The overall efficacy of neoadjuvant chemotherapy for locally advanced gastric cancer has been recognized. However, neoadjuvant chemotherapy is ineffective in a subset of patients due to tumor heterogeneity. The tumor regression grade (TRG) has unique advantages in assessing the efficacy of neoadjuvant chemotherapy for gastric cancer. Nonetheless, since TRG is dependent on postoperative pathology, it becomes a significant topic today to mine TRG predictors to more accurately select appropriate patients for neoadjuvant chemotherapy. Therefore, to understand the relevant research progress and current research challenges of TRG predictors after neoadjuvant chemotherapy for gastric cancer from the aspects of biomarkers, immunity, inflammatory indicators, body composition, imaging indicators, etc., is conducive to further clinical research and practice.

Purpose To investigate the evaluation value of right-to-left shunt in atrial septal aneurysm(ASA)via contrast-enhanced transcranial Doppler,and analyze its clinical significance.Materials and Methods Forty patients with ASA who were performed on contrast-enhanced transcranial Doppler in Jiaozuo People's Hospital from June 2020 to July 2021,and 242 patients without ASA during the same period were enrolled.The overall incidence of right-to-left shunt was compared between the two groups in resting state and after Valsalva maneuver.All patients with right-to-left shunt were divided into small shunt group and large shunt group according to the number of microbubbles detected,comparing the incidence of small and big shunt,as well as alterations of shunt after Valsalva maneuver between the two groups.Results Contrast-enhanced transcranial Doppler in resting state:positive rate of ASA patients with right-to-left shunt was significantly higher than that of non-ASA patients via contrast-enhanced transcranial Doppler in resting state[47.5%(19/40)vs.29.8%(72/242);χ2=4.95,P=0.03].There were 14 ASA patients(73.7%)with small shunt and five ASA patients(26.3%)with large shunt.There were 61 non-ASA patients(84.7%)with small shunt and 11 non-ASA patients(15.3%)with large shunt.In resting state,there was no significant difference in ratio between small and large shunts,though there were mainly small shunt patients between the two groups(χ2=1.26,P=0.264).The positive rate of patients with or without ASA were significantly higher after Valsalva maneuver than those in resting state(positive rate of ASA patients was 77.5%,χ2=8.64,P=0.002;positive rate of non-ASA patients was 48.8%,χ2=80.49,P<0.001).The number of cases with massive shunt in ASA group were significantly higher than those in non-ASA group[64.5%(20/31)vs.47.5%(56/118);χ2=12.58,P<0.001].Conclusion ASA is often accompanied by right-to-left shunt,especially those with a substantial right-to-left shunt can trigger by the Valsalva maneuver.Therefore,attention should be paid to patients with ASA in clinical practice with standardized diagnosis and treatment.