OBJECTIVE: To investigate the clinicopathological features of Helicobacter pylori (Hp)-negative early gastric cancer. METHODS: The clinicopathological data of 30 cases of Hp-negative early gastric cancer were collected retrospectively at Pingdingshan Medical District, 989 Hospital of PLA Joint Logistics Support Force, and Beijing Chaoyang Hospital, Capital Medical University, from 2009 to 2021, and the histomorphological characteristics and immunophenotype were observed, and combined with the literature to explore. RESULTS: The median age of 30 patients was 58.5 years (range: 21-80 years), including 13 males and 17 females. The upper part of the stomach was 13 cases, the middle part of the sto-mach was 9 cases, and the lower part of the stomach was 8 cases. The median diameter of the tumor was 11 mm (range: 1-30 mm). According to the Paris classification, 9 cases were 0-Ⅱa, 7 cases were 0-Ⅱb, and 14 cases were 0-Ⅱc. Endoscopic examination showed that 18 cases of lesions were red, 12 cases of lesions were faded or white, and microvascular structures and microsurface structures were abnormal. In all the cases, collecting venules were regularly arranged in the gastric body and corner mucosa. There were 18 cases of well differentiated adenocarcinoma in the mucosa. The tumor presented glandular tubular-like and papillary structure, with dense glands and disordered arrangement; the cells were cuboidal or columnar, with increased nuclear chromatin and loss of nuclear polarity, and most of them expressed gastric mucin. Signet-ring cell carcinoma was found in 7 cases, all the cancer tissues were composed of signet-ring cells, and the cancer cells were mainly distributed in the middle layer to the surface layer of mucosa. Gastric oxyntic gland adenoma (gastric adenocarcinoma of the fundic gland type confined to mucosa) in 2 cases, gastric adenocarcinoma of the fundic gland type in 2 cases, and gastric adenocarcinoma of fundic gland mucosa type in 1 case. The tumor tissue was composed of branching tubular glands, except 1 case of mucosal surface epithelium was partially neoplastic, the other 4 cases of mucosal surface epi-thelium were all non-neoplastic; the cells were arranged in a single layer, and the nucleus was close to the basal side, and the nucleus was only slightly atypical. Pepsinogen I and H⁺/K⁺ ATPase were positive in 5 cases of gastric fundus gland type tumors, and 1 case of foveolar-type tumor cells at the surface and depth of mucosa showed MUC5AC positive. The gastric mucosa adjacent to cancer was generally normal in all cases, without atrophy, intestinal metaplasia and Hp. CONCLUSION Hp-negative early gastric cancer is a heterogeneous disease group with various histological types, and tubular adenocarcinoma and signet-ring cell carcinoma are common. Tubular adenocarcinoma mostly occurs in the elderly and the upper to middle part of the stomach, while signet-ring cell carcinoma mostly occurs in young and middle-aged people and the lower part of the stomach. Gastric neoplasm of the fundic gland type is relatively rare.
Male ; Aged ; Middle Aged ; Female ; Humans ; Young Adult ; Adult ; Aged, 80 and over ; Stomach Neoplasms/pathology* ; Helicobacter pylori ; Retrospective Studies ; Helicobacter Infections/diagnosis* ; Adenocarcinoma/pathology* ; Carcinoma, Signet Ring Cell/pathology*

Tumor deposit (TD) is a common histopathological finding in gastric cancer. With the improved ability of lymphadenectomy and pathological examination, the positive rate and harvested number of TD are also increasing. The role of TD in staging and prognosis prediction for gastric cancer patients is getting more attention. However, due to the lack of standardization and unification, the denomination, definition and diagnostic criteria are still controversial. The previous studies on the definition and diagnostic criteria of TD were reviewed to standardize the items and improve the awareness. TD is an independent prognostic factor in gastric cancer. Each TD should be counted separately as a lymph node in the final pN determination according to TNM staging system of the Union for International Cancer Control (UICC) or American Joint Committee on Cancer(AJCC) or Japanese classification of gastric carcinoma. But this rule is just an experience-based practice, without support from high-level evidence. Several studies have tried to incorporate TD into TNM staging system to improve the accuracy and discriminative ability. With the wide use of the 8th TNM staging system, how to incorporate TD into the new staging system in an easy and reasonable way still needs more investigations.
Humans ; Lymph Node Excision ; Lymph Nodes ; pathology ; surgery ; Neoplasm Staging ; methods ; Prognosis ; Stomach Neoplasms ; diagnosis ; pathology ; therapy

OBJECTIVE: To explore association of the expression levels of adenylate cyclase-associated protein 2 (CAP2) in gastric cancer tissues with the histopathology and long-term prognosis of the malignancy. METHODS: This study was conducted among a total of 105 patients with gastric cancer undergoing radical gastrectomy in our hospital between January, 2010 and October, 2013. Immunohistochemistry was used to quantitatively assess the expression of CAP2 in gastric cancer tissues and the adjacent tissues. Based on the median relative expression level of CAP2 of 3.5, the patients were divided into low CAP2 expression group (=52) and high CAP2 expression group (=53). The Cox regression model was used to analyze the effect of CAP2 expression on the 5-year survival rate of the patients, and ROC curve analysis was used to assess the predictive value of CAP2 expression for the patients' long-term survival. RESULTS: Immunohistochemical analysis showed that the expression levels of CAP2 ( < 0.01) and Ki67 ( < 0.01) were significantly higher in gastric cancer tissues than in the adjacent tissues, and the expression level of CAP2 was positively correlated with Ki67 ( < 0.01), peripheral blood CEA ( < 0.01) and CA19-9 ( < 0.01). The percentages of patients with CEA≥5 μg/L, CA19-9≥37 kU/L, pathological grade of G3-G4, T stage of 3-4, and N stage of 2-3 were significantly higher in patients with high CAP2 expression than in those with low CAP2 expression ( < 0.05). Kaplan- Meier survival analysis showed that the 5-year survival rate was significantly lower in patients with a high CAP2 expression ( < 0.01). A high expression level of CAP2, CEA≥5μg/L, CA19-9≥37 and pathological grades G3-G4 were all independent risk factors for shortened 5-year survival after radical gastrectomy ( < 0.01). With the relative expression level of 3.45 as the cut-off value, the sensitivity of CAP2 was 70.15% for predicting death 5 years after the surgery, with a specificity of 71.05% and an area under the curve of 0.779 ( < 0.01). CONCLUSIONS CAP2 is highly expressed in gastric cancer tissues in close relation with the tumor progression. CAP2 is an independent risk factor for 5-year survival rate after radical gastrectomy for gastric cancer and can be of clinical value in prognostic evaluation of the patients.
Adaptor Proteins, Signal Transducing ; metabolism ; Gastrectomy ; Humans ; Immunohistochemistry ; Membrane Proteins ; metabolism ; Neoplasm Staging ; Prognosis ; Retrospective Studies ; Stomach Neoplasms ; diagnosis ; metabolism ; pathology ; Survival Rate

Artificial intelligence is likely to perform several roles currently performed by humans, and the adoption of artificial intelligence-based medicine in gastroenterology practice is expected in the near future. Medical image-based diagnoses, such as pathology, radiology, and endoscopy, are expected to be the first in the medical field to be affected by artificial intelligence. A convolutional neural network, a kind of deep-learning method with multilayer perceptrons designed to use minimal preprocessing, was recently reported as being highly beneficial in the field of endoscopy, including esophagogastroduodenoscopy, colonoscopy, and capsule endoscopy. A convolutional neural network-based diagnostic program was challenged to recognize anatomical locations in esophagogastroduodenoscopy images, Helicobacter pylori infection, and gastric cancer for esophagogastroduodenoscopy; to detect and classify colorectal polyps; to recognize celiac disease and hookworm; and to perform small intestine motility characterization of capsule endoscopy images. Artificial intelligence is expected to help endoscopists provide a more accurate diagnosis by automatically detecting and classifying lesions; therefore, it is essential that endoscopists focus on this novel technology. In this review, we describe the effects of artificial intelligence on gastroenterology with a special focus on automatic diagnosis, based on endoscopic findings.
Ancylostomatoidea ; Artificial Intelligence ; Capsule Endoscopy ; Celiac Disease ; Colonoscopy ; Diagnosis ; Diagnosis, Computer-Assisted ; Endoscopy ; Endoscopy, Digestive System ; Endoscopy, Gastrointestinal ; Gastroenterology ; Helicobacter pylori ; Humans ; Intestine, Small ; Learning ; Methods ; Neural Networks (Computer) ; Pathology ; Polyps ; Stomach Neoplasms

Immunoglobulin G4-related disease (IgG4-RD) is an immune-mediated fibro-inflammatory disorder characterized by specific pathological findings and elevated serum IgG4 level. IgG4-RD in the stomach is rare, and occasionally diagnosed as gastric subepithelial tumor (SET) by endoscopy or computed tomography scan. Two female patients in the age group of 40–50 years were diagnosed with 4 cm sized gastric SET. One underwent laparoscopic gastric wedge resection. Another one had a history of subtotal gastrectomy for early gastric cancer and idiopathic thrombocytopenic purpura with oral steroids administration. She underwent a completion total gastrectomy with splenectomy for the gastric SET and ITP. The pathology showed storiform fibrosis, and IgG4 was positive in immunohistochemistry (IHC) stain. IgG4-RD is known as a medical disease that could be treated with oral steroids. The difficulty in preoperative diagnosis of the disease occasionally causes unnecessary gastric resection. Thus, preoperative diagnostic methods for IgG4-RD such as deep biopsy with IHC stain or magnetic resonance imaging are needed.
Biopsy ; Diagnosis ; Endoscopy ; Female ; Fibrosis ; Gastrectomy ; Gastrointestinal Stromal Tumors* ; Humans ; Immunoglobulin G ; Immunoglobulins ; Immunohistochemistry ; Magnetic Resonance Imaging ; Pathology ; Purpura, Thrombocytopenic, Idiopathic ; Splenectomy ; Steroids ; Stomach Neoplasms ; Stomach*

PURPOSE: Pre-operative lymph node (LN) size is a valuable parameter for determining treatment strategy for gastric cancer. However, a correlation between LN size and metastasis has not been established. MATERIALS AND METHODS: Thirty-six LN-positive (LNP) and matched 36 LN-negative (LNN) patients were included, and pathology slides of the LNs of these patients were reviewed. All the LNs were measured along the long-axis (LA) and short-axis (SA), manually. RESULTS: Average retrieved LNs were 37.3±19.8 and 40.5±11.6 in the LNN and LNP groups, respectively. In total 2,800 LNs, including 136 metastatic LNs (MLNs) and 2,664 non-metastatic LNs (nMLNs), were evaluated. Mean length was significantly more in MLNs along both, the LA and SA (MLN_LA vs. nMLN_LA: 4.97±3.84 vs. 3.37±2.40 mm, MLN_SA vs. nMLN_SA: 3.86±3.19 vs. 2.43±1.59 mm; P<0.001). However, 92.6% (126/136) and 95.6% (130/136) of MLNs were <10 mm along the LA and SA, respectively. In addition, only 22.2% of the LNP group exhibited an MLN as the largest LN. CONCLUSIONS: Pre-operative multi-detector computed tomography has limited ability in estimating the presence of metastasis in LNs because most MLNs are less than 10 mm, and only a small proportion of the LNP group exhibits an MLN as the largest MLN.
Diagnosis ; Humans ; Lymph Nodes* ; Neoplasm Metastasis* ; Pathology ; Stomach Neoplasms*

OBJECTIVETo evaluate the clinical significance of No.12 lymph node dissection for advanced gastric cancer with D2 lymphadenectomy.

METHODSClinicopathologic data and No.12 lymph node dissection of 256 advanced gastric cancer patients undergoing radical operation in our department between January 2005 and December 2010 were retrospectively summarized and the influence factors of metastasis in No.12 lymph nodes were analyzed.

RESULTSOf 256 patients, 179 were male and 77 were female with the average age of 59.2 years. Tumor located in the upper of stomach in 24 cases, middle of stomach in 41 cases, lower of stomach in 174 cases, multi-focus or diffuse distribution of stomach in 17 cases. Tumor diameter was <3 cm in 39 cases, 3 to 5 cm in 100 cases, >5 cm in 117 cases. Serum carcinoembryonic antigen (CEA) level increased in 61 cases, serum carbohydrate antigens (CA)72-4 increased in 56 cases and CA19-9 increased in 61 cases. The number of No.12 lymph nodes resected from all the patients was 1 152, and the average number was 4.5±1.9. The metastasis rate of No.12 lymph nodes was 9.4%(24/256) after hematoxylin eosin staining (positive group). All the patients received effective follow-up to December 2015, and the average follow-up time was 101.2 months. The median survival time of positive No.12 group (24 cases) was 29.8 months and of negative No.12 group (232 cases) was 78.2 months, whose difference was statistically significant (χ=21.715, P=0.000). Univariate analysis found that No.12 lymph node metastasis was not associated with age, gender, tumor differentiation (all P>0.05), but was associated with tumor location, tumor diameter, invasive depth (all P<0.05), and was closely associated with Borrmann type, outside metastatic lymph nodes of No.12 and high levels of serum CEA, CA72-4 and CA19-9 (all P=0.000). Multivariate regression analysis found that tumor location (RR=2.452, 95%CI:1.537 to 3.267, P=0.000), Borrmann type (RR=1.864, 95%CI:1.121 to 3.099, P=0.016) and number of outside metastatic lymph nodes of No.12 (RR=2.979, 95%CI: 2.463 to 3.603, P=0.000) were the independent risk factors of the No.12 metastasis (P<0.05).

CONCLUSIONSMetastasis in No.12 lymph nodes indicates poorer prognosis. The No.12 lymph nodes of advanced gastric cancer patients with curative resection, especially those with the tumor located in the lower part, Borrmann type IIII(, outside metastatic lymph nodes of No.12, should be regularly cleaned.

Antigens, Tumor-Associated, Carbohydrate ; blood ; CA-19-9 Antigen ; blood ; Carcinoembryonic Antigen ; blood ; Female ; Follow-Up Studies ; Humans ; Lymph Node Excision ; methods ; Lymph Nodes ; pathology ; surgery ; Lymphatic Metastasis ; diagnosis ; pathology ; physiopathology ; Male ; Middle Aged ; Multivariate Analysis ; Neoplasm Grading ; statistics & numerical data ; Neoplasm Invasiveness ; Neoplasm Staging ; statistics & numerical data ; Prognosis ; Retrospective Studies ; Risk Factors ; Stomach Neoplasms ; blood ; mortality ; pathology ; Survival Rate

OBJECTIVETo analyze relationships between the tumor deposits (TD) and clinicopathologic features of gastric cancer and investigate the value of TD in staging and prognosis in gastric cancer patients.

METHODSRetrospective cohort study was conducted to evaluate the clinicopathologic data of 388 gastric cancer patients who underwent surgical procedures in Chinese PLA General Hospital between November 2011 and December 2012. Relationships between TD and clinicopathologic features were analyzed by χor Fisher exact tests. Survival curves were also generated by Kaplan-Meier method. The univariate and multivariate analysis were performed with Log-rank and COX proportional hazard model to examine the association between prognosis and TD.

RESULTSTD were observed in 67 (17.3%) of 388 gastric cancer patients, including 48 male patients (48/289, 16.6%) and 19 female patients (19/99, 19.2%). There were 40 patients (40/198, 20.2%) whose age was above 64 years old. TNM staging of positive TD patients was as follows: for pathology, there were 5 patients (5/64, 7.8%) in stage II(b, 6 patients (6/58, 10.3%) in stage III(a, 14 patients (14/75, 18.7%) in stage III(b, 30 patients (30/135, 22.2%) in stage III(c, 12 patients (12/39, 30.8%) in stage IIII( and no one in stage I(b or II(a; for T-staging, there were 2 patients (2/18, 11.1%) in stage T2, 2 patients (2/27, 7.4%) in stage T3, 36 patients (36/259, 13.9%) in stage T4a and 27 patients (27/84, 32.1%) in stage T4b; for N-stage, there were 5 patients (5/72, 6.9%) in stage N0, 6 patients (6/72, 8.3%) in stage N1, 19 patients (19/82, 23.2%) in stage N2, 27 patients (27/100, 27.0%) in stage N3a and 10 patients(10/62, 16.1%) in stage N3b; for M-stage, there were 12 patients (12/40, 30.0%) in distal metastases; for vascular invasion, there were 29 patients (29/129, 22.5%). Among positive TD patients, the number of TD >3 was found in 38 of 67 cases(56.7%). TD was associated with pTNM-stage (χ=16.898, P=0.010), T-stage (χ=17.382, P=0.001), N-stage (χ=18.080, P=0.001), M-stage (χ=5.060, P=0.036) and vascular invasion(χ=3.675, P=0.039). The median survival time of positive TD patients was significantly shorter as compared to negative TD patients (22 months vs. 32 months, χ=23.391, P=0.012). Among positive TD patients, the median survival time of patients with TD number >3 was significantly shorter as compared to those with TD number <3 (17 months vs. 25 months, χ=5.157, P=0.023). Multivariate survival analysis showed that TD number >3 was the independent risk factor of prognosis (RR=2.350, 95%CI:1.345 to 4.106, P=0.003).

CONCLUSIONSTD state is closely associated with the staging of gastric cancer and TD number >3 indicates a poor prognosis.

Aged ; China ; Cohort Studies ; Female ; Humans ; Lymphatic Metastasis ; Male ; Middle Aged ; Multivariate Analysis ; Neoplasm Invasiveness ; pathology ; Neoplasm Metastasis ; Neoplasm Staging ; methods ; statistics & numerical data ; Prognosis ; Proportional Hazards Models ; Retrospective Studies ; Risk Factors ; Stomach Neoplasms ; classification ; diagnosis ; mortality ; pathology ; Survival Rate

OBJECTIVETo explore the risk factors and prognosis of No.8p lymph node metastasis in cases with advanced gastric cancer.

METHODSClinicopathological and follow-up data of 790 cases with advanced gastric cancer undergoing gastrectomy (including No.8p lymphadenectomy) from October 2003 to October 2013 in Fujian Provincial Tumor Hospital were analyzed retrospectively. Patients receiving neoadjuvant chemotherapy were excluded. Associations of No.8p lymph node metastasis with clinicopathological characteristics and metastasis in other regional lymph node were analyzed. Prognostic difference between positive No.8p group and negative No.8p group was examined.

RESULTSPositive No.8p lymph node was found in 93 cases (11.8%) among 790 cases with advanced gastric cancer. Univariate analysis showed that gender [male 9.8%(56/572) vs. female 17.0%(37/218), P=0.005], preoperative CEA level [<5 μg/L 28.0%(61/218) vs. ≥5 μg/L 5.6%(32/572), P=0.005], tumor size[diameter <5 cm 3.8%(13/346) vs. ≥5 cm 18.0%(80/445), P=0.000], tumor location [gastric fundus and cardiac 10.7% (26/244) vs. gastric body 13.5% (30/222) vs. gastric antrum 10.1% (31/308) vs. total gastric 37.5%(6/16), P=0.007], Borrmann staging [type II( 1.9%(4/211) vs. type III( 11.6% (54/464) vs. type IIII( 30.4%(35/115), P=0.000], tumor differentiation [high 0/8 vs. moderate 6.7%(25/372) vs. low 16.6%(68/410), P=0.000], T staging [T2 2.4%(4/170) vs. T3 13.1%(35/267) vs. T4 15.3%(54/353), P=0.000], N staging [N0 0 (0/227) vs. N1 2.2%(5/223) vs. N2 15.2%(26/171) vs. N3 36.7%(62/169), P=0.000] were closely associated with the No.8p lymph node metastasis. Multivariate analysis that revealed gender (OR=1.762, 95%CI: 1.020-3.043), tumor size (OR=1.107, 95%CI: 1.020-1.203), N staging (OR=4.093, 95%CI: 2.929-5.718), tumor differentiation (OR=1.782, 95%CI:1.042-3.049), and metastasis in No.8a(OR=5.370, 95%CI: 3.425-8.419), No.3(OR=1.127, 95%CI:1.053-1.206), No.6(OR=1.221,95%CI: 1.028-1.450), No.7(OR=2.149, 95%CI: 1.711-2.699), No,11p(OR=2.085, 95%CI: 1.453-2.994), No.14v(OR=2.604, 95%CI: 1.038-6.532) group lymph nodes were the independent risk factors of No.8p lymph node metastasis. One-year, 3-year and 5-year survival rates in positive No.8p group were 85.7%, 47.5% and 22.6%, and those in negative No.8p group were 96.2%, 82.5% and 70.3% respectively, whose differences were significant (χ=109.767, P<0.05).

CONCLUSIONSMetastasis in Np.8p lymph nodes is an important factor affecting the prognosis of patients with advanced gastric cancer. In patients with female gender, tumor diameter ≥5 cm, preoperative late N staging, low tumor differentiation or metastasis in No.8a, No.3, No.6, No.7, No.11p, No.14v group lymph nodes, thorough clean rance of No.8p group lymph node should be considered.

Carcinoembryonic Antigen ; blood ; Female ; Gastrectomy ; Humans ; Lymph Node Excision ; methods ; Lymph Nodes ; physiopathology ; surgery ; Lymphatic Metastasis ; diagnosis ; pathology ; physiopathology ; Male ; Multivariate Analysis ; Neoplasm Grading ; statistics & numerical data ; Neoplasm Staging ; statistics & numerical data ; Prognosis ; Retrospective Studies ; Risk Factors ; Sex Factors ; Stomach Neoplasms ; diagnosis ; mortality ; surgery ; Survival Rate

OBJECTIVETo investigate the clinicopathological characteristics, diagnosis, treatment and prognosis of patients with primary gastric adenosquamous cell carcinoma.

METHODSA total of 5 562 patients with gastric neoplasm were admitted in Tianjin Medical University Cancer Institute and Hospital from January 2001 to January 2011. Among them 42 patients were diagnosed as primary gastric adenosquamous cell carcinoma, accounting for 0.76% of all the patients. The clinicopathological and follow-up data of these 42 patients with primary gastric adenosquamous cell carcinoma were retrospectively analyzed, and Cox proportional hazard model was used to analyze the prognostic factors of gastric adenocarcinoma squamous cell carcinoma.

RESULTSAmong above 42 patients, 32 were male and 10 were female, with a male-to-female ratio of 3.2/1.0 and the average age was 63 years (range: 46 to 77 years). Five patients (11.9%) were confirmed as adenosquamous cell carcinoma by preoperative pathological examination, while other 37 patients were diagnosed as adenocarcinoma preoperatively. According to the 7th edition AJCC TNM classification system for gastric adenocarcinoma, 5 patients (11.9%) were in stage II(, 30 patients (71.4%) in stage III( and 7 patients (16.7%) in stage IIII(. The maximum tumor diameter was > 5 cm in 18 patients (42.9%). Borrmann type III(-IIII( was found in 29 patients (69.0%), and poorly differentiated (or undifferentiated) tumor was found in 32 patients (76.2%). Radical operations were performed in 31 patients (73.8%), the reasons of non radical operations included infiltration of pancreas in 3 patients, infiltration of radices mesocili transvers in 1 patient and classification of stage IIII( in 7 patients. Lymph node dissection was performed in 37 patients, 83.8% of them (31/37) was found with lymphatic metastases. Twenty-five patients received adjuvant chemotherapy except for 7 patients in stage IIII( and 10 patients who refused adjuvant chemotherapy. All the patients had an average survival time of 36.4 months and median survival time of 28.0 months, and the overall 1-, 3- and 5-year survival rates were 82.2%, 42.3% and 18.2% respectively. Univariate analysis revealed that tumor size (χ=4.039, P=0.044), Borrmann type (χ=18.728, P=0.000), tumor differentiation (χ=19.612, P=0.000), radical gastectomy (χ=41.452, P=0.000), lymph node metastasis (χ=9.689, P=0.002) and clinical stage (χ=26.277, P=0.000) were associated with postoperative survival. Multivariate analysis revealed that tumor differentiation (HR=10.560, 95%CI:2.263-49.281, P=0.003), radical gastrectomy (HR=4.309, 95%CI:1.311-14.168, P=0.016) and clinical stage (HR=2.392, 95%CI:1.022-5.600, P=0.044) were independent prognosis factors.

CONCLUSIONSPrimary gastric adenosquamous cell carcinoma is rare with poor prognosis. Radical gastrectomy is recommended. Tumor differentiation, radical gastrectomy and clinical stage are important indicators to evaluate prognosis of primary gastric adenosquamous cell carcinoma.

Adenocarcinoma ; diagnosis ; mortality ; pathology ; therapy ; Aged ; Carcinoma, Squamous Cell ; diagnosis ; mortality ; pathology ; therapy ; Chemotherapy, Adjuvant ; statistics & numerical data ; Female ; Gastrectomy ; methods ; statistics & numerical data ; Humans ; Lymph Node Excision ; statistics & numerical data ; Lymphatic Metastasis ; Male ; Middle Aged ; Multivariate Analysis ; Neoplasm Grading ; statistics & numerical data ; Neoplasm Invasiveness ; pathology ; Neoplasm Staging ; statistics & numerical data ; Prognosis ; Proportional Hazards Models ; Retrospective Studies ; Stomach Neoplasms ; diagnosis ; mortality ; pathology ; therapy ; Survival Rate