Optimal postoperative surveillance strategies for cancer survivors with gastric neuroendocrine carcinoma based on individual risk: a multicenter real-world cohort study.

BACKGROUND: The best follow-up strategy for cancer survivors after treatment should balance the effectiveness and cost of disease detection while detecting recurrence as early as possible. Due to the low incidence of gastric neuroendocrine carcinoma and mixed adenoneuroendocrine carcinoma [G-(MA)NEC], high-level evidence-based follow-up strategies is limited. Currently, there is a lack of consensus among clinical practice guidelines regarding the appropriate follow-up strategies for patients with resectable G-(MA)NEC. MATERIALS AND METHODS: The study included patients diagnosed with G-(MA)NEC from 21 centers in China. The random forest survival model simulated the monthly probability of recurrence to establish an optimal surveillance schedule maximizing the power of detecting recurrence at each follow-up. The power and cost-effectiveness were compared with the National Comprehensive Cancer Network, European Neuroendocrine Tumor Society, and European Society for Medical Oncology Guidelines. RESULTS: A total of 801 patients with G-(MA)NEC were included. The patients were stratified into four distinct risk groups utilizing the modified TNM staging system. The study cohort comprised 106 (13.2%), 120 (15.0%), 379 (47.3%), and 196 cases (24.5%) for modified groups IIA, IIB, IIIA, and IIIB, respectively. Based on the monthly probability of disease recurrence, the authors established four distinct follow-up strategies for each risk group. The total number of follow-ups 5 years after surgery in the four groups was 12, 12, 13, and 13 times, respectively. The risk-based follow-up strategies demonstrated improved detection efficiency compared to existing clinical guidelines. Further Markov decision-analytic models verified that the risk-based follow-up strategies were better and more cost-effective than the control strategy recommended by the guidelines. CONCLUSIONS: This study developed four different monitoring strategies based on individualized risks for patients with G-(MA)NEC, which may improve the detection power at each visit and were more economical, effective. Even though our results are limited by the biases related to the retrospective study design, we believe that, in the absence of a randomized clinical trial, our findings should be considered when recommending follow-up strategies for G-(MA)NEC.

Totally laparoscopic total gastrectomy using the "enjoyable space" approach coupled with self-pulling and latter transection reconstruction versus laparoscopic-assisted total gastrectomy for upper gastric cancer: short-term outcomes.

Introduction: With the development of minimally invasive surgery in recent years, totally laparoscopic total gastrectomy (TLTG) has attracted more attention. Aim: To introduce the more comprehensive "enjoyable space" approach coupled with the self-pulling and latter transaction (SPLT) reconstruction technique to perform TLTG and investigate its safety and feasibility. Material and methods: Ninety-seven patients with primary upper gastric cancer underwent laparoscopic radical total gastrectomy between January 2020 and December 2020. Among these patients, 46 underwent laparoscopic-assisted total gastrectomy (LATG), and 51 underwent TLTG. We compared the clinicopathological characteristics, surgical outcomes and postoperative complications between the two groups. Results: There were no significant differences in the clinicopathological characteristics between the two groups (p > 0.05). However, the TLTG group had a slightly lower mean operative time and mean blood loss than the LATG group (p < 0.05 each). Although there were similarities in the mean times to first flatus, liquid diet, and soft diet, the duration of hospital stay was significantly reduced in the TLTG group (p < 0.05). No significant differences in overall complications and E-J-related complications were found between the two groups (15.2% vs. 25.4%, p > 0.05). Conclusions: TLTG is a safe and feasible procedure for treating upper gastric cancer. The enjoyable space approach in conjunction with SPLT reconstruction is an appropriate comprehensive technique with several advantages over LATG.

Laparoscopic D2 plus complete mesogastrium excision using the "enjoyable space" approach versus conventional D2 total gastrectomy for local advanced gastric cancer: short-term outcomes.

INTRODUCTION: Laparoscopy-assisted radical total gastrectomy is technically demanding. AIM: To introduce the "enjoyable space" approach to achieve D2 plus complete mesogastrium excision (CME) and to investigate its safety and feasibility. MATERIAL AND METHODS: Between January 2015 and December 2017, 165 patients with primary advanced upper gastric cancer underwent laparoscopy-assisted radical total gastrectomy. Among these patients, 81 underwent conventional D2 total gastrectomy (D2 group) and 84 underwent D2 plus CME total gastrectomy (D2 + CME group). Clinicopathological characteristics, surgical outcomes and postoperative complications were compared between the two groups. RESULTS: There were no significant differences between the two groups (p > 0.05) in clinicopathological characteristics. However, the D2 + CME group had a longer mean operative time, lower mean blood loss and slightly higher mean number of retrieved lymph nodes (LNs) than the D2 group (p < 0.05 each). The mean time to first flatus, liquid diet, and soft diet and the duration of hospital stay were similar between the two groups (p > 0.05 each). No significant difference in postoperative complication rates was found between the groups (16.0% vs. 9.5%, p > 0.05). CONCLUSIONS: The "enjoyable space" approach is an option to achieve D2 + CME, and its safety and feasibility over conventional method are confirmed with lower intraoperative blood loss and more harvested LNs.

Conditional survival and recurrence of remnant gastric cancer after surgical resection: A multi-institutional study.

The present study was designed to evaluate the dynamic survival and recurrence of remnant gastric cancer (RGC) after radical resection and to provide a reference for the development of personalized follow-up strategies. A total of 298 patients were analyzed for their 3-year conditional overall survival (COS3), 3-year conditional disease-specific survival (CDSS3), corresponding recurrence and pattern changes, and associated risk factors. The 5-year overall survival (OS) and the 5-year disease-specific survival (DSS) of the entire cohort were 41.2% and 45.8%, respectively. The COS3 and CDDS3 of RGC patients who survived for 5 years were 84.0% and 89.8%, respectively. The conditional survival in patients with unfavorable prognostic characteristics showed greater growth over time than in those with favorable prognostic characteristics (eg, COS3, ≥T3: 46.4%-83.0%, Δ36.6% vs ≤T2: 82.4%-85.7%, Δ3.3%; P < 0.001). Most recurrences (93.5%) occurred in the first 3 years after surgery. The American Joint Committee on Cancer (AJCC) stage was the only factor that affected recurrence. Time-dependent Cox regression showed that for both OS and DSS, after 4 years of survival, the common prognostic factors that were initially judged lost their ability to predict survival (P > 0.05). Time-dependent logistic regression analysis showed that the AJCC stage independently affected recurrence within 2 years after surgery (P < 0.05). A postoperative follow-up model was developed for RGC patients. In conclusion, patients with RGC usually have a high likelihood of death or recurrence within 3 years after radical surgery. We developed a postoperative follow-up model for RGC patients of different stages, which may affect the design of future clinical trials.

Development and External Validation of Web-Based Models to Predict the Prognosis of Remnant Gastric Cancer after Surgery: A Multicenter Study.

BACKGROUND: Remnant gastric cancer (RGC) is a rare malignant tumor with poor prognosis. There is no universally accepted prognostic model for RGC. METHODS: We analyzed data for 253 RGC patients who underwent radical gastrectomy from 6 centers. The prognosis prediction performances of the AJCC7th and AJCC8th TNM staging systems and the TRM staging system for RGC patients were evaluated. Web-based prediction models based on independent prognostic factors were developed to predict the survival of the RGC patients. External validation was performed using a cohort of 49 Chinese patients. RESULTS: The predictive abilities of the AJCC8th and TRM staging systems were no better than those of the AJCC7th staging system (c-index: AJCC7th vs. AJCC8th vs. TRM, 0.743 vs. 0.732 vs. 0.744; P>0.05). Within each staging system, the survival of the two adjacent stages was not well discriminated (P>0.05). Multivariate analysis showed that age, tumor size, T stage, and N stage were independent prognostic factors. Based on the above variables, we developed 3 web-based prediction models, which were superior to the AJCC7th staging system in their discriminatory ability (c-index), predictive homogeneity (likelihood ratio chi-square), predictive accuracy (AIC, BIC), and model stability (time-dependent ROC curves). External validation showed predictable accuracies of 0.780, 0.822, and 0.700, respectively, in predicting overall survival, disease-specific survival, and disease-free survival. CONCLUSIONS: The AJCC TNM staging system and the TRM staging system did not enable good distinction among the RGC patients. We have developed and validated visual web-based prediction models that are superior to these staging systems.

Laparoscopic perigastric mesogastrium excision technique for radical total gastrectomy.

INTRODUCTION: Complete mesogastrium excision (CME) of the perigastric mesogastrium and dissection of lymph nodes (LNs) no. 10 and no. 11 remain technically challenging aspects of laparoscopic radical total gastrectomy (LRTG) plus CME. To address some of these difficulties, we introduced the laparoscopic perigastric mesogastrium excision technique (LPMET) and the concept of the "enjoyable space" to partly modify the procedures of conventional radical surgery and characterize the perigastric space and the surgical plane as well as its boundaries. AIM: To introduce the laparoscopic perigastric mesogastrium excision technique (LPMET) and the "enjoyable space" when undergoing laparoscopic radical total gastrectomy. MATERIAL AND METHODS: From July 2016 to June 2017, 79 cases of upper gastric cancer that were treated by laparoscopic D2 gastrectomy plus CME were investigated. The retrospective database included the patient characteristics, intraoperative and postoperative outcomes, and morbidity and mortality rates depending on the completeness of their medical records. RESULTS: Laparoscopic D2 gastrectomy plus CME was successfully performed in all 79 cases. The mean surgical time was 232.5 ±46.0 min, and the intraoperative blood loss was 67.6 ±52.3 ml. A total of 2245 LNs were retrieved (mean 28.1 ±10.8 retrieved from each specimen). The mean postoperative hospital stay was 10.3 ±1.6 days. The postoperative morbidity rate was 17.7%. After a median follow-up period of 12 months, one patient experienced liver metastasis; of the other 78 patients, none died or experienced tumor recurrence or metastasis. CONCLUSIONS: Laparoscopic perigastric mesogastrium excision technique and the "enjoyable space" could be a novel, minimally invasive approach and space to achieve CME and provide benefit for the dissection of LNs no. 10 and no. 11.