Purpose To explore the relationship between the proportion of HER2 low expression and clinicopatho-logical characteristics of gastric adenocarcinoma patients.Methods Clinical data from 3 779 gastric adenocarcinoma patients who underwent radical resection were collected.HER2 expression was categorized using immunohistochemistry combined with FISH,and the clinicopathological characteristics and prognosis of HER2 low expression gastric adeno-carcinoma patients were analyzed.Results Among the 3 779 gastric adenocarcinoma cases,1 251 cases(33.10％)showed HER2 low expression.Compared with HER2 negative expression,HER2 low expression patients were more likely to be older males,present with well-differentiated Lauren's intestinal-type adenocarcinoma,and have less nerve invasion.Furthermore,compared to HER2 negative expression,they showed higher Ki67 proliferation index and more advanced clinical stage.Meanwhile,compared with patients with HER2 over expression,those with low HER2 expres-sion were more likely to be younger females,present with well-differentiated Lauren's diffuse-type adenocarcinoma,and have more nerve invasion.Furthermore,compared to HER2 over expression,they showed lower Ki67 proliferation index and more advanced clinical stage.There was no significant difference in prognosis between HER2 low expression,HER2 negative,and HER2 over expression groups.Conclusion HER2 low expression have a relatively large propor-tion in gastric adenocarcinoma patients,and HER2-targeted antibody-drug conjugates may provide an effective treatment option for these patients with HER2 low expression.

Purpose To explore the relationship between the proportion of HER2 low expression and clinicopatho-logical characteristics of gastric adenocarcinoma patients.Methods Clinical data from 3 779 gastric adenocarcinoma patients who underwent radical resection were collected.HER2 expression was categorized using immunohistochemistry combined with FISH,and the clinicopathological characteristics and prognosis of HER2 low expression gastric adeno-carcinoma patients were analyzed.Results Among the 3 779 gastric adenocarcinoma cases,1 251 cases(33.10％)showed HER2 low expression.Compared with HER2 negative expression,HER2 low expression patients were more likely to be older males,present with well-differentiated Lauren's intestinal-type adenocarcinoma,and have less nerve invasion.Furthermore,compared to HER2 negative expression,they showed higher Ki67 proliferation index and more advanced clinical stage.Meanwhile,compared with patients with HER2 over expression,those with low HER2 expres-sion were more likely to be younger females,present with well-differentiated Lauren's diffuse-type adenocarcinoma,and have more nerve invasion.Furthermore,compared to HER2 over expression,they showed lower Ki67 proliferation index and more advanced clinical stage.There was no significant difference in prognosis between HER2 low expression,HER2 negative,and HER2 over expression groups.Conclusion HER2 low expression have a relatively large propor-tion in gastric adenocarcinoma patients,and HER2-targeted antibody-drug conjugates may provide an effective treatment option for these patients with HER2 low expression.

Objective To apply real-time transperineal ultrasound ( TPUS) to monitor the intra-fractional prostate motion,collect and analyze the data of the prostate motion,aiming to provide evidence for the optimization of the target area and plan of radiotherapy for prostate cancer. Methods TPUS is a non-invasive monitoring technique that utilizes an automatic scanning ultrasound probe to dynamically monitor and correct the motion of organs during radiotherapy. In this study, TPUS was utilized to collect 1588 intra-fractional data of 70 patients with prostate cancer. Prior to each cycle of radiotherapy,CBCT was adopted to correct the errors between intra-factional data by using VMAT. During radiotherapy, real-time ( once per second) ultrasound images were acquired to monitor the 3D motion of the prostate on the x (left+,right-),y (cranial+, caudal-), and z ( abdominal+, dorsal-) axes, emphasizing the analysis of 4D motion of the prostate. Results All patients successfully completed the treatment and data collection. The median time of effective monitoring per faction was 179 seconds (132-286 seconds). During 95% of the monitoring time,the distance of prostate motion was 2. 22 mm in the left direction,2. 17 mm in the right,2. 08 mm in the cranial, 1. 98 mm in the caudal,2. 44 mm in the abdominal and 2. 97 mm in the dorsal direction,respectively. In the x,y and z axes,the percentage of time in which the distance of prostate motion less than 1 mm among the total time was 83. 07%,85. 46% and 78. 27%,respectively,whereas 97. 70%,97. 87% and 96. 45% for＜3 mm, respectively. Conclusions TPUS is a non-invasive real-time monitoring technique,which can detect the 4D motion of the prostate during radiotherapy. By using VMAT,the range of prostate motion is relatively small, and the motion range is less than 3 mm in each direction within 95% of the time.