Signet ring cell carcinoma of the stomach

Survival impact of gastrectomy and chemotherapy on gastric signet ring-cell carcinoma with different metastatic lesions: A population-based study

BACKGROUND

A comprehensive understanding of gastric signet ring cell carcinoma (SRCC) is limited. The aim of our study was to analyze metastatic patterns of gastric SRCC and evaluate impacts of gastrectomy and chemotherapy for metastatic gastric SRCC.

METHODS

We obtained data of gastric cancer patients between 2010 and 2017 in the Surveillance, Epidemiology, and End Results database. Chi-square tests were used to compare data significance. Kaplan-Meier, Cox proportional hazards regression and Fine-Gray competing risk analysis were used to analyze the difference in the overall survival (OS) and cancer-specific survival (CSS). Propensity-score matching was used to adjust numerical difference.

RESULTS

Among 36,459 eligible gastric cancer patients, 6264 (17.2 %) were SRCC patients. Bone metastasis was more common in SRCC patients than in non-SRCC patients. The multivariate analysis showed that chemotherapy (HR = 0.30, 95 %CI = 0.27-0.33, p < 0.01) and gastrectomy (HR = 0.51, 95 %CI = 0.45-0.59, p < 0.01) were protective prognostic factors in certain stage Ⅳ SRCC patients. For the effect of gastrectomy, survival benefits could be found in patients with liver metastasis. The gastrectomy was not associated with improved OS in patients with lung or multiple metastases. In subgroup analysis, SRCC patients with metastasis who received gastrectomy and chemotherapy (HR = 0.17, p < 0.01; HR = 0.03, p < 0.01) had a better OS and CSS than those who had chemotherapy only (HR = 0.30, p < 0.01; HR = 0.18, p < 0.01).

CONCLUSION

Our study analyzed the unique metastatic patterns of gastric SRCC and recommended chemotherapy as the first choice in metastatic SRCC. For patients with liver metastasis, gastrectomy plus chemotherapy can be considered.

The percentages of signet-ring cells (SRCs) affects the prognosis after radical gastrectomy for advanced gastric cancer

PURPOSE

Only recently has the percentage of signet-ring cells (SRCs) been shown to affect the prognosis following gastric cancer surgery. It is uncertain whether the SRC percentage has a role in tumour biology or prognosis of gastric signet-ring cell carcinoma (GSRCC). For this research, we assessed the effect of the SRC percentage on the clinicopathological and prognostic characteristics of gastric cancer (GC) tumours and created and verified a prognostic nomogram to assess the overall survival (OS) of GSRCC patients.

METHODS

In our study, 1100 GC patients with signet-ring cell carcinoma (SRCC) at Zhejiang Cancer Hospital from December 2013 to December 2018 who underwent curative gastric cancer resection were retrospectively analysed. The patients were separated into two groups: those with SRCC (SRC percentage >50%; n = 157) and those with partial signet-ring cell carcinoma (PSRCC) (SRC percentage ≤50%; n = 943). We compared the clinicopathological characteristics of both groups. To estimate OS and determine correlations with the SRC percentage, the Kaplan-Meier method and log-rank test were used. To develop the prognostic nomogram, independent prognostic indicators for OS were identified using Cox regression analyses. Predictions were assessed using the calibration curve and C-index.

RESULTS

Our research showed that there was no discernible difference in OS between the two groups. The preoperative CA242 level, pT stage, pN stage, age, nerve invasion, neoadjuvant chemotherapy, postoperative chemotherapy, and maximum tumour diameter were independent prognostic risk factors for OS for GC (all p < 0.05). However, for advanced GC, the SRC percentage (HR = 1.571, 95% CI 1.072-2.302, p = 0.020) was an independent prognostic factor of OS. Other independent prognostic risk factors were age, pT stage, pN stage, nerve invasion, tumour location, neoadjuvant chemotherapy, postoperative chemotherapy, preoperative CA50 level, and preoperative CEA level (all p < 0.05). On these bases, nomograms were constructed for GC and advanced GC, with C-indexes of 0.806 (95%CI 0.782-0.830) and 0.728 (95%CI 0.697-0.759), respectively.

CONCLUSIONS

In cases of advanced gastric cancer, the SRC percentage served as a standalone prognostic indicator for OS. An effective tool for assessing the prognosis of GSRCC was offered by the nomogram.

The Prognostic Significance and Gene Expression Characteristics of Gastric Signet-Ring Cell Carcinoma: A Study Based on the SEER and TCGA Databases

Purpose

This study is based on the Surveillance, Epidemiology, and End Results (SEER) program to explore the prognostic differences between signet-ring cell carcinoma (SRC) and intestinal-type gastric carcinoma (ITGC). This study is also based on gene sequencing data from The Cancer Genome Atlas (TCGA) to identify unique genetic contributions to the prognostic differences between the two subtypes of gastric cancer.

Patients and Methods

The clinical data were based on the SEER database from 2004 to 2015. Kaplan–Meier (KM) curves were used to compare 5-year overall survival (OS), and Cox regression was used for univariate and multivariate analyses. Gene expression profiles were obtained from TCGA database, and differentially expressed genes (DEGs) were screened. Functional enrichment analysis, protein interaction and survival analysis will be further carried out. Genes of interest were verified by the Human Protein Atlas, immunohistochemistry, and encyclopedia of Cancer Cell Lines (CCLE). The relationship between genes of interest and immune cell infiltration was also analyzed by Tumor Immune Estimation Resource (TIMER).

Results

Compared with ITGC patients, SRC patients were more likely to be female, tended to be younger, and have a greater tumor distribution in the middle and lower stomach (p &lt; 0.01). SRCs showed a significantly better prognosis than ITGCs (p &lt; 0.01) in early gastric cancer (EGC), while the prognosis of SRCs was significantly worse than ITGCs (p &lt; 0.05) in advanced gastric cancer (AGC). A total of 256 DEGs were screened in SRCs compared to ITGCs, and the enrichment analysis and protein interactions revealed that differential genes were mainly related to extracellular matrix organization. Thrombospondin1 (THBS1) and serpin peptidase inhibitor, clade E, member 1 (SERPINE1) are significantly differentially expressed between SRC and ITGC, which has been preliminarily verified by immunohistochemistry and open-source databases. THBS1 and SERPINE1 are also associated with multiple immune cell infiltrates in gastric cancer.

Conclusions

There were significant differences in the clinicopathological features and prognosis between SRC and ITGC. These results suggest that SRC and ITGC may be two distinct types of tumors with different pathogeneses. We found many codifferentially expressed genes and important pathways between SRC and ITGC. THBS1 and SERPINE1 were significantly differentially expressed in the two types of gastric cancer, and may have potentially important functions.

Mutational characteristics of young and elderly gastric cancer: a comparative study

BACKGROUND

Young gastric cancer (YGC) has been indicated as having a worse prognosis than in elderly gastric cancer (EGC). It has been reported that YGC and EGC patients show different genomic profiles; however, there has been no comparative study conducted to reveal their mutational characteristics.

METHODS

Firstly, we divided and analyzed the mutational landscape and 50 cancer-related genes characters of YGC (n=18) and EGC (n=18) patients from The Cancer Genome Atlas-Stomach Adenocarcinoma (TCGA-STAD). A total of 8 gastric cancer samples including 4 YGC and 4 EGC patients were collected to detect 50 cancer-related genes by multiplex polymerase chain reaction (PCR) next generation sequencing. The R/maftools package was used to describe the mutational characteristics.

RESULTS

Our results showed that the EGC group harbored more mutations than the YGC group. In 50 cancer-related genes in our cohort, the YGC group tended to be different from the EGC group using multiplex PCR next generation sequencing. In the YGC group, candidate mutations were identified within the following genes: IDH2, PDGFRA, KRAS, FLT3, FGFR2, and FGFR3. The YGC group showed less tumor mutational burden (TMB) level then EGC.

CONCLUSIONS

The YGC group tended to be more sensitive to molecularly targeted therapy because of it having more somatic mutations in 50 cancer-related genes using targeted next-generation sequencing.

Signet ring cell percentage in poorly cohesive gastric cancer patients: A potential novel predictor of survival

BACKGROUND AND OBJECTIVES

Signet ring cells (SRC) are widely acknowledged as a prognostically unfavorable histotype amongst poorly cohesive gastric cancer. In this study we evaluated the impact of SRC percentage on the clinical, pathological and prognostic features of these tumors according to the classification by the European Chapter of the IGCA.

METHODS

We retrospectively reviewed records of patients with poorly cohesive gastric cancer that underwent surgery between 1995 and 2016, whose tissue specimens were available in a biological bank. All slides were put under revision, patients were reclassified into three groups according to the proportion of signet ring cells: "pure" SRC (containing ≥90% of SRCs), Poorly Cohesive-Not Otherwise Specified (PC-NOS) (containing ≤10% of SRCs), and PC-NOS/SRC (containing <90% but >10% of SRCs). The clinicopathological factors between different types were analyzed and prognostic differences were compared.

RESULTS

Among 143 enrolled patients, 51% were male and 49% were female. The mean (±SD) age at diagnosis was 61 ± 13.9 years. Eighty-seven patients (60.8%) were reclassified as PC-NOS, 56 (39.2%) as PC-NOS/SRC and none as "pure" SRC. Five-years overall survival was significantly higher in PC-NOS/SRC group (63.3%) compared with PC-NOS group (12.7%). The increase in mortality risk was more than four-fold in patients with PC-NOS pattern compared to those with PC-NOS/SRC (HR 4.32 [95% CI 2.5-7.4]. After adjustment for potential confounding factors, SRC pattern was still an independent predictor of survival.

CONCLUSIONS

The percentage of SRCs is inversely related to tumor aggressiveness, confirming the role of SRC pattern as an independent predictor of survival.

The efficiency of D1(+) lymphadenectomy in signet ring cell carcinoma: comparison of postoperative early and late outcomes between standard lymphadenectomy and D1(+) lymphadenectomy

Signet ring cell carcinoma (SRCC) is a poorly cohesive subtype of gastric cancer. It is more aggressive than other types of gastric cancer. There is no special method for its treatment, but gastrectomy and lymphadenectomy is the standard approach. The aim of this study is to investigate postoperative outcomes of D1 lymphadenectomy and D1(+)lymphadenectomy in gastric SRCC.

A total of 358 cases whohad a gastrectomy performed forthe diagnosis of gastric cancer between 2013 and 2019 in Ankara University Medical Faculty, Surgical Oncology Department were retrospectively investigated. In all, 128 of the cases had SRCC in the final pathology. We separated the cases into two types,D1 lymphadenectomy and D1(+) lymphadenectomy. The 5-year survival, early mortality, hospital mortality and postoperative complication rates were evaluated.

There were 59 patients in the D1 group and 64 patients in the D1(+) group.Metastatic lymph node amount and therefore N stage was found to be significantly higher in the D1(+) group (p=0.00 and p=0.03, respectively). Postoperative chyle fistula was found to be significantly higher in the D1(+) group (p=0.003). There was no statistically significant difference between the groups with regard tomean survival (p=0.065);the 5-year mean survival was 21% in the D1 group and 7% in the D1(+) group. Present findings suggest that extended lymphadenectomy does not provide a benefit in cases of SRCC.

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.

Signet ring cell carcinoma of the Ampulla of Vater: outcomes of patients in the United States

BACKGROUND

Signet ring cell carcinoma (SRCC) of the ampulla of Vater is poorly understood, with approximately 22 reported cases. Our study sought to create a comprehensive review of cases in the United States.

METHODS

We used the Surveillance, Epidemiology, and End Results Program to collect all cases of ampullary adenocarcinoma diagnosed between 2010 and 2015.

RESULTS

The age-adjusted incidence rate of SRCC of the ampulla of Vater was 1.2 cases per 10,000,000 persons per year, with 50% more cases in males than females. We identified 3448 cases of adenocarcinoma of the ampulla of Vater, 81 of which were SRCC (2.3%). SRCC tended to present a later stage than other ampullary cancers, with median survival times of 17 vs. 25 months, (p = 0.07). Survival was significantly worse for SRCC when accounting for other clinical features (HR 1.46, p = 0.01). Factors portending worse prognosis in SRCC of the ampulla of Vater were advanced age, late stage and lack of surgical intervention.

CONCLUSION

Our study represents the largest study of SRCC of the ampulla of Vater to date. SRCC has a poorer prognosis compared with other ampullary cancers. Optimal treatment regimen is the most important future area of study.

Predictors of Lymph Node Metastasis and Differences Between Pure and Mixed Histologic Types of Early Gastric Signet-ring Cell Carcinomas

The aim of this study was to investigate predictors of lymph node metastasis (LNM) in early gastric signet-ring cell carcinoma (SRCC) and determine clinicopathologic and prognostic differences of different histologic subtypes. We retrospectively analyzed 13,661 gastric cancer patients; 231 were eligible for inclusion. Data for clinical, endoscopic, and histopathologic characteristics and prognoses were collected. Patients were followed up regarding postresection survival; overall and disease-specific survival rates were estimated by the Kaplan-Meier method with a log-rank test, and prognostic factors were evaluated by Cox regression. LNM incidence in early SRCC was 16.0% (37/231) overall: 6.9% (8/116) and 25.2% (29/115) in patients with pure and mixed SRCC, respectively. Univariate and multivariate analyses revealed SM2 invasion (odds ratio [OR]=5.070, P=0.003), lymphovascular invasion (LVI) (OR=14.876, P<0.001), pathologic pattern of mixed SRCC (OR=3.226, P=0.026), ulcer presence (OR=3.340, P=0.019) and lesion size over 20 mm (OR=2.823, P=0.015) as independent risk factors for LNM. Compared with pure SRCC, the mixed subtype was associated with older age, larger lesion size, higher LVI frequency, more frequent perineural invasion, and most importantly, higher LNM incidence. Patients with pure SRCC showed significantly longer overall survival (P=0.004) and disease-specific survival (P=0.002) than mixed SRCC patients. Pathologic subtype (hazard ratio [HR]=3.682; P=0.047), age (HR=5.246; P=0.001), SM1 invasion (HR=6.192; P=0.023), SM2 invasion (HR=7.529; P=0.021) and LNM (HR=5.352; P<0.001) were independent prognostic factors. Independent risk factors for LNM in early gastric SRCC were SM2 invasion, LVI, pathologic pattern, ulcer presence and lesion size over 20 mm. Early SRCC should be further classified by the purity of the SRC component.

Peri-operative Outcomes and Survival Following Palliative Gastrectomy for Gastric Cancer: a Systematic Review and Meta-analysis

BACKGROUND

Many patients with gastric cancer present with late stage disease. Palliative gastrectomy remains a contentious intervention aiming to debulk tumour and prevent or treat complications such as gastric outlet obstruction, perforation and bleeding.

METHODS

We conducted a systematic review of the literature for all papers describing palliative resections for gastric cancer and reporting peri-operative or survival outcomes. Data from peri-operative and survival outcomes were meta-analysed using random effects modelling. Survival data from patients undergoing palliative resections, non-resective surgery and palliative chemotherapy were also combined. This study was registered with the PROSPERO database (CRD42019159136).

RESULTS

One hundred and twenty-eight papers which included 58,675 patients contributed data. At 1 year, there was a significantly improved survival in patients who underwent palliative gastrectomy when compared to non-resectional surgery and no treatment. At 2 years following treatment, palliative gastrectomy was associated with significantly improved survival compared to chemotherapy only; however, there was no significant improvement in survival compared to patients who underwent non-resectional surgery after 1 year. Palliative resections were associated with higher rates of overall complications versus non-resectional surgery (OR 2.14; 95% CI, 1.34, 3.46; p < 0.001). However, palliative resections were associated with similar peri-operative mortality rates to non-resectional surgery.

CONCLUSION

Palliative gastrectomy is associated with a small improvement in survival at 1 year when compared to non-resectional surgery and chemotherapy. However, at 2 and 3 years following treatment, survival benefits are less clear. Any survival benefits come at the expense of increased major and overall complications.

Metastasis From Gastric Signet Ring Cell Adenocarcinoma Presenting as a Rectosigmoid Stricture: A Rare Case

We present the case of a 55-year-old man who was admitted with new abdominal ascites and change in stool caliber. The colonoscopy examination revealed a severe stricture with inflamed friable mucosa measuring 8 cm in length in the rectosigmoid colon. Histologically, poorly differentiated adenocarcinoma with signet ring cells was seen. The patient underwent esophagogastroduodenoscopy (EGD), which was suggestive of linitis plastica of the stomach. On microscopic examination, biopsy reported poorly differentiated adenocarcinoma with occasional signet ring cells as the primary source.

Mucin expression in gastric- and gastro-oesophageal signet-ring cell cancer: results from a comprehensive literature review and a large cohort study of Caucasian and Asian gastric cancer

BACKGROUND

The literature on the prognostic relevance of signet-ring cell (SRC) histology in gastric cancer (GC) is controversial which is most likely related to inconsistent SRC classification based on haematoxylin-eosin staining. We hypothesised that mucin stains can consistently identify SRC-GC and predict GC patient outcome.

METHODS

We performed a comprehensive literature review on mucin stains in SRC-GC and characterised the mucin expression in 851 Caucasian GC and 410 Asian GC using Alcian Blue (AB)-Periodic Acid-Schiff (PAS), MUC2 (intestinal-type mucin), and MUC5AC (gastric-type mucin). The relationship between mucin expression and histological phenotype [poorly cohesive (PC) including proportion of SRCs, non-poorly cohesive (non-PC), or mucinous (MC)], clinicopathological variables, and patient outcome was analysed.

RESULTS

Depending on mucin expression and cut-offs, the positivity rates of SRC-GC reported in the literature varied from 6 to 100%. Patients with MUC2 positive SRC-GC or SRC-GC with (gastro)intestinal phenotype had poorest outcome. In our cohort study, PC with ≥ 10% SRCs expressed more frequently MUC2, MUC5AC, and ABPAS (p < 0.001, p = 0.004 and p < 0.001, respectively). Caucasians with AB positive GC or combined ABPAS-MUC2 positive and MUC5AC negative had poorest outcome (all p = 0.002). This association was not seen in Asian patients.

CONCLUSIONS

This is the first study to suggest that mucin stains do not help to differentiate between SRC-GC and non-SRC-GC. However, mucin stains appear to be able to identify GC patients with different outcome. To our surprise, the relationship between outcome and mucin expression seems to differ between Caucasian and Asian GC patients which warrants further investigations.

Effect of double-layer structure in intramucosal gastric signet-ring cell carcinoma on lymph node metastasis: a retrospective, single-center study

BACKGROUND

Among all types of gastric cancer (GC), signet-ring cell carcinoma (sig-GC) accounts for 4-17% of cases. The prognosis of early sig-GC is relatively good, with the 5-year survival rate at 99.7%. However, the correlation between histological features and lymph node metastasis (LNM) among pT1a (M) sig-GC remains unclear. Sig-GC often exhibits a double-layer structure (DLS) in the intramucosal layer, demonstrating functional differentiation into the normal gastric gland. Assumedly, the loss of the differentiation makes the DLS deranged, accounting for the occurrence of submucosal invasion and LNM. This study aimed to assess the proportion of DLS, to elucidate the correlation between histological features (including DLS) and LNM status, and to determine the LNM-negative condition in pT1a (M) sig-GC.

METHODS

We reviewed the pathological data of 310 patients with 310 intramucosal sig-GCs who received gastrectomy with lymph node dissection. Immunohistochemistry was performed on all specimens to evaluate the presence of DLS. Furthermore, we review the clinicopathological features, including tumor size, lymphovascular invasion (LVI), ulceration (UL), and DLS results, and then statistically analyze the correlation between these features and LNM status.

RESULTS

Overall, 129 pT1a (M) sig-GCs (42%) were DLS present. The univariate analysis revealed that "Tumor size > 20 mm", "UL present", and "DLS absent" were significant risk factors of LNM. The multivariate logistic regression analysis revealed only "DLS absent" as statistically significant.

CONCLUSIONS

"DLS absent" is a risk factor of LNM detected by the multivariate analysis. In pT1a (M), LVI absent, UL absent, tumor size > 20 mm, sig-GC, no LNM occurred in "DLS present" cases.

Targeting the differentiation of gastric cancer cells (KATO‑III) downregulates epithelial‑mesenchymal and cancer stem cell markers

The aim of the present study was to analyze the acquisition of the differentiated phenotype in the human gastric signet ring cell adenoma cancer KATO-III cell line in vitro. The morphology of KATO-III cells was explored by microcinematography. Different cytokines secreted by both adherent and non-adherent KATO-III cells into medium were observed. The cancer stem cell phenotypes were identified by reverse transcription-quantitative polymerase chain reaction using primers (E-Cad, Slug, Snail, vimentin, NANOG, NESTIN, OCT3/4 and C-X-C motif chemokine receptor 4) or antibodies [cluster of differentiation (CD)90 and CD117] by flow cytometry (FACS). The influence of the induction media for the differentiation of mesenchymal cells was studied through viability and proliferation assays, by evaluating gene expression and the expression of markers via FACS. Cell viability and cell cycle distribution were evaluated following the treatment of KATO-III with acetyl salicylic acid and using the induction media as an inhibitor of epithelial-mesenchymal transition (EMT) and heparanase. A total of 3 phenotypes of KATO-III were observed (adherent, non-adherent and cell cluster), which have internal potential for cell transition into one of the other phenotypes. KATO-III was differentiated into adipocyte-, chondrocyte-, osteocyte- and neurocyte-like cells by the induction media. Identification of the induced cells was conducted using cell dyes. Reduced mRNA expression of EMT-associated molecules, stem cell markers and heparanase was observed with acetyl salicylic acid and induction media. An inhibitory effect of acetyl salicylic acid and the induction media was also noted in regard to cell proliferation. In addition, acetyl salicylic acid induced G0/G1 phase cell cycle arrest in KATO-III cells. In conclusion, the induction of the differentiation of cancer stem cells into non-proliferating cells offers the possibility for novel drug design to overcome the issues associated with metastasis, drug resistance and systemic toxicity with improved therapeutic efficacy.

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.

Clinicopathological differences in signet ring cell adenocarcinoma between early and advanced gastric cancer

BACKGROUND

Signet ring cell adenocarcinoma is a histological classification based on the WHO classification. The presence of this specific histological type is associated with a worse pathological appearance. The prognosis of signet ring cell adenocarcinoma in gastric cancer patients after curative surgery is still under debate.

METHODS

From January 1988 to December 2012, a total of 2971 patients, including 819 early and 2152 advanced gastric cancer patients underwent curative resection for gastric cancer. Among them, there were 185 cases of signet ring cell adenocarcinoma in early gastric cancer patients, while there were 570 cases in advanced gastric cancer patients.

RESULTS

The overall incidence of signet ring cell adenocarcinoma was 25.4%. Our results showed that the 5-year overall survival rates of early gastric cancer patients with signet ring cell adenocarcinoma and non-signet ring cell adenocarcinoma were 90.7 and 83.2%, respectively (P = 0.001). The 5-year disease-free survival rates of early gastric cancer patients with signet ring cell adenocarcinoma and non-signet ring cell adenocarcinoma were 87.4 and 81.6%, respectively (P = 0.003). The 5-year overall survival rates of advanced gastric cancer patients with signet ring cell adenocarcinoma and non-signet ring cell adenocarcinoma were 32.1 and 37.9%, respectively (P = 0.041). The 5-year disease-free survival rates of advanced gastric cancer patients with signet ring cell adenocarcinoma and non-signet ring cell adenocarcinoma were 28.6 and 35.2%, respectively (P = 0.037). Signet ring cell adenocarcinoma was an independent predictor for overall survival in advanced gastric cancer (P = 0.017).

CONCLUSION

The clinical features and prognosis of signet ring cell adenocarcinoma are different between early and advanced gastric cancer. Signet ring cell adenocarcinoma is a poor prognostic factor in advanced gastric cancer after curative resection.

Can Preoperative Examination Help Choose the Best Surgical Procedure in Gastric Cancer?

Aim

Gastrectomy with lymph node dissection is standard treatment in gastric cancer. This study aimed to explore whether preoperative investigation finds could predict lymph node metastatic scope in gastric carcinoma so that the optimal surgical procedure could be selected.

Materials and Methods

Radical gastrectomy patients (n = 378) were separated into two groups according to the lymph node metastatic scope. Univariate and multivariate analyses of preoperative examination results were performed to identify the predictors of metastatic scope. ROC curves were constructed, and the area under the curve (AUC) was calculated to estimate diagnostic values.

Results

Serum CEA (OR: 3.73; 95% CI: 1.84–7.56; P ≤ 0.001), tumor size (OR: 2.07; 95% CI: 1.08–3.98; P = 0.03), and CT examination results (OR: 17.81; 95% CI: 9.18–34.55; P ≤ 0.001) were identified as independent predictors. The AUC proved that they possessed significant diagnostic value. When CT examination was negative, the combination of serum CEA and tumor size showed high specificity (95.3%; 164/172), negative predictive value (92.7%; 164/177), and accuracy (89.0%; 170/191).

Conclusions

Preoperative serum CEA, tumor size, and CT examination are independent predictors of lymph node metastatic scope and can be used for selecting the appropriate lymphadenectomy pattern in gastric cancer patients.

Breast Metastasis from Gastric Signet Ring Cell Carcinoma, Mimicking Inflammatory Carcinoma. A Case Report

We report a case of breast metastasis of signet ring cell gastric cancer clinically presented as a primary inflammatory carcinoma. Metastases to the breast are uncommon; review of the literature demonstrated only 300 cases. The clinical and radiographic features of the metastatic lesion were unlike those reported in the literature. Although a primary signet ring cell breast carcinoma was described, the pathologic patterns of the breast lesion, here reported, lead us to conclude this was a metastasis and not another primary tumor.

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.

Survival predictors associated with signet ring cell carcinoma of the esophagus (SRCCE): A population-based retrospective cohort study

Purpose

Signet ring cell carcinoma of the esophagus (SRCCE) is an uncommon tumor associated with significant morbidity and mortality. There is still no consensus regarding cut-off values for tumor size, age and optimal treatment for SRCCE. Thus, we elucidated the current survival outcomes of patients with SRCCE and analyzed factors associated with prognosis.

Methods

A retrospective cohort study based on the SEER (The Surveillance, Epidemiology, and End Results) program database was conducted. We identified 537 patients (461 men and 76 women) newly diagnosed with SRCCE between January 2004 and December 2014. A multivariate Cox proportional hazards model was utilized to measure the mortality-associated risk factors in patients with SRCCE after adjusting for various variables.

Results

The 1-, 2- and 5-year disease-specific mortalities (DSM) were 51.6%, 67.6%, and 78.4%, respectively, and the median survival time was 12.0 months. The factors correlated with mortality hazard were marital status (unmarried versus married, Hazard Ratio (HR) = 1.443), tumor size (≥ 5 cm versus < 5 cm, HR = 1.444), tumor grade (high grade versus low grade, HR = 3.001), condition of primary tumor (T4 versus T1, HR = 2.178), regional lymph node metastasis (N1 versus N0, HR = 1.739), further metastasis (M1 versus M0, HR = 1.951) and chemotherapy (receiving chemotherapy versus no chemotherapy, HR = 0.464).

Conclusions

The contemporary 5-year DSM was 78.4%. Being unmarried, having a tumor size ≥ 5 cm, a high tumor grade, a score of T4 for tumor invasion of adjacent organs, a score of N1 for regional lymph node metastasis, a score of M1 for distant metastasis and no chemotherapy were independent predictors of high DSM.

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 potential pitfall in evaluating HER2 immunohistochemistry for gastric signet ring cell carcinomas

Signet ring cell carcinoma (SRC) more commonly presents as metastatic disease and renders patients to be considered for chemotherapy. While treatment options are limited overall, trastuzumab has been shown to be effective for HER2 positive SRC cases. The current algorithm for HER2 evaluation heavily relies on positive membrane-specific staining by immunohistochemistry (IHC), but several anecdotal reports have suggested that SRCs may be susceptible to misinterpretation due to non-specific staining in the marginated cytoplasm with/without nucleus. Results of two FDA-approved IHC methods of HER2 evaluation, Pathway and HercepTest, along with silver in situ hybridisation were interpreted retrospectively and compared in 155 primary SRC cases. IHC results were discrepant between the two assays in SRC even at the strongest IHC scores. Discordance indeed occurred due to dark, non-specific staining obscured by the unique SRC morphology. True HER2 positive SRC was identified in three cases (3/155, 1.9%). In this study, we demonstrate the importance of recognising potential discrepancy in interpreting HER2 status depending on the assay used. Understanding this possible pitfall may prevent unnecessary trastuzumab in SRC patients.

Is signet-ring cell carcinoma a specific entity among gastric cancers?

BACKGROUND

The prognosis and chemoresistance of signet-ring cell (SRC) gastric adenocarcinoma have been reported and debated, and the utility of perioperative chemotherapy for such a tumor has been questioned . This study was performed to assess the impact of the SRC type on survival following resection of gastric adenocarcinoma, and to assess whether the prognostic factors (including perioperative chemotherapy) for non-SRC adenocarcinoma differed from those for SRC adenocarcinoma.

METHODS

1799 cases of adenocarcinoma that were consecutively treated from 1997 to 2010 in 19 French centers by subtotal or total gastrectomy were included in a retrospective study. A D2 lymphadenectomy was performed for antropyloric tumors, and a modified D2 for upper tumors. SRC adenocarcinoma was diagnosed based on the presence of isolated carcinoma cells containing mucin.

RESULTS

A total gastrectomy was performed in 979 (54.4 %) patients. SRC adenocarcinoma was diagnosed in 899 (50 %) patients. Patients with an SRC tumor were more frequently female, younger, and malnourished, had lower ASA scores, and had larger tumors than non-SRC patients. Median survival in patients with non-SRC carcinoma was 51 months, as compared to 26 months in patients with SRC carcinoma (p < 0.001). At multivariate analysis, SRC type remained an independent adverse prognostic factor (HR = 1.182). Factors that were prognostic in the SRC subgroup but not in the non-SRC subgroup were age >60 years, linitis, and involvement of adjacent organs. In contrast to non-SRC tumors, pre- and postoperative chemotherapy did not significantly impact on survival following resection of SRC adenocarcinoma.

CONCLUSION

In comparison to non-SRC adenocarcinoma, the SRC type has a worse prognosis, different prognostic factors, and is only poorly sensitive to perioperative chemotherapy. Non-SRC and SRC adenocarcinomas should be considered different entities in future therapeutic trials.

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.

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.

Clinicopathological features and outcomes in patients undergoing radical resection for early gastric cancer with signet ring cell histology

BACKGROUND

The signet ring cell histology is regarded as an independent predictor of poor prognosis in advanced gastric adenocarcinomas, but its biologic behavior in early gastric cancer remains highly controversial.

OBJECTIVE

Our objective was to compare the clinicopathological features and outcomes in patients undergoing curative resection between SRCs and non-SRCs histologic types of early gastric cancer.

METHODS

Clinicopathologic features and the overall survival rates of 334 patients with early gastric cancer undergoing D2 curative resection from January 1994 to December 2008 were retrospectively reviewed and compared according to the histologic type.

RESULTS

Clinicopathologic features were comparable between two groups, except age, ulcer findings and the presence of lymph node metastasis. The incidence of recurrence for SRCs group was significantly lower than that for non-SRCs group (10.4% vs. 19.6%; P<0.05). The overall 5-year survival rate was 88.6% in all cases. The overall survival rate of patients in SRCs group was significantly better than that of patients in non-SRCs group (5-year survival, 93.9% vs. 85.8%; P=0.027). Multivariable analysis revealed that SRCs subtype, lymphovascular invasion, and lymph node metastasis were independent prognostic factors.

CONCLUSION

Our analysis revealed that the biological behavior of SRCs was different from other undifferentiated cancer histologic subtypes in early stage. Early gastric cancer with signet ring cell histology had low incidence of lymph node metastasis and a relatively favorable prognosis.

Intramucosal Signet Ring Cell Gastric Cancer Diagnosed 15 Months after the Initial Endoscopic Examination

The size and shape of intramucosal signet ring gastric cancer in this case remained endoscopically unchanged for 15 months. Laparoscopy-assisted distal gastrectomy was performed, and immunohistochemical analysis revealed Ki-67 and p53 mutations to be negative in this case. Signet ring gastric cancer has long been thought to confer a worse prognosis than other forms of gastric cancer; however, our case did not progress to advanced gastric cancer for 15 months.

What are the risk factors for residual tumor cells after endoscopic complete resection in gastric epithelial neoplasia?

BACKGROUND

In early gastric cancer (EGC) and gastric adenoma, residual tumors may develop despite complete endoscopic resection (ER). To improve the chance of curative resection, we investigated the risk factors of residual tumor development in completely resected gastric epithelial neoplasia after ER.

METHODS

In total, 3,879 gastric epithelial neoplasms showing complete resection after ER were examined; 46 (1.2 %) residual tumors were found upon follow-up endoscopy. Clinicopathological characteristics were evaluated between those with and without residual tumors.

RESULTS

For gastric adenoma, high-grade dysplasia and severe intestinal metaplasia (IM) in the background mucosa were significantly associated with residual tumors. For EGC, poorly differentiated adenocarcinoma (PD), signet ring cell carcinoma (SRC), having a minimum lateral safety margin of <3 mm, and localization in the upper third of the stomach were significantly associated with residual tumors. Multivariate analysis revealed that a lateral safety margin of <3 mm (OR 13.8; p < 0.001), PD (OR 16.3; p = 0.014), and SRC (OR 9.8; p = 0.009) among EGC patients, and severe IM in the background mucosa (OR 9.0; p = 0.024) among gastric adenoma patients, were significantly associated with residual tumors.

CONCLUSIONS

For neoplasms with undifferentiated histology (PD or SRC), short-term endoscopic follow-up may help to detect residual tumors that form after complete resection via ER. For EGC, the lateral margin may be considered safe if greater than 3 mm. However, the possibility of satellite lesions should be investigated when the gastric adenoma to be resected is surrounded by severe IM.

Intramucosal gastric cancer: the rate of lymph node metastasis in signet ring cell carcinoma is as low as that in well-differentiated adenocarcinoma

OBJECTIVE

Endoscopic resection (ER) plays a major role in the management of early gastric cancer. Less lymph node metastasis (LNM) and better survival rates were reported in early gastric signet ring cell carcinoma (SRC) than adenocarcinoma. We investigated and compared the clinicopathologic characteristics of endoscopic and surgical features in early gastric SRC and adenocarcinoma in accordance with histologic differentiation to examine the feasibility of ER in early gastric SRC.

PATIENTS AND METHODS

From January 2003 to September 2011, patients diagnosed with early gastric cancer among patients who had undergone a curative gastrectomy with lymph node dissection were enrolled. Patients' age, sex, tumor size, location, macroscopic type, depth of invasion, lymphovascular invasion (LVI), and LNM were determined.

RESULTS

A total of 696 patients were enrolled. SRC was more frequent in women and more common at the mid-body than differentiated adenocarcinoma. SRC was more common in patients younger than 50 years of age (P < 0.001) and the elevated type was less common in SRC than other adenocarcinomas (P < 0.001). The incidence of submucosal invasion, LVI, and LNM in SRC were similar to well-differentiated adenocarcinoma. Moderately and poorly differentiated group, tumor size greater than 20 mm, submucosal invasion, and LVI were independent risk factors predicting LNM. Intramucosal SRC less than 20 mm had no LNM.

CONCLUSION

Rate of LNM and submucosal invasion in early SRC was as low as those in early well-differentiated adenocarcinoma. ER for early gastric SRC may be an alternative to surgical gastrectomy under certain conditions.

Pancytopenia and isolated bone marrow recurrence in a case of previously resected gastric carcinoma: a rare finding

Recurrences in resected cases of gastric carcinomas are well known. However isolated involvement of bone marrow is a rare presentation. We present a previously treated case of gastric carcinoma-signet-ring cell type who had a progressive shortness of breath since 1 month. A hemogram done at this occasion showed pancytopenia and leucoerythroblastic picture. Bone marrow examination revealed infiltration by signet-ring cells. All such patients who presents with unexplained pancytopenia should prompt us to suspect a bone marrow recurrence.

Tumour size is related to the curability of signet ring cell early gastric cancer with endoscopic submucosal dissection: a retrospective single centre study

BACKGROUND

Endoscopic submucosal dissection is applied in selected cases of signet ring cell early gastric cancer. However, factors related to curability of signet ring cell early gastric cancer with this method have not been fully evaluated. Our aim was to evaluate factors related to incomplete resection in signet ring cell early gastric cancer with endoscopic submucosal dissection.

METHODS

A retrospective analysis was performed on a total of 126 consecutive patients with signet ring cell early gastric cancer who had undergone endoscopic submucosal dissection at the Severance Hospital in Korea, between March 2007 and March 2012. The clinical outcomes were reviewed and factors related to incomplete resection were analysed.

RESULTS

Multivariate analysis showed that large tumour size was the only significant factor related to incomplete resection (P=0.006; hazard ratio, 1.040; 95% confidence interval, 1.101-1.084). In addition, large tumour size was the only significant factor related to endoscopic size underestimation (P<0.001; hazard ratio, 1.391; 95% confidence interval, 1.221-1.586). The rate of endoscopic size underestimation was significantly higher in tumours with a size ≥20mm (P<0.001).

CONCLUSIONS

To improve the curability of signet ring cell early gastric cancer with endoscopic submucosal dissection, larger tumours (especially tumour with a size ≥20mm) should be resected with a larger margin.

Signet ring cell type and other histologic types: differing clinical course and prognosis in T1 gastric cancer

BACKGROUND

The behavior of early stage signet ring cell carcinoma (SRC) is controversial. The purpose of this study was to clarify the behavior of early gastric SRC.

METHODS

We retrospectively analyzed data from 2,085 patients who had undergone curative gastrectomy for early gastric cancer between 1989 and 2000. Clinicopathologic outcomes and prognoses were evaluated, and we investigated whether these variables were correlated with histopathologic type.

RESULTS

Patients with early gastric SRC were younger and had a greater proportion of females than other histologic types. Lymph node metastasis was the only independent prognostic factor for both mucosal and submucosal forms of SRC. Mucosal SRC had a similar rate of lymph node metastasis to poorly differentiated (PD) tubular adenocarcinoma (TUB), and a higher rate than well-differentiated (WD) or moderately differentiated (MD)-TUB. However, its submucosal form had a similar rate of lymph node metastasis to WD-TUB, and a lower rate than MD- or PD-TUB. There was no difference in tumor recurrence or disease-related death according to histopathologic type or depth of invasion.

CONCLUSION

In mucosal gastric cancer, SRC has an unfavorable risk factor of lymph node metastasis than that of others and should not be considered for endoscopic resection. In submucosal gastric cancer, SRC is a more favorable risk factor of lymph node metastasis than that of other histologic types.

Stage-stratified prognosis of signet ring cell histology in patients undergoing curative resection for gastric adenocarcinoma

BACKGROUND

The prognosis of signet ring cell (SRC) gastric adenocarcinoma is regarded as poor, although studies addressing outcomes in relation to non-SRC tumors are conflicting. Our objective was to compare the survival of SRC tumors with stage-matched intestinal-type tumors in a cohort of Western patients.

METHODS

Review of a prospectively maintained database identified 569 patients undergoing curative resection (R0) from 1990 to 2009. Patients were divided into three histologic groups on the basis of the Lauren classification: SRC (n = 210), intestinal well- or moderately differentiated (WMD, n = 242) disease, and intestinal poorly differentiated (PD, n = 117) disease. Patient demographics, clinicopathologic features, and postoperative outcomes were determined. Stage-stratified disease-specific mortality was calculated and multivariate analysis performed.

RESULTS

When compared with WMD and PD tumors, SRC tumors were associated with younger age (63 years SRC vs. 71 years WMD and 72 years PD, p < 0.0001) and with female sex (58 % SRC vs. 40 % WMD and 40 % PD, p = 0.0003). Median follow-up was 115 months. Patients with stage Ia SRC lesions had a better 5-year disease-specific mortality compared with stage-matched intestinal-type tumors (0 % SRC vs. 8 % WMD and 24 % PD, p = 0.001). In contrast, SRC patients with stage III disease fared significantly worse (78 % SRC vs. 54 % WMD and 72 % PD, p = 0.001). On multivariate analysis, the risk of death from gastric cancer comparing all three groups was lowest for SRC in stage I and highest for SRC in stage III disease (stage III hazard ratio: SRC 1 vs. 0.47 WMD and 0.85 PD).

CONCLUSIONS

When compared with intestinal-type tumors, SRC tumors at early stages are not necessarily associated with poor outcomes.

Isolated ovarian metastasis of gastric cancer: Krukenberg tumor

Introduction

Gastric cancer, one of the most common cancers in the world, rarely metastasizes to the ovaries. Ovarian metastases of gastric signet ring cell cancer (SRCC) are referred to as Krukenberg tumors and account for 1–2% of all ovarian cancers. Here, we analyze the characteristics, treatment, and prognosis of patients with Krukenberg tumors.

Material and methods

We retrospectively analyzed the demographic characteristics, treatment modalities, progression-free survival (PFS), and overall survival (OS) of patients who were diagnosed with Krukenberg tumors of gastric cancer origin and who underwent treatment and follow-up between January 2005 and January 2012 in the Ankara Oncology Education and Research Hospital.

Results

Among 1755 patients diagnosed with gastric cancer between January 2005 and January 2012, eight patients (0.45%) with histopathologically identified Krukenberg tumors were enrolled. The median age of the eight patients was 42.2 years (range, 32–69 years). Two (25%) of the patients were stage 3A, two (25%) were stage 3C, and four (50%) were stage 4 at the time of diagnosis. The median PFS was 13.2 months (1–25 months), the median OS after the original diagnosis was 16.7 months (1–41 months), and the median OS after ovarian metastasis was 3.6 months (1–10 months).

Discussion

Krukenberg tumors were seen particularly in young patients and more frequently during the premenopausal period. The prognosis was poor. When only the ovaries were affected, metastasectomy prolonged the survival time.

Factors that affect life expectancy of patients with gastric adenocarcinoma

BACKGROUND & AIMS

We used a new, semi-parametric method to estimate life expectancy and expected years of life lost (EYLL) after diagnosis of gastric cancer and assess whether patients' sex or tumor type or location had any effects.

METHODS

We performed a nationwide retrospective cohort study of 35,576 patients with gastric cancer who were registered in the Taiwan Cancer Registry from 1998 through 2007; data were collected until the end of 2010. The Monte Carlo method and tables in Taiwan National Vital Statistics database were matched to the cohort reference populations on the basis of age and sex. The estimated regression line and the survival curve of reference populations were used to extrapolate the survival curve beyond 2010. We compared patients' age at diagnosis, life expectancy, and EYLL based on sex, tumor type, and location.

RESULTS

In Taiwan, gastric cancer is more prevalent among men, and 88.6% of tumors are adenocarcinomas. Patients with adenocarcinoma of the gastric cardia have shorter life expectancies and greater EYLL than those with noncardia tumors (P < .05). Women with gastric adenocarcinoma are diagnosed at a younger age and have longer life expectancies but more EYLL than men with such tumors (P < .05). The estimated years of life saved if gastric adenocarcinoma is diagnosed at an early stage and cured are 22,827 years (2.62 years/case) for women and 33,700 years (1.97 years/case) for men.

CONCLUSION

Among patients with gastric cancer, men and patients with adenocarcinomas of the cardia have shorter life expectancies and more EYLL. Early detection of gastric adenocarcinoma can increase life expectancy.

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.

Adenocarcinoma of the esophagus with signet ring cell features portends a poor prognosis

BACKGROUND

Adenocarcinoma with signet ring cell (SRC) features has been reported to be a poor prognostic marker in gastric and colorectal carcinomas. Although uncommon in the esophagus, SRC histology, interestingly, has been correlated with improved survival. Our impression has been that the incidence of esophageal adenocarcinomas with SRC features is increasing and is associated with worse outcomes. We hypothesize that patients with SRC histology present with more advanced disease, respond less well to induction therapy, and have decreased survival after resection compared with patients with non-SRC adenocarcinoma.

METHODS

The medical records of 151 consecutive patients who underwent resection for adenocarcinoma of the esophagus or gastroesophageal junction in a prospectively maintained database from 1998 to 2011 were reviewed. Outcomes of 23 patients (15%) with SRC histology (21 men, 2 women; average age, 66 years) were compared with 128 patients (85%) with non-SRC adenocarcinoma (116 men, 12 women; average age, 63 years). Overall survival, stage-specific survival, and response to induction therapy were evaluated. Cox regression multivariate analysis was used to identify independent predictors of 3-year survival.

RESULTS

SRC and non-SRC patients were evenly matched for clinical and tumor characteristics. Downstaging achieved with induction therapy was 13.3% (2 of 15) in SRC histology patients vs 67.1% (53 of 79) in non-SRC patients (p ≤ 0.001). Patients with SRC histology who did not respond well to induction treatment demonstrated strong trends toward a worse 3-year survival than patients with non-SRC adenocarcinoma (p = 0.084). The overall 3-year survival was 65.6% in patients without SRC histology vs 34.8% in those with SRC (p = 0.006). Patients with pathologic stage II or III and SRC histology had a 3-year survival of 27.3% compared with 57.4% in patients with non-SRC adenocarcinoma (p = 0.01). Multivariate analysis showed SRC histology trended toward significance as an independent risk factor for poor survival (p = 0.060).

CONCLUSIONS

Patients with adenocarcinoma of the esophagus or gastroesophageal junction and SRC histology respond less well to induction therapy and have decreased overall survival compared with patients with non-SRC histology.

Predictive factors for lymph node metastasis in signet ring cell gastric cancer and the feasibility of endoscopic submucosal dissection

PURPOSE

Endoscopic submucosal dissection has recently been practiced on a differentiated type of early gastric cancer. However, there is no clear evidence for endoscopic treatments of signet ring cell carcinoma. The aim of this study is to identify the predictive clinicopathological factors for lymph node metastasis in signet ring cell carcinoma for assisting endoscopic submucosal dissection trials.

MATERIALS AND METHODS

A total of 186 patients with early signet ring cell carcinoma who underwent radical curative gastrectomy between January 2001 and September 2009 were enrolled in this study. Retrospective reviews of their medical records are being conducted. Several clinicopathologic factors were being investigated in order to identify predictive factors for lymph nodes metastasis: age, gender, tumor size, type of operation, tumor location, gross type, ulceration, Lauren's classification, depth of invasion, and lymphatic invasion.

RESULTS

The lymph node metastasis rate for signet ring cell carcinoma was 4.3% (n=8). Of the 186 lesions with early signet ring cell carcinoma, 91 (48.9%) tumors were larger than 15 mm in size and 40 (21.5%) showed submucosal invasions in the resection specimens. In multivariate analysis, only the lymphatic invasion (P<0.0001) showed an association with lymph node metastasis. To evaluate cutoff values for tumor sizes in the presence of lymph node metastasis, early signet ring cell carcinomas with lymphatic invasions were excluded. In the absence of lymphatic invasion, mucosal cancer with tumor sizes <15 mm had no lymph node metastasis.

CONCLUSIONS

Endoscopic submucosal dissection can be performed on patients with early signet ring cell carcinoma limited to the mucosa and less than 15 mm.

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.

Establishment and characterization of novel gastric signet-ring cell and non signet-ring cell poorly differentiated adenocarcinoma cell lines with low and high malignant potential

BACKGROUND

Poorly differentiated signet-ring cell carcinoma (SRCC) and non signet-ring cell carcinoma (NSRCC) are prevalent histological subtypes of gastric cancers with distinct morphological features. To date, however, the molecular basis of their growth, differentiation, and metastasis still remains unclear, because of the limitation of available cell lines.

METHODS

In the present study, we established novel SRCC and NSRCC cell lines (designated GPM-2 and GPM-1) derived from the ascites of two individual gastric cancer patients with peritoneal metastasis.

RESULTS

Immunohistochemical and quantitative reverse transcription polymerase chain reaction (qRT-PCR) analysis revealed that GPM-2 cells showed both gastric and intestinal differentiation phenotypes (E-cadherin+/MUC5AC+/MUC6+/Villin+), and formed xenografted tumors with typical SRCC histology in nude mice. In contrast, GPM-1 cells only weakly expressed differentiation markers, showing a phenotype of E-cadherin(low)+/MUC2-/MUC5AC-/Villin(low)+. Characteristically, GPM-2 cells were found to highly express both membrane-bound mucin (MUC1/MUC4) and secreted mucin glycoproteins (MUC5AC/MUC6), whose expression is regulated by an epigenetic mechanism such as histone acetylation. GPM-2 cells also secreted a large amount of sTn antigen into the culture medium. These mucin profiles of GPM-2 cells are distinct from those of conventional SRCC cell lines (KATO III and HSC-39), which preferentially express intestinal MUC2/MUC4 as well as sLe(x) and sLe(A) antigens. In addition, GPM-2 cells showed a slow growth rate, and a lower metastatic potential than GPM-1 cells.

CONCLUSIONS

These results indicate that the cells of the new SRCC line, GPM-2 cells, are more differentiated and less aggressive than NSRCC-type GPM-1 cells, and would thus offer an excellent model for understanding the molecular mechanism underlying the growth, differentiation, and mucin production of an SRCC gastric cancer cell line.

Change of mucosal color in early gastric cancer

OBJECTIVE

To investigate the association between mucosal color change and the characteristics of early gastric cancer (EGC).

METHODS

Data of consecutive patients with EGC resected between August 2005 and October 2010 at Konkuk University Medical Center were analyzed retrospectively. The characteristics of EGC relative to mucosal color change were analyzed.

RESULTS

Whitish discoloration of the cancer was linked to female to male gender ratio (P = 0.009), large tumor size (P < 0.001), deep invasion (P = 0.046) and depressed contours (P < 0.001) compared with EGC without discoloration or with hyperemic change. In addition, a whitish discoloration was also related to signet ring cell carcinoma (P < 0.001) and diffuse type carcinoma based on Lauren's classification (P < 0.001). On multiple linear regression analysis, diffuse type based on Lauren's classification (P = 0.017) and depth of invasion (P = 0.003) were significant independent factors for whitish discoloration.

CONCLUSIONS

Mucosal color change is an important clue in the diagnosis of EGC. EGC with whitish discoloration needs more attention due to its link with the diffuse type of Lauren's classification.

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.

Familial gastric cancer: genetics, diagnosis, and management

This article focuses on the diagnosis and management of familial gastric cancer, particularly hereditary diffuse gastric cancer (HDGC). First, existing consensus guidelines are discussed and then the pathology and genetics of HDGC are reviewed. Second, patient management is covered, including surveillance gastroscopy, prophylactic total gastrectomy, and management of the risk of breast cancer.

Spectrum of mucin-producing neoplastic conditions of the abdomen and pelvis: Cross-sectional imaging evaluation

Various mucin-producing neoplasms originate in different abdominal and pelvic organs. Mucinous neoplasms differ from non-mucinous neoplasms because of the differences in clinical outcome and imaging appearance. Mucinous carcinoma, in which at least 50% of the tumor is composed of large pools of extracellular mucin and columns of malignant cells, is associated with a worse prognosis. Signet ring cell carcinoma is characterized by large intracytoplasmic mucin vacuoles that expand in the malignant cells with the nucleus displaced to the periphery. Its prognosis is also generally poor. In contrast, intraductal papillary mucinous neoplasm of the bile duct and pancreas, which is characterized by proliferation of ductal epithelium and variable mucin production, has a better prognosis than other malignancies in the pancreaticobiliary tree. Imaging modalities play a critical role in differentiating mucinous from non-mucinous neoplasms. Due to high water content, mucin has a similar appearance to water on ultrasound (US), computed tomography (CT), and magnetic resonance imaging, except when thick and proteinaceous, and then it tends to be hypoechoic with fine internal echoes or have complex echogenicity on US, hyperdense on CT, and hyperintense on T1- and hypointense on T2-weighted images, compared to water. Therefore, knowledge of characteristic mucin imaging features is helpful to diagnose various mucin-producing neoplastic conditions and to facilitate appropriate treatment.

Early gastric cancer with signet ring cell histology remained unresected for 53 months

The natural course of untreated patients with signet ring cell carcinoma of the stomach remains poorly understood while assumptions have been made to distinguish it from other types of gastric cancer. A 74-year-old Korean woman was diagnosed with early gastric cancer with signet ring cell histology and refused surgery. A satellite lesion was identified 46 months after the initial diagnosis. The patient finally agreed to undergo distal subtotal gastrectomy 53 months following the initial diagnosis. Postoperative histological examination of both lesions confirmed signet ring cell carcinoma associated with submucosal invasion. There was no evidence of lymph node metastasis.

Early signet ring cell gastric cancer

BACKGROUND

Signet ring cell carcinoma (SRC) is defined as a histological entity. The clinicopathological characteristics and prognosis of gastric SRC remain controversial.

METHODS

From 1994 to 2006, 2,439 patients with gastric carcinoma who underwent gastrectomy were enrolled. Of these, 505 patients (20.7%) had SRC and were compared to 1,934 patients with other histological types.

RESULTS

Twenty-nine percent of patients in the SRC group (n = 149) had early gastric cancer, with tumor invasion limited to the mucosa or submucosa, compared to 22.2% of patients in the non-SRC group (n = 430). The proportion of regional LN metastases was 10.7 and 16.0% in early SRC and early non-SRC, respectively, (p = 0.115). The 5-year survival rates for patients with early SRC were better than those for patients with early non-SRC (96.1 vs. 89.6%, p = 0.01).

CONCLUSIONS

Early gastric SRC has favorable prognosis. There is no significant difference in terms of LN metastasis between SRC histologic type and other histological types. Less-invasive strategies may be acceptable in selected patients with early gastric SRC.