Signet Ring Cell Gastric Cancer Research Articles

Experience of prolonged palliative treatment in a patient with signet ring cell gastric cancer with peritoneal recurrence and metastases to the ovaries after prior gastrectomy

Experience of prolonged palliative treatment in a patient with signet ring cell gastric cancer with peritoneal recurrence and metastases to the ovaries after prior gastrectomy

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

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. 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. 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. 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.

Prognostic Survival Significance of Signet Ring Cell (SRC) Gastric Cancer: Retrospective Analysis from a Single Western Center.

Signet ring cell carcinoma accounts for 35% to 45% of all gastric cancer. Despite the acknowledgment of its more aggressive pathological features, various controversies surrounding this topic still exist. Thus, we investigate the clinical pathological characteristics and survival prognostic significance of signet ring cell components in patients affected by gastric cancer. From January 2004 to December 2020, in a retrospective study, we enrolled 404 patients with gastric cancer who were curatively treated in our department. The male-to-female ratio was 249/142, and the median age was 75 (range 37-94). We dichotomized patients into two groups (75 patients vs. 316 patients) based on the signet ring cell presence; according to preoperative, operative, and postoperative characteristics, we performed a univariate and multivariate analysis for overall survival. Signet ring cell carcinoma indicated an increasing incidence trend over the time analyzed. Overall median survival of signet ring cell and non-signet ring cell carcinoma were, respectively, 16 vs. 35 months, p < 0.05. In early gastric cancer, the prognosis of the signet ring cell is better than that of the non-signet ring cell, as opposed to advanced cancer. Among the entire population in the multivariate analysis, the only independent factors were preoperative serum albumin level, complete surgical resection, level of lymphadenectomy, and pathological stage. Recurrence occurred more frequently in patients affected by signet ring cell, but in our data, we could not identify a peculiar site of recurrence. Signet ring cell carcinoma has a specific oncogenetic phenotype and treatment resistance heterogeneity; however, it is not always associated with poor prognosis. According to our results, a radical surgical procedure associated with an adequate lymphadenectomy should be advocated to improve patients survival. Gastric cancer patients with signet ring cell components should draw clinicians' attention.

AB133. SOH23ABS_112. Colonic carcinoma metastasized from signet-ring cell gastric cancer: a case report

Background: Gastric carcinoma accounts for 2.7% of all malignant neoplasms in Ireland. Colorectal metastases from the gastric primary are exceedingly rare. We report an unusual case of colonic metastasis of gastric carcinoma. An 84-year-old male presented with abdominal pain associated with constipation and tenderness in the lower abdomen. The patient was previously diagnosed as cT4aN1M1 with poorly differentiated adenocarcinoma of the stomach invading the pancreas. A restaging scan and oesophago-gastro-duodenoscopy (OGD) performed to the patient revealed a good response upon chemotherapy with 5-FU.

Factors affecting prognosis in signet ring cell gastric cancers with expanded lymph node dissection; high volume centre experience

Background: Signet ring cell gastric cancer differs from gastric adenocarcinoma in terms of demographic and clinical features, age, gender, tumour grade and stage. In this study, we aimed to evaluate the clinical features and overall survival of gastric signet ring cell carcinoma and the prognostic factors affecting survival.Methods: We analysed 138 patients who were operated on with the diagnosis of signet ring cell gastric cancer. The univariant and multivariate hazard ratios of these parameters were analysed and the factors affecting the long-term average survival outcomes were investigated.Results: We performed Cox regression univariate analysis to investigate the effects of clinicopathological factors on mean survival follow-up in signet ring cell gastric cancer. As age increases, the mean survival follow-up period decreases. This relationship is also statistically significant. Mean survival follow-up for the open technique was lower than for laparoscopic procedures. The mean survival follow-up time of patients with positive perineural invasion (PNI) and lymphovascular invasion (LVI) is lower than patients with negative LVI and PNI. We did not find a significant relationship between the hazard ratios (HRs) of tumour markers and systemic inflammatory response parameters. However, we found a significant relationship between the increase in fibrinogen value and HR.Conclusions: We investigated the clinicopathological features of nonmetastatic signet ring cell gastric carcinomas and identified predictors of long survival. Age, lymphovascular and perineural invasion, open surgery, higher tumor infiltration, and lymph node involvement were independent predictors of shorter survival times in nonmetastatic signet ring cell gastric cancers.

Endoscopic submucosal dissection for early signet ring cell gastric cancer: A systematic review and meta-analysis.

BACKGROUNDThe use of endoscopic submucosal dissection (ESD) for treating early signet ring cell carcinoma (SRC) is controversial due to the risk of lymph node metastasis. AIMTo carry out a meta-analysis to evaluate ESD for therapeutic efficacy and safety in early signet ring cell gastric cancer.METHODSThe PubMed, Web of Science, Cochrane Library, and EMBASE databases were used to search for relevant studies evaluating the therapeutic efficacy and safety of ESD in SRC. The rates of recurrence, complete resection, incomplete resection, curative resection, en bloc resection, and adverse events were extracted and analyzed. The methodological quality of the enrolled studies was assessed using the Newcastle-Ottawa Scale. Publication bias was evaluated by the Egger’s test. Institutional review board approval and written consent were not needed for this report.RESULTSThis meta-analysis enrolled seven studies with 653 participants undergoing ESD treatment for early SRC. The overall recurrence rate was 0.010 [95% confidence interval (CI): 0.000-0.040, Z = 1.422, P = 0.155]. The total lymphovascular invasion rate was 0.038 (95%CI: 0.007-0.088, Z = 3.026, P = 0.002). The total en bloc resection rate was estimated at 0.984 (95%CI: 0.925-1.000, Z = 19.463, P = 0.000). The total complete and incomplete resection rates were estimated at 0.785 (95%CI: 0.596-0.928, Z = 9.789, P = 0.000) and 0.188 (95%CI: 0.016-0.468, Z = 2.531, P = 0.011), respectively. The total procedure-associated gastric hemorrhage and perforation rates were estimated at 0.026 (95%CI: 0.005-0.061, Z = 3.006 P = 0.003) and 0.004 (95%CI: 0.000-0.028, Z = 0.938, P = 0.348), respectively. The curative resection, vertical margin invasion, and lateral margin invasion rates were 72.1% (145/341), 2.3% (8/348), and 34.45% (41/119), respectively.CONCLUSIONESD constitutes a promising therapeutic approach for early undifferentiated SRC gastric cancer. However, further improvements are required for increasing its treatment efficacy and reducing adverse outcomes.

Glycan expression profile of signet ring cell gastric cancer cells and potential applicability of rBC2LCN-targeted lectin drug conjugate therapy.

Signet ring cell carcinoma (SRC) is a distinct subtype of gastric cancer (GC); however, the specific characteristics of cancer cell surface glycans and glycosylation remain unclear. In this study, we investigated SRC-specific glycans using lectin microarray and evaluated the potential applicability of a glycan-targeting therapy. SRC cell lines (NUGC-4 and KATO-III) and non-SRC (NSRC) cell lines (NCI-N87, SNU-1, and MKN-45) were subjected to lectin microarray analysis to identify the SRC-specific glycans. Additionally, we performed immunohistochemical lectin staining and evaluated the anti-tumor effects of lectin drug conjugates (LDCs) using high-affinity lectins for SRC. Among the 96 lectins tested, 11 high-affinity and 8 low-affinity lectins were identified for SRC. Glycan-binding motifs varied in the high-affinity lectins, but 5 (62.5%) low-affinity lectins bound the same glycan structure, α2-6-linked sialic acids. The ratio of signal intensity in SRC to NSRC (SRC/NSRC) was highest in the rBC2LCN lectin (1.930-fold), followed by the BPL lectin (1.786-fold). rBC2LCN lectin showed high affinity for both SRC cell lines and one of the three NSRC cell lines (NCI-N87). The therapeutic effects of the LDC, rBC2LCN-PE38 (rBC2LCN, and Pseudomonas exotoxin A), showed cytocidal effects in vitro and tumor regression in in vivo mouse xenograft models. We reported specific glycan profiles in SRC cells, showing reduced α2-6-linked sialic acids. Additionally, we found a targeted therapy using rBC2LCN lectin might be applicable as an alternative treatment option for patients with SRC.

CT-based radiomics nomograms for preoperative prediction of diffuse-type and signet ring cell gastric cancer: a multicenter development and validation cohort

BackgroundThe prevalence of diffuse-type gastric cancer (GC), especially signet ring cell carcinoma (SRCC), has shown an upward trend in the past decades. This study aimed to develop computed tomography (CT) based radiomics nomograms to distinguish diffuse-type and SRCC GC preoperatively.MethodsA total of 693 GC patients from two centers were retrospectively analyzed and divided into training, internal validation and external validation cohorts. Radiomics features were extracted from CT images, and the Lauren radiomics model was established with a support vector machine (SVM) classifier to identify diffuse-type GC. The Lauren radiomics nomogram integrating radiomics features score (Rad-score) and clinicopathological characteristics were developed and evaluated regarding prediction ability. Further, the SRCC radiomics nomogram designed to identify SRCC from diffuse-type GC was developed and evaluated following the same procedures.ResultsMultivariate analysis revealed that Rad-scores was significantly associated with diffuse-type GC and SRCC (p < 0.001). The Lauren radiomics nomogram showed promising prediction performance with an area under the curve (AUC) of 0.895 (95%CI, 0.957–0.932), 0.841 (95%CI, 0.781–0.901) and 0.893 (95%CI, 0.831–0.955) in each cohort. The SRCC radiomics nomogram also showed good discrimination, with AUC of 0.905 (95%CI,0.866–0.944), 0.845 (95%CI, 0.775–0.915) and 0.918 (95%CI, 0.842–0.994) in each cohort. The radiomics nomograms showed great model fitness and clinical usefulness by calibration curve and decision curve analysis.ConclusionOur CT-based radiomics nomograms had the ability to identify the diffuse-type and SRCC GC, providing a non-invasive, efficient and preoperative diagnosis method. They may help guide preoperative clinical decision-making and benefit GC patients in the future.

Association Between Hereditary Lobular Breast Cancer Due to CDH1 Variants and Gastric Cancer Risk

Hereditary cancer risk is informed by the presence of a germline gene variant more so than by family history of cancer. To assess gastric cancer risk among patients who received a diagnosis of hereditary lobular breast cancer (HLBC) owing to a germline loss-of-function variant in CDH1 by establishing prevalence of signet ring cell carcinomas among asymptomatic patients. A prospective cohort study of patients with germline CDH1 pathogenic or likely pathogenic (P/LP) variants at a quaternary medical center were enrolled between October 2017 and January 2021. Data analysis was performed in May 2021. Analyses for associations were performed for these 3 patient groups: (1) family history of breast cancer and no gastric cancer in the HLBC group; (2) family history of gastric cancer and no breast cancer in the hereditary diffuse gastric cancer (HDGC) group; and (3) family history of both breast and gastric cancers in the mixed group. Categorical variables were compared using the Pearson χ2 test. The primary end point of this study was the prevalence of occult signet ring cell carcinoma of the stomach in patients with HLBC. Personal and family medical history, genotype, and pathologic data from risk-reducing total gastrectomy and surveillance endoscopy were examined. A total of 283 patients with CDH1 P/LP variants (199 [70.3%] were female, and 259 [91.5%] were White; median age, 48 years [range, 18-81 years]) were enrolled in a prospective study of HDGC. The cohort consisted of 151 families. Patients were categorized according to family history of breast and/or gastric cancer: HLBC 15.5% [44 of 283 patients]), HDGC (16.2% [46 of 283 patients]), and mixed (68.2% [193 of 283 patients]). The HLBC group included 31 distinct families with 19 CDH1 variants; 10 of those variants were also present in the HDGC and mixed groups (52.6% [10 of 19 variants]). Nearly all of the patients with HLBC (93.8% [15 of 16 variants]) who elected for risk-reducing total gastrectomy owing to their underlying CDH1 P/LP variant harbored occult signet ring cell gastric adenocarcinoma on final pathology (median age, 50 years [range, 21-67 years]). The prevalence of occult gastric cancer among asymptomatic patients in the HDGC group was similar (94.7% [18 of 19 of variants]; P = .98). Carriers of CDH1 P/LP variants with no family history of gastric cancer exhibited high rates of occult signet ring cell gastric cancer. Germline CDH1 P/LP variants appear to have a highly penetrant gastric phenotype irrespective of family history. These data may prove useful for counseling families with CDH1 variants presumed to have HLBC.

Clinicopathological Characteristics and Prognosis of Signet Ring Gastric Cancer: A Population-Based Study.

BackgroundTo better define the clinicopathologic characteristics of signet ring cell (SRC) gastric cancer and build a prognostic model for it.MethodsSRC patient information from 2010 to 2015 were identified using Surveillance, Epidemiology, and End Results (SEER) database. Kaplan-Meier method and log-rank test were used to estimate Overall survival (OS) and to determine associations with histologic subtypes. In COX proportional hazards regression model–based univariate and multivariate analyses, significant variables for construction of a nomogram were screened out. The nomogram was validated by means of the concordance index (CI), calibration plots, and receiver operating characteristics (ROCs) curves.ResultsA total of 11,363 gastric cancer patients were enrolled. On dividing the patients into SRC, well-to-moderately differentiated (WMD) adenocarcinoma, and poorly differentiated (PD) adenocarcinoma, differences among these subgroups emerged. SRC patients were more likely to occur in female and young patients than other histologic subtypes. Larger tumors, stage T4, and node stage N3 were more likely to be found in the SRC group. The survival for SRC patients was better than non-SRC patients in stage I. Univariate and multivariate analyses identified age, tumor site, larger tumor size, advanced T classification, advanced N classification, advanced TNM stage, and surgery of primary site as independent prognostic indicators. Then an OS nomogram was formulated.ConclusionsSRC had distinct clinicopathological characteristics. The nomogram provided an accurate tool to evaluate the prognosis of SRC.

Clinical Features and Risk Factors for Lymph Node Metastasis in Early Signet Ring Cell Gastric Cancer.

Signet ring cell carcinoma (SRCC) was previously thought to have a worse prognosis than differentiated gastric carcinoma (DC). However, recent studies have shown that its prognosis is related to staging. Here, we analyzed the clinicopathological features and the rate of lymph node metastasis (LNM) in 2166 patients with gastric cancer (605 early and 1561 advanced cases) who underwent gastrectomy and lymph node dissection (D2) from 2016 to 2019. The LNM rate for early and advanced cases was 18.0% and 74.2%, respectively. Regarding early cases, the LNM rate in SRCC was similar to that in DC (10% vs. 16.1%, p=0.224), and significantly lower than that in undifferentiated carcinoma (UDC; 10% vs. 23.3%, p=0.024). Tumor size, infiltration depth, pathological type, and mixed type were risk factors for LNM in early cases. Regarding intramucosal cases, the LNM rate in SRCC was similar to that in DC (4.3% vs. 3.7%, p=0.852), and significantly lower than that in UDC (11.2%). The LNM rate was significantly higher in submucosal than intramucosal cases (28.1% vs. 6.3%, p<0.001), and in early mixed cases than early pure cases (23.2% vs. 12.4%, p<0.001). Regarding early pure cases, the LNM rate in SRCC was similar to that in DC (9.3% vs. 7.2%, p=0.641), but significantly lower than that in UDC (9.3% vs. 24.7%, p=0.039). In summary, the LNM rate in early SRCC was similar to that in early DC but significantly lower than that in early UDC. Early SRCC fits with the endoscopic submucosal dissection (ESD) indication related to undifferentiated cases, and ESD may be effective. Additionally, the LNM rate was markedly higher for submucosal cases than intramucosal cases, and for mixed cases than pure cases.

Partial Gastrectomy is Associated with Improved Overall Survival in Signet-Ring Cell Gastric Cancer

Signet-ring cell gastric cancer (SRGC) is a histological variant of gastric adenocarcinoma (GAC) with a worse prognosis compared to non-signet-ring cell gastric cancer (NSRGC). To our knowledge, the overall survival (OS) among patients with SRGC undergoing total/near-total (TG) versus partial gastrectomy (PG) has never been reported from a large-scale Western database. We performed a retrospective analysis of patients with both SRGC and NSRGC using The National Cancer Database. In total, 17,086 patients were included. Patients who underwent TG versus PG were 25.5% (n=770) versus 74.5% (n=2246) for SRGC, and 20.9% (n=2943) versus 79.1% (n=11,127) for NSRGC, respectively. Patients who had SRGC were more likely to undergo TG (25.5% versus 20.9% P< 0.0001). Patients with distal gastric tumors were less likely to undergo TG (16.5% versus 25.4% P < 0.0001). Patients undergoing PG for the SRGC histological variant had better OS (HR=0.68, CI=0.61-0.76; P < 0.0001) versus those who underwent TG. Similarly, NSRGC patients undergoing PG also had improved OS, but to a lesser extent (HR=0.91, CI=0.85-0.96; P= 0.002). Overall, PG for GAC was associated with improved OS compared to TG, although the OS benefit is more profound in the SRGC histological variant (P < 0.0001). Our results show that TG is not associated with improved OS in patients who undergo gastrectomy for GAC, even when adjusted for tumor location. The survival differences are more pronounced in the SRGC histology variant. The worst survival is observed in patients with SRGC who undergo TG after adjusting for different covariates.

Transcriptome Analysis and the Prognostic Role of NUDC in Diffuse and Intestinal Gastric Cancer.

Introduction:There have been few studies about gene differences between patients with diffuse-type gastric cancer and those with intestinal-type gastric cancer. The aim of this study was to compare the transcriptomes of signet ring cell gastric cancer (worst prognosis in diffuse-type) and well-differentiated gastric cancer (best prognosis in intestinal-type); NUDC was identified, and its prognostic role was studied.Materials and Methods:We performed next-generation sequencing with 5 well-differentiated gastric cancers and 3 of signet ring cell gastric cancer surgical samples. We performed gene enrichment and functional annotation analysis using the Database for Annotation, Visualization and Integrated Discovery bioinformatics resources. Immunohistochemistry was used to validate NUDC expression.Results:Overall, 900 genes showed significantly higher expression, 644 genes showed lower expression in signet ring cell gastric cancer than in well-differentiated gastric cancers, and there was a large difference in adhesion, vascular development, and cell-to-cell junction components between the 2 subtypes. We performed variant analysis and found 52 variants and 30 cancer driver genes, including NUDC. We analyzed NUDC expression in gastric cancer tissue and its relationship with prognosis. Cox proportional hazard analysis identified T stage, N stage, and NUDC expression as independent risk factors for survival (P < 0.05). The overall survival of the NUDC-positive group was significantly higher (53.2 ± 0.92 months) than that of the NUDC-negative group (44.6 ± 3.7 months) (P = 0.001) in Kaplan-Meier survival analysis.Conclusion:We found 30 cancer driver gene candidates and found that the NUDC-positive group showed significantly better survival than the NUDC-negative group via variant analysis.

Incidentally Detected Gastric Cancer in Pancreaticoduodenectomy Specimen

The incidence of synchronous pancreatic carcinoma with another carcinoma varies between 1.2% and 20%. Synchronous incidence of pancreatic cancer and stomach cancer is quite low. In our study, a 63-year-old male patient was admitted to our clinic with complaints of fatigue, weight loss and jaundice. In contrast-enhanced abdominal tomography, a lesion with malignant radiological features was observed in the head of the pancreas. Signet-ring cell gastric cancer was found incidentally in the antrum of the stomach in the pathology specimen. Thereupon, a complementary total gastrectomy operation was performed on the patient. Coexistence of gastric and pancreatic cancer is a clinically serious condition. However, surgery can be curative in completely resectable tumors.

Should signet-ring cell histology alter the treatment approach for clinical stage I gastric cancer?

321 Background: Upfront surgery is standard of care for stage I gastric cancer. Despite this, many clinicians administer preoperative therapy for clinical stage I disease with signet ring cell histology, given its aggressive biology. We aimed to assess the validity of this practice. Methods: The National Cancer Database (2004-2015) was reviewed for pts with non-metastatic signet ring cell gastric cancer who underwent treatment with surgery alone, perioperative chemotherapy, neoadjuvant therapy, or adjuvant therapy. Analysis was stratified by preoperative clinical stage and pathologic stage. Primary outcome was overall survival (OS). Results: Of 3000 pts, median age was 61 (IQR: 51-70). 34% were clinical stage I (n = 1018) of which 53% received surgery alone (n = 542), 5% perioperative chemotherapy (n = 47), 12% neoadjuvant therapy (n = 125), and 30% adjuvant therapy (n = 304). Median follow-up was 26 mos. For clinical stage I disease, surgery alone was associated with improved median OS (108 mos) when compared to perioperative chemotherapy (80 mos), neoadjuvant therapy (41 mos), or adjuvant therapy (73 mos, all p &lt; 0.001). For pathologic stage I, surgery alone had equivalent survival to perioperative and adjuvant therapy (5-yr OS: 81 vs 82 vs 79%, p = 0.22). Concordance between clinical and pathologic stage I was 56%, specifically, 41% of clinical stage I pts were upstaged to pathologic stage II (44%) and stage III (56%). Adjuvant therapy for these pts was associated with improved median OS compared to pretreatment (perioperative chemotherapy / neoadjuvant therapy) for those upstaged to pathologic stage II (122 vs 37mos, p &lt; 0.001) or stage III (40 vs 18mos, p &lt; 0.001) disease. Conclusions: Our stage-stratified study demonstrates improved survival with upfront surgery for clinical stage I signet ring cell gastric cancer. Despite 41% of clinical stage I pts being upstaged to stage II or III on final pathology, adjuvant therapy offers a favorable rescue strategy, with improved outcomes compared to those treated preoperatively. Surgery alone also affords similar survival for pathologic stage I disease compared to multimodal therapy. This study challenges the intrinsic bias to over-treat stage I signet ring cell gastric cancer.

24-year-old Male patient Diagnosed with Intramucosal Signet Ring Cell Gastric Cancer with Molecular Analysis: A Case Report

24-year-old Male patient Diagnosed with Intramucosal Signet Ring Cell Gastric Cancer with Molecular Analysis: A Case Report

Large tumor size is a poor prognostic factor of gastric cancer with signet ring cell: Results from the surveillance, epidemiology, and end results database.

There has been a steady increase in the incidence of signet ring cell (SRC) carcinoma, a distinct histological type with cells containing abundant intracytoplasmic mucin. We aimed to analyze the clinicopathological characteristics and prognostic value of patients with SRC gastric cancer (GC) who underwent gastrectomy.Clinical data of 10,312 GC patients who underwent D2 radical gastrectomy were obtained from the Surveillance, Epidemiology, and End Results database and were retrospectively analyzed. X-tile plots were constructed to illustrate the optimal cut-off points using the minimum P-value from the log-rank Chi-squared test. The Kaplan–Meier method was used for the analysis of the overall cumulative probability of survival. Their differences were evaluated using the log-rank test. The Cox multiple factors analysis was performed using the logistic regression method.In total, 946 (9.17%) SRC GC patients with pT1a-4bN0-3bM0 stage cancer were recruited. The optimal cut-off point for size was 49 mm. The 3-year overall survival (OS) rates of the SRC GC, large-size, and small-size groups were 35.89%, 30.63%, and 44.96%, respectively (P < .05). Cox multivariate analysis showed that tumor size (odds ratio [OR] = 2.032), T3 category (OR = 1.324), T4a category (OR = 1.945), and T4b category (OR = 2.163) were independent hazard prognostic factors.SRC GC has a distinct biological behavior, presents as a large-sized tumor (≥49 mm), and is associated with worse outcomes. SRC GC patients have 2.032 times risk of mortality. SRC patients with larger tumors are at higher risk for infiltrative growth, lymph node metastasis, and distant metastasis.

Blocked by a Ring: A Case of Gastric Linitis Plastica Presenting as Large Bowel Obstruction Secondary to Rectal Stenosis.

Metastatic gut lesions from primary gastric carcinoma occur via hematogenous, lymphatic, or peritoneal seeding. We report an unusual case of large bowel obstruction secondary to rectal stenosis due to metastatic signet ring cell gastric cancer. A 61-year-old woman with a history of 8 weeks' duration of alternation in bowel movements presented with symptoms of bowel obstruction. Computed tomography revealed rectal wall thickening, and sigmoidoscopy demonstrated edematous and fibrotic rectal mucosa. Superficial biopsies were negative for malignant disease. Because of worsening of obstructive symptoms, an emergent surgical diversion was performed. Surgical biopsies were consistent with poorly differentiated adenocarcinoma. Gastroscopy established diagnosis of gastric adenocarcinoma with signet ring type cells. Rectal stenosis on examination and demonstration of rectal wall thickening on imaging should raise suspicion for Schnitzler's metastasis, and an upper endoscopy should be performed.

Deficiency of mismatch repair genes is less frequently observed in signet ring cell compared with non-signet ring cell gastric cancer.

Signet ring cell (SRC) gastric cancer at advanced stage has poor prognosis. While a recent study reported nearly one-third of SRC cases contain tumors with deficient mismatch repair (MMR) genes, other studies in SRC have been inconclusive. To re-analyze the results, we performed immunohistochemical staining of MLH1, MSH2, MSH6 and PMS2 proteins in 38 SRC gastric tumors compared with 109 non-SRC (NSRC) tumorsfrom 94 patients. In contrast to the previous study, all SRC gastric tumors normally expressed MMR proteins, whereas 22 of 109 of NSRC (20%) showed deficient MMR proteins. To reinforce our results, we referred to the Cancer Genome Atlas (TCGA) genomic database and found that only 6 (6%) of 99 samples with diffuse gastric tumors showed deficient MMR, whereas 64 (21%) of 304 in intestinal gastric tumors showed deficient MMR. Our results as well as the TCGA database indicated that MMR genes are infrequently inactivated in SRC gastric cancer. These findings indicate that SRC patients may not be the best candidates for immuno-oncology therapy.

INTRODUCTION OF THE NEW LYMPHOPARIETAL INDEX FOR GASTRIC CANCER PATIENTS.

ABSTRACT Background: The identification of prognostic factors of gastric cancer (GC) has allowed to predict the evolution of patients. Aim: Assess the reliability of the lymphoparietal index in the prediction of long-term survival in GC treated with curative intent. Method: Prospective study of the Universidad de Chile Clinical Hospital, between May 2004 and May 2012. Included all gastric cancer surgeries with curative intent. Exclusion criteria were: gastrectomies due to benign lesions, stage 4 cancers, R1 resections, palliative procedures, complete esophagogastrectomies and emergency surgeries. Results: A total of 284 patients were included; of the sample 65.4% were male,mean age of 64.5 years,75% were advanced cancers, 72.5% required a total gastrectomy, 30 lymph nodes harvest. Surgical morbidity and mortality were 17.2% and 1.7%. 5-year survival was 56.9%. The N+/T index could predict long-term survival in all de subgrups (p<0.0001), although had a reliable prediction in early GC (p=0.005), advanced GC (p<0.0001), signet ring cell GC (p<0.0001), proximal GC (p<0.0001) and distal GC (p<0.0001). The ROC curves N+/T index, LNR and T classification presented areas below the curve of 0.789, 0.786 and 0,790 respectively, without a significant statistical difference (p=0.96). Conclusion: The N+/T index is a reliable quotient in the prognostic evaluation of gastric adenocarcinoma patients who have been resected with curative intent.