Long-term Survival After Endoscopic Resection For Gastric Cancer: Real-world Evidence From a Multicenter Prospective Cohort

BACKGROUND & AIMS

We aimed to clarify the long-term outcomes of endoscopic resection (ER) for early gastric cancers (EGCs) based on pathological curability in a multicenter prospective cohort study.

METHODS

We analyzed the long-term outcomes of 9054 patients with 10,021 EGCs undergoing ER between July 2010 and June 2012. Primary endpoint was the 5-year overall survival (OS). The hazard ratio for all-cause mortality was calculated using the Cox proportional hazards model. We also compared the 5-year OS with the expected one calculated for the surgically resected patients with EGC. If the lower limit of the 95% confidence interval (CI) of the 5-year OS exceeded the expected 5-year OS minus a margin of 5% (threshold 5-year OS), ER was considered to be effective. Pathological curability was categorized into en bloc resection, negative margins, and negative lymphovascular invasion: differentiated-type, pT1a, ulcer negative, ≤2 cm (Category A1); differentiated-type, pT1a, ulcer negative, >2 cm or ulcer positive, ≤3 cm (Category A2); undifferentiated-type, pT1a, ulcer negative, ≤2 cm (Category A3); differentiated-type, pT1b (SM1), ≤3 cm (Category B); or noncurative resections (Category C).

RESULTS

Overall, the 5-year OS was 89.0% (95% CI, 88.3%-89.6%). In a multivariate analysis, no significant differences were observed when the hazard ratio of Categories A2, A3, and B were compared with that of A1. In all the pathological curability categories, the lower limit of the 95% CI for the 5-year OS exceeded the threshold 5-year OS.

CONCLUSION

ER can be recommended as a standard treatment for patients with EGCs fulfilling Category A2, A3, and B, as well as A1 (UMIN Clinical Trial Registry, UMIN000005871).

Early Gastric Cancer: identification of molecular markers able to distinguish submucosa-penetrating lesions with different prognosis

BACKGROUND

Early Gastric Cancer (EGC) reaches 25% of the gastric cancers surgically treated in some areas of Northeastern Italy and is usually characterized by a good prognosis. However, among EGCs classified according to Kodama's criteria, Pen A subgroup is characterized by extensive submucosal invasion, lymph node metastases and worse prognosis, whereas Pen B subgroup by better prognosis. The aim of the study was to characterize the differences between Pen A, Pen B and locally advanced gastric cancer (T3N0) in order to identify biomarkers involved in aggressiveness and clinical outcome.

METHODS

We selected 33 Pen A, 34 Pen B and 20 T3N0 tumors and performed immunohistochemistry of mucins, copy number variation analysis of a gene panel, microsatellite instability (MSI), TP53 mutation and loss of heterozygosity (LOH) analyses.

RESULTS

Pen A subgroup was characterized by MUC6 overexpression (p = 0.021). Otherwise, the Pen B subgroup was significantly associated with the amplification of GATA6 gene (p = 0.002). The higher percentage of MSI tumors was observed in T3N0 group (p = 0.002), but no significant differences between EGC types were found. Finally, TP53 gene analysis showed that 32.8% of Pen tumors have a mutation in exons 5-8 and 50.0% presented LOH. Co-occurrence of TP53 mutation and LOH mainly characterized Pen A tumors (p = 0.022).

CONCLUSIONS

Our analyses revealed that clinico-pathological parameters, microsatellite status and frequency of TP53 mutations do not seem to distinguish Pen subgroups. Conversely, the amplification of GATA6 was associated with Pen B, as well as the overexpression of MUC6 and the TP53^mut/LOH significantly characterized Pen A.

Endoscopic resection versus surgery for early gastric cancer: a systematic review and meta-analysis

OBJECTIVES

Endoscopic resection (ER) is becoming an increasingly used treatment option for early gastric cancer (EGC); however, data comparing the long-term outcomes of ER and surgery are limited. Accordingly, we here aimed to perform a meta-analysis to clarify the long-term outcomes and safety of ER and surgery for EGC.

METHODS

Literature on the direct comparison of ER and surgery for EGC was retrieved from the Medline, PubMed and Scopus databases. We selected the eligible studies, extracted data, and assessed the quality scores according to the guidelines. The overall survival (OS), recurrence-free survival (RFS), and adverse event rates were investigated, and the pooled hazard ratio (HR), odds ratio (OR), and 95% confidence interval (CI) were estimated.

RESULTS

Nine retrospective studies were identified, including 973 and 1190 participants undergoing ER and surgery, respectively. There were no significant differences regarding the OS (HR: 0.995, 95% CI: 0.836-1.185; P = 0.959) and adverse event rates (OR: 0.50, 95% CI: 0.20-1.28, P = 0.148) between ER and gastrectomy. However, patients undergoing ER had significantly shorter RFS (HR: 7.226, 95% CI: 1.718-30.400, P = 0.007) than those undergoing gastrectomy.

CONCLUSIONS

Despite the limitations of this review, including the retrospective nature of all included studies, our results suggest that ER might be a feasible and safe treatment strategy compared to that of gastrectomy for EGC; however, careful endoscopic surveillance is needed for ensuring favorable outcomes. These findings should be confirmed in further large-scale, prospective, randomized, controlled trials from different countries.

Mixed Carcinoma as an Independent Prognostic Factor in Submucosal Invasive Gastric Carcinoma

Mixed carcinoma shows a mixture of glandular and signet ring/poorly cohesive cellular histological components and the prognostic significance of each component is not fully understood. This study aimed to investigate the significance of the poorly cohesive cellular histological component as a risk factor for lymph node metastasis and to examine the diagnostic reliability of endoscopic biopsy. Clinicopathologic characteristics of 202 patients who underwent submucosal invasive gastric carcinoma resection with lymph node dissection in 2005-2012 were reviewed. Mixed carcinoma accounted for 27.2% (56/202) of cases. The overall prevalence of lymph node metastasis was 17.3% (35/202). Lymphatic invasion (P < 0.001), family history of carcinoma (P = 0.025), tumor size (P = 0.004), Lauren classification (P = 0.042), and presence of any poorly cohesive cellular histological component (P = 0.021) positively correlated with the lymph node metastasis rate on univariate analysis. Multivariate analyses revealed lymphatic invasion, family history of any carcinoma, and the presence of any poorly cohesive cellular histological component to be significant and independent factors related to lymph node metastasis. Review of preoperative biopsy slides showed that preoperative biopsy demonstrated a sensitivity of 63.6% and a specificity of 100% in detecting the presence of the poorly cohesive cellular histological component, compared with gastrectomy specimens. The presence of any poorly cohesive cellular histological component was an independent risk factor associated with lymph node metastasis in submucosal invasive gastric carcinoma. Endoscopic biopsy had limited value in predicting the presence and proportion of the poorly cohesive cellular histologic component due to the heterogeneity of mixed carcinoma.

Novel endoscopic therapeutics for early gastric cancer

Gastrointestinal cancers are among the commonest cancers worldwide. Treatment of these cancers at an early stage will result in a significantly better prognosis. Endoscopic submucosal dissection (ESD) is a new method of endoscopic resection that can achieve higher rates of en bloc resection for early gastrointestinal neoplasia. Three retrospective case-control studies showed that ESD achieved significantly higher en bloc resection with lower recurrence rates than endoscopic mucosal resection for treatment of early gastric cancers. Most of the reports on clinical outcomes of ESD were from countries with a high incidence of gastric cancers, including Japan and Korea. The development of ESD has been slow for countries outside Japan and Korea because ESD requires a high level of endoscopic skills, and the dissection was performed single-handedly without assistance. A newly developed robotic endoscopic platform will enhance the performance of ESD through the use of 2 robotic arms: one arm for retraction of the mucosa and the other arm for dissection.

Clinicopathological characteristics and predictive markers of early gastric cancer with recurrence

Early gastric cancer (EGC) is a "curable" disease with a high cure rate made possible through proper surgical treatment; nonetheless, some patients sustain a disease recurrence after curative resection. The aim of this study was to identify the clinicopathological characteristics of recurrent EGC and determine predictable immunohistochemical markers for recurrence. We investigated the clinicopathological features of 1,786 EGC cases, and using tissue microarray, the expression of c-erbB-2, EGFR, MLH1, MSH2, p53, and AQP1 was examined in group with recurrence and control group without recerrence. In the clinical analysis, 32 of 1,786 (1.79%) patients showed recurrence, with a 2.04% five-year cumulative recurrence rate. Age, submucosal invasion, and lymph node metastasis significantly correlated with tumor recurrence (P=0.044, 0.019, and <0.001, respectively). Multivariate analysis showed lymph node status and old age (>or=57 yr) as independent risk factors of recurrence. In a case-control study, immunopositivity for c-erbB-2 was significantly associated with disease recurrence (P=0.024). There is the probability that EGC patients with old age (>or=57 yr), lymph node metastasis, submucosal invasion, and c-erbB-2 immunopositivity will experience recurrence; therefore, it is critical that patients with these risk factors be followed-up closely and considered candidates for adjuvant treatment.