Background. The prognostic relevance of gastric tumor location has been reported and debated. Our study was conducted to examine the differences in clinicopathological features, prognostic factors, and overall survival (OS) between patients with proximal gastric cancer (PGC) and distal gastric cancer (DGC). Patients and Methods. Patients with PGC or DGC were identified from the China National Cancer Center Gastric Cancer Database (NCCGCDB) during 1997–2017. Survival analysis was performed via Kaplan-Meier estimates and Cox proportional hazards models. Results. We reviewed 16,119 cases of gastric cancer patients, including 6,479 of PGC and 9,640 of DGC. PGC patients presented as older patients (61.5 versus 56.4 years, P<0.001) and more males (82.9% versus 68.2%, P<0.001). Compared with DGC, PGC was more likely to be in later pT stage (pT3 and pT4, 65.0% versus 52.8%, P<0.001) and lymph node metastasis (54.8% versus 50.9%, P<0.001). In univariate analysis, PGC patients had a worse survival outcome in stage I (Hazard ratio [HR] = 2.04, 95% CI: 1.42-2.94) but a better prognosis in stage IV (HR = 0.85, 95% CI: 0.73-0.98) when compared to DGC patients. However, multivariate analysis demonstrated that PGC was not an independent predictor for poor survival (HR = 1.07, 95% CI: 1.00-1.14). Results from multivariate analysis also revealed that pT4, lymph node metastasis, distant metastasis, no gastrectomy, and Borrmann IV were independent predictors associated with poor survival for both PGC and DGC patients. Additional prognostic factors for PGC patients included underweight (BMI < 18.5) (HR = 1.29, 95% CI: 1.06-1.58), linitis plastica (HR = 2.13, 95% CI: 1.25-3.65), and overweight (23 ≤ BMI <27.5) (HR = 0.80, 95% CI: 0.71-0.90). During the 20-year study period, the 5-year OS increased significantly for both PGC and DGC, with the increase rate of 91.7% and 67.7%, respectively. Conclusion. In China, PGC significantly differed from DGC in clinicopathological characteristics and prognostic factors. However, there was no significant relationship between survival outcome and gastric tumor location.

Higher BMI increases the risk for postoperative complications after pancreatectomy in the Chinese population. The findings require replication in future studies with larger sample sizes.

Peritoneal dissemination (PD) is the major type of gastric cancer (GC) recurrence and leads to rapid death. Current approach cannot precisely determine which patients are at high risk of PD. In this study, we developed a technology to detect minimal residual cancer cells in peritoneal lavage fluid (PLF) samples by parallel profiling tumor-specific mutations. We applied the technology to a prospective cohort of 110 GC patients. The technology showed ultra-high sensitivity by successfully detecting all the 27 cases that developed PD. The minimal residual cancer cells in PLF was associated with an increased risk of PD (HR = 145.13; 95%CI = 20.20-18435.79; p < 0.001) and significantly shorter overall survival. In pathologically high-risk (T4) patients, the PLF mutation profiling model exhibited even greater specificity of 91% and positive predictive value of 88%, while retaining sensitivity of 100%. PLF cancer cell fraction remained the strongest independent predictor of PD and recurrence-free survival over pathologic diagnosis and cytological diagnosis in GC patients. This approach may help in the postsurgical management of GC patients by detecting PD far before the metastatic lesions grow to significant size detectable by conventional methods such as MRI and CT scanning.

Background Peri-operative chemo-radiotherapyplayed important rolein locally advanced gastric cancer. Whether preoperative strategy can improve the long-term prognosis compared with postoperative treatment is unclear. The study purpose to compare oncologic outcomes in locally advanced gastric cancer patients treated with preoperative chemo-radiotherapy (pre-CRT) and postoperative chemo-radiotherapy (post-CRT). Methods From January 2009 to April 2019, 222 patients from 2 centers with stage T3/4 and/or N positive gastric cancer who received pre-CRT and post-CRT were included. After propensity score matching (PSM), comparisons of local regional control (LC), distant metastasis-free survival (DMFS), disease-free survival (DFS) and overall survival (OS) were performed using Kaplan-Meier analysis and log-rank test between pre- and post-CRT groups. Results The median follow-up period was 30 months. 120 matched cases were generated for analysis. Three-year LC, DMFS, DFS and OS for pre- vs. post-CRT groups were 93.8% vs. 97.2% (p = 0.244), 78.7% vs. 65.7% (p = 0.017), 74.9% vs. 65.3% (p = 0.042) and 74.4% vs. 61.2% (p = 0.055), respectively. Pre-CRT were significantly associated with DFS in uni- and multi-variate analysis. Conclusion Preoperative CRT showed advantages of oncologic outcome compared with postoperative CRT. Trial registration ClinicalTrial.gov NCT01291407, NCT03427684 and NCT04062058, date of registration: Feb 8, 2011.