Survival outcomes after D1 and D2 lymphadenectomy with R0 resection in stage II-III gastric cancer: Longitudinal follow-up in a single center

Lymph Node Dissection of Choice in Older Adult Patients with Gastric Cancer: A Systematic Review and Meta-Analysis

Background: Although the current literature has shown an increasing interest in surgical treatment of gastric cancer (GC) in older adults in recent years, there is still no consensus on proper management in this subgroup of patients. This study was designed with the objective of evaluating the current evidence that compares limited lymph node dissection with extended lymph node dissection in older adult patients (≥65 years) coursing with resectable GC. Methods: A systematic review of PubMed, Cochrane library, and ScienceDirect was performed according to PRISMA guidelines. All studies before 2018 were selected using a systematic review by Mogal et al. Studies were eligible for this meta-analysis if they were randomized controlled trials or non-randomized comparative studies comparing limited lymph node dissection versus extended lymph node dissection in patients with resectable GC taken to gastrectomy. Results: Seventeen studies and a total of 5056 patients were included. There were not any statistically significant differences in OS (HR = 1.04, CI95% = 0.72-1.51), RFS (HR = 0.92, CI95% = 0.62-1.38), or CSS (HR = 1.24, CI95% = 0.74-2.10) between older adult patients taken to limited and extended lymphadenectomy in addition to gastrectomy as the current surgical treatment for GC. Although a higher rate of major complications was observed in the extended lymphadenectomy group, this difference was not statistically significant in incidence between both groups of patients (OR = 1.92, CI95% = 0.75-4.91). Conclusions: Limited lymphadenectomy must be considered as the better recommendation for surgical treatment for GC in older adult patients, considering the oncological outcomes and lower rates of complications compared with more radical lymph node dissections.

Development of a deep learning-based model to diagnose mixed-type gastric cancer accurately

OBJECTIVE

The accurate diagnosis of mixed-type gastric cancer from pathology images presents a formidable challenge for pathologists, given its intricate features and resemblance to other subtypes of gastric cancer. Artificial Intelligence has the potential to overcome this hurdle. This study aimed to leverage deep machine learning techniques to establish a precise and efficient diagnostic approach for this cancer type which can also predict the metastatic risk using two software, U-Net and QuPath, which have not been trialled in gastric cancers.

METHODS

A U-Net neural network was trained to recognise, and segment differentiated components from 186 pathology images of mixed-type gastric cancer. Undifferentiated components in the same images were annotated using the open-source pathology imaging software QuPath. The outcomes from U-Net and QuPath were used to calculate the ratios of differentiation/undifferentiated components which were correlated to lymph node metastasis.

RESULTS

The models established by U-Net recognised ∼91% of the regions of interest, with precision, recall, and F1 values of 90.2%, 90.9% and 94.6%, respectively, indicating a high level of accuracy and reliability. Furthermore, the receiver operating characteristic curve analysis showed an area under the cure of 91%, indicating good performance. A bell-curve correlation between the differentiated/undifferentiated ratio and lymphatic metastasis was found (highest risk between 0.683 and 1.03), which is paradigm-shifting.

CONCLUSION

U-Net and QuPath exhibit promising accuracy in the identification of differentiated and undifferentiated components in mixed-type gastric cancer, as well as paradigm-shifting prediction of metastasis. These findings bring us one step closer to their potential clinical application.

Laparoscopic vs Open Gastrectomy: an Updated Meta-analysis of Randomized Control Trials for Short-Term Outcomes

The aim of this meta-analysis was to compare short-term outcomes of laparoscopic and open gastrectomy for gastric cancer. EMBASE, MEDLINE, PubMed, and the Cochrane Database were searched for randomized control trials comparing outcomes in patients undergoing laparoscopic gastrectomies with those patients undergoing open gastrectomies. The primary outcome was 30-day morbidity and mortality. Secondary outcomes studied included length of stay, blood loss, d2 gastrectomies, lymph node retrieval, operative time, wound complications, and intraabdominal complications. Systemic review and meta-analysis were done according to MOOSE and PRISMA guidelines. Eleven RCTs consisting of 4614 patients were included in the study. A total of 2452 patients were there in laparoscopic gastrectomy group while 2162 patients were included in open gastrectomy group. Morbidity was significantly low in laparoscopic group (p = 0.003). There was no significant difference in mortality between the two groups (P = 0.75). There were fewer wound complications in laparoscopic group and no difference intra-abdominal complications in both groups. Blood loss was significantly lesser in laparoscopic group (p < 0.001). Hospital stay was similar in both groups (p = 0.30). Operative time was significantly higher in laparoscopic group (p < 0.001). Laparoscopic group patients had a lesser number of lymph node retrieval compared to open group (p = 0.002). Laparoscopic group also contained similar advanced staged gastric cancer than open gastrectomies (p = 0.64). Laparoscopic gastrectomies were associated with lesser wound-related complications without decreasing hospital stay with a smaller number of lymph nodes retrieval.

The efficacy of clinical pathway in gastric cancer surgery

OBJECTIVES

Clinical pathways are useful tools for surgical quality improvement and better peri-operative clinical outcomes for patients undergoing major surgery. This study aimed to evaluate the influence of clinical pathway on early postoperative outcomes for gastric cancer patients.

MATERIAL AND METHODS

The study was designed as a retrospective cohort observational study. Patients who had undergone curative gastrectomy for gastric cancer were evaluated by using the gastric cancer database, which was prospectively maintained. The patients were divided into two groups based on the date when the clinical pathway was first used: The control group (May 2015-May 2016) and the clinical pathway group (June 2016-December 2017). Early postoperative outcomes including the length of hospital stay, start of the day of diet, and 30-day complications including reoperation, and operative mortality were compared after propensity score matching.

RESULTS

A total of 101 patients were analyzed, and the data of 70 patients (35 patients in each group) were compared after matching. Clinical pathway group demonstrated shorter hospital stay, earlier nasogastric tube removal, and start of earlier liquid/soft diet. Overall complication rate was lower in the clinical pathway group, while there was no statistically significant difference in major complication rates. No statistically significant difference was observed between the groups in terms of reoperation and operative mortality.

CONCLUSION

Clinical pathway may shorten the postoperative length of hospital stay and reduce the overall complication rate without increasing major morbidity in patients undergoing elective gastric cancer surgery.

Anatomical location-based nodal staging system is superior to the 7th edition of the American Joint Committee on Cancer staging system among patients with surgically resected, histologically low-grade gastric cancer: A single institutional experience

Background

A hybrid topographic and numeric lymph node (LN) staging system for gastric cancer, which was recently proposed by Japanese experts as a simple method with a prognostic predictive power comparable to the N staging of the American Joint Committee on Cancer (AJCC) Tumor-node-metastasis classification, has not yet been validated in other Asian countries. This study aimed to examine the prognostic predictability of the hybrid staging system with the current AJCC staging system in gastric cancer.

Methods

Overall, 400 patients with gastric cancer who underwent surgery at Changhua Christian Hospital from January 2007 to December 2017 were included in the study. Univariate and multivariate analyses were performed to identify prognostic factors for gastric cancer-related death. Homogeneity and discrimination abilities of the two staging systems were compared using likelihood ratio chi-square test, linear trend chi-square test, Harrell’s c-index, and bootstrap analysis.

Results

One-third of the LN-positive patients were reclassified into the new N and Stage system. The concordance rates of the two staging systems and the N staging between the two staging systems were 0.810 and 0.729, respectively. Harrell’s c-indices for the stage and N staging were higher in the 7^th AJCC staging system than the hybrid staging system (c-index for stage, 0.771 vs 0.764; c-index for nodal stage, 0.713 vs 0.705). Stratification of the patients according to the histological grade revealed that Harrell’s c-indices for the stage and N stage of the hybrid staging system were comparable with those of the 7^th AJCC staging system (c-index for AJCC stage vs hybrid stage, 0.800 vs 0.791; c-index for AJCC N stage vs hybrid N stage, 0.746 vs 0.734) among patients with histologically lower grade gastric cancer. The performance of the new nodal staging system was better than that of the 7^th AJCC staging system by likelihood ratio and linear trend tests and bootstrap analysis in the low-grade group.

Conclusions

The hybrid anatomical location-based classification may have better prognostic predictive ability than the 7^th AJCC staging system for LN metastasis of low-grade gastric cancer. Further studies involving different ethnic populations are necessary for the validation of the new staging system.