliton molecules by introducing velocity resonance.On the basis of soliton molecules,asymmetric solitons are obtained by changing the distance between two solitons of molecules.Based on the N-soliton solutions,several novel types of mixed solutions are generated,which include the mixed breather-soliton molecule solution by the module resonance of the wave number and partial velocity resonance,the mixed lump-soliton molecule solution obtained by partial velocity resonance and partial long wave limits,and the mixed solutions composed of soliton molecules(asymmetric solitons),lump waves,and breather waves.Some plots are presented to clearly illustrate the dynamic features of these solutions.