Risk factors for lymph node metastasis in patients with early gastric cancer and signet ring cell histology

A Rare Case of Primary Gastric Signet Ring Cell Carcinoma: a Review of Guidelines for the Management of Gastric Cancer

Gastric carcinoma is the fifth most common and the third leading cause of cancer deaths worldwide. The incidence of diffuse-type gastric cancer, of which signet ring cell carcinoma is a subtype, is rising in the world. Due to non-specific gastritis-like symptoms, difficulty in assessing true tumor characteristics owing to its horizontal spread, and non-distinguishable endoscopic appearance from other gastric pathologies, the diagnosis of this subtype is challenging. We present a case of a 67-year-old woman with progressively worsening abdominal pain who came for an endoscopic ultrasound evaluation of an incidentally noted pancreatic cyst on a previous MRI. During endoscopy, a 1-cm gastric ulcer was noted along the lesser curvature of the gastric body. Biopsy confirmed a diagnosis of gastric signet ring cell carcinoma (SRCC) with CDX-2 and keratin positivity. The patient underwent total gastrectomy with Roux-en-Y reconstruction. Gross specimen revealed a diffuse SRCC invading the muscularis propria, along with lymphovascular and perineural invasion. In the context of our case, we discuss the morphological features of SRCC and the effectiveness of treatment options based on existing literature. Early accurate diagnosis and staging play an important role in determining treatment options as well as the clinical course of gastric SRCC.

Clinical Features of Gastric Signet Ring Cell Cancer: Results from a Systematic Review and Meta-Analysis

BACKGROUND

Conflicting results about the prognostic relevance of signet ring cell histology in gastric cancer have been reported. We aimed to perform a meta-analysis focusing on the clinicopathological features and prognosis of this subgroup of cancer compared with other histologies.

METHODS

A systematic literature search in the PubMed database was conducted, including all publications up to 1 October 2021. A meta-analysis comparing the results of the studies was performed.

RESULTS

A total of 2062 studies referring to gastric cancer with signet ring cell histology were identified, of which 262 studies reported on its relationship with clinical information. Of these, 74 were suitable to be included in the meta-analysis. A slightly lower risk of developing nodal metastases in signet ring cell tumours compared to other histotypes was found (especially to undifferentiated/poorly differentiated/mucinous and mixed histotypes); the lower risk was more evident in early and slightly increased in advanced gastric cancer. Survival tended to be better in early stage signet ring cell cancer compared to other histotypes; no differences were shown in advanced stages, and survival was poorer in metastatic patients. In the subgroup analysis, survival in signet ring cell cancer was slightly worse compared to non-signet ring cell cancer and differentiated/well-to-moderately differentiated adenocarcinoma.

CONCLUSIONS

Most of the conflicting results in signet ring cell gastric cancer literature could be derived from the lack of standardisation in their classification and the comparison with the different subtypes of gastric cancer. There is a critical need to strive for a standardised classification system for gastric cancer, fostering clarity and coherence in the forthcoming research and clinical applications.

Development and Validation of Models to Predict Lymph Node Metastasis in Early Gastric Cancer Using Logistic Regression and Gradient Boosting Machine Methods

PURPOSE

To identify important features of lymph node metastasis (LNM) and develop a prediction model for early gastric cancer (EGC) using a gradient boosting machine (GBM) method.

MATERIALS AND METHODS

The clinicopathologic data of 2556 patients with EGC who underwent gastrectomy were used as training set and the internal validation set (set 1) at a ratio of 8:2. Additionally, 548 patients with EGC who underwent endoscopic submucosal dissection (ESD) as the initial treatment were included in the external validation set (set 2). The GBM model was constructed, and its performance was compared with that of the Japanese guidelines.

RESULTS

LNM was identified in 12.6% (321/2556) of the gastrectomy group (training set & set 1) and 4.3% (24/548) of the ESD group (set 2). In the GBM analysis, the top five features that most affected LNM were lymphovascular invasion, depth, differentiation, size, and location. The accuracy, sensitivity, specificity, and the area under the receiver operating characteristics of set 1 were 0.566, 0.922, 0.516, and 0.867, while those of set 2 were 0.810, 0.958, 0.803, and 0.944, respectively. When the sensitivity of GBM was adjusted to that of Japanese guidelines (beyond the expanded criteria in set 1 [0.922] and eCuraC-2 in set 2 [0.958]), the specificities of GBM in sets 1 and 2 were 0.516 (95% confidence interval, 0.502-0.523) and 0.803 (0.795-0.805), while those of the Japanese guidelines were 0.502 (0.488-0.509) and 0.788 (0.780-0.790), respectively.

CONCLUSION

The GBM model showed good performance comparable with the eCura system in predicting LNM risk in EGCs.

Prognostic Performance of Three Lymph-Node Staging Systems on Gastric Signet-Ring-Cell Carcinoma

BACKGROUND

The lymph-node staging system can predict the prognosis of gastric signet-ring-cell carcinoma (SRCC). However, there are significant differences in lymph-node status between early SRCC and advanced SRCC. Additionally, the optimal system for early and advanced SRCC remains unknown.

METHODS

This study retrospectively analyzed 693 SRCC patients who underwent radical resection in the Department of Gastrointestinal Surgery, Harbin Medical University Cancer Hospital. The predicted performance of three lymph-node staging systems, including pN staging, lymph-node metastasis rate (LNR), and log odds of positive lymph nodes (LODDS), was compared using the receiver characteristic operating curve (ROC) and c-index. The Kaplan-Meier method and the log-rank test analyzed the overall survival of patients. The Cox risk regression model identified independent risk factors associated with patient outcomes. The nomogram was made by R studio.

RESULTS

The 693 SRCC included 165 early SRCC and 528 advanced SRCC. ROC showed that LODDS had better predictive performance than pN and LNR in predicting prognosis regardless of early or advanced SRCC. LODDS can be used to predict the prognosis of early and advanced SRCC and was an independent risk factor associated with patient outcomes (p = 0.002, p < 0.001). Furthermore, the nomogram constructed by LODDS and clinicopathological features had good predictive performance.

CONCLUSIONS

LODDS showed clear prognostic superiority over both pN and LNR in early and advanced SRCC.

Predictive factors of lymphatic metastasis and evaluation of the Japanese treatment guidelines for endoscopic resection of early gastric cancer in a high-volume center in Perú

Purpose

This study aimed to identify the predictive factors of lymph node metastasis (LNM) in patients with early gastric cancer (EGC) and to evaluate the applicability of the Japanese treatment guidelines for endoscopic resection in the western population.

Methods

Five hundred-one patients with pathological diagnoses of EGC were included. Univariate and multivariate analyses were conducted to identify the predictive factors of LNM. EGC patients were distributed according to the indications for endoscopic resection of the Eastern guidelines. The incidence of LNM was evaluated in each group.

Results

From 501 patients with EGC, 96 (19.2%) presented LNM. In 279 patients with tumors with submucosal infiltration (T1b), 83 (30%) patients had LNM. Among 219 patients who presented tumors > 3 cm, 63 (29%) patients had LNM. Thirty-one percent of patients with ulcerated tumors presented LMN (33 out of 105). In 76 patients and 24 patients with lymphovascular and perineural invasion, the percentage of LMN was 84% and 87%, respectively. In the multivariate analysis, a tumor diameter >3 cm, submucosal invasion, lymphovascular, and perineural invasion were independent predictors of LMN in EGC. No patient with differentiated, non-ulcerated mucosal tumors presented LNM regardless of tumor size. Three of 17 patients (18%) with differentiated, ulcerated mucosal tumors and ≤ 3 cm presented LNM. No LNM was evidenced in patients with undifferentiated mucosal tumors and ≤ 2 cm.

Conclusions

The presence of LNM in Western EGC patients was independently related to larger tumors (>3 cm), submucosal invasion, lymphovascular and perineural invasion. The Japanese absolute indications for EMR are safe in the Western population. Likewise, Western patients with differentiated, non-ulcerated mucosal tumors, and larger than 2 cm are susceptible to endoscopic resection. Patients with undifferentiated mucosal tumors smaller than 2 cm presented encouraging results and ESD could be recommended only for selected cases.

Prognosis and Biological Behavior of Gastric Signet-Ring Cell Carcinoma Better or Worse: A Meta-Analysis

BACKGROUND

The clinical pathology of gastric signet-ring cell carcinoma (SRC) is still unclear. This meta-analysis was performed to evaluate the difference in biological behavior and prognosis between SRC and non-signet ring cell carcinoma (NSRC).

METHODS

A total of 58 eligible studies were analyzed using RevMan and other auxiliary software. Biological behaviors were compared based on odds ratio (OR) and mean difference (MD). Hazards ratio (HR) was calculated for prognosis based on Kaplan-Meier curves.

RESULTS

Totally, 28,946 SRC patients were compared with 81,917 NSRC patients. Compared with NSRC patients, lower male: female ratio (OR = 0.53, P < 0.01), younger age (MD = -4.89, P < 0.01), more middle location (OR = 1.64, P < 0.01), more depressed type at early stage (OR = 1.31, P < 0.05), higher incidence of Borrmann type IV (OR = 1.96, P < 0.01), less lymph node metastasis at early stage (OR = 0.78, P < 0.05), better prognosis at early stage (HR = 0.59, P < 0.01), and worse prognosis at advanced stage (HR = 1.19, P < 0.01) were associated with SRC patients.

CONCLUSION

The prognosis of SRC at early stage is better than other types of gastric cancer, while that of SRC at advanced stage is relatively poorer.

Difference Between Signet Ring Cell Gastric Cancers and Non-Signet Ring Cell Gastric Cancers: A Systematic Review and Meta-Analysis

Background: There is controversy about the characteristics and prognostic implications of signet ring cell gastric cancers and non-signet ring cell gastric cancers.

Objective: This study aims to evaluate clinicopathological characteristics and prognoses of signet ring cell carcinoma (SRCC) and non-signet ring cell carcinoma (NSRCC) of stomach.

Methods: Studies compared between SRCC and NSRCC of the stomach after gastrectomy and published before September 1st, 2020, in the PubMed, Cochrane, and Embase databases, were identified systematically.

Results: A total of 2,865 studies were screened, and 36 studies were included, with 19,174 patients in the SRCC group and 55,942 patients in the NSRCC group. SRCC patients were younger in age (P < 0.001), less likely to be male patients (P < 0.001), more afflicted with upper third lesions (P < 0.001), and presenting with more Borrmann type IV tumors (P = 0.005) than NSRCC patients. Lymph nodes metastasis was similar between SRCC and NSRCC patients with advanced tumor stage (OR: 0.86, 95% CI: 0.671.10, P = 0.23), but lower in the SRCC than NSRCC patients with early tumor stage (OR: 0.73; 95% CI: 0.560.98, P = 0.02). SRCC patients had comparable survival outcomes with NSRCC patients for early gastric cancers (HR: 1.05, 95% CI: 0.651.68, P < 0.001) but had significantly poor prognosis for patients with advanced tumor stage (HR: 1.50, 95% CI: 1.281.76, P < 0.001).

Conclusions: Signet ring cell carcinomas of the stomach are an increasingly common histopathological subtype of gastric cancers. These kinds of patients tend to be younger in age and more often female. Although, signet ring cell gastric cancer is a negative prognostic factor for patients with advanced stage. The difference is that for early stage of signet ring cell gastric cancers, it has low lymph nodes metastasis rate and comparable prognosis with non-signet ring cell cancers.

Comparison between endoscopic submucosal resection and surgery for the curative resection of undifferentiated-type early gastric cancer within expanded indications: a nationwide multi-center study

BACKGROUND AND AIMS

Endoscopic submucosal dissection (ESD) for undifferentiated early gastric cancer (UD EGC) has debate due to the risk of lymph node metastasis. We investigated the outcomes of ESD compared to those of surgery for the UD EGC within expanded indication.

METHODS

We reviewed 971 UD EGC patients performed ESD across 18 hospitals in Korea and 1812 patients who underwent surgical resection in two hospitals between February 2005 and May 2015. Of these cases, we enrolled a curative resected ESD group of 328 patients and surgery group of 383 cases within an expanded indication. Overall outcomes and one-to-one propensity score-matched (218 ESD group vs 218 surgery group cases) outcomes for these two groups were analyzed.

RESULTS

Over the 75.6 month median follow-up period for the 711 enrolled cases, recurrences occurred in 22 patients (6.7%) in the ESD group but not in the surgery group. Overall survival (OS) was higher in the surgery group (p = 0.0316) in all cases, but there was no significant difference after propensity score matching (p = 0.069). According to the histologic type in propensity score matching, the OS of signet ring cell carcinoma and poorly differentiated carcinoma patients did not differ between the ESD and surgery groups (p = 0.1189 and p = 0.3087, respectively). In the surgery group involving expanded criteria, lymph node metastasis was found in six cases (1.56%).

CONCLUSIONS

Although ESD shows comparable outcomes to surgery for the UD EGC within expanded indications, appropriate patient selection is needed for the ESD due to the possibility of lymph node metastasis.

Expanding the indication of endoscopic submucosal dissection for undifferentiated early gastric cancer is safe or not?

BACKGROUND

Endoscopic submucosal dissection (ESD) has gained more popularity in the treatment of early gastric cancer (EGC). Although there is a lack of confirmed evidence for the feasibility of ESD for undifferentiated EGC. The aim of the study was to investigate the feasibility of ESD with expanded indications for undifferentiated EGC patients.

METHODS

Data from patients with undifferentiated EGC (including signet-ring cell carcinoma, mucinous adenocarcinoma, mixed adenocarcinoma, and poorly differentiated adenocarcinoma) who underwent radical surgical resection were retrospectively reviewed. The relationship between the clinical parameters and the incidence of lymph node metastasis (LNM) was investigated.

RESULTS

A total of 517 patients were included in this study. The results showed that LNM was significantly associated with ulceration, tumor size, depth of invasion, lymphatic invasion, vascular invasion, and perineural invasion. Multivariate stepwise logistic regression analysis revealed that tumor size (OR = 1.61, 95% CI = 1.03-2.52, P = 0.0367), depth of tumor invasion (OR = 2.77, 95% CI = 1.66-4.63, P = 0.0001), and lymphatic invasion (OR = 14.74, 95% CI = 1.58-137.36, P = 0.0182) were independent risk factors for LNM. In the patients who would be included under the new proposed guidelines for ESD, including men with mucosal tumors ≤2 cm and without ulceration or lymphatic or venous infiltration, LNM was present in 11.9% (14/118).

CONCLUSION

Caution to be exercised in expanding application of ESD should be carefully weighed in undifferentiated EGC.

State of the art for gastric signet ring cell carcinoma: from classification, prognosis, and genomic characteristics to specified treatments

Gastric cancer (GC) is responsible for 9% of cancer deaths worldwide. Over 950,000 new cases are diagnosed each year, and about 90% of them are in advanced stage, requiring chemotherapy. In Europe there has been research based on pre- and postoperative chemotherapy treatment, using 5-fluorouracil, epirubicin, cisplatin, capecitabine, and docetaxel. Chemotherapy significantly impairs the quality of life of patients; however, the final effects are not always satisfactory. There is scientific evidence that gastric mucus tumors and signet ring cell carcinomas have a pattern of specific signatures, that distinguish them from other gastric cancer subtypes, and may be associated with a poor response to systematic treatment. Signet ring cell carcinoma is less chemosensitive than others, and the increase in the percentage of signet ring cells correlates with resistance to chemotherapy. Perioperative chemotherapy in advanced signet ring cell carcinomas is an independent factor of poor prognosis and survival, which is explained by the toxicity of neoadjuvant treatment. Therefore, curative surgical resection enhanced by standardized lymphadenectomy remains the recommended gold standard in GC therapy. According to presented studies, early detection and aggressive treatments for this subtype of GC is a reasonable approach. This review paper is mostly addressed to physicians who are interested in updating to the state of the art concerning different subtypes of gastric carcinoma.

Risk of lymph node metastasis in undifferentiated-type mucosal gastric carcinoma

BACKGROUND

Endoscopic resection (ER) has come to be recognized as a standard treatment for early gastric cancer (EGC). While its adoption is expanding, ER remains restricted to cases of EGC without lymph node metastasis for the treatment of local resection. On the other hand, histopathological analyses of surgically resected specimens of EGC have revealed the presence of lymph node (LN) metastasis in some cases of mucosal gastric cancer (MGC) and undifferentiated MGC (UD-MGC) is considered to have higher risk of nodal metastases than differentiated MGC (D-MGC). To evaluate the risk factors for LN metastasis in MGC, we investigated the characteristics of UD-MGC associated with LN metastasis.

METHODS

Among all UD-MGC patients who underwent surgery as initial treatment, between January 2000 and March 2016, we reviewed the clinicopathological data, including the preoperative endoscopic findings and histopathological findings in the resected specimens, of the 11 UD-MGC patients who were identified as having lymph node metastasis. Furthermore, in comparison with cases without lymph node metastasis, we examined the possibility of expansion of the indication for local treatment.

RESULTS

In most of the cases of UD-MGC with LN metastasis, the lesions were relatively large (> 20 mm in diameter) and of the clearly depressed type with faded color and apparent border, and histopathology revealed a high percentage of cases with lymphatic invasion and a predominance of signet ring cell carcinomas. No cases with LN metastasis without depressed macroscopic type nor signet ring cell carcinoma component existed. A degree of invasion of lamina propria (LP) or muscularis mucosae (MM) had same relation to the risk of LN metastasis.

CONCLUSIONS

In this study, none of the cases of undifferentiated-type mucosal cancer (UD-MGC) with LN metastasis satisfied the current adoption criteria for ER. We suggested significant risk factors for LN metastasis in UD-MGC cases as depressed tumor type, presence of a signet ring cell carcinoma component, presence of lymphatic tumor invasion, and a large tumor size. More detailed analyses of the endoscopic and histopathological findings may allow further risk classification for LN metastasis in cases of UD-MGC.

Tailored treatment for signet ring cell gastric cancer

Gastric cancer with Laurèn diffuse types is increasing in the West. The raising trend is more evident when considering signet ring cells (SRC) histology. However, to control the biologic potential of this GC subtype, some hypotheses of tailored therapeutic strategies for SRC cancers have been made. A review of the literature was performed using the key words "signet ring cells" AND "gastric cancer". Results of literature review were descriptively reported. Endoscopic submucosal dissection (ESD), according to the Japanese extended criteria, could be a therapeutic option for early SRC tumours. However, according to the evidences from more recent studies, indications for ESD to these tumours types should be carefully considered. Concerning the optimal surgical treatment, considering the high lymphotropism and infiltrating behaviour of SRC histotype, the extension of gastric resection should be wider than for intestinal type cancer and laparoscopic surgery should be performed carefully. Moreover, D3 lymphadenectomy could provide a benefit in diffuse-type and SRC histology. The role of surgery in gastric cancer with peritoneal carcinomatosis is still debated and studies on this topic should stratify the good results according to GC histotype. Finally, despite the evidences of chemoresistance in SRC, ongoing randomized trials suggest that multimodal therapy could be the best treatment. Based on the assumption that SRC tumours have specific features, they deserve a specific multimodal treatment. However, a preliminary step to generate strong evidences in this field is the standardization of terminology used to define signet ring cells carcinoma.

Clinicopathological Characteristics and Prognostic Value of Signet Ring Cells in Gastric Carcinoma: A Meta-Analysis

Background and Objectives: Previous studies of the prognostic value of the signet ring cell (SRC) type have yielded inconsistent results. Therefore, the aim of the present meta-analysis is to explore the clinicopathological characteristics and prognostic value of SRCs.

Methods: Relevant articles that compared SRC and non-SRC type in PubMed and Web of Science were comprehensively searched. Then, a meta-analysis was performed.

Results: A total of 19 studies including 35947 cases were analyzed. Compared with non-SRC patients, SRC patients tended to be younger (WMD: -3.88, P=0.001) and predominantly female (OR: 1.60, P<0.001). Additionally, SRC patients exhibited less upper third tumor location (OR: 0.62, P<0.001) and less frequent hematogenous metastasis (OR: 0.41, P<0.001). There was no difference in overall survival (OS) between SRC and non-SRC patients in the total population (HR: 1.02, P=0.830). Early gastric cancer with SRCs was associated with better OS (HR: 0.57, P=0.002), while advanced gastric cancer with non-SRCs was associated with a worse prognosis (HR: 1.17, P<0.001).

Conclusions: This meta-analysis revealed that SRC tends to affect young females and tends to be located in the middle and lower third of the stomach. Early SRCs are associated with better prognoses, while advanced SRCs are associated with worse prognoses.

Signet ring cell carcinoma of early gastric cancer, is endoscopic treatment really risky?

Signet ring cell carcinoma (SRC) is a poorly differentiated cancer of the stomach. Generally, poorly differentiated cancer is believed to show poor prognosis and aggressive behavior. Recently, however, there is debate on the aggressiveness of SRC in early gastric cancer (EGC). We therefore studied postoperation biopsies to investigate the aggressiveness of SRC in EGC.We reviewed medical records of patients with EGC who had surgery from January 2011 to December 2015 in a tertiary hospital in Daejeon, South Korea. We evaluated the histologic type, invasion depth, lymphovascular invasion (LVI), and lymph node (LN) metastasis.A total of 822 EGC lesions from 789 patients were studied. Approximately 498 differentiated cancer, 65 poorly differentiated cancer, 91 SRC, 26 poorly differentiated with SRC, 41 mixed type, 10 medullary carcinoma, and 91 poorly cohesive carcinoma other than SRC were included. LN metastasis was associated with the histologic type of EGC (P = .000). Nine percent of differentiated cancer, 21.5% of poorly differentiated cancer, 5.5% of SRC, 11.5% of poor differentiation with SRC, 26.8% of mixed type, 20% of medullary type, and 15.4% of poorly cohesive carcinoma other than SRC showed LN metastasis. The risk of SRC was not higher than well to moderated differentiated cancer (odds ratio [OR] = 0.842, P = .768). Risk of LVI was also similar with LN metastasis. Compared with differentiated cancer, OR of SRC was 1.969 (P = .172).Our results show that SRC is not more aggressive than differentiated cancer. SRC may be considered a candidate for endoscopic treatment.

Predictive factors for lymph node metastasis in early gastric cancer with signet ring cell histology: a meta-analysis

BACKGROUND

Less invasive surgery is widely used in the treatment of early gastric cancer; however, no definite guidelines exist regarding indications for less invasive surgery to treat early gastric cancer with signet ring cell histology. The aim of this study was to identify risk factors for lymph node metastasis (LNM) in early signet ring cell carcinoma (SRC). An extensive search of PubMed, Embase and the Cochrane library was performed for pertinent articles involving early SRC and LNM.

METHODS

Eligible data (gender, depth of invasion, lymphovascular invasion, size, ulceration, macroscopic type and location) were extracted from the included studies and systematically reviewed via a meta-analysis. Review Manager version 5.3 was used to perform the data processing. The Newcastle-Ottawa Scale was utilized to evaluate the quality of the included articles.

RESULTS

Fourteen studies were included in the final analysis. After meta-analysis, female gender, submucosal invasion, lymphovascular invasion and size >20 mm were associated with LNM in early SRC.

CONCLUSION

Four variables were identified as risk factors for LNM in early SRC. The significance of the results of the present study should be further confirmed in more early SRC patients for future clinical use.

Lymph Node Metastasis in Mucosal Gastric Cancer: Reappraisal of Expanded Indication of Endoscopic Submucosal Dissection

OBJECTIVE

To evaluate risk factors for lymph node (LN) metastasis in mucosal gastric cancer, particularly the effect of cellular differentiation, and implications for the indication of endoscopic submucosal dissection (ESD).

SUMMARY BACKGROUND DATA

The indication of ESD has been expanded to undifferentiated-type (UD-type) gastric cancer despite risk of LN metastasis.

METHODS

Patients who underwent radical gastrectomy for pT1a stage primary gastric adenocarcinoma between 2008 and 2012 were retrospectively analyzed. We evaluated risk factors of LN metastasis using univariate and multivariate analyses. Pathologic slides of primary tumor and metastatic LNs from LN positive patients were reviewed.

RESULTS

A total of 1003 mucosal gastric cancer patients were enrolled, and mean number of retrieved LNs was 35.5. Eighteen (1.8%) among them had LN metastasis: 2 of the 502 differentiated-type (D-type) patients and 16 of the 501 UD-type patients (0.4% vs 3.2%, P < 0.001). Type of cellular differentiation was a significant risk factor for LN metastasis in univariate and multivariate analyses. Of 216 UD-type patients satisfying the expanded indication of ESD, 5 patients (2.3%) showed LN metastasis. Despite more aggressive clinical features such as larger size of tumor and more LN metastasis, the UD-type cancer showed a less invasion into the muscularis mucosae layer than the D-type cancer.

CONCLUSIONS

Because UD-type cancer is a risk factor for LN metastasis in mucosal gastric cancer, ESD cannot be concluded to be a better option than surgery in all UD-type cancer patients. Redefinition of the expanded indication of ESD is required.

Predictive Factors for Lymph Node Metastasis in Undifferentiated Early Gastric Cancer: a Systematic Review and Meta-analysis

OBJECTIVES

Less invasive surgery is gaining popularity for the treatment of early gastric cancer (EGC), but there are no definitive guidelines for the use of less invasive surgery for the treatment of undifferentiated EGC. The aims of this meta-analysis were to identify potential predictive factors for lymph node metastasis (LNM) in undifferentiated EGC and to guide the personalized therapeutic modality for patients with undifferentiated EGC.

METHODS

An extensive search of the PubMed, Embase, and Cochrane Library databases was performed to identify relevant articles involving undifferentiated EGC and LNM. Eligible data were systematically reviewed through a meta-analysis using Review Manager 5.3.

RESULTS

In total, 23 studies were included in this analysis. The meta-analysis found that the variables sex (female), age (greater than 60 years), tumor size (greater than 20 mm), depth of invasion (submucosal invasion), presence of lymphovascular involvement, presence of ulcer findings, histology type (non-signet ring carcinoma), and tumor location (not in the middle part of the stomach) were significantly associated with LNM.

CONCLUSIONS

Eight variables were identified as predictive factors for LNM in undifferentiated EGC. The significance of these variables should be further confirmed during the process of LNM in undifferentiated EGC patients for future clinical application.

Clinicopathology of Early Gastric Carcinoma: An Update for Pathologists and Gastroenterologists

BACKGROUND

The WHO defines early gastric carcinoma (EGC) as invasive carcinoma up to the submucosal layer, regardless of nodal metastasis. The recent study results indicate that EGC varies in location, histology, nodal metastasis, and prognosis.

SUMMARY

The heterogeneity in EGC may be related to various types of epithelial stem cells. The most important stem cells include Lgr5+ cells at the base of a gastric unit in the antrum-pylorus-cardia, Mist1+ cells at the isthmus/Troy+ cells at the base in the corpus-fundus, and Sox2+ cells at the base in almost all regions. Dysregulation of these cells along with environmental factors transform stem cells in different regions into malignancy in genetically susceptible populations.

KEY MESSAGE

The 2 most vulnerable regions for EGC have been found along the lesser curvature: the cardia in elderly patients and antrum-angularis in mid-aged and elderly patients. Most hereditary early-onset gastric carcinomas are concentrated in the corpus-fundus of young women. By histology, the most common EGC type is tubular adenocarcinoma in many growth patterns, starting in the neck of a gastric unit. Worse prognosis has been found in early papillary, compared to tubular, adenocarcinoma, related to deeper penetration, more lymphovascular invasion, and more liver and nodal metastases. Contrary to the common belief, intramucosal signet ring cell carcinoma demonstrates low risk of nodal metastasis, comparable to early intestinal-type EGC.

PRACTICAL IMPLICATIONS

The overall risk for nodal metastasis in EGC is low but significant. It is urgent to organize multicenter studies on risk of nodal metastasis in EGC in order to establish more reliable clinical practice guidelines to treat EGC patients.

Prognostic Impact of Different Histological Types on Gastric Adenocarcinoma: a Surveillance, Epidemiology, and End Results Database Analysis

The clinicopathological characteristics and prognosis of gastric mucinous adenocarcinoma (MAC) and signet ring cell carcinoma (SRC) are still controversial. We designed our study to evaluate the clinicopathologic features and prognosis of MAC, SRC and ordinary gastric adenocarcinoma (OGAC) by analyzing the Surveillance, Epidemiology, and End Results (SEER)-registered database. The 5-year overall survival (OS) of patients with SRC was significantly lower than that of patients with MAC (P = 0.001) and OGAC (P < 0.001), and there was no significant difference in 5-year OS between MAC and OGAC (P = 0.804). Furthermore, there were no significant differences of 5-years OS among these three groups at stage I, II and III (all P > 0.05) and no significant difference between MAC and OGAC at stage IV (P = 0.110). Patients in SRC group had significantly worse survival than those in MAC and OGAC at stage IV (both P = 0.008), with 5-year OS of 3.3%, 5.8%, and 5.8%, respectively. However, the histological type was not found to be an independent prognostic factor of gastric cancer according to the multivariate analysis with Cox regression.

A Concurrent Case of Ménétrier's Disease and Signet Ring Carcinoma

Ménétrier's disease, also known as hyperplastic protein-losing gastropathy, is a rare, idiopathic, acquired, premalignant condition associated with gastric carcinoma. Its association with signet ring cell cancer of the stomach has been previously reported only twice. We present the third case of histologically confirmed concurrent Ménétrier's disease with signet ring carcinoma of the stomach, interrogated by esophagogastroduodenoscopy and endoscopic ultrasound.

Applicability of endoscopic submucosal dissection for undifferentiated early gastric cancer: Mixed histology of poorly differentiated adenocarcinoma and signet ring cell carcinoma is a worse predictive factor of nodal metastasis

BACKGROUND

Endoscopic submucosal dissection (ESD) is not considered an appropriate treatment for undifferentiated early gastric cancer (UEGC) due to the higher risk of nodal metastases. We aimed to investigate predictive factors for nodal metastases in UEGCs, determine whether the tumor histology is an independent factor for it, and explore whether ESD is applicable for UEGC.

METHODS

We reviewed the medical records of 1837 patients who underwent curative gastrectomy for poorly differentiated adenocarcinoma, signet ring cell carcinoma, and a mixed type of both tumors between 2008 and 2012.

RESULTS

Nodal metastases were found in 208 (11.3%) patients. Multivariate analysis revealed that lymphovascular invasion and tumor histology were significantly associated with nodal metastases in mucosal cancers, the rates of which were higher in mixed type tumors (6.3%) than in the other two types (2.0-2.5%; p = 0.005). No nodal metastases were observed in poorly differentiated adenocarcinomas <2 cm and signet ring cell carcinomas <1 cm without lymphovascular invasion and confined to the mucosa.

CONCLUSION

Mixed type tumors should not be considered for endoscopic resection. ESD might be applicable for mucosal tumors with poorly differentiated adenocarcinoma <2 cm and signet ring cell carcinoma <1 cm without lymphovascular invasion.

A nomogram for predicting the likelihood of lymph node metastasis in early gastric signet ring cell carcinoma: A single center retrospective analysis with external validation

Treatment algorithm has not been established for early gastric cancer with signet ring cell carcinoma (SRC), which has a reported low rate of lymph node metastasis (LNM) similar to differentiated cancer. A cohort of 256 patients with early gastric SRC at our center between January 2002 and December 2015 were retrospectively reviewed. Multivariate logistic regression analysis was used to determine the independent factors of LNM. A nomogram for predicting LNM was constructed and internally validated. Additional external validation was performed using the database from Cancer Institute Ariake Hospital in Tokyo (n = 1273). Clinical performance of the model was assessed by decision analysis of curve. The overall LNM incidence was 12.9% (33/256). The multivariate logistic model identified sex, tumor size, and LVI as covariates associated with LNM. Subsequently, a nomogram consisted of sex, tumor size, and depth of invasion was established. The model showed qualified discrimination ability both in internal validation (area under curve, 0.801; 95% confidence interval [CI], 0.729-0.873) and in external dataset (area under curve, 0.707; 95% CI, 0.657-0.758). Based on the nomogram, treatment algorithm for early gastric SRC was proposed to assist clinicians in making better decisions. We developed a nomogram predicting risk of LNM for early gastric SRC, which should be helpful for patient counseling and surgical decision-making.

Early signet ring cell carcinoma of the stomach is related to favorable prognosis and low incidence of lymph node metastasis

BACKGROUND

The aim of this study was to evaluate the clinical characteristics of early signet ring cell carcinoma of the stomach (SRC) and to investigate the optimal treatment strategy for early SRC.

METHODS

A total of 746 patients with pT1 gastric cancer (GC), who had undergone surgical resection between 1997 and 2012 were analyzed. Of these, 190 patients with SRC were enrolled in this study.

RESULTS

(i) The patients with SRC showed a significantly longer overall survival (P = 0.012) and disease free survival (P = 0.004) than patients with the other histological types. Multivariate analysis identified SRC as an independent factor predicting favorable prognosis in pT1 GC (HR = 0.38; 95% CI: 0.11-0.96; P = 0.041). Specifically, in undifferentiated pT1 GC, SRC was significantly less associated with lymph node metastasis (LNM) (OR = 0.39; 95% CI: 0.15-0.96; P = 0.042). (ii) From the viewpoint of a histological mixed-type, pure-SRC with pT1a was not associated with LNM regardless of tumor size (0.0%, 0/110), whereas mixed-SRC was an independent risk factor for LNM (OR = 7.19; 95% CI: 1.51-43.9; P = 0.012).

CONCLUSIONS

Patients with early SRC have a favorable prognosis with a low incidence of LNM. However, care should be taken with mixed-SRC, which consists of SRC and other histological types. J. Surg. Oncol. 2016;114:607-612. © 2016 Wiley Periodicals, Inc.

Endoscopic resection of early gastric cancer: current status and new approaches

Endoscopic resection (ER) of early gastric cancer (EGC) has been an optimal treatment for selected patients. As endoscopic submucosal dissection (ESD) has been widely used for treatment of EGC, concerns have been asked to achieve curative resection for EGC while guaranteeing precise prediction of lymph node metastasis (LNM). Moreover, a new microscopic imaging for precise endoscopic diagnosis of EGC is introduced. This review covers the current status and new approaches of ER of EGC.

Upgrading the definition of early gastric cancer: better staging means more appropriate treatment

Since Murakami defined early gastric cancer (EGC) as a "carcinoma limited to the gastric mucosa and/or submucosa regardless of the lymph node status", several authors have focused on the most influential histopathological parameters for predicting the development of lymph node metastases by considering the lymph node status as an important prognostic factor. A few authors have also considered the depth of invasion as one of the keys to explaining the existence of subgroups of patients affected by EGC with poor prognoses. In any case, EGC is still considered an initial phase of tumor progression with good prognosis. The introduction of modern endoscopic devices has allowed a precise diagnosis of early lesions, which can lead to improved definitions of tumors that can be radically treated with endoscopic mucosal resection or endoscopic submucosal dissection (ESD). Given the widespread use of these techniques, the Japanese Gastric Cancer Association (JGCA) identified in 2011 the standard criteria that should exclude the presence of lymph node metastases. At that time, EGCs with nodal involvement should have been asserted as no longer fitting the definition of an early tumor. Some authors have also demonstrated that the morphological growth pattern of a tumor, according to Kodama's classification, is one of the most important prognostic factors, thereby suggesting the need to report it in histopathological drafts. Notwithstanding the acquired knowledge regarding the clinical behavior of EGC, Murakami's definition is still being used. This definition needs to be upgraded according to the modern staging of the disease so that the appropriate treatment would be selected.

miR-935 suppresses gastric signet ring cell carcinoma tumorigenesis by targeting Notch1 expression

Gastric signet ring cell carcinoma (GSRCC) is a unique pathological type of gastric carcinoma that is extremely invasive and has a poor prognosis. Expression of microRNAs (miRNAs) has been closely linked to the carcinogenesis of gastric cancer and has been considered as a powerful prognostic marker. The function of miR-935 has never been reported in cancer before. We found, using microRNA array, that expression of miR-935 in GSRCC cell lines is lower than in non-GSRCC cell lines, and enhanced expression of miR-935 in GSRCC cell-lines inhibit cell proliferation, migration and invasion. We also identified Notch1 as a direct target of miR-935. Knockdown of Notch1 reduced proliferation, migration/invasion of GSRCC cells, and overexpression Notch1's activated form (Notch intracellular domain) could rescue miR-935's tumor suppressive effect on GSRCC. Expression of miR-935 was lower in gastric carcinoma tissue than in paired normal tissue samples, and lower in GSRCC than in non-GSRCC. Our results demonstrate the inverse correlation between the expression of miR-935 and Notch1 in gastric tissues. We conclude that miR-935 inhibits gastric carcinoma cell proliferation, migration and invasion by targeting Notch1, suggesting potential applications of the miR-935-Notch1 pathway in gastric cancer clinical diagnosis and therapeutics, especially in gastric signet ring cell carcinoma.

Clinicopathological Characteristics and Survival Outcomes of Primary Signet Ring Cell Carcinoma in the Stomach: Retrospective Analysis of Single Center Database

Purpose

To investigate the clinicopathological features and prognosis of signet ring cell carcinoma of the stomach (SRC).

Methods

A total of 1464 gastric cancer patients who underwent curative gastrectomy from 2000 to 2008 at a single center were evaluated. Signet ring cell carcinoma (SRC) was defined as the presence of at least 50% signet ring cells in the pathologic specimen. The clinicopathological parameters and prognosis of SRC were analyzed by comparing with non-signet ring cell carcinoma (NSRC).

Results

Of 1464 patients, 138 patients (9.4%) were classified as SRC. There were significant differences in gender, age, tumor location, TNM stage, p21 expression, and p53 expression between SRC and NSRC. The 5-year survival rates of SRC and NSRC were 36.2% and 49.5%, respectively. The prognosis of SRC was poorer than that of NSRC (P <0.001). Multivariate analysis showed that SRC histology was an independent factor for poor prognosis (P <0.001).

Conclusion

Patients with SRC tend to present with a more advanced stage and poorer prognosis than patients with other types of gastric carcinoma.

Is It Reasonable to Treat Early Gastric Cancer with Mucosal Infiltration and Well Differentiation by Endoscopic Submucosal Resection?

BACKGROUND

While limited endoscopic submucosal dissection (ESD) is increasingly applied in the treatment of early gastric cancer, preoperative prediction of lymph node metastasis is very critical for determining treatment strategies preoperatively. Thus, the aim of this study was to accurately assess the prevalence and pattern of lymph node metastasis in early gastric cancer patients and to identify the best candidates for ESD.

METHODS

From September 2008 to December 2013, a total of 539 patients with early gastric cancer were retrospectively analyzed in the present study. Of them, 503 patients underwent radical gastrectomy and 36 patients underwent ESD. The clinicopathological features were collected and correlations with lymph node metastasis were analyzed. The survival rates of patients were also analyzed.

RESULTS

Lymph node metastasis was observed in 80 of 503 patients (15.9 %). Among these, the rate for mucosal cancer was 8.3 %, and 20.1 % for submucosal cancer. By univariate analysis, risk factors for lymph node metastasis were growth pattern, tumor size, pathological type, depth of invasion, lymphatic-vascular invasion, and neural invasion. By multivariate analysis, risk factors for lymph node metastasis were tumor size, pathological type, depth of invasion, and lymphatic-vascular invasion. The incidence of lymph node metastasis was 0 % in the well-differentiated mucosal cancers, irrespective of tumor size. For the well-differentiated mucosal cancers, the overall survival rates were comparable between patients underwent gastrectomy with lymph node dissection and patients underwent ESD (100 vs 100 %).

CONCLUSIONS

The most important factors for predicting lymph node metastasis in early gastric cancer are tumor size, pathological type, depth of invasion, and lymphatic-vascular invasion. Well-differentiated mucosal gastric cancers could be candidates for ESD.

Risk Factors for Lymph Node Metastasis in Early Gastric Cancer with Signet Ring Cell Carcinoma

BACKGROUND

Gastrectomy was reported to be an excessive approach for early gastric cancer with signet ring cell carcinoma. This study was conducted to explore the feasibility of endoscopic submucosal dissection for early gastric with signet ring cell carcinoma.

METHODS

Data from 1067 patients who underwent gastrectomy for early gastric cancer were collected retrospectively. The association between the clinicopathological factors and the lymph node metastasis was analyzed by univariate and multivariate logistic regression analyses.

RESULTS

Lymph node metastasis was confirmed in 17.2 % (184/1067) of patients. Meanwhile, the incidence of lymph node metastasis with each histology type was 13.1 % (26/198), 9.8 % (34/347), and 23.8 % (124/522) for signet ring cell carcinoma, differentiated carcinomas, and undifferentiated carcinomas, respectively. Signet ring cell carcinoma occurs more in women and young patients, with a higher predominance for mucosa. Various factors-including sex, tumor size, depth of tumor, and lymphovascular invasion-were found to be associated with lymph node metastasis for signet ring cell carcinoma (P < 0.05). Multivariate analysis revealed that tumor size (7.489, 95 % CI 2.025-27.701) and lymphovascular invasion (18.434, 95 % CI 3.256-104.359) were independent risk factors for lymph node metastasis (P < 0.05). Further analysis reveals there was no positive lymph node in patients with signet ring cell carcinoma when tumor confined to mucosa, size ≤2 cm and without lymphovascular invasion and ulceration.

CONCLUSIONS

Given the low risk of lymph node involvement, we recommend that endoscopic submucosal dissection be safely applied for early gastric signet ring cell carcinoma when tumor confined to mucosa, size ≤2 cm, and without lymphovascular invasion and ulceration.

Redefining early gastric cancer

BACKGROUND

The problem is that current definitions of early gastric cancer allow the inclusion of regional lymph node metastases. The increasing use of endoscopic submucosal dissection to treat early gastric cancer is a concern because regional lymph nodes are not addressed. The aim of the study was thus to critically evaluate current evidence with regard to tumour-specific factors associated with lymph node metastases in "early gastric cancer" to develop a more precise definition and improve clinical management.

METHODS

A systematic and comprehensive search of major reference databases (MEDLINE, EMBASE, PubMed and the Cochrane Library) was undertaken using a combination of text words "early gastric cancer", "lymph node metastasis", "factors", "endoscopy", "surgery", "lymphadenectomy" "mucosa", "submucosa", "lymphovascular invasion", "differentiated", "undifferentiated" and "ulcer". All available publications that described tumour-related factors associated with lymph node metastases in early gastric cancer were included.

RESULTS

The initial search yielded 1494 studies, of which 42 studies were included in the final analysis. Over time, the definition of early gastric cancer has broadened and the indications for endoscopic treatment have widened. The mean frequency of lymph node metastases increased on the basis of depth of infiltration (mucosa 6% vs. submucosa 28%), presence of lymphovascular invasion (absence 9% vs. presence 53%), tumour differentiation (differentiated 13% vs. undifferentiated 34%) and macroscopic type (elevated 13% vs. flat 26%) and tumour diameter (≤2 cm 8% vs. >2 cm 25%).

CONCLUSION

There is a need to re-examine the diagnosis and staging of early gastric cancer to ensure that patients with one or more identifiable risk factor for lymph node metastases are not denied appropriate chemotherapy and surgical resection.

Clinicopathologic factors and molecular markers related to lymph node metastasis in early gastric cancer

AIM: To analyze predictive factors for lymph node metastasis in early gastric cancer.

METHODS: We analyzed 1104 patients with early gastric cancer (EGC) who underwent a gastrectomy with lymph-node dissection from May 2003 through July 2011. The clinicopathologic factors and molecular markers were assessed as predictors for lymph node metastasis. Molecular markers such as microsatellite instability, human mutL homolog 1, p53, epidermal growth factor receptor (EGFR) and human epidermal growth factor receptor 2 (HER2) were included. The χ² test and logistic regression analysis were used to determine clinicopathologic parameters.

RESULTS: Lymph node metastasis was observed in 104 (9.4%) of 1104 patients. Among 104 cases of lymph node positive patients, 24 patients (3.8%) were mucosal cancers and 80 patients (16.7%) were submucosal. According to histologic evaluation, the number of lymph node metastasis found was 4 (1.7%) for well differentiated tubular adenocarcinoma, 45 (11.3%) for moderately differentiated tubular adenocarcinoma, 36 (14.8%) for poorly differentiated tubular adenocarcinoma, and 19 (8.4%) for signet ring cell carcinoma. Of 690 EGC cases, 77 cases (11.2%) showed EGFR overexpression. HER2 overexpression was present in 110 cases (27.1%) of 406 EGC patients. With multivariate analysis, female gender (OR = 2.281, P = 0.009), presence of lymphovascular invasion (OR = 10.950, P < 0.0001), diameter (≥ 20 mm, OR = 3.173, P = 0.01), and EGFR overexpression (OR = 2.185, P = 0.044) were independent risk factors for lymph node involvement.

CONCLUSION: Female gender, tumor size, lymphovascular invasion and EGFR overexpression were predictive risk factors for lymph node metastasis in EGC.

Is endoscopic resection an alternative to surgery for early low-risk submucosal gastric cancers: analysis of a large surgical database

BACKGROUND

Although endoscopic resection (ER) for early gastric cancers (EGCs) has become popular with the development of endoscopic instruments and skillful endoscopists, the risk of lymph node metastasis (LNM) is still an obstacle in performing ER. In this study, we aimed to identify the risk factors of LNM and validated the expanded criteria, with the goal of suggesting modified criteria for ER in submucosal EGCs.

METHODS

Of patients who underwent gastrectomy with LN dissection and were diagnosed as EGCs with depth of invasion such as sm1, sm2 or ≤ 500 μm from 1999 to 2008, 318 EGCs with submucosal invasion ≤ 500 μm were enrolled through pathologic evaluations. To identify the risk factors of LNM, a multivariate analysis of clinicopathologic factors was performed. By combining the independent risk factors of LNM, the risk of LNM was analyzed.

RESULT

LNM were detected in 35 cases (11.0 %). Tumors >30 mm in size and with lymphatic invasion were identified as an independent risk factor for LNM in EGCs with depth of invasion ≤ 500 μm. Among 94 cases meeting the expanded criteria, two cases (2.1 %) were found to have LNM. Based on the submucosal invasion <300 μm, there was no LNM in EGCs with a size ≤ 30 mm and no lymphovascular invasion, regardless of differentiation grade.

CONCLUSION

To exclude the possibility of LNM, applying the modified criteria based on the submucosal invasion <300 μm in performing ER might be worthwhile.

Ever-changing endoscopic treatment for early gastric cancer: Yesterday-today-tomorrow

Endoscopic resection has been an optimal treatment for selected patients with early gastric cancer (EGC) based on advances in endoscopic instruments and techniques. As endoscopic submucosal dissection (ESD) has been widely used for treatment of EGC along with expanding ESD indication, concerns have been asked to achieve curative resection for EGC while guaranteeing precise prediction of lymph node metastasis (LNM). Recently, new techniques including ESD or endoscopic full-thickness resection combined with sentinel node navigation enable minimal tumor resection and a laparoscopic lymphadenectomy in cases of EGC with high risk of LNM. This review covers the development and challenges of endoscopic treatment for EGC. Moreover, a new microscopic imaging and endoscopic techniques for precise endoscopic diagnosis and minimally invasive treatment of EGC are introduced.

Tumor differentiation is not a risk factor for lymph node metastasis in elderly patients with early gastric cancer

BACKGROUND

The aim of this study was to identify risk factors for lymph node metastasis in elderly patients (70 years or more) with early gastric cancer.

METHODS

We reviewed the prospectively collected database of 6893 patients with early gastric cancer who had undergone curative gastrectomy in 3 tertiary cancer centers between January 2003 and December 2009 in Korea. Patients were sorted into 4 groups according to age: less than 50, fifties, sixties, and 70 years or more. Risk factors for lymph node metastasis in early gastric cancer were analyzed.

RESULTS

One thousand and thirty five patients (15.0%) were 70 years or more. As age increased, the frequency of large differentiated tumor, lymphatic and submucosa invasion increased. Old age was associated with a lower risk for lymph node metastasis in patients with early gastric cancer (Odds ratio [OR], OR, 0.622; 95% CI, 0.5466-0.830, P = 0.010). Ulceration or differentiation of tumor was not associated with lymph node metastasis in elderly patients with early gastric cancer.

CONCLUSIONS

Elderly patients with undifferentiated type histology early gastric cancer without other risk factors for lymph node metastasis may be candidates for endoscopic resection.

Prognostic role of lymph node metastasis in early gastric cancer

OBJECTIVE

To clarify the relationship between clinicopathological features and lymph node metastasis and to propose the potential indications of lymph node metastasis for prognosis in early gastric cancer (EGC) patients.

METHODS

We retrospectively observed 226 EGC patients with lymph node resection, and analyzed the associations between lymph node metastasis and clinicopathological parameters using the chi-square test in univariate analysis and logistic regression analysis in multivariate analysis. Overall survival analysis was determined using the Kaplan-Meier and log-rank test. We conducted multivariate prognosis analysis using the Cox proportional hazards model.

RESULTS

Of all the EGC patients, 7.5% (17/226) were histologically shown to have lymph node metastasis. The differentiation, lymphovascular invasion and depth of invasion were independent risk factors for lymph node metastasis in EGC. The 5- and 10-year survival rates were significantly lower in patients with lymph node metastasis than in those without and the patients also had shorter progress-free survival time. Lymph node metastasis and tumor size were independent prognostic factors for EGC. The status of the lymph nodes was a significant factor in predicting recurrence or metastasis after surgery.

CONCLUSIONS

The undifferentiated carcinoma and lymphovascular and/or submucosal invasion were associated with a higher incidence of lymph node metastasis in EGC patients, whom need to perform subsequent D2 lymphadenectomy or laparoscopic lymph node dissection and more rigorous follow-up or additional chemotherapy/radiation after D2 gastrectomy for poor prognosis and high recurrence/metastasis rate.

Predictive factors for lymph node metastasis in early gastric cancer with signet ring cell histology and their impact on the surgical strategy: analysis of single institutional experience

BACKGROUND

The prognosis of early gastric cancer (EGC) with signet ring cell histology is more favorable than other undifferentiated gastric adenocarcinomas. An accurate assessment of potential lymph node metastasis is important for the appropriate treatment of EGC with signet ring cell histology. Therefore, this study analyzed the predictive factors associated with lymph node metastasis in patients with this type of EGC.

METHODS

A total of 136 EGC with signet ring cell histology patients who underwent D2 radical gastrectomy were reviewed in this study. The clinicopathologic features were analyzed to identify predictive factors for lymph node metastasis.

RESULTS

The overall rate of lymph node metastasis in EGC with signet ring cell histology was 10.3%. Using a univariate analysis, the risk factors for lymph node metastasis were identified as the tumor size, depth of tumor invasion, and lymphovascular invasion. The multivariate analysis revealed that tumor size >2 cm, submucosal invasion, and lymphovascular invasion were independent risk factors of lymph node metastasis (P < 0.05).

CONCLUSIONS

The risk of lymph node metastasis of EGC with signet ring cell histology was high in those with tumor sizes ≥2 cm, submucosal tumors, and lymphovascular invasion. A minimally invasive treatment, such as endoscopic resection, might be possible in highly selective cases of EGC with signet ring cell histology with intramucosal invasion, tumor size <2 cm, and no lymphovascular invasion.

High Fas expression in gastric carcinoma cells as a factor correlating with the occurrence of metastases to regional lymph nodes

PURPOSE

The aim of this study was to evaluate the correlation of the expression of Fas and Fas-L proteins in gastric carcinoma cells on the occurrence of metastases to regional lymph nodes.

MATERIAL/METHODS

The study included 89 patients treated surgically for gastric carcinoma. The evaluated clinicomorphological parameters were verified based on both histopathological material collected at surgery and intraoperative image. Fas and Fas-L expression was evaluated immunohistochemically in the neoplastic tissue of the removed gastric tumors.

RESULTS

A statistically significant positive correlation between Fas expression in gastric carcinoma cells and the number of regional lymph nodes affected by metastases was observed (p<0.05). No such correlation was noticed with respect to Fas-L. A statistically significant correlation between the depth of neoplastic infiltration of the stomach wall (T feature) and the number of affected lymph nodes was observed (p<0.05). No statistically significant correlations in the other examined clinicomorphological features and the number of metastatic lymph nodes was observed.

CONCLUSION

A positive Fas expression correlates with more frequent occurrence of metastases to regional lymph nodes. Determination of this protein expression in cancer cells prior to surgery may be helpful for planning the surgical procedure, especially with respect to the extent of lymph node excision.

Clinicopathological characteristics and prognosis of signet ring cell carcinoma of the stomach

BACKGROUND

Signet ring cell carcinoma (SRC) of the stomach is a histological type based on microscopic characteristics. Although the distinctive clinicopathological features of SRC have been reported, results are inconsistent and survival outcomes are uncertain.

METHODS

We retrospectively studied 769 patients with gastric carcinoma who underwent gastrectomy in our institute from 1999 to 2009. Among them, 326 patients (42.4 %) had early gastric cancer (EGC) and 443 patients (57.6 %) had advanced gastric cancer (AGC). Sex, age, tumor location, macroscopic type, tumor size, microscopic invasion, and survival rate were compared between patients with SRC, differentiated-, and undifferentiated-type gastric carcinomas.

RESULTS

Fifty-one patients (15.6 %) had SRC in EGC; there were significant differences in sex, age, location, macroscopic type, and size between SRC and the differentiated histological type. However, there was no difference between SRC and undifferentiated-type gastric carcinoma, except for the macroscopic type. Fifty-seven patients (12.9 %) had SRC in AGC. Sex, age, location, size, macroscopic type, perineural invasion, N stage, and hepatic metastasis were significantly different between SRC and the differentiated histological type. Undifferentiated-type gastric carcinoma differed in sex, macroscopic type, and hepatic metastasis. The overall survival rate differed between SRC and other cell types (P < 0.001). Among all the study patients, age [hazard ratio (HR) 1.013, P = 0.041] and tumor, node, and metastasis (TNM) stage (HR 2.350, P < 0.001) were important factors for predicting survival. Omitting patients with palliative resection or metastases, TNM stage was still an important factor for survival (HR 2.077, P < 0.001).

CONCLUSIONS

Patients with SRC showed similar clinicopathological features with undifferentiated histology. The survival of patients with SRC reflected a better prognosis in patients with undifferentiated gastric carcinoma. However, when narrowing the patients to those with EGC only, survival in EGC patients exhibited no difference between histological types. Among AGC patients, SRC patients had a worse prognosis than other cell types.

Seven synchronous early gastric cancer with 28 lymph nodes metastasis

An 85 year male patient complaining epigastric discomfort was admitted. From the esophagogastroduodenoscopy, three early gastric cancer (EGCa) lesions had been identified and these were diagnosed as adenocarcinoma with poorly differentiated cell type. The patient underwent operation. From the post-operative mapping, however, additional 4 EGCa lesions were found, and the patient was diagnosed with 7 synchronous EGCa. Out of the 7 EGCa lesions, 6 had shown invasion only to the mucosal layer and one had shown invasion into the 1/3 layer of submucosa. In spite of such superficial invasions, 28 of 48 lymph nodes had been identified as metastases. The multiple lesions of EGCa do not increase the risk of lymph node metastasis, but if their differentiations are poor or if they have lympho-vascular invasion, multiple lymph node metastases could incur even if the depth of invasion is limited to the mucosal layer or the upper portion of the submucosal layer.

Is the negative prognostic impact of signet ring cell histology maintained in early gastric adenocarcinoma?

BACKGROUND

Although the signet ring cell histologic subtype (SRC) is an independent predictor of poor prognosis in advanced gastric adenocarcinomas (GA), its prognostic value in early GA remains highly controversial. The aim of the study was to evaluate the prognostic impact of SRC in mucosal and submucosal GAs.

METHODS

Based on a multicenter cohort of 3,010 patients operated on for GA between January 1997 and January 2010, patients with pTis or pT1 tumors were extracted and analyzed comparatively between the SRC and non-SRC groups. The primary objective was to compare the 5-year survival rate between groups.

RESULTS

Among 421 patients with a pTis or pT1 tumor, 104 (25%) were SRC and 317 (75%) were non-SRC. Demographic variables were comparable between groups, except median age, which was less in the SRC group (59.6 vs 68.8 years; P < .001). Submucosal involvement was more frequent in the SRC group (94% vs 85%; P = .043), whereas lymph node involvement and number of invaded nodes were comparable between the 2 groups. When comparing SRC and non-SRC, recurrence rates (6% vs 9%; P = .223) and sites of recurrence were similar. The 5-year overall survival benefit in SRC patients (85% vs 76%, respectively; P = .035), was not evident when considering exclusively disease-specific survival or in multivariable analysis.

CONCLUSION

Contrary to more advanced GA, SRC morphologic subtype is not a negative prognostic factor in early GA. Better survival identified in some reports may be related to the younger age in SRC patients.

Can we resect EGC with Signet ring cells in Europe?

PURPOSE

The proposed guideline for performing endoscopic resection of early gastric carcinoma (EGC) in Paris classification is a well-differentiated carcinoma with maximum involvement Sm1. Signet ring cell carcinomas (SRC) are excluded from this recommendation. Authors from Eastern countries have proposed extending this resection to include selected undifferentiated EGC. Via an analysis of a series of cases of signet ring carcinoma, we will discuss whether it is possible to resect EGC with signet ring cells in Europe.

METHODS

We retrospectively included patients with histological classification pT1 of EGC showing SRC. Data was extracted from the hospital gastrectomy register. Lymphadenomectomy D1.5 was performed on all patients. Histology results were retrospectively obtained from the electronic patient file.

RESULTS

Twelve patients (mean age = 55.4, four women, eight men) underwent surgery, without previous chemotherapy, between 2000 and 2012, for EGC with SRC. Mean size of the lesions was 20.2 mm (5-35 mm). Seven lesions were located in the antrum, five in the fundus. In the case of nine patients, histology showed no lymphovascular involvement. None of these nine patients presented lymph node metastases (LNM). Five patients had intramucosal carcinoma, four were classified as Sm1, one patient was Sm2, and one patient was Sm3. On surgery, the three patients with lymphovascular invasion showed LNM.

CONCLUSION

Endoscopic resection of EGC with SRC does not systematically imply complementary treatment by surgery, although criteria for endoscopic resection are difficult to determine because of the lack of data in Europe.

Prediction of risk factors for lymph node metastasis in early gastric cancer

AIM: To explore risk factors for lymph node metastases in early gastric cancer (EGC) and to confirm the appropriate range of lymph node dissection.

METHODS: A total of 202 patients with EGC who underwent curative gastrectomy with lymphadenectomy in the Department of Surgery, Xinhua Hospital and Ruijin Hospital of Shanghai Jiaotong University Medical School between November 2003 and July 2009, were retrospectively reviewed. Both the surgical procedure and the extent of lymph node dissection were based on the recommendations of the Japanese gastric cancer treatment guidelines. The macroscopic type was classified as elevated (type I or IIa), flat (IIb), or depressed (IIc or III). Histopathologically, papillary and tubular adenocarcinomas were grouped together as differentiated adenocarcinomas, and poorly differentiated and signet-ring cell adenocarcinomas were regarded as undifferentiated adenocarcinomas. Univariate and multivariate analyses of lymph node metastases and patient and tumor characteristics were undertaken.

RESULTS: The lymph node metastases rate in patients with EGC was 14.4%. Among these, the rate for mucosal cancer was 5.4%, and 8.9% for submucosal cancer. Univariate analysis showed an obvious correlation between lymph node metastases and tumor location, depth of invasion, morphological classification and venous invasion (χ² = 122.901, P = 0.001; χ² = 7.14, P = 0.008; χ² = 79.523, P = 0.001; χ² = 8.687, P = 0.003, respectively). In patients with submucosal cancers, the lymph node metastases rate in patients with venous invasion (60%, 3/5) was higher than in those without invasion (20%, 15/75) (χ² = 4.301, P = 0.038). Multivariate logistic regression analysis revealed that the depth of invasion was the only independent risk factor for lymph node metastases in EGC [P = 0.018, Exp (B) = 2.744]. Among the patients with lymph node metastases, 29 cases (14.4%) were at N1, seven cases were at N2 (3.5%), and two cases were at N3 (1.0%). Univariate analysis of variance revealed a close relationship between the depth of invasion and lymph node metastases at pN₁ (P = 0.008).

CONCLUSION: The depth of invasion was the only independent risk factor for lymph node metastases. Risk factors for metastases should be considered when choosing surgery for EGC.

Cathepsin E is a marker of gastric differentiation and signet-ring cell carcinoma of stomach: a novel suggestion on gastric tumorigenesis

Gastric cancer (GC) presents various histological features, though the mechanism underlying its diversity is seldom elucidated. It is mainly classified into well differentiated tubular adenocarcinoma (tub1), moderately differentiated tubular adenocarcinoma (tub2), poorly differentiated adenocarcinoma (por), signet-ring cell carcinoma (sig), mucinous adenocarcinoma (muc), and papillary adenocarcinoma (pap). By screening, we found cathepsin E (CTSE) expresses universally in sig-type, occasionally in por-type, and rarely in tub1/tub2-type GC cell lines. In surgically-resected specimens, CTSE was immunostained in 50/51 sig-type (98.0%), 3/10 tub1-type (30.0%), 7/18 tub2-type (38.9%), 15/26 por-type (57.7%), 4/10 pap-type (40.0%), and 0/3 muc-type (0.0%) GC. In endoscopically-resected specimens, 6/7 sig-type (85.7%), 7/52 tub1-type (13.7%), 5/12 tub2-type (41.7%), 2/7 pap-type (28.6%) GC and 0/6 adenoma (0.0%) expressed CTSE. For non-malignant tissues, CTSE is universally expressed in normal fundic, pyloric, and cardiac glands of stomach, but hardly in other digestive organs. In the precancerous intestinal metaplasia of stomach, CTSE is mostly observed in mixed gastric-and-intestinal type and deficient in solely-intestinal type. CTSE expression is positively correlated with gastric marker MUC5AC (p<0.0001) and negatively correlated with intestinal marker MUC2 (p = 0.0019). For sig-type GC, in both tumors and background mucosa, expression of MUC5AC and CTSE is high whereas that of MUC2 is low, indicating that sig-type GC reflects the features of background mucosa. For gastric adenoma and tub1/tub2-type GC, more undifferentiated tumors tend to show higher expression of CTSE with MUC5AC and lower expression of MUC2 in tumors, but they tend to present lower expression of CTSE, MUC5AC and MUC2 in background mucosa. These suggest that more malignant gastric adenocarcinoma with stronger gastric and weaker intestinal properties tend to arise from background mucosa with decreased both gastric and intestinal features. In conclusion, CTSE is a marker of both gastric differentiation and signet-ring cell carcinoma, which should shed light on the mechanism of gastric tumorigenesis.

Predictive factors for lymph node metastasis in patients with poorly differentiated early gastric cancer

BACKGROUND

Endoscopic submucosal dissection is gaining popularity in the treatment of early gastric cancer. This study aimed to identify clinicopathological factors predictive of lymph node metastasis in patients with the poorly differentiated early gastric cancer to assess the feasibility of using endoscopic submucosal dissection for these cancers.

METHODS

The records of patients with poorly differentiated early gastric cancer who had undergone gastric cancer surgery between January 2002 and December 2009 were reviewed. Associations between clinicopathological factors and the presence of lymph node metastasis were analysed by univariable and multivariable logistic regression analysis.

RESULTS

Some 1005 patients were included in the analysis. Univariable analysis indicated that lymph node metastasis was associated with sex, ulceration, tumour size, depth of invasion, macroscopic type, lymphatic invasion and venous invasion. Logistic regression revealed that lymph node metastasis was significantly associated with sex, tumour size, depth of tumour invasion and lymphatic involvement. In the group with none of these risk factors (men with mucosal tumour no larger than 2 cm in size, with no lymphatic involvement), lymph node metastasis was present in four (3·2 per cent) of 124 patients.

CONCLUSION

In the present study 3·2 per cent of patients who were negative for all identified risk factors had lymph node metastasis. The use of endoscopic submucosal dissection should be considered carefully in the treatment of poorly differentiated early gastric cancer.

Prognostic significance of signet ring gastric cancer

PURPOSE

Studies in Asia have questioned the dictum that signet ring cell carcinoma (SRC) has a worse prognosis than other forms of gastric cancer. Our study determined differences in presentation and outcomes between SRC and gastric adenocarcinoma (AC) in the United States.

PATIENTS AND METHODS

The National Cancer Institute Surveillance, Epidemiology, and End Results database was reviewed for SRC and AC from 2004 to 2007.

RESULTS

We reviewed 10,246 cases of patients with gastric cancer, including 2,666 of SRC and 7,580 of AC. SRC presented in younger patients (61.9 v 68.7 years; P < .001) and less often in men (52.7% v 68.7%; P < .001). SRC patients were more frequently black (11.3% v 10.9%), Asian (16.4% v 13.2%), American Indian/Alaska Native (0.9% v 0.8%), or Hispanic (23.3% v 14.0%; P < .001). SRC was more likely to be stage T3-4 (45.8% v 33.3%), have lymph node spread (59.7% v 51.8%), and distant metastases (40.2% v 37.6%; P < .001). SRC was more likely to be found in the lower (30.7% v 24.2%) and middle stomach (30.6% v 20.7%; P < .001). Median survival was not different between the two (AC, 14.0 months v SRC, 13.0 months; P = .073). Multivariable analyses demonstrated SRC was not associated with mortality (hazard ratio [HR], 1.05; 95% CI, 0.96 to 1.11; P = .150). Mortality was associated with age (HR, 1.01; 95% CI, 1.01 to 1.02; P < .001), black race (HR, 1.10; 95% CI, 1.01 to 1.20; P = .026), and tumor grade. Variables associated with lower mortality risk included Asian race (HR, 0.83; 95% CI, 0.77 to 0.91; P < .001) and surgery (HR, 0.37; 95% CI, 0.34 to 0.39; P < .001).

CONCLUSION

In the United States, SRC significantly differs from AC in extent of disease at presentation. However, when adjusted for stage, SRC does not portend a worse prognosis.