Objective: To evaluate the accuracy of the clinical staging by comparing preoperative clinical stage and pathological stage in gastric cancer patients, and to explore the potential beneficial population of neoadjuvant chemotherapy for gastric cancer. Methods: We retrospectively collected the clinical data of consecutive patients with gastric cancer who met the inclusion criteria (gastric adenocarcinoma, undergoing laparoscopic or open D2 radical operation, definite cTNM and pTNM) for admission of the Gastrointestinal Center of Peking University Cancer Hospital from July 2013 to April 2019. Patients with the number of harvested lymph nodes less than 16, history of gastric operation or preoperative radiochemotherapy were excluded. Preoperative clinical stage was obtained from abdominal and pelvic enhanced CT by radiologists, and postoperative pathological stage was derived from postoperative pathology reports. The concordance rate between preoperative clinical stage and postoperative pathological stage, and the proportion of pathological stage I in patients with specific preoperative clinical TNM stage were analyzed and compared. The potential beneficial population of neoadjuvant chemotherapy were considered as pI < 5%. Relationship between clinical features and concordance rate of stage was further analysed. Results: A total of 459 patients were included in the analysis, including 321 males and 138 females with mean age of 60 (23 to 85) years old. The concordance rate from T1 to T4 between preoperative clinical T staging and postoperative pathological T staging was 82.5% (33/40), 31.1% (28/90), 34.4% (62/180), and 55.0% (96/149), respectively. The concordance rate from N0 to N3 between preoperative clinical N staging and postoperative pathological N staging was 58.8% (134/228), 22.1% (19/86), 23.6% (26/110), and 54.3% (19/35), respectively. The sensitivity and specificity of abdominal enhanced CT in the diagnosis of lymph node metastasis were 64.5% (171/265) and 69.1% (134/194) respectively. The clinical stage of cT3/T4 patients with pathological stage I was 9.1% (30/329), and the sensitivity of corresponding pathological stage III was 94.8% (164/173), while the cT3/4+cN1-3 patients with pathological stage I stage was 1.4% (3/218), and the sensitivity of corresponding pathological phase III was 76.9% (133/173). Tumor location was associated with the concordance of cT/pT staging [gastroesophageal junction: 64 (56.6%), upper stomach: 9 (9/17), middle stomach: 31 (40.3%), lower stomach: 97 (39.9%), whole stomach: 4(4/9), χ²=9.845, P=0.043]; the degree of tumor differentiation was associated with the concordance of cN/pN staging [poorly differentiated: 94 (42.3%), moderated differentiated: 92 (41.1%), well differentiated: 12 (12/13), χ²=13.261, P=0.001], whose differences were statistically significant (all P<0.05). Conclusion Based on a single-center retrospective data from Peking University Cancer Hospital, we think that the potential beneficial population of neoadjuvant chemotherapy for gastric cancer are those clinically staged as cT3/4+N1-3.

Objective:To investigate the effect of lateral tibial periosteum distraction on diabetic foot and vasculitis foot.Methods:A retrospective analysis of 13 patients (16 feet) who received lateral tibial periosteal distraction between June 2019 and May 2020 were included in the study. 9 males and 4 females; aged 39-77 years (average 66 years); left foot 7 cases, right foot 9 cases. 5 cases were patients with diabetic foot, 1 case was diabetic foot with arteriosclerosis obliterans, 2 cases were thromboembolic vasculitis, and 5 cases were arteriosclerosis obliterans. The tibial periosteum was dissected and a distraction device was placed. In the 3 patients with foot ulcers, tibial periosteum distraction devices were placed on the severer side. The periosteal distraction began on the third day after surgery, about 0.75 mm/d, the adjustment was done usually in two weeks. Two weeks later, the stretch plate was removed surgically. The followings were evaluated: visual analogue scale (VAS) pain score, foot peripheral oxygen saturation, foot capillary filling test, lower extremity arterial CT angiography (CTA), etc.Results:All 13 patients were followed up for 2-12 weeks, with an average of 3.85 weeks. VAS pain score: the average pain score of 13 patients with preoperative foot pain was 5.31±1.84 (range, 2-9) points, and 2 weeks after surgery, the average value was 2.46±1.39 (range, 1-6) points with statistical significance ( t=6.124, P<0.001) ; peripheral foot oxygen saturation: the average preoperative blood oxygen saturation of 12 patients was 87.83%±14.83% (range, 50%-98%), 1 patient was not detected before surgery, and 2 weeks after operation, the average blood oxygen saturation was 92.33%±7.91% (range, 75%-99%). There was no significant difference between them ( t=1.124, P=0.285). The foot skin temperature of 10 patients was 35.68±0.85 ℃ (range, 34.00-36.60 ℃) before surgery and 36.23±0.46 ℃ (range, 35.50-36.90 ℃) after surgery, and the difference was statistically significant ( t=3.197, P=0.008) . Capillary filling test: 2 weeks after operation, the capillary filling response was significantly improved. All 13 patients had improved CTA of both lower extremity arteries before operation, and 11 patients had CTA taken back after two weeks of operation. Compared with preoperative CTA, new vascular network was found in the operation limb. In addition to 1 patient with thromboangiitis obliterans (mainly suffering from foot pain, no wound symptoms), 2 of 12 patients with heart failure, renal failure and other basic diseases did not heal, and the wounds of the other 10 patients had improved significantly 1 month later. Conclusion:Lateral tibia periosteum distraction can be used to treat chronic ischemic diseases of lower extremities with satisfactory postoperative results.

Objective:To investigate the computed tomography (CT) features of adenocarcinoma of esophagogastric junction (AEG) after neoadjuvant chemotherapy.Methods:The retrospective and descriptive study was conducted. The clinicopathological data of 59 patients with AEG who underwent neoadjuvant chemotherapy in Peking University Cancer Hospital from February 2010 to November 2014 were collected. There were 51 males and 8 females, aged from 46 to 82 years, with a median age of 63 years. All the 59 patients underwent enhanced CT examination before and after neoadjuvant chemotherapy. Observation indicators: (1) pathological examination and neoadjuvant chemotherapy of patients with AEG; (2) results of CT examination in patients with AEG, including ① qualitative indicators of CT and ② quantitative indicators of CT. Measurement data with skewed distribution were represented as M( P25, P75) or M (range), and comparison between groups was analyzed using the Mann-Whitney U test. Count data were described as absolute numbers, and comparison between groups was analyzed by the chi-square test. Results:(1) Pathological examination and neoadjuvant chemotherapy of patients with AEG: of the 59 patients with AEG, high-differentiated adenocarcinoma was observed in 1 patient, moderate-differentiated adenocarcinoma in 40 patients, and low-differentiated adenocarcinoma in 18 patients. Effective response to neoadjuvant chemotherapy was observed in 13 patients, including 6 patients of pathological tumor regression grading (pTRG) 0 and 7 of pTRG 1; poor response was observed in 46 patients, including 12 patients of pTRG 2 and 34 patients of pTRG 3. (2) Results of CT examination in patients with AEG. ① Qualitative indicators of CT: for the 13 patients with effective response to neoadjuvant chemotherapy, 13 had the presence of ulcers, 5 had layered enhancement, 10 had infiltration of adventitia surface, and 2 had positive extramural venous invasion (EMVI) before neoadjuvant chemotherapy; after neoadjuvant chemotherapy, 13 had shallowed or disappeared ulcers, 7 patients had changed enhancement pattern, 3 had infiltration of adventitia surface, and 1 had positive EMVI. For the 46 patients with poor response to neoadjuvant chemotherapy, 28 had the presence of ulcers, 18 had layered enhancement, 37 had infiltration of adventitia surface, and 22 had positive EMVI before neoadjuvant chemotherapy; after neoadjuvant chemotherapy, 23 had shallowed or disappeared ulcers, 7 patients had changed layered enhancement pattern, 33 had infiltration of adventitia surface and 21 had positive EMVI, respectively. There was no significant difference in the layered enhancement or infiltration of adventitia surface before neoadjuvant chemotherapy between patients with different treatment response ( χ2=0.002, 0.000, P>0.05). There were significant differences in the presence of ulcers and positive EMVI before neoadjuvant chemotherapy between patients with different treatment response ( χ2=5.591, 4.421, P<0.05). After neoadjuvant chemotherapy, there were significant differences in the changes of layered enhancement pattern, infiltration of adventitia surface and positive EMVI between patients with different treatment response ( χ2=6.359, 10.090, 4.728, P<0.05); while there was no significant difference in the shallowed or disappeared ulcers between patients with different treatment response ( χ2=1.239, P>0.05). ② Quantitative indicators of CT: for the 13 patients with good response to neoadjuvant chemotherapy, the maximum tumor height, the maximum tumor area, enhanced CT value of the lesion before neoadjuvant chemotherapy were 1.37 cm(0.94 cm, 1.88 cm), 8.9 cm 2 (4.7 cm 2, 9.9 cm 2), 53 HU(47 HU, 63 HU), respectively. After neoadjuvant chemotherapy, the above indicators were 1.17 cm(0.79 cm, 1.29 cm), 4.4 cm 2(2.5 cm 2, 6.1 cm 2), 30 HU(25 HU, 53 HU), respectively. The change rates of the maximum tumor height, the maximum tumor area, and enhanced CT value of the lesion were -23%(-42%, 9%), -51%(-60 %, -21%), -44%(-51%, 19%), respectively. For the 46 patients with poor response to neoadjuvant chemotherapy, the maximum tumor height, the maximum tumor area, enhanced CT value of the lesion were 1.57 cm(1.21 cm, 1.96 cm), 9.4 cm 2(6.6 cm 2, 13.1 cm 2), 60 HU(53 HU, 66 HU) before neoadjuvant chemotherapy, respectively. After neoadjuvant chemotherapy, the above indicators were 1.16 cm(0.94 cm, 1.37 cm), 6.2 cm 2(4.8 cm 2, 8.1 cm 2), 55 HU(47 HU, 65 HU), respectively. The change rates of the maximum tumor height, the maximum tumor area, and enhanced CT value of the lesion were -27%(-38%, -9%), -33%(-47%, -12%), -9%(-22%, 9%), respectively. There was no significant difference in the maximum tumor height, the maximum tumor area, enhanced CT value of the lesion before neoadjuvant chemotherapy between patients with different treatment response ( Z=-1.372, -1.372, -1.331, P>0.05). There was no significant difference in the maximum tumor height after neoadjuvant chemotherapy between patients with different treatment response ( Z=-0.503, P>0.05), while there were significant differences in the maximum tumor area and CT value of the lesion ( Z=-2.743, -3.049, P<0.05). There was no significant difference in the change rate of the maximum tumor height or the maximum tumor area between patients with different treatment response ( Z=0.000, -1.481, P>0.05), while there was a significant difference in the change rate of CT value of the lesion ( Z=-3.231, P<0.05). Conclusion:Effective response of AEG to neoadjuvant chemotherapy was characterized by the changes in tumor layered enhancement pattern, reduction in the maximum tumor area, reduced CT value of the lesion, negative infiltration of adventitia surface, and negative EMVI.