A risk score system to preoperatively predict TNM stages in gastric cancer. Am J Clin Oncol. 2011;34:130-134. [PMID: 20375834 DOI: 10.1097/coc.0b013e3181d31eeb]

Staging of gastric cancer with the Clinical Stage Prediction score

Background

Chemotherapy with or without surgery is the first-line treatment for stage III/IV gastric cancer, while surgery is the first-line treatment for stage I/II gastric cancer. Accordingly, it is important to distinguish between stage III/IV and stage I/II gastric cancer, but clinical staging is less accurate than pathological staging. This study was performed to develop a clinical score that could distinguish stage III/IV gastric cancer from stage I/II gastric cancer.

Methods

We reviewed 2722 patients who underwent gastrectomy at our hospital from January 1996 to December 2015. As pretreatment factors potentially related to tumor stage, we assessed age, sex, tumor markers, tumor diameter, tumor location, tumor histology, and macroscopic type. Factors showing significance on multivariate analysis were used to develop the Clinical Stage Prediction score (CSP score), and a cutoff value for the score was determined by receiver operating characteristics analysis.

Results

According to multivariate analysis, clinical factors associated with stage III/IV disease were elevation of the carcinoembryonic antigen level, tumor diameter ≥ 60 mm, circumferential gastric involvement, esophageal infiltration, mucinous adenocarcinoma, and macroscopic types 2–4.

The CSP score was obtained by weighting these factors according to the non-standardized β-coefficient. Receiver operating characteristics analysis indicated that the optimum cutoff value of the CSP score was 17 points. Among 1042 patients with a CSP score ≥ 17 points, 820 patients (78.7%) had stage III/IV gastric cancer. Conversely, among 1680 patients with a CSP score < 17 points, 1547 patients (92.1%) had stage I/II gastric cancer. When discrimination of stage III/IV gastric cancer from stage I/II gastric cancer by the CSP score was assessed, the sensitivity was 78.7%, specificity was 92.1%, positive predictive value was 86.0%, and negative predictive value was 87.5%.

Conclusions

The CSP score can be helpful for differentiating stage III/IV gastric cancer from stage I/II gastric cancer based on pretreatment clinical factors.

Computed Tomography Features associated With the Eighth Edition TNM Stage Classification for Thymic Epithelial Tumors

PURPOSE

The eighth edition of the TNM classification of malignant tumors for the first time includes an official staging system for thymic epithelial tumors (TETs) recognized by the American Joint Committee on Cancer (AJCC) and the Union for International Cancer Control (UICC). Staging is critical for the management of TETs, and determining stage accurately from imaging has the potential to improve clinical outcomes. We examine preoperative computed tomography (CT) characteristics of TETs associated with AJCC/UICC pathologic TNM stage.

MATERIALS AND METHODS

In this retrospective study, patients were included if they met all the following criteria: (1) diagnosis of TET, (2) had primary curative intent surgery performed at Stanford University, and (3) had available preoperative CT imaging for review. Tumor pathology was staged according to the eighth edition TNM classification. Fifteen CT scan features were examined from each patient case according to the International Thymic Malignancy Interest Group standard report terms in a blinded manner. A Lasso-regularized multivariate model was used to produce a weighted scoring system predictive of pathologic TNM stage.

RESULTS

Examining the 54 patients included, the following CT characteristics were associated with higher pathologic TNM stage when using the following scoring system: elevated hemidiaphragm (score of 6), vascular endoluminal invasion (score of 6), pleural nodule (score of 2), lobulated contour (score of 2), and heterogeneous internal density (score of 1). Area under the receiver operating characteristic curve was 0.76.

CONCLUSIONS

TETs with clearly invasive or metastatic features seen on CT are associated with having higher AJCC/UICC pathologic TNM stage, as expected. However, features of lobulated contour and heterogeneous internal density are also associated with higher stage disease. These findings need to be validated in an independent cohort.

ZNF280B promotes the growth of gastric cancer in vitro and in vivo

Zinc finger protein 280B (ZNF280B) mediates pro-survival and pro-growth functions in prostate cancer. However, in gastric cancer, its clinical significance remains poorly characterized. In the present study, the expression levels of ZNF280B in 60 patients with gastric cancer were examined using immunohistochemistry. The association between ZNF280B expression and clinicopathological features was assessed. Positive ZNF280B staining was demonstrated for 38 (63.3%) samples out of 60 gastric cancer cases in immunohistochemical analysis. ZNF280B expression was significantly associated with tumor size (P=0.017) and TNM stage (P=0.001). Furthermore, the proliferation index in the positive ZNF280B expression group was significantly higher (38.8±6.2) compared with that of the negative ZNF280B expression group (16.9±8.9; P<0.01). These results suggest that ZNF280B expression may be associated with the proliferation of gastric cancer cells. The role of ZNF280B in the growth of gastric cancer cells (MGC-803) was also investigated in vitro and in vivo by enhancing the expression of ZNF280B. A colony formation assay indicated that the number of colonies in the MGC-803 cells with enhanced ZNF280B (146±5.8) was significantly higher than that of the MGC-803 control group (97±5.1) and the negative control group (101±6.5; P<0.05). An MTT assay demonstrated that ZNF280B significantly promoted the proliferation of MGC-803 cells at days 3 and 4 (P<0.05). It was observed that the overexpression of ZNF280B may promote the growth of gastric cancer in vivo in xenograft studies. These findings indicate that ZNF280B may be a novel therapeutic target for gastric cancer.

New approaches to gastric cancer staging: Beyond endoscopic ultrasound, computed tomography and positron emission tomography

Currently, there is no single gold standard modality for staging of gastric cancer and several methods have been used complementarily in the each clinical situation. To make up for the shortcomings of conventional modalities such as endoscopic ultrasound, computed tomography and ¹⁸F-fluoro-2-deoxyglucose positron emission tomography, numerous attempts with new approaches have been made for gastric cancer staging. For T staging, magnifying endoscopy with narrow-band was evaluated to differentiate mucosal cancer from submucosal cancer. Single/double contrast-enhanced ultrasound and diffusion-weighted magnetic resonance imaging were also tried to improve diagnostic accuracy of gastric cancer. For intraoperative staging with sentinel node mapping, indocyanine green infrared and fluorescence imaging was introduced. In addition, to detect micrometastasis, real-time reverse transcription-polymerase chain reaction system with multiple markers was studied. Staging laparoscopy using 5-aminolevulinic acid-mediated photodynamic diagnosis and percutaneous diagnostic peritoneal lavage were also evaluated. However, most studies reporting new staging methods is preliminary and further studies for validation in clinical practice are needed. In this mini-review, we discuss new progress in gastric cancer staging. Especially, we focus on new diagnostic approach to gastric cancer staging beyond the conventional modalities and briefly review the remarkable clinical results of the studies published over the past three years.

Association of EMP1 with gastric carcinoma invasion, survival and prognosis

The aim of this study was to determine the expression and function of epithelial membrane protein 1 (EMP1) in gastric carcinoma. Gastric samples were taken from cancer lesions and adjacent normal tissue in gastric cancer patients immediately after endoscopic biopsy. A portion of the sample was either fixed in 4% paraformaldehyde and embedded in paraffin for immunohistochemistry or stored in liquid nitrogen for western blotting. In order to determine protein expression of EMP1 in gastric cancer (n=65) and normal tissue (n=27), semi-quantitative immunohistochemistry and western blotting were utilized. For in vitro studies, the human gastric cancer cell line SGC-7901 was maintained in RPMI-1640 medium supplemented with 10% fetal bovine serum. Recombinant lentivirus mediated overexpression of EMP1 in SGC-7901 cells was quantified with quantitative polymerase chain reaction (qPCR) and western blotting. Control SGC-7901 cells were transfected with an empty vector. To further study the effect of EMP1 overexpression in SGC-7901 cells, cell proliferation, cell apoptosis and migration and invasion assays were conducted. The expression of EMP1 was significantly lower in gastric cancer tissue compared to normal tissue using both immunohistochemistry (41.5 vs. 70.4% of tissues, P<0.05) and western blotting (0.153 ± 0.012 vs. 0.626 ± 0.058, P<0.05). Decreased expression of EMP1 was significantly correlated with tumor invasion, lymph node metastasis, clinical stage and histological grade of patients with gastric cancer (P<0.05). According to Kaplan-Meier analysis, low EMP1 expression correlated significantly with poor overall 5-year survival (47.4 vs. 70.3% survival, P<0.05). SGC-7901 cells transfected with EMP1 had a lower survival fraction, higher cell apoptosis (13.2 ± 1.5% vs. 2.2 ± 0.5%, P<0.05), significant decrease in migration and invasion (157.0 ± 16.0 and 112.0 ± 12.0, respectively vs. 243.0 ± 21.0 and 203.0 ± 19.0, respectively, P<0.05), higher caspase-9 (0.501 ± 0.050 vs. 0.114 ± 0.010, P<0.05) and lower VEGFC protein expression 0.135 ± 0.011 vs. 0.619 ± 0.074, P<0.05) relative to cells not transfected with EMP1. Low EMP1 expression in gastric cancer is associated with increased disease severity, suggesting that EMP1 may be a negative regulator of gastric cancer.

Evaluation of the staging systems for gastric cancer

BACKGROUND

Some staging systems for gastric cancer (GC) have been developed as alternatives to the 6th and 7th TNM staging systems, including the Hybrid, tumor-ratio-metastasis (TRM), and Kiel staging systems. This study evaluated the overall performance of these systems for GC.

METHODS

A total of 540 GC patients undergoing surgical resection were staged using these five systems. Homogeneity, discrimination power, predictive accuracy, and complexity of these systems were compared.

RESULTS

Multivariate analyses showed that all of 7th pT, pN, and pM classifications were independent factors for GC prognosis (P < 0.001 for all). Compared with the other four systems, 7th TNM system had improved stage groups homogeneity (7 of 8 stage groups homogeneous), enhanced discrimination power (4 of 5, 5 of 7, 4 of 7, 3 of 7, and 1 of 4 adjacent stage groups were differentiated by the 6th, 7th TNM, Hybrid, TRM, and Kiel systems, respectively), and better prediction value for GC patients' outcome (AUC = 0.801, P < 0.001). In addition, the 7th TNM system did not increase the staging complexity (9 groups and 21 subgroups).

CONCLUSIONS

The 7th TNM staging system represents advancement in GC staging system for better prediction of clinical outcomes.