[The impact of different comprehensive treatment models on patients with adenocarcinoma of esophagogastric junction based on propensity score matching: a single center cohort study].

Objective: To compare the prognostic influence and postoperative pathology of different comprehensive treatment models for adenocarcinoma of esophagogastric junction. Methods: Between January 2012 and December 2017, a total of 219 patients with adenocarcinoma of esophagogastric junction underwent surgery in Gastrointestinal Cancer Center, Peking University Cancer Hospital & Institute and were enrolled in this study. The clinicopathological data of these patients were collected. The patients were categorized into 3 groups according to different treatment models: surgery-first group, neoadjuvant chemotherapy (NAC) group and neoadjuvant chemoradiotherapy (nCRT) group. A trimatch propensity score analysis was applied to control potential confounders among the three groups by using R language software. A total of 7 covariates including gender, age, comorbidity, body mass index, clinical T stage, clinical N stage and Siewert type were included, and the caliper value was taken as 0.2. After matching, a total of 87 patients were included for analysis with 27 patients for each group. There were 82 males and 5 females, with a median age of 63 years (range: 38 to 76 years). The effect of preoperative treatment on postoperative tumor pathology among the three different comprehensive treatment models was explored by χ2 test, ANOVA or Wilcoxon rank sum test. Mann-Whitney U test or χ2 test were used to undergo pairwise comparisons. Kaplan-Meier method and Log-rank test were used to analyze the overall survival and progression-free survival. Results: The proportion of vascular embolism in the surgery-first group was 72.4% (21/29), which was significantly higher than NAC group (37.9% (11/29), χ2=6.971, P=0.008) and nCRT group (6.9% (2/29), χ2=26.696, P<0.01). The proportions of pathological T3-4 stage in nCRT group and NAC group were 55.2% (16/29) and 62.1% (18/29), respectively, which were significantly lower than the surgery-first group (93.1% (27/29), χ2=10.881, P=0.001; χ2=8.031, P=0.005). Compared with the NAC group (55.2% (16/29), χ2=6.740, P=0.009) and nCRT group (31.0% (9/29), χ2=18.196, P<0.01), the proportion of lymph node positivity 86.2% (25/29) were significantly higher in the surgery-first group. The 5-year overall survival rates were 62.1%, 68.6% and 41.4% for the surgery-first group, NAC group and nCRT group, respectively (χ2=4.976, P=0.083). The 5-year progression-free survival rates were 61.7%, 65.1% and 41.1% for the surgery-first group, NAC group and nCRT group, respectively. The differences in overall survival (χ2=4.976, P=0.083) and progression-free survival (χ2=4.332, P=0.115) among the three groups were nonsignificant. Conclusions: Postoperative pathology is significantly different among the three groups. Neoadjuvant chemotherapy and neoadjuvant chemoradiotherapy could decrease the proportions of vascular embolism, pathological T3-4 stage and lymph node positivity to achieve local tumor control. The prognosis of overall survival and progression-free survival are not significantly different among the three groups.

[Accuracy comparision of abdominal enhanced CT and endoscopic ultrasound in the staging of gastric cancer after neoadjuvant chemotherapy: a post hoc analysis of a randomized clinical trial].

Objective: To compare the accuracy of abdominal enhanced CT and endoscopic ultrasound in the staging of gastric cancer after neoadjuvant chemotherapy (yc stage). Methods: Clinic data of 86 locally advanced gastric cancer patients admitted in Gastrointestinal Cancer Center, Peking University Cancer Hospital & Institute from April 2015 to November 2017 were analyzed retrospectively. Totally 86 patients completed both abdominal enhanced CT and endoscopic ultrasound after neoadjuvant chemotherapy. There were 60 males and 26 females, aged (57.8±9.7) years (range: 32 to 76 years). The diagnostic accuracy of abdominal enhanced CT and endoscopic ultrasound for yc stage were calculated by the area under the multiclass receiver operation characteristic curve (M-AUC), retrospectively. McNemar test was used to compared the diagnostic sensitivity. Results: The M-AUC of ycT stage evaluated by abdominal enhanced CT (CT-ycT stage) and by endoscopic ultrasound (EUS-ycT stage) was 0.614 and 0.704, respectively. For middle and lower gastric cancer, the M-AUC of CT-ycT stage was 0.599 and 0.613, respectively, while EUS-ycT stage was 0.558 and 0.709, respectively. For tumor in the lesser and non-lesser curvature, the M-AUC of CT-ycT stage was 0.630 and 0.607, respectively, while EUS-ycT stage was 0.616 and 0.749, respectively. For patients in CT-ycT1-CT-ycT4, there was no statistically significant difference in the sensitivity between CT-ycT stage and EUS-ycT stage (2/18, 2/15, 52.8%(19/36), 8/13 vs. 0, 4/15, 55.6%(20/36), 7/13; χ(2)=2.00, P=0.157; χ(2)=2.00, P=0.157; χ(2)=0.08, P=0.782; χ(2)=0.33, P=0.564). The M-AUC of ycN stage evaluated by abdominal enhanced CT (CT-ycN stage) was 0.654, while ycN stage evaluated by endoscopic ultrasound (EUS-ycN stage) was 0.533. For patients in CT-ycN0, there was statistically significant difference in the sensitivity between CT-ycN stage and EUS-ycN stage (12.7%(7/55) vs. 5.5%(3/55); χ(2)=4.00, P=0.046). For patients in CT-ycN1, N2, and N3, there was no statistically significant difference in the sensitivity between CT-ycN stage and EUS-ycN stage (2/19, 1/10, 0 vs. 1/19, 1/10, 0; χ(2)=1.00, P=0.317; the other P cannot be estimated). Conclusions: There was no significant difference between the diagnostic efficacy of abdominal enhanced CT and endoscopic ultrasound for yc stage of gastric cancer. Considering the invasiveness of ultrasound gastroscopy, it should not be recommend for patients after neoadjuvant chemotherapy routinely.

Development and validation of an individualized nomogram to identify occult peritoneal metastasis in patients with advanced gastric cancer.

BACKGROUND: Occult peritoneal metastasis (PM) in advanced gastric cancer (AGC) patients is highly possible to be missed on computed tomography (CT) images. Patients with occult PMs are subject to late detection or even improper surgical treatment. We therefore aimed to develop a radiomic nomogram to preoperatively identify occult PMs in AGC patients. PATIENTS AND METHODS: A total of 554 AGC patients from 4 centers were divided into 1 training, 1 internal validation, and 2 external validation cohorts. All patients' PM status was firstly diagnosed as negative by CT, but later confirmed by laparoscopy (PM-positive n = 122, PM-negative n = 432). Radiomic signatures reflecting phenotypes of the primary tumor (RS1) and peritoneum region (RS2) were built as predictors of PM from 266 quantitative image features. Individualized nomograms of PM status incorporating RS1, RS2, or clinical factors were developed and evaluated regarding prediction ability. RESULTS: RS1, RS2, and Lauren type were significant predictors of occult PM (all P < 0.05). A nomogram of these three factors demonstrated better diagnostic accuracy than the model with RS1, RS2, or clinical factors alone (all net reclassification improvement P < 0.05). The area under curve yielded was 0.958 [95% confidence interval (CI) 0.923-0.993], 0.941 (95% CI 0.904-0.977), 0.928 (95% CI 0.886-0.971), and 0.920 (95% CI 0.862-0.978) for the training, internal, and two external validation cohorts, respectively. Stratification analysis showed that this nomogram had potential generalization ability. CONCLUSION: CT phenotypes of both primary tumor and nearby peritoneum are significantly associated with occult PM status. A nomogram of these CT phenotypes and Lauren type has an excellent prediction ability of occult PM, and may have significant clinical implications on early detection of occult PM for AGC.