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

Prognostic relevance of the most predominant and least differentiated grades of gastric adenocarcinoma after curative gastrectomy

BACKGROUND

Prognostic relevance of differentiation grade has remained controversial in gastric adenocarcinoma (GAC) after curative resection.

METHODS

GAC patients who underwent curative gastrectomy were analyzed. Differentiation grade was evaluated according to either the most predominant or least differentiated component. Impacts of clinicopathologic parameters on postoperative recurrence and nodal metastasis were analyzed by the multivariate Cox regression analysis in pT1/2/3/4a and pT1b/2/3 GAC and by the logistic regression analysis in pT1b GAC, respectively.

RESULTS

154 patients with GAC, consisting of 34 pT1a (recurrence rate 0%), 45 pT1b (4.4%), 18 pT2 (22.2%), 40 pT3 (35.0%), and 17 pT4a (76.5%), were included. In pT1/2/3/4a GAC, recurrence was significantly associated with only depth of invasion (pT) and grade of venous invasion (VI), although either mode of differentiation grade was significantly associated with pT by the Spearman's rank correlation test. Next, given no recurrence in pT1a and high-grade histopathology in nearly all pT4a, pT1b/2/3 GAC was analyzed, revealing that recurrence was significantly associated with only VI grade and nodal metastasis. Finally, nodal metastasis was not found in any pT1a GAC, of which 44.1% was predominantly high-grade. In pT1b GAC, nodal metastasis was irrelevant to either mode of differentiation grade, tumor size, and ulceration status but was only associated with lymphatic invasion, suggesting that endoscopic resection of pT1 GAC with negative margin can be curative even with high-grade histopathology.

CONCLUSION

Either mode of differentiation grade revealed limited prognostic relevance after curative gastrectomy. Our results may warrant a controversy over current curability evaluation of endoscopic GAC resection.

The effect of surgery and metastatic risk prediction in patients with gastrointestinal tract signet-ring cell carcinoma

PURPOSE

This study aimed to assess the efficacy of surgery as a treatment option for patients with signet-ring cell carcinoma in the gastrointestinal tract (GI-SRCC).

METHODS

Using the Surveillance Epidemiology and End Results (SEER) database, GI-SRCC patients who underwent surgery or received non-surgical treatment were included. Propensity score matching (PSM) analysis was used to balance baseline characteristics and reduce bias. Overall survival (OS) was calculated in matching cohorts to estimate prognosis for GI-SRCC patients. Nomogram was established to predict metastasis for GI-SRCC patients.

RESULTS

The study enrolled a total of 9428 GI-SRCC patients, with 1689 patients in the non-surgery group and 7739 patients in the surgery group. Following 1:1 PSM, we analyzed 743 patients from each group. Our survival analyses revealed that surgery independently correlated with improved OS for GI-SRCC patients (HR = 0.37, 95% CI: 0.33-0.42, P < 0.001). Subgroup analysis further confirmed the positive impact of surgery on the prognosis of patients with non-metastatic GI-SRCC. Notably, distinct subsets of metastatic patients, particularly those originating from the upper GI (esophagus, proximal stomach, distal stomach) and left colon, demonstrated a significant improvement in OS post-surgery. However, no significant survival difference was observed for patients with metastatic right colon-SRCC and rectum-SRCC. Utilizing nomogram, we quantitatively assessed the risk of metastasis in patients with right colon and rectum SRCC, which exhibited robust predictive accuracy, with area under the curve (AUC) values of 0.829.

CONCLUSIONS

Our study highlights surgery's positive impact on prognosis for both non-metastatic and metastatic upper GI-SRCC and left colon-SRCC patients. Hence, we recommend surgery as a treatment option for these groups. Additionally, for metastatic right colon and rectum SRCC patients ineligible for surgery, our predictive nomogram can offer a convenient tool to aid early intervention and improve prognosis.

Fibroblast Activation Protein-Targeted PET/CT with 18F-Fibroblast Activation Protein Inhibitor-74 for Evaluation of Gastrointestinal Cancer: Comparison with 18F-FDG PET/CT

Fibroblast activation protein is overexpressed in the stroma of several cancer types. 18F-fibroblast activation protein inhibitor (FAPI)-74 is a PET tracer with high selectivity for fibroblast activation protein and has shown high accumulation in human tumors in clinical studies. However, the use of 18F-FAPI-74 for PET imaging of gastrointestinal cancer has not been systematically investigated. Herein, we investigated the diagnostic accuracy of 18F-FAPI-74 (18F-LNC1005) PET/CT in gastric, liver, and pancreatic cancers and compared the results with those of 18F-FDG PET/CT. Methods: This prospective study analyzed patients with confirmed gastric, liver, or pancreatic malignancies who underwent concurrent 18F-FDG and 18F-FAPI-74 PET/CT between June 2022 and December 2022. PET/CT findings were confirmed by histopathology or radiographic follow-up. 18F-FDG and 18F-FAPI-74 uptake and tumor-to-background ratios were compared using the Wilcoxon signed-rank test. The McNemar test was used to compare the diagnostic accuracy of the 2 scans. Results: Our cohort consisted of 112 patients: 49 with gastric cancer, 39 with liver cancer, and 24 with pancreatic cancer. Among them, 69 patients underwent PET/CT for initial staging and 43 for recurrence detection. Regarding lesion-based diagnostic accuracy, 18F-FAPI-74 PET/CT showed higher sensitivity than did 18F-FDG in the detection of primary tumors (gastric cancer, 88% [22/25] vs. 60% [15/25], P = 0.016; liver cancer, 100% [22/22] vs. 82% [18/22], P = 0.125; pancreatic cancer, 100% [22/22] vs. 86% [19/22], P = 0.250), local recurrence (92% [23/25] vs. 56% [14/25]; P = 0.021), involved lymph nodes (71% [41/58] vs. 40% [23/58]; P < 0.001), and bone and visceral metastases (98% [350/358] vs. 47% [168/358]; P < 0.001). Compared with 18F-FDG, 18F-FAPI-74 PET/CT upstaged 17 patients' TNM staging among all treatment-naïve patients (17/69, 25%) and changed the clinical management of 4 patients (4/43, 9%) in whom recurrence or metastases were detected. Conclusion: 18F-FAPI-74 PET/CT is superior to 18F-FDG PET/CT in detecting primary tumors, local recurrence, lymph node involvement, and bone and visceral metastases in gastric, pancreatic, and liver cancers, with higher uptake in most primary and metastatic lesions.

Gastrointestinal signet ring cell malignancy: current advancement and future prospects

Globally, gastrointestinal cancer is the most widespread neoplastic disease and the primary contributor to cancer-associated fatalities. Gastrointestinal signet ring cell carcinoma (SRCC) exhibits unique distinguishing features in several aspects when compared to adenocarcinomas (ACs). The scarcity of signet ring cell carcinoma has resulted in a heightened significance of related clinical and molecular investigations. However, a comprehensive and systematic review of the clinical, molecular, therapeutic, and research aspects of this disease is currently absent. This review provides an overview of the latest developments in our understanding of the clinical and molecular features of gastrointestinal signet ring cell carcinoma (SRCC). Additionally, we have compiled a list of potential therapeutic targets or biomarkers, as well as an examination of the current treatment options and the possible mechanisms of formation.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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 Clinicopathological Features of Mixed Carcinoma in 7,215 Patients with Gastric Cancer in a Tertiary Hospital in South Korea

Background/Aims

There are few reports regarding mixed carcinoma, defined as a mixture of glandular and poorly cohesive components, in patients with gastric cancer (GC). The aim of this study was to evaluate the proportion and characteristics of mixed carcinoma in GC patients.

Methods

A total of 7,215 patients diagnosed with GC at Seoul National University Bundang Hospital were enrolled from March 2011 to February 2020. GC was divided into four groups (well-moderately differentiated GC, poorly differentiated GC, poorly cohesive carcinoma, and mixed carcinoma). The proportion of each GC type and the clinicopathological features were analyzed and divided into early GC and advanced GC.

Results

The proportion of mixed carcinoma was 10.9% (n=787). In early GC, submucosal invasion was the most common in poorly differentiated (53.7%), and mixed carcinoma ranked second (41.1%). Mixed carcinoma showed the highest proportion of lymph node metastasis in early GC (23.0%) and advanced GC (78.3%). In advanced GC, the rate of distant metastasis was 3.6% and 3.9% in well-moderately differentiated GC and mixed carcinoma, respectively, lower than that in poorly differentiated GC (6.4%) and poorly cohesive carcinoma (5.7%), without statistical significance.

Conclusions

Mixed carcinoma was associated with lymph node metastasis compared to other histological GC subtypes. And it showed relatively common submucosal invasion in early GC, but the rates of venous invasion and distant metastasis were lower in advanced GC. Further research is needed to uncover the mechanism underlying these characteristics of mixed carcinoma (Trial registration number: NCT04973631).

Superficial Flat-Type Early-Stage Gastric Signet Ring Cell Carcinoma in the Atrophic Background Mucosa: Two Case Reports

OBJECTIVES

Gastric signet ring cell carcinoma is a rare and highly malignant adenocarcinoma, which is characterized by early metastasis, rapid progression and poor prognosis. Several studies have shown that early-stage gastric signet ring cell carcinoma may have equal or better prognosis than other types of gastric cancer. However, most of the early-stage lesions are difficult to detect by endoscopy. We aim to illustrate the difficulty of early detection of gastric signet ring cell carcinoma with mucosal atrophy.

METHODS

The endoscopic and pathological features of two female cases were analyzed by upper gastrointestinal white light endoscopy combined with narrow-band imaging and endoscopic biopsy.

RESULTS

Two female cases were diagnosed with early-stage gastric signet ring cell carcinoma with atrophic background mucosa occurring in the middle and lower part of the stomach. Both lesions less than 2.0 cm in diameter were surgically removed and identified as intramucosal adenocarcinoma.

CONCLUSION

We can roughly identify the demarcation of the lesion by combining white light endoscopy and narrow-band imaging, and slightly irregular microsurface and microvascular pattern of the lesion were found via magnifying endoscopic observation, but the demarcation can hardly be accurately identified.

Lymphovascular or perineural invasion is associated with lymph node metastasis and survival outcomes in patients with gastric cancer

BACKGROUND

Lymphovascular invasion (LVI) and perineural invasion (PNI) are associated with poorer prognosis in several human malignancies, but their significance in gastric cancer (GC) remains to be clearly defined. Our study aimed to investigate the prognostic value of LVI/PNI in patients with curative resected GC.

METHODS

Records of 1488 patients with stage I--III GC and 3327 patients with stage I-III colorectal cancer (CRC) were reviewed retrospectively, and difference in the incidence of LVI/PNI between GC and CRC was compared. Univariate and multivariate analyses were used to evaluate whether LVI/PNI was an independent risk factor for lymph node metastasis (LNM) and overall survival (OS) in GC.

RESULTS

Patients with stage I-III GC had a significantly higher incidence of LVI/PNI than patients with stage I-III CRC (50.54% vs. 21.91%, p  < 0.001). LVI/PNI was significantly associated with higher CEA, higher CA199, deeper tumor invasion, more lymph node metastasis, and advanced TNM stage in GC ( p  < 0.05). Multivariate logistic regression analysis identified LVI/PNI (OR = 2.64, 95%CI: 2.05-3.40, p  < 0.001) as an independent risk factor for LNM in GC. The OS rate was significantly lower in the LVI/PNI-positive GC group than that in the LVI/PNI-negative GC group ( p  < 0.001). On multivariate Cox regression analysis, LVI/PNI (HR = 1.34, 95%CI: 1.04-1.71, p  = 0.023) was an independent prognostic factor for OS in GC.

CONCLUSION

GC has a high incidence of LVI/PNI, which was closely associated with disease progression. LVI/PNI could serve as an independent risk factor for LNM and the prognosis of patients with curative resected GC. These findings will be helpful in predicting survival outcomes more accurately and establishing individualized treatment plans.

Human epidermal growth factor receptor-2 gene expression positivity determined by silver in situ hybridization/immunohistochemistry methods and associated factors in a cohort of Sri Lankan patients with gastric adenocarcinoma: a prospective study

OBJECTIVE

Positive human epidermal growth factor 2 (HER2) expression and its predictive clinicopathological features remain unclear in Sri Lankan gastric cancer (GC) patients. Here, we aimed to determine GC HER2 status predictors by analyzing associations between clinicopathological features and HER2 expression using immunohistochemistry (IHC) and silver in situ hybridization (SISH).

METHODS

During this 4-year prospective study, clinicopathological data were collected from participants in the National Hospital of Sri Lanka. HER2 IHC and SISH were performed using commercial reagents. Using chi-square tests, associations of HER2-IHC/SISH with clinicopathological features were analyzed.

RESULTS

Overall, 145 GC patients were included, 69 had gastrectomies and 76 had biopsies. Positive HER2 expression by IHC was associated with age <60 years, high T stage (assessed pathologically in resections and radiologically in biopsies), high nuclear grade, tumor necrosis, mitosis >5/high-power field, with additional perineural invasion and lymphovascular invasion in resections. These features, excluding lymphovascular invasion but including male sex, were associated with HER2 expression by SISH.

CONCLUSIONS

Age <60 years, high nuclear grade, tumor necrosis, and perineural invasion are associated factors of HER2 status. These could be used to triage GC patients for HER2 status testing in limited resource settings where IHC/SISH analysis is costly.

Comparison of [68Ga]Ga-FAPI and [18F]FDG uptake in patients with gastric signet-ring-cell carcinoma: a multicenter retrospective study

OBJECTIVE

In this study, we investigated the role of [⁶⁸Ga]Ga-FAPI PET imaging in the detection of primary and metastatic gastric signet-ring-cell carcinoma (GSRCC) and compared with [¹⁸F]FDG PET.

METHODS

This retrospective multicenter analysis included 34 patients with histologically confirmed GSRCCs from four medical centers. The maximum standard uptake value (SUV_max), tumor-to-background ratio (TBR), and diagnostic accuracy were compared between the two modalities. [¹⁸F]FDG and [⁶⁸Ga]Ga-FAPI uptakes were compared by using the Wilcoxon signed-rank test. McNemar's test was used to compare the diagnostic accuracy between the two techniques.

RESULTS

Data were analyzed from 27 paired PET/CT and 7 paired PET/MRI scans for 34 GSRCC patients (16 men and 18 women) who had a median age of 51 years (range: 25-85 years). [⁶⁸Ga]Ga-FAPI PET showed higher SUV_max and TBR values than did [¹⁸F]FDG PET in the primary tumors (SUV_max: 5.2 vs. 2.2, p = 0.001; TBR: 7.6 vs. 1.3, p < 0.001), involved lymph nodes (SUV_max: 6.8 vs. 2.5, p < 0.001; TBR: 5.8 vs. 1.3, p < 0.001), and bone and visceral metastases (SUV_max: 6.5 vs. 2.4, p < 0.001; TBR: 6.3 vs. 1.3, p < 0.001). In diagnostic performance, [⁶⁸Ga]Ga-FAPI PET exhibited higher sensitivity than [¹⁸F]FDG PET for detecting primary tumors (73% [16/22] vs. 18% [4/22], p < 0.001), local recurrences (100% [7/7] vs. 29% [2/7], p = 0.071), lymph node metastases (77% [59/77] vs. 23% [18/77], p < 0.001), and distant metastases (93% [207/222] vs. 39% [86/222], p < 0.001).

CONCLUSION

The results from this multicenter retrospective analysis justify the clinical use of [⁶⁸Ga]Ga-FAPI tracers for GSRCC diagnosis and staging.

KEY POINTS

• [⁶⁸Ga]Ga-FAPI PET/CT is a promising imaging modality for the detection of primary and metastatic disease and has implications for TNM staging in GSRCC. • In this multicenter study of 34 patients with GSRCC, [⁶⁸Ga]Ga-FAPI PET exhibited greater radiotracer uptake, tumor-to-background ratios, and diagnostic accuracy than [¹⁸F]FDG PET for detecting primary/recurrent tumors and metastatic lesions.

Endoscopic submucosal dissection versus surgery for patients with undifferentiated early gastric cancer

BACKGROUND AND AIMS

endoscopic submucosal dissection (ESD) is the standard treatment for differentiated early gastric cancer (EGC). However, its expanded indication for undifferentiated EGC is controversial. In this study, the efficacy and safety of ESD versus surgery in patients with undifferentiated EGC were compared.

METHODS

four databases were searched until February 24, 2022, for studies assessing patients with undifferentiated EGC that met an expanded indication for endoscopic resection and who were treated with ESD or surgery. Primary outcomes were all-cause mortality and any recurrence. Secondary outcomes were complete histological resection, local recurrence, metachronous recurrence, synchronous recurrence, distant metastasis, overall complication, and bleeding. All meta-analyses were performed using a random-effects models. Unadjusted (risk ratio [RR]) and adjusted (aRR and hazard ratio [aHR]) estimates with 95 % confidence interval (CI) were calculated.

RESULTS

seven cohort studies were included (n = 2637). The use of ESD was significantly associated with higher all-cause mortality compared to surgery (RR, 2.17; 95 % CI, 1.24-3.81); adjusted all-cause mortality effects were not significant (aRR, 2.28; 95 % CI, 0.95-5.47 and aHR, 1.97; 95 % CI, 0.85-4.53). ESD was associated with a higher risk of any recurrence using unadjusted (RR, 5.24; 95 % CI, 1.49-18.46) and adjusted (aRR, 7.89; 95 % CI, 1.52-40.95 and aHR, 3.73; 95 % CI, 1.17-11.90) estimates. The risk of local recurrence, synchronous recurrence and bleeding were significantly higher for ESD versus surgery. No significant differences were found for other secondary outcomes.

CONCLUSIONS

although ESD is associated with a higher risk of any recurrence, adjusted all-cause mortality is similar during follow-up. Overall complications were similar between ESD and surgery.

Clinicopathological characteristics and prognosis of gastric signet ring cell carcinoma

BACKGROUND

The clinicopathological features and prognosis of gastric signet ring cell carcinoma (GSRC) remain controversial, particularly with regard to sensitivity to postoperative adjuvant therapy.

AIM

To compare the pathological features of GSRC with those of gastric adenocarcinoma of different degrees of differentiation and the differences in survival prognosis between the different disease processes.

METHODS

By screening gastric cancer patients from 2010 to 2015 in the database of Surveillance, Epidemiology and End Results, and collecting the clinicopathological and prognostic data of gastric cancer patients who underwent surgery from January 2014 to December 2016 in the Second Affiliated Hospital of Nanchang University, we analyzed the general pathological characteristics of GSRC by the chi-square test. Univariate and multivariate analyses were conducted to compare the factors affecting the survival and prognosis of early and advanced gastric adenocarcinoma. The Kaplan-Meier curves were plotted to reveal the survival difference between early and advanced GSRC and different differentiated types of gastric adenocarcinoma. The prognosis model of advanced GSRC was established with R software, and the area under curve (AUC) and C-index were used to assess the accuracy of the model.

RESULTS

Analysis of pathological features revealed that signet ring-cell carcinoma (SRC) was more frequently seen in younger (< 60 years), female, and White patients compared to non-SRC patients. SRC was less commonly associated with early gastric cancer (EGC) (23.60% vs 39.10%), lower N0 (38.61% vs 61.03%), and larger tumour sizes > 5 cm (31.15% vs 27.10%) compared to the differentiated type, while the opposite was true compared to the undifferentiated type. Survival prognostic analysis found no significant difference in the prognosis of SRC patients among EGC patients. In contrast, among advanced gastric cancer (AGC) patients, the prognosis of SRC patients was correlated with age, race, tumour size, AJCC stage, T-stage, and postoperative adjuvant therapy. The predictive model showed that the 3-year AUC was 0.787, 5-year AUC was 0.806, and C-index was 0.766. Compared to non-SRC patients, patients with SRC had a better prognosis in EGC [hazard ratio (HR): 0.626, 95% confidence interval (CI): 0.427-0.919, P < 0.05] and a worse prognosis in AGC (HR: 1.139, 95%CI: 1.030-1.258, P < 0.05). When non-SRC was divided into differentiated and undifferentiated types for comparison, it was found that in EGC, SRC had a better prognosis than differentiated and undifferentiated types, while there was no significant difference between differentiated and undifferentiated types. In AGC, there was no significant difference in prognosis between SRC and undifferentiated types, both of which were worse than differentiated types. A prognostic analysis of postoperative adjuvant therapy for SRC in patients with AGC revealed that adjuvant postoperative radiotherapy or chemotherapy significantly improved patient survival (34.6% and 36.2% vs 18.6%, P < 0.05).

CONCLUSION

The prognosis of SRC is better than that of undifferentiated type, especially in EGC, and its prognosis is even better than that of differentiated type. SRC patients can benefit from early detection, surgical resection, and aggressive adjuvant therapy.

Predicting Overall Survival in Patients with Nonmetastatic Gastric Signet Ring Cell Carcinoma: A Machine Learning Approach

Background and Aims

Accurate prediction is essential for the survival of patients with nonmetastatic gastric signet ring cell carcinoma (GSRC) and medical decision-making. Current models rely on prespecified variables, limiting their performance and not being suitable for individual patients. Our study is aimed at developing a more precise model for predicting 1-, 3-, and 5-year overall survival (OS) in patients with nonmetastatic GSRC based on a machine learning approach.

Methods

We selected 2127 GSRC patients diagnosed from 2004 to 2014 from the Surveillance, Epidemiology, and End Results (SEER) database and then randomly partitioned them into a training and validation cohort. We compared the performance of several machine learning-based models and finally chose the eXtreme gradient boosting (XGBoost) model as the optimal method to predict the OS in patients with nonmetastatic GSRC. The model was assessed using the receiver operating characteristic curve (ROC).

Results

In the training cohort, for predicting OS rates at 1-, 3-, and 5-year, the AUCs of the XGBoost model were 0.842, 0.831, and 0.838, respectively, while in the testing cohort, the AUCs of 1-, 3-, and 5-year OS rates were 0.749, 0.823, and 0.829, respectively. Besides, the XGBoost model also performed better when compared with the American Joint Committee on Cancer (AJCC) stage. The performance for this model was stably maintained when stratified by age and ethnicity.

Conclusion

The XGBoost-based model accurately predicts the 1-, 3-, and 5-year OS in patients with nonmetastatic GSRC. Machine learning is a promising way to predict the survival outcomes of tumor patients.

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

BACKGROUND

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.

METHODS

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.

RESULTS

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.

CONCLUSION

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.

Poorly cohesive cells gastric carcinoma including signet-ring cell cancer: Updated review of definition, classification and therapeutic management

While the incidence of gastric cancer (GC) in general has decreased worldwide in recent decades, the incidence of diffuse cancer historically comprising poorly cohesive cells-GC (PCC-GC) and including signet ring cell cancer is rising. Literature concerning PCC-GC is scarce and unclear, mostly due to a large variety of historically used definitions and classifications. Compared to other histological subtypes of GC, PCC-GC is nevertheless characterized by a distinct set of epidemiological, histological and clinical features which require a specific diagnostic and therapeutic approach. The aim of this review was to provide an update on the definition, classification and therapeutic strategies of PCC-GC. We focus on the updated histological definition of PCC-GC, along with its implications on future treatment strategies and study design. Also, specific considerations in the diagnostic management are discussed. Finally, the impact of some recent developments in the therapeutic management of GC in general such as the recently validated taxane-based regimens (5-Fluorouracil, leucovorin, oxaliplatin and docetaxel), the use of hyperthermic intraperitoneal chemotherapy as well as pressurized intraperitoneal aerosol chemotherapy and targeted therapy have been reviewed in depth for their relative importance for PCC-GC in particular.

Clinicopathological Features and Prognostic-Related Risk Factors of Gastric Signet Ring Cell Carcinoma: A Meta-Analysis

Background

Gastric signet ring cell carcinoma (SRCC) has shown a growth growing trend worldwide, but its clinicopathological features and prognostic-related risk factors have not been systematically studied. This systematic review was devoted to this.

Method

PubMed, Embase, Cochrane Library, and Web of Science databases were retrieved, and retrospective cohort studies comparing clinicopathological features and related risk factors in SRCC patients were included.

Results

In SRCC patient population, males were more than females (male, OR = 1.38, 95% CI: 1.20-1.60); N3 patients were more than N0-2 patients (N0-2, OR = 3.19, 95% CI: 1.98-5.15); M1 patients were more than M0 patients (M0, OR = 3.30, 95% CI: 1.88-5.80); patients with tumor > 5 cm were more than those with tumor (≤5 cm, OR = 7.36, 95% CI: 1.33-40.60). Patients with age < 60 years (age ≥ 60 years, OR = 1.03, 95% CI: 1.01-1.05), lymphatic vessel invasion (no, OR = 1.74, 95% CI: 1.03-2.45), T2 (T1, OR = 1.17, 95% CI: 1.07-1.28) and T4 (T1, OR = 2.55, 95% CI: 2.30-2.81) stages, and N1 (N0, OR = 1.73, 95% CI: 1.08-2.38), N2 (N0, OR = 2.24, 95% CI: 1.12-3.36), and N3 (N0, OR = 3.45, 95% CI: 1.58-5.32) stages had higher hazard ratio (HR).

Conclusion

SRCC may occur frequently in male. Age, lymphatic vessel invasion, TN, and M stage may be risk factors for poor prognoses of SRCC patients.

Comparison between signet-ring cell carcinoma and non-signet-ring cell carcinoma of the stomach: clinicopathological parameters, epidemiological data, outcome, and prognosis-a cohort study of 123 patients from a non-endemic country

Background

Signet-ring cell carcinoma of the stomach (SRCC) is a particular gastric cancer entity. Its incidence is increasing. Its diagnosis is pathological; it corresponds to adenocarcinoma with a majority of signet-ring cells component (> 50%).

These histological features give it its aggressiveness characteristics. This has repercussions on the prognostic level and implications for the alternatives of therapy, especially since some authors suggest a potential chemoresistance.

This survey aimed to identify the epidemiological, pathological, therapeutic, and prognostic characteristics of SRCC as a separate disease entity.

Methods

This was a retrospective study of 123 patients admitted for gastric adenocarcinoma to Habib Thameur Hospital in Tunis over 11 years from January 2006 to December 2016. A comparative study was performed between 2 groups: the SRCC group with 62 patients and the non-SRCC (non-signet-ring cell carcinoma of the stomach) with 61 patients.

Results

The prevalence of SRCC in our series was 50%. SRCC affected significantly younger patients (55 vs 62 years; p = 0.004). The infiltrative character was more common in SRCC tumors (30.6 vs 14.8%; p = 0.060), whereas the budding character was more often noted in non-SRCC tumors (78.7 vs 58.1%; p = 0.039). There was no significant difference in tumor localization between both groups. Linitis plastica was noted in 14 patients with SRCC against a single patient with non-SRCC (p = 0.001). The tumor size was more important in the non-SRCC group (6.84 vs 6.39 cm; p = 0.551). Peritoneal carcinomatosis was noted in 4.3% of cases in the SRCC group versus 2.2% of cases in the NSRCC group (p = 0.570). Total gastrectomy was more often performed in the SRCC group (87 vs 56%; p = 0.001). Resection was more often curative in the non-SRCC group (84.4 vs 78.3%; p = 0.063). Postoperative chemotherapy was more commonly indicated in the SRCC group (67.4 vs 53.3%; p = 0.339). Tumor recurrence was more common in the non-SRCC group (35.7 vs 32%; p = 0.776). The most common type of recurrence was peritoneal carcinomatosis in the SRCC group (62.5%) and hepatic metastasis in the non-SRCC group (60%; p = 0.096). The overall 5-year survival in the SRCC group was lower than in the non-SRCC group, with no statistically significant difference (47.1 vs 51.5%; p = 0.715). The overall survival was more important for SRCC in early cancer (100 vs 80%; p = 0.408), whereas it was higher for non-SRCC in advanced cancer (48.1 vs 41.9%; p = 0.635).

Conclusion

Apart from its epidemiological and pathological features, SRCC seems to have a worse prognosis. Indeed, it is diagnosed at a more advanced stage and has a worse prognosis in advanced cancer than non-SRCC. It is therefore to be considered as a particular entity of gastric adenocarcinoma requiring a specific therapeutic protocol where the place of chemotherapy remains to be more investigated.

Development and validation of two nomograms for predicting overall survival and cancer-specific survival in gastric cancer patients with liver metastases: A retrospective cohort study from SEER database

•

Nomograms constructed by overall survival and cancer-specific survival can predict more accurately than AJCC stage system for GCLM patients.

•

The study includes the prognostic factor as many as possible and evaluated all of them in the cohort.

•

In our cohort, surgery is a beneficial factor associated with survival.

Background

Gastric cancer is heterogeneous and aggressive, especially with liver metastasis. This study aims to develop two nomograms to predict the overall survival (OS) and cancer-specific survival (CSS) of gastric cancer with liver metastasis (GCLM) patients.

Methods

From January 2000 to December 2018, a total of 1936 GCLM patients were selected from the Surveillance, Epidemiology, and End Results Program (SEER) database. They were further divided into a training cohort and a validation cohort, with the OS and CSS serving as the study's endpoints. The correlation analyses were used to determine the relationship between the variables. The univariate and multivariate Cox analyses were used to confirm the independent prognostic factors. To discriminate and calibrate the nomogram, calibration curves and the area under the time-dependent receiver operating characteristic curve (time-dependent AUC) were used. DCA curves were used to examine the accuracy and clinical benefits. The clinical utility of the nomogram and the AJCC Stage System was compared using net reclassification improvement (NRI) and integrated differentiation improvement (IDI) (IDI). Finally, the nomogram and the AJCC Stage System risk stratifications were compared.

Results

There was no collinearity among the variables that were screened. The results of multivariate Cox regression analysis showed that six variables (bone metastasis, lung metastasis, surgery, chemotherapy, grade, age) and five variables (lung metastasis, surgery, chemotherapy, grade, N stage) were identified to establish the nomogram for OS and CSS, respectively. The calibration curves, time-dependent AUC curves, and DCA revealed that both nomograms had pleasant predictive power. Furthermore, NRI and IDI confirmed that the nomogram outperformed the AJCC Stage System.

Conclusion

Both nomograms had satisfactory accuracy and were validated to assist clinicians in evaluating the prognosis of GCLM patients.

Molecular profiling of signet-ring-cell carcinoma (SRCC) from the stomach and colon reveals potential new therapeutic targets

Signet ring cell carcinoma (SRCC) is rare: about 10% of gastric cancer (GC) and 1% of colorectal cancer (CRC). SRCC is associated with poor prognosis, however the underlying molecular characteristics are unknown. SRCCs were analyzed using NGS, immunohistochemistry, and in situ hybridization. Tumor mutational burden (TMB) was calculated based on somatic nonsynonymous missense mutations, and microsatellite instability (MSI) was evaluated by NGS of known MSI loci. A total of 8500 CRC and 1100 GC were screened. Seventy-six SRCC were identified from the CRC cohort (<1%) and 98 from the GC cohort (9%). The most frequently mutated genes in CRC-SRCC were TP53 (47%), ARID1A (26%), APC (25%); in GC-SRCC were TP53 (42%), ARID1A (27%), CDH1 (11%). When compared to non-SRCC histology (N = 3522), CRC-SRCC (N = 37) more frequently had mutations in BRCA1 (11% vs 1%, P < 0.001) and less frequently mutations in APC (19% vs 78%, P < 0.001), KRAS (22% vs 51%, P = 0.001) and TP53 (47% vs 73%, P = 0.001). Among the GC cohort, SRCC (N = 54) had a higher frequency of mutations in CDH1, BAP1, and ERBB2, compared to non-SRCC (N = 540). Our data suggest that SRCCs harbor a similar molecular profile, regardless of the tumor location. Tailored therapy may become available for these patients.

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.

Characteristics and Predictors of Long-Time Survivors in Non-Metastatic Gastric Signet Ring Cell Carcinoma: A Large Population-Based Study

Objective

Gastric signet ring cell carcinoma (SRCC) is a distinct entity with a relatively poor prognosis. This study analyzed the clinicopathological characteristics of long-time survivors (LTSs) and identified independent predictors of long-term survival (LTS) in non-metastatic gastric SRCC.

Methods

Data from 3906 patients with non-metastatic gastric SRCC were retrieved from Surveillance, Epidemiology and End Results according to the inclusion and exclusion criteria. Patients were randomly divided into training and validation cohorts. Predictors of LTS in the training cohort were identified by multivariate logistic regression. A nomogram-based predictive model for LTS was constructed in non-metastatic gastric SRCC.

Results

There were 800 patients who survived for >5 years and were defined as TLSs. Young age, other race (not black or white population), female gender, married status, small tumor size, low tumor infiltration, and negative lymph node involvement were independent predictors of LTS in non-metastatic gastric SRCC. These seven variables were incorporated into a nomogram model for predicting LTS. The calibration curve showed good consistency between observed and predicted probability of LTS, and the receiver operating characteristic curve showed acceptable discriminative capacity in the training and validation cohorts.

Conclusion

This study provides an overview of the features of patients with non-metastatic gastric SRCC. Age, race, sex, marital status, tumor size, tumor infiltration, and lymph node involvement were identified as independent predictors of LTS.

Clinicopathological characteristics and prognosis of poorly cohesive cell subtype of gastric cancer

BACKGROUND

The new World Health Organization (WHO) classification of gastric cancer includes a histological subtype of poorly cohesive carcinoma (PCC), which includes signet-ring cell (SRC) phenotype. We aimed to examine the concordance between preoperative clinical and postoperative histological diagnoses according to the 2010 WHO histological subtypes and to compare the prognoses of these subtypes.

METHODS

The study cohort comprised 665 patients who underwent gastrectomy from 2005 to 2019. Histological subtypes were classified into PCC-NOS (non-signet ring cell subtype), SRC, and non-PCC, which were defined by the predominant component in accordance with the 2010 WHO classification of gastric cancer. The concordance of clinical and pathological diagnosis was examined and clinicopathological characteristics and survival outcome of the three subtypes compared.

RESULTS

The cancers of 443 patients (66.7%) were classified as non-PCC, of 112 patients (16.8%) as PCC-NOS, and of 110 patients (16.5%) as SRC predominant subtypes. Significant differences in sex, age, tumor location, size, macroscopic type, and pathological TNM category (all P<0.05) were found. The concordance rate of preoperative and postoperative histological subtypes was significantly lower for poorly cohesive than other subtypes (P<0.0001). Preoperative stage tended to be underestimated for PCC-NOS subtype and these patients had poorer overall survival than those with the other two subtypes (P=0.005). Multivariate logistic regression analysis of overall survival showed that WHO histological subtype (PCC-NOS vs. non-PCC/SRC, HR: 1.64, 95% CI: 1.18-2.29, P=0.0034) was a significant independent prognostic factor.

CONCLUSION

Our results suggest that poorly cohesive carcinoma subtypes have different biological characteristics and prognoses.

Molecular mechanism of therapeutic approaches for human gastric cancer stem cells

Gastric cancer (GC) is a primary cause of cancer-related mortality worldwide, and even after therapeutic gastrectomy, survival rates remain poor. The presence of gastric cancer stem cells (GCSCs) is thought to be the major reason for resistance to anticancer treatment (chemotherapy or radiotherapy), and for the development of tumor recurrence, epithelial–mesenchymal transition, and metastases. Additionally, GCSCs have the capacity for self-renewal, differentiation, and tumor initiation. They also synthesize antiapoptotic factors, demonstrate higher performance of drug efflux pumps, and display cell plasticity abilities. Moreover, the tumor microenvironment (TME; tumor niche) that surrounds GCSCs contains secreted growth factors and supports angiogenesis and is thus responsible for the maintenance of the growing tumor. However, the genesis of GCSCs is unclear and exploration of the source of GCSCs is essential. In this review, we provide up-to-date information about GCSC-surface/intracellular markers and GCSC-mediated pathways and their role in tumor development. This information will support improved diagnosis, novel therapeutic approaches, and better prognosis using GCSC-targeting agents as a potentially effective treatment choice following surgical resection or in combination with chemotherapy and radiotherapy. To date, most anti-GCSC blockers when used alone have been reported as unsatisfactory anticancer agents. However, when used in combination with adjuvant therapy, treatment can improve. By providing insights into the molecular mechanisms of GCSCs associated with tumors in GC, the aim is to optimize anti-GCSCs molecular approaches for GC therapy in combination with chemotherapy, radiotherapy, or other adjuvant treatment.

Adenocarcinoma with Mixed Subtypes in the Early and Advanced Gastric Cancer

Objective

Adenocarcinoma with mixed subtypes (AM) is a histological classification based on the WHO classification. We aimed to compare the prognosis among AM, classic adenocarcinoma (CA), mucinous adenocarcinoma (MAC), and signet-ring cell carcinoma (SRCC) in early and advanced gastric cancer (EGC and AGC), respectively.

Methods

The Surveillance, Epidemiology, and End Results (SEER) database was queried from 2001 to 2016. Univariate and multivariate Cox analyses were performed to compare prognosis between AM and histologic subtypes of CA, SRCC, and MAC in ECG and ACG. A nomogram was established to predict the cancer-specific survival (CSS) of gastric cancer (GC) patients with AM. C-index, calibration curves, and receiver operating characteristic (ROC) and decision curve analysis (DCA) curves were applied to examine the accuracy and clinical benefits.

Results

In the prognosis among these four histological subtypes in EGC patients, there are no differences. For AGC patients, AM had a significantly poorer prognosis compared with CA and MAC (P=0.003, 0.029) but similar prognosis to SRCC. A nomogram based on race, T stage, N stage, M stage, and surgical modalities was proposed to predict 1- and 3-year CSS for GC patients with AM (C-index: training cohort: 0.804, validation cohort: 0.748. 1- and 3-year CSS AUC: training cohort: 0.871 and 0.914, validation cohort: 0.810 and 0.798). 1- and 3-year CSS DCA curves showed good net benefits.

Conclusions

EGC patients with AM had similar survival to those with CA, MAC, and SRCC. AM was an independent predictor of poor prognosis in AGC. A nomogram for predicting the prognosis of GC patients with AM was proposed to quantitatively assess the long-term survival.

Prevalence of Regional Lymph Node Metastasis of Mucosal Gastric Signet Ring Cell Carcinoma: Analysis of the Collaborative Stage Data Survey of the Korean Central Cancer Registry

INTRODUCTION

Patients with very early-stage gastric signet ring cell carcinoma (SRC) are eligible for minimally invasive treatment, like endoscopic submucosal dissection. However, population-based data on regional lymph node metastasis (LNM) and distant metastasis of gastric SRC are lacking. This study aimed to identify the prevalence of LNM and distant metastasis in mucosal cancer (T1a) of gastric SRC.

METHODS

The Collaborative Stage Data Survey was performed by the Korean Center of Cancer Registry between 2010 and 2015 to establish collaborative stage data of the stomach, colon, rectum, rectosigmoid junction, and breast. From the survey data, information on patients with gastric SRC was extracted for analysis. Variables including age, sex, diagnosis date, primary site, tumor size, histology, American Joint Committee on Cancer staging system scores, and Surveillance, Epidemiology, and End Results summary stage were analyzed.

RESULTS

A total of 1,335 (65.7%) patients had mucosal gastric SRC, and 1,189 (89.1%) patients had surgery and 134 (10%) had endoscopic treatment. Of them, 1,283 (96.1%) patients did not have regional LNM, and 52 (3.9%) patients had regional LNM and 6 (0.4%) had distant metastasis. The hazard ratios of LNM and distant metastasis were 14.98 (95% CI: 4.18-53.2) and 10.09 (95% CI: 2.30-44.17).

CONCLUSIONS

Reginal LNM and distant metastasis occur very less in mucosal gastric SRC, but they are associated with an increased risk of cancer-related death. Even in early stage, surgery should be considered as a standard treatment of mucosal gastric SRC.

Gastric Signet Ring Cell Carcinoma: A Comparative Analysis of Clinicopathologic Features

Signet ring cell carcinoma (SRC) is a distinct histological subtype of gastric carcinoma. Our aim is to investigate differential characteristics between gastric SRC and other non SRC carcinomas (nSRC). It was a retrospective study including 183 patients diagnosed with gastric carcinoma over a period of 5 years at our pathology department. We performed statistical comparison of clinicopathological features between patients with SRC and those with nSRC. 127 patients (69.4%) had nSRC, 56 had SRC (30.6%), the mean age was 56.67 ± 14.03 years. Patients with SRC were younger than those with nSRC (mean age of 49.66 versus 59.76, P = 0.030). Patients with SRC tend to have more diffuse tumors in the stomach (P = 0.005), with flat macroscopic appearance (P = 0.001). Patients with SRC present more often with pT3 tumors (P < 0.001), lymph node metastasis (P = 0.024) and perineural invasion (P = 0.003). There were no significant differences between SRC and nSRC in gender, vascular invasion or distant metastasis (P > 0.05). The median survival time was 42.82 ± 1.70 months. Patients with nSRC live longer than those with SRC, but the difference was not significant (P = 0.28). SRC is a histological subtype of gastric carcinoma with distinctive clinicopathologic features. The clinical management of patients should take into account these particular features.

A Prognostic Model for Patients With Gastric Signet Ring Cell Carcinoma

Background:

The aim of our study was to develop a nomogram model to predict overall survival (OS) and cancer-specific survival (CSS) in patients with gastric signet ring cell carcinoma (GSRC).

Methods:

GSRC patients from 2004 to 2015 were collected from the Surveillance, Epidemiology, and End Results (SEER) database and randomly assigned to the training and validation sets. Multivariate Cox regression analyses screened for OS and CSS independent risk factors and nomograms were constructed.

Results:

A total of 7,149 eligible GSRC patients were identified, including 4,766 in the training set and 2,383 in the validation set. Multivariate Cox regression analysis showed that gender, marital status, race, AJCC stage, TNM stage, surgery and chemotherapy were independent risk factors for both OS and CSS. Based on the results of the multivariate Cox regression analysis, prognostic nomograms were constructed for OS and CSS. In the training set, the C-index was 0.754 (95% CI = 0.746-0.762) for the OS nomogram and 0.762 (95% CI: 0.753-0.771) for the CSS nomogram. In the internal validation, the C-index for the OS nomogram was 0.758 (95% CI: 0.746-0.770), while the C-index for the CSS nomogram was 0.762 (95% CI: 0.749-0.775). Compared with TNM stage and SEER stage, the nomogram had better predictive ability. In addition, the calibration curves also showed good consistency between the predicted and actual 3-year and 5-year OS and CSS.

Conclusion:

The nomogram can effectively predict OS and CSS in patients with GSRC, which may help clinicians to personalize prognostic assessments and clinical decisions.

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 Gastric Carcinoma: Clinical Epidemiology and Outcomes in a Predominantly Latino County Hospital Population

BACKGROUND

Gastric signet ring cell carcinoma (GSRC) is a rare but increasingly prevalent tumor histotype whose clinical features and natural history are poorly understood, particularly in the USA and minorities.

AIMS

To examine the occurrence, clinico-demographic characteristics, oncologic features, treatment, and outcomes of GSRC in a predominantly minority county hospital setting and benchmark them against data from the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) program.

METHODS

We queried biopsy-proven GSRC cases at a Los Angeles County hospital, from 2004 to 2017. Clinical characteristics, treatment, and survival data were collected and compared to SEER data.

RESULTS

We identified 63 patients with GSRC. Compared to SEER, our cohort was significantly younger (52.6 vs. 63.5 years, p < 0.01), Hispanic/Latino predominant (81% vs. 20%, p < 0.01), had higher overall stage (86% vs. 69% with stage III/IV, p < 0.01), and more frequent node involvement (89% vs. 49%, p < 0.01). Lower tumor stage, Helicobacter pylori positivity, and surgical intervention were associated with significantly longer median survival (all p < 0.05), which was similar in our study compared to SEER (median 12.6 vs. 9.0 months, p = 0.26).

CONCLUSIONS

Patients with GSRC within the Los Angeles County population have different clinical characteristics compared to what has been reported in SEER. Our cohort was younger, and despite having more advanced disease, did not have shorter survival. Further study is needed to better identify protective and risk factors in this population and improve understanding of the etiopathogenesis and natural history of this malignancy.

The efficacy and toxicity of adjuvant S-1 schedule with 2-week administration followed by 1-week rest in gastric cancer patients

Background

This study aimed to investigate the clinical outcome of adjuvant S-1 with 2-week administration followed by a 1-week rest for locally advanced gastric cancer (GC) patients.

Methods

The current study was a single retrospective cohort study that focused on the efficacy and toxicity of adjuvant S-1 with a 3-week schedule. A total of 60 patients who underwent total or subtotal gastrectomy plus D2 lymph node dissection and adjuvant S-1 treatment were identified. S-1 treatment began within 4 weeks after the operation; it was administered orally for 2 weeks, followed by a 1-week rest. The dose of S-1 was adjusted depending on adverse events (AEs), with at least 80 mg administered daily. The completion of 1-year S-1 was defined as S-1 continuation for 1 year with over 70% of the planned dose. Patients were followed up with for 5 years postoperatively and underwent hematologic tests and assessments of clinical symptoms every 3-6 weeks for 1 year after surgery. Computed tomography of the abdomen and panendoscopy were performed every 6 months during the first 2 years and at 1-year intervals thereafter until year 5 after surgery.

Results

The completion rate of 1-year adjuvant S-1 was 71.7%, and the 3-year disease-free survival and overall survival rates were 70.2% and 79.5%, respectively. Seventeen patients did not complete S-1 for 1 year, including 11 patients with tumor recurrence and 6 patients who developed intolerance. Most AEs of S-1 were grade 1-2, and the most frequent AEs (>20%) included anemia, fatigue, pigmentation, nausea, and diarrhea. The most common grade 3-4 AE was fatigue, which was observed in 6.7% of patients. Most patients tolerated the side effects.

Conclusions

The results of our study confirm that the efficacy and safety of schedule modification of adjuvant S-1 treatment in patients with GC who underwent gastrectomy with D2 lymph node dissection are equal to those in a previous phase 3 study.

Differential prognostic implications of gastric adenocarcinoma based on Lauren's classification: a Surveillance, Epidemiology, and End Results (SEER)-based cohort study

Background

Our study aims to analyze the association between Lauren's classification and gastric adenocarcinoma prognosis using comprehensive statistical analyses.

Methods

According to the selection criteria, patients were included from the Surveillance, Epidemiology, and End Results (SEER) database. Univariate and multivariate Cox regression, propensity score matching, and a multivariate competing risk model were used to investigate the association between Lauren's classification and prognosis. Subgroup analysis was used to investigate the role of confounding factors on the association between Lauren types and prognosis.

Results

After exclusion, a total of 20,218 patients from the SEER database were included, with 14,374 intestinal types and 5,844 diffuse types. The univariate Cox regression analysis revealed that the diffuse type had a poorer cancer-specific survival (CSS) rate [hazard ratio (HR), 1.44; 95% confidence interval (CI), 1.38-1.50]. After adjusting for confounding variables, the diffuse type also showed a higher risk of cancer-specific death (HR, 1.20; 95% CI, 1.15-1.20). Sensitivity analysis showed that after propensity score matching, the diffuse type had a poorer CSS rate (HR, 1.23; 95% CI, 1.10-1.36), and the competing risk model further validated these results [subdistribution HR (SHR), 1.32; 95% CI, 1.23-1.41]. Moreover, subgroup analysis demonstrated stable results in the subgroups, except for patients with T1 stage (HR, 1.06; 95% CI, 0.87-1.28) and a tumor size <2 cm (HR, 1.00; 95% CI, 0.83-1.21).

Conclusions

Diffuse-type gastric adenocarcinoma had an overall poorer prognosis compared to the intestinal type. However, in patients with T1 stage and tumor size <2 cm, the diffuse type had a comparable survival rate with the intestinal type.

Clinicopathological factors affecting the effect of neoadjuvant chemotherapy in patients with gastric cancer

BACKGROUND

Neoadjuvant chemotherapy is an important part of the comprehensive treatment of advanced gastric cancer (GC). The effect of neoadjuvant chemotherapy plays a key role in the prognosis of GC patients. Pathological response can represent the effect of neoadjuvant chemotherapy. However, evidence focused on pathological response and associated clinicopathological factors in GC patients is quite little. In this retrospective study, the clinicopathological factors affecting the effect of neoadjuvant chemotherapy in GC patients were investigated, and suggestions were proposed to improve the effect of neoadjuvant chemotherapy on GC.

METHODS

Retrospective analysis was performed on GC patients who received radical surgery after neoadjuvant chemotherapy from February 2016 to December 2019 at Peking Union Medical College Hospital. Relevant clinicopathological data was collected to analyze the factors influencing the effect of neoadjuvant chemotherapy. Chi-square test was used for univariate analysis. Logistic regression was used for multivariate analysis. Receiver operating characteristic curve (ROC) was used to determine the cutoff value of variables which significantly influenced the effect of neoadjuvant chemotherapy.

RESULTS

A total of 203 GC patients were included in the study. Analyses showed that patients < 60 years old (OR = 1.840 [1.016-3.332], P = 0.044), histological type of poor differentiation or signet-ring cell carcinoma (OR = 2.606 [1.321-5.140], P = 0.006), and weight loss during neoadjuvant chemotherapy (OR = 2.110 [1.161-3.834], P = 0.014) were independent risk factors for neoadjuvant chemotherapy effect. In ROC analysis of weight change and neoadjuvant chemotherapy effect, area under the curve (AUC) was 0.593 (P = 0.024) and cutoff value of weight change was - 2.95%. Chi-square test showed that patients without weight loss during neoadjuvant chemotherapy had a higher rate of oral nutritional supplement (ONS) than patients with weight loss (P = 0.039).

CONCLUSIONS

Patients <60 years old, histological type of poor differentiation or signet-ring cell carcinoma, and weight loss during neoadjuvant chemotherapy were independent risk factors for neoadjuvant chemotherapy effect in GC patients. Patients with weight loss > 2.95% during neoadjuvant may have a worse chemotherapy effect. Timely nutritional support such as ONS to maintain patients' body weight is crucial for improving the effect of neoadjuvant chemotherapy.

Estrogen Receptor Beta Prevents Signet Ring Cell Gastric Carcinoma Progression in Young Patients by Inhibiting Pseudopodia Formation via the mTOR-Arpc1b/EVL Signaling Pathway

Signet ring cell gastric carcinoma (SRCGC) is a poorly differentiated malignancy, and can be highly dangerous in the progression stage. There is a higher male to female ratio among patients with signet ring cell carcinoma as compared to patients with non-SRCGC. ERβ has been found to express in stomach adenocarcinoma, but how it affects tumor progression remains unclear. Here, we studied estrogen receptor beta (ERβ) to explore the role of sex-associated factors in SRCGC. We analyzed the clinicopathological statistics of patients with SRCGC, and conducted a series of in vitro experiments. Immunohistochemistry showed that patients with low ERβ expression were at risk of poor prognosis and higher T stage. In vitro assays indicated that ERβ might prevent SRCGC progression by inhibiting cell proliferation and invasiveness and by promoting anoikis. Western blotting and quantitative RT-PCR proved that the mTOR-Arpc1b/EVL signaling pathway might participate in the negative regulatory role of ERβ. In conclusion, our findings show that ERβ might inhibit the malignancy of signet ring cells in patients with SRCGC, indicating that ERβ might be a potential target in adjuvant treatment.

Different clinicopathologic features and prognostic significance of signet ring cell histology in early and locally advanced gastric cancer patients

BACKGROUND

Although many studies have evaluated the prognostic significance of signet ring cell (SRC) histology for gastric cancer (GC) patients, the results were conflicting. The objective of this study was to compare clinicopathologic characteristics between SRC type and other types, and evaluate its impact on survival outcome.

METHODS

We retrospectively reviewed clinicopathologic and survival data of 1891 patients who underwent curative resection for GC. All patients were divided into differentiated, undifferentiated and SRC type according to the histological classification. The prognostic differences between different types were compared and clinicopathologic factors were analyzed.

RESULTS

SRC histology type had a poorer disease-free survival (DFS) than differentiated type (5-year DFS, 37.7% vs 52.2%, P<0.001), but there was no prognostic difference between SRC type and undifferentiated type (37.7% vs 41.9%, P>0.05). For early GC patients, SRC type was more frequent in younger, female patients and T1a stage tumors; the 5-year DFS of SRC type was similar to that of any other histology type (P>0.05). SRC type showed more aggressive biological features, including extensive stomach involvement, large tumor size, advanced pTstage and pN stage, than other types for locally advanced GC patients; poorer DFS was observed in SRC type compared with differentiated type. Multivariate analysis indicated that SRC type (HR:1.71, 95%CI:1.10-1.68, P<0.01) and undifferentiated type (HR:1.21, 95%CI:1.04-1.40, P<0.05) were independently associated with poor DFS in locally advanced GC patients.

CONCLUSION

There was a significant difference between early and locally advanced GC patients with regard to clinicopathologic features and prognostic significance of SRC histology. SRC type was an independent prognostic factor for locally advanced GC patients, but not for early GC patients.

Incidence and prognosis of undifferentiated cancers of the digestive system: a population-based cohort study

Background

Cases of undifferentiated cancers of the digestive system (UCDS) are occasionally encountered in clinical practice; however, no large-scale studies have described their characteristics. This study aimed to investigate the incidence, prognosis, and treatment strategies of UCDS.

Methods

We used the data from the Surveillance, Epidemiology, and End Results database to evaluate clinical characteristics in UCDS patients. A cohort of 1,372 patients was included to estimate UCDS incidence; another cohort of 1,816 patients was followed up until December 31, 2017 to evaluate treatment and prognosis. The incidence, trends, treatments, overall survival, and cause-specific survival were assessed.

Results

The estimated incidence of UCDS was 0.136 per 100,000 people-years [95% confidence interval (CI): 0.129-0.143] from 1975 to 2016 with respect to sex, age, year of diagnosis, race, region, site, income, and education. The age-adjusted rates of UCDS dropped from 0.567 per 100,000 people-years in 1978 to 0.031 per 100,000 people-years in 2016. The rates of surgery, beam radiation, and chemotherapy in patients with UCDS were 37.3%, 17.3%, and 30.7%, respectively. Overall, the 5-year cause-specific survival rate was 18%, with a median cause-specific survival of 4 months. Patient prognosis improved significantly over the decades; stage, site, year of diagnosis, surgery, beam radiation, and chemotherapy were independent prognostic factors for UCDS mortality.

Conclusions

The incidence of UCDS has decreased in the United States over the past 40 years. Patients benefited from surgery, beam radiation, and chemotherapy. The survival of patients with UCDS has improved. Further research on developing decision-making recommendations for UCDS treatment is crucial.

Clinical Outcomes of Mucinous Gastric Carcinomas Compared with Non-mucinous and Signet Ring Cell Carcinomas

Background/Aims

This study examined the clinical features and prognosis of patients with mucinous gastric carcinoma (MGC), non-mucinous gastric carcinoma (NMGC), and signet ring cell gastric carcinoma (SRC).

Methods

A retrospective cohort study was performed, enrolling 65 patients with MGC from January 2007 to December 2016. During the same period, 1,814 patients with histologically proven gastric cancers underwent curative or palliative operations. One hundred and ninety-five NMGC patients were selected as the 1:3 age- and sex-matched control groups. In addition, 200 SRC patients were identified. This study evaluated the demographic features of the patients, pathologic features of the tumor, and the predictive factors, such as the recurrence-free survival and overall survival.

Results

The recurrence rates were significantly high in MGC than in NMGC or SRC (both p<0.01). The proportion of early gastric cancer was lower in the MGC group than in the other groups (p<0.01). In addition, metastatic lymph nodes were found more frequently in the MGC group (p<0.01), and the proportion of initial pT4, M1 stage, was highest in the MGC group. The recurrence-free survival and overall survival in the MGC group were significantly lower than those in the NMGC or SRC. Subgroup analysis showed that patients with the same American Joint Committee on Cancer (AJCC) stage of each cancer group showed a similar prognosis.

Conclusions

MGC frequently presents an advanced stage with an unfavorable prognosis compared to NMGC or SRC. On the other hand, MGC of the same AJCC stage had a similar prognosis to NMGC and SRC.

Angiogenesis-Related Gene Expression Signatures Predicting Prognosis in Gastric Cancer Patients

Simple Summary

To elucidate the role of angiogenesis as a prognostic signature in gastric cancer, we analyzed the expression level of 36 angiogenesis-related genes (ARGs) from Stomach Adenocarcinoma (STAD) from The Cancer Genome Atlas (TCGA). Consensus clustering analysis showed two major angiogenesis-related types: one related to more aggressive clinicopathological characteristics and worse survival, and the other related to lower tumor, lymph node, metastasis (TNM) stage and better outcomes. Our analysis of TCGA with a least absolute shrinkage and selection operator (LASSO) regression model identified 10 genes associated with overall survival in gastric cancer patients. With this gene signature, we computed angiogenesis-related gene signature risk scores for individual cancer patients that predicted overall and disease-free survival, which were further validated in the independent dataset Asian Cancer Research Group (ACRG). Moreover, an overall survival (OS)-related nomogram was established and had better performance in prognosis prediction than TNM stage. Our analysis provides a comprehensive map of ARGs that can be serve as useful biomarkers for gastric cancer.

Abstract

Increasing evidence indicates that angiogenesis is crucial in the development and progression of gastric cancer (GC). This study aimed to develop a prognostic relevant angiogenesis-related gene (ARG) signature and a nomogram. The expression profile of the 36 ARGs and clinical information of 372 GC patients were extracted from The Cancer Genome Atlas (TCGA). Consensus clustering was applied to divide patients into clusters 1 and 2. Least absolute shrinkage and selection operator (LASSO) Cox regression analyses were used to identify the survival related ARGs and establish prognostic gene signatures, respectively. The Asian Cancer Research Group (ACRG) (n = 300) was used for external validation. Risk score of ARG signatures was calculated, and a prognostic nomogram was developed. Gene set enrichment analysis of the ARG model risk score was performed. Cluster 2 patients had more advanced clinical stage and shorter survival rates. ARG signatures carried prognostic relevance in both cohorts. Moreover, ARG-risk score was proved as an independent prognostic factor. The predictive value of the nomogram incorporating the risk score and clinicopathological features was superior to tumor, lymph node, metastasis (TNM) staging. The high-risk score group was associated with several cancer and metastasis-related pathways. The present study suggests that ARG-based nomogram could serve as effective prognostic biomarkers and allow a more precise risk stratification.

Prognostic analysis of gastric signet ring cell carcinoma and mucinous carcinoma: a propensity score-matched study and competing risk analysis

Background: Limited evidence and contradictory results have been reported regarding the impact of signet ring cell carcinoma (SRC) and mucinous gastric cancer (MGC) classifications on the prognosis of gastric cancer (GC).

Results: Information on 6017 patients and 266 patients was extracted from the SEER database and our hospital records, respectively. We found that patients with MGC had a better survival rate than those with SRC (P=0.012), but in the early stage, MGC was a risk factor for a poor prognosis. After PSM, for both patients from the SEER database and our hospital, the prognosis of patients with SRC was poorer than that of patients with MGC (P<0.05), but patients with MGC in early-stage GC showed poorer survival. Additionally, SRC was demonstrated to be a risk factor in the multivariate competing risk regression model for cancer-specific survival.

Conclusion: Patients with SRC may have a worse prognosis than those with MGC, but for early-stage GC, patients with SRC have a better prognosis than those with MGC.

Method: Patients from the SEER database and from our hospital diagnosed with SRC or MGC were included in a Cox regression analysis, multivariate competing risk model and propensity score matching (PSM) analysis.

Comparison of metastasis between early-onset and late-onset gastric signet ring cell carcinoma

Background

There is little knowledge to date about the distant metastasis of early-onset gastric signet ring cell carcinoma (SRCC) or the difference in metastasis based on age. Therefore, we conducted a comprehensive retrospective study using the Surveillance, Epidemiology, and End Results (SEER) database and data from our hospital.

Methods

Patients were collected from the SEER database and our hospital. Univariate and multivariate logistic regression analyses and propensity score matching (PSM) were used to identify risk factors for metastasis. K-M survival curves were generated to analyse patient survival.

Results

In total, we retrieved 2052 EOGC patients diagnosed with SRCC from the SEER database and included 403 patients from our hospital. K-M survival curves showed that late-onset SRCC patients had worse survival than early-onset patients but that late-onset SRCC patients were less likely to have distant metastasis, as validated by SEER data (OR = 0.462, 95%CI, 0.272–0.787; P = 0.004) and our data (OR = 0.301, 95%CI, 0.135–0.672; P = 0.003). Multivariate logistic regression and PSM analysis revealed that age of 45 or younger was an independent risk factor for distant metastasis.

Conclusion

Our study showed that distant metastasis was more common in early-onset SRCC than in late-onset SRCC. However, further studies are needed to explore the potential aetiologic basis for this disparity.

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.

The Clinicopathological Characteristics And Genetic Alterations of Signet-ring Cell Carcinoma in Gastric Cancer

Signet-ring cell carcinoma (SRC) in advanced gastric cancer (GC) is often associated with more invasiveness and a worse prognosis than other cell types. The genetic alterations associated with gastric carcinogenesis in SRC are still unclear. In this study, 441 GC patients receiving curative surgery for GC between 2005 and 2013 were enrolled. The clinicopathological characteristics and genetic alterations of GC patients with and without SRC were compared. Among the 441 GC patients, 181 had SRC. For early GC, patients with SRC had more tumors located in the middle and lower stomach, more infiltrating tumors and better overall survival (OS) rates than those without SRC. For advanced GC, patients with SRC had more scirrhous type tumors, more PIK3CA amplifications, fewer microsatellite instability-high (MSI-H) tumors, more peritoneal recurrences and worse 5-year OS rates than those without SRC. For advanced GC with SRC, patients with peritoneal recurrence tended to have PD-L1 expression. For advanced GC without SRC, patients with liver metastasis tended to have PD-L1 expression, PI3K/AKT pathway mutations, TP53 mutations and MSI-H tumors. For advanced GC, PD-L1 expression was associated with peritoneal recurrence in SRC tumors, while non-SRC tumors with liver metastasis were likely to have PI3K/AKT pathway mutations, TP53 mutations and PD-L1 expression; immunotherapy and targeted therapy may be beneficial for these patients.

DOCK6 promotes chemo- and radioresistance of gastric cancer by modulating WNT/β-catenin signaling and cancer stem cell traits

Gastric cancer (GC) is the third leading cause of cancer-related mortality worldwide and prognosis after potentially curative gastrectomy remains poor. Administration of GC-targeting molecules in combination with adjuvant chemo- or radiotherapy following surgical resection has been proposed as a potentially effective treatment option. Here, we have identified DOCK6, a guanine nucleotide exchange factor (GEF) for Rac1 and CDC42, as an independent biomarker for GC prognosis. Clinical findings indicate the positive correlation of higher DOCK6 expression with tumor size, depth of invasion, lymph node metastasis, vascular invasion, and pathological stage. Furthermore, elevated DOCK6 expression was significantly associated with shorter cumulative survival in both univariate and multivariate analyses. Gene ontology analysis of three independent clinical GC cohorts revealed significant involvement of DOCK6-correlated genes in the WNT/β-catenin signaling pathway. Ectopic expression of DOCK6 promoted GC cancer stem cell (CSC) characteristics and chemo- or radioresistance concomitantly through Rac1 activation. Conversely, depletion of DOCK6 suppressed CSC phenotypes and progression of GC, further demonstrating the pivotal role of DOCK6 in GC progression. Our results demonstrate a novel mechanistic link between DOCK6, Rac1, and β-catenin in GCCSC for the first time, supporting the utility of DOCK6 as an independent marker of GC.

Should Signet Ring Cell Histology Alter the Treatment Approach for Clinical Stage I Gastric Cancer?

BACKGROUND

Surgery alone is standard-of-care for stage I gastric adenocarcinoma; however, clinicians can offer preoperative therapy for clinical stage I disease with signet ring cell histology, given its presumed aggressive biology. We aimed to assess the validity of this practice.

METHODS

The National Cancer Database (2004-2015) was reviewed for patients with clinical stage I signet ring cell gastric adenocarcinoma who underwent treatment with surgery alone, perioperative chemotherapy, neoadjuvant therapy, or adjuvant therapy. Analysis was stratified by preoperative clinical/pathologic stage. Primary outcome was overall survival (OS).

RESULTS

Of 1018 patients, median age was 60 years (±14); 53% received surgery alone (n = 542), 5% received perioperative chemotherapy (n = 47), 12% received neoadjuvant therapy (n = 125), and 30% received adjuvant therapy (n = 304). For clinical stage I disease, surgery alone was associated with an improved 5-year OS rate (71%) versus perioperative chemotherapy (58%), neoadjuvant therapy (38%), or adjuvant therapy (52%) [overall p < 0.01]. For pathologic stage I, surgery alone had equivalent or improved survival compared with perioperative, neoadjuvant, and adjuvant therapy (5-year OS: 78% vs. 89% [p = 0.77] vs. 64% [p = 0.04] vs. 84% [p = 0.99]). Adjuvant therapy was associated with improved 5-year OS compared with pretreatment for those patients upstaged (37%) to pathologic stage II/III (55% vs. 36% and 34% vs. 7%; all p < 0.01).

CONCLUSIONS

This stage-specific study demonstrates improved survival with surgery alone for clinical stage I signet ring cell gastric adenocarcinoma. Despite 37% of clinical stage I patients being upstaged to pathologic stage II/III, adjuvant therapy offers a favorable rescue strategy, with improved outcomes compared with those treated preoperatively. Surgery alone also affords similar or improved survival for pathologic stage I disease versus multimodality therapy. This study challenges the bias to overtreat stage I signet ring cell gastric adenocarcinoma.

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.

Different prognostic significance of signet ring cell histology for early and advanced gastric cancer patients: a systematic review and meta-analysis

OBJECTIVE

To review relevant studies and perform a meta-analysis to evaluate the prognostic significance of signet ring cell (SRC) histology for gastric cancer (GC) patients.

METHODS

Systematic literature search was performed using PubMed and Embase databases. The relevant data were extracted and the association between SRC histology and survival outcome were evaluated using a fixed-effect or random-effect model.

RESULTS

A total of 21 studies were included in this meta-analysis. The prevalence of SRC histology varied from 8.7% to 50%. SRC histology type was associated with poorer OS (HR: 1.12, 95%CI: 1.01-1.23, P = 0.034; I² = 85.1%) and DFS (HR: 1.17, 95%CI: 1.00-1.37, P = 0.040; I² = 63.6%). The subgroup analysis indicated that SRC type had a better OS than non-SRC type for early GC patients (HR: 0.60, 95%CI: 0.48-0.75, P < 0.001; I² = 33.7%). However, it was a poor prognostic factor for advanced GC when excluding stage IV patients (HR: 1.18, 95%CI: 1.07-1.29, P < 0.001; I² = 6.5%). SRC type had a higher risk of peritoneal recurrence than non-SRC type (OR: 1.36, 95%CI: 1.06-1.75, P = 0.017; I² = 1.3%).

CONCLUSION

SRC type had a distinctly different prognostic significance for early and advanced GC patients. SRC type was associated with better survival outcomes in early GC patients, but it was a predictive factor for poor survival in advanced GC patients.

Preoperative Systemic Immune-Inflammation Index (SII) for Predicting the Survival of Patients with Stage I-III Gastric Cancer with a Signet-Ring Cell (SRC) Component

Background

Recently, a novel systemic immune-inflammation index (SII) based on peripheral lymphocytes, neutrophils, and platelets has been reported to be correlated with patient prognosis in several malignancies, including gastric cancer. However, the prognostic value of the SII for gastric cancer patients with a signet-ring cell (SRC) component has not yet been reported. In this study, we aimed to assess the prognostic value of the SII in gastric cancer patients with an SRC component after curative resection.

Methods

This study was a retrospective analysis of 512 GC patients with an SRC component who underwent curative resection. The prognostic value of the SII was analyzed by the Kaplan-Meier method and Cox proportional hazards regression model.

Results

In our study cohort, an optimal cut-off value for the SII of 527 was used to stratify patients with gastric cancer (GC) into low (<527) and high SII (≥527) groups. Our study indicated that a high SII (≥527) was significantly correlated with a large tumor size (p < 0.001), infiltration of serosa (p < 0.001), lymph node metastasis (p < 0.001), and advanced TNM stage (p < 0.001). Univariate and multivariate analyses further demonstrated that a low SII was correlated with better clinical outcome and was an independent prognostic predictor in GC patients with an SRC component. Furthermore, the SII retained prognostic value in the subgroup analysis, including subgroup of different TNM stages and pure or mixed signet-ring cell carcinomas (SRCCs).

Conclusion

The SII is a simple, promising, and practical prognostic biomarker for patients with surgically resected mixed SRCC and pure SRCC. The SII could complement current prognostic tools for better treatment planning and stratification of patients.

Prognosis factors of advanced gastric cancer according to sex and age

BACKGROUND

Gastric cancer has a relatively high prevalence and is one of the most common causes of cancer-related death worldwide. However, the prognosis for gastric cancer remains poor, especially in the advanced stages, despite many improvements in diagnosis and treatment.

AIM

To evaluate the outcomes regarding advanced gastric cancer development according to sex and age.

METHODS

We retrospectively reviewed 2005 patients who underwent curative gastrectomy for advanced gastric cancer between 2002 and 2007 at a single Korean centre. Prognosis and risk factors for nodal involvement were evaluated according to sex and age.

RESULTS

In this retrospective cohort study, we examined the cases of 2005 patients [sex, 1384 men (69%), 621 women (31%)] with advanced gastric cancer. The patients’ age range was 22-87 years (mean age: 57.7 ± 12.3 years), with approximately 53.3% of the patients being ≤ 60 years old. Based on a Cox proportional hazards model, overall survival was independently predicted by older age, larger tumour size, lymphovascular invasion, lymph node metastasis, deeper tumour invasion, moderately-to-poorly differentiated tubular adenocarcinoma, and signet ring cell carcinoma. The same model revealed that relapse-free survival was independently predicted by advanced age, larger tumour size, lymphovascular invasion, deeper tumour invasion, poorly differentiated tubular adenocarcinoma, and signet ring cell carcinoma.

CONCLUSION

Among patients with advanced gastric cancer, older age independently predicted poor overall survival and relapse-free survival. However, there were no significant sex-based differences in relapse-free and overall survival.