Gastric Cancer: Endoscopic Diagnosis and Staging

Homocystein, Vitamin B12 and Folic Acid as Screening Biomarkers in Early Diagnosis and Gastric Cancer Monitoring

Gastric cancer has been demonstrating a reduction in the number of cases over the past decades, largely attributed to advancements in public health practices and increased accessibility to educational initiatives for the general population. Nevertheless, it persists as the third leading cause of mortality globally among both men and women. These fatalities are typically associated with delayed disease detection. The current study assessed the levels of homocysteine, vitamin B12, and folic acid as a means of establishing a screening biomarker profile that could be integrated into routine testing protocols to facilitate swift diagnosis of the illness. A total of 207 control subjects and 207 individuals with gastric cancer were scrutinized, with biochemical measurements conducted using chemiluminescence for homocysteine, folic acid, and vitamin B12. The two groups were matched based on age, tumor location, subtype, tumor classification, presence of Epstein-Barr Virus infection (EBV), and Helicobacter pylori (H. pylori). Significant statistical variances were identified in the mean levels of the triad of substances among cancer patients when compared to the control group for all corresponding variables. In conclusion, our study indicated that analyzing the triad of homocysteine, vitamin B12, and folic acid holds diagnostic value for gastric cancer and could potentially serve as an effective screening marker for this type of cancer in the future.

Bovine Omasum-Inspired Interfacial Carbon-Based Nanocomposite for Saliva Metabolic Screening of Gastric Cancer

Gastric cancer is one of the most common malignant digestive cancers, and its diagnostic has still faced challenges based on metabolic analysis due to complex sample pretreatment and low metabolite abundance. In this study, inspired by the structure of bovine omasum, we in situ synthesized a novel interfacial carbon-based nanocomposite of graphene supported nickel nanoparticles-encapsulated in the nitrogen-doped carbon nanotube (Ni/N-CNT/rGO), which was served as a novel matrix with enhanced ionization efficiency for the matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS) saliva metabolic analysis of gastric cancer. Benefiting from its high sp² graphitic degree, large surface area, strong UV absorption, and rich active sites, Ni/N-CNT/rGO matrix exhibited excellent performances of reproducibility, coverage, salt-tolerance, sensitivity, and adsorption ability in MALDI-TOF MS. The differential scanning calorimetry (DSC) and thermal conversion behaviors explained the highly efficient LDI mechanism. Based on saliva metabolic fingerprints, Ni/N-CNT/rGO assisted LDI MS with cross-validation analysis could successfully distinguish gastric cancer patients from healthy controls through the screening of four potential biomarkers with an accuracy of 92.50%, specificity of 88.03%, and sensitivity of 97.12%. This work provided a fast and sensitive MS sensing platform for the metabolomics characterization of gastric cancer and might have potential value for precision medicine in the future.

Endoscopic advances in the management of gastric cancer and premalignant gastric conditions

Gastric cancer is the fifth most common cancer and in 2018, it was the third most common cause of cancer-related deaths worldwide. Endoscopic advances continue to be made for the diagnosis and management of both early gastric cancer and premalignant gastric conditions. In this review, we discuss the epidemiology and risk factors of gastric cancer and emphasize the differences in early vs late-stage gastric cancer outcomes. We then discuss endoscopic advances in the diagnosis of early gastric cancer and premalignant gastric lesions. This includes the implementation of different imaging modalities such as narrow-band imaging, chromoendoscopy, confocal laser endomicroscopy, and other experimental techniques. We also discuss the use of endoscopic ultrasound in the diagnosis and staging of early gastric cancer. We then discuss the endoscopic advances made in the treatment of these conditions, including endoscopic mucosal resection, endoscopic submucosal dissection, and hybrid techniques such as laparoscopic endoscopic cooperative surgery. Finally, we comment on the current suggested recommendations for surveillance of both gastric cancer and its premalignant conditions.

Gastric cancer in 2022: Is there still a role for endoscopic ultrasound?

Gastric cancer (GC) represents the fourth leading cause of cancer death worldwide and many factors can influence its development (diet, geographic area, genetic, Helicobacter pylori or Epstein-Barr virus infections). High quality endoscopy represents the modality of choice for GC diagnosis. The correct morphologic classification during a high-resolution endoscopy is fundamental for oncologic diagnosis, staging and therapeutic decisions. Since its initial introduction in clinical practice the endoscopic ultrasound (EUS) has been considered a valuable tool for tumor (T-) and lymph nodes (N-) staging also in GC, in order to establish the best therapeutic strategy for the patient (e.g., upfront surgery vs neoadjuvant treatments). EUS tools as elastography, Doppler and contrast administration can improve diagnosis mainly in case of malignant lymph node evaluation. EUS has a marginal role in disease staging but has a fundamental role in case of a pre-endoscopic resection management and in the new era of endoscopic mucosal resection or submucosal dissection as minimally invasive surgery. Diagnosis and locoregional staging of GC with EUS are a method of inarguable value for the assessment of gastric wall involvement and presence of infiltrated paragastric lymph nodes. EUS can also have a role in disease restaging in those patients who have undergone neoadjuvant treatment. EUS can also have a role in the advanced phases of the disease, in facilitating palliative, minimally-invasive treatments, such as gastroenterostomy or biliary drainages. This review intends to discuss the modern role of EUS in GC topic.

Circulating Exosomal Gastric Cancer-Associated Long Noncoding RNA1 as a Biomarker for Early Detection and Monitoring Progression of Gastric Cancer: A Multiphase Study

Questions

What role does circulating exosomal long noncoding RNA-GC1 (lncRNA-GC1) play in gastric cancer (GC), and does lncRNA-GC1 exhibit sufficient diagnostic performance for detecting early-stage GC and for monitoring disease progression?

Findings

In this multiphase study involving 826 participants, including patients with GC, patients with gastric precancerous lesions, and healthy donor individuals, circulating exosomal lncRNA-GC1 served as a noninvasive biomarker for detecting early-stage GC and for monitoring disease progression.

Meaning

For patients with gastric cancer, detection of circulating exosomal lncRNA-GC1 may improve the early diagnostic rate and monitor disease progression.

Importance

The gastric cancer (GC)–associated long noncoding RNA1 (lncRNA-GC1) plays an important role in gastric carcinogenesis. However, exosomal lncRNA-GC1 and its potential role in GC are poorly understood.

Objective

To evaluate the diagnostic value of circulating exosomal lncRNA-GC1 for early detection and monitoring progression of GC.

Design, Setting, and Participants

We performed a multiphase investigation of circulating exosomal lncRNA-GC1 for early detection of GC involving consecutive patients with GC (n = 522), patients with gastric precancerous lesions (n = 85), and healthy donor individuals (HDs; n = 219) from December 2016 to February 2019 at Chinese People’s Liberation Army General Hospital, China. LncRNA-GC1 was measured by reverse transcription–polymerase chain reaction by independent researchers who had no access to patients’ information. Receiver operating characteristic curves were used to calculate diagnostic efficiency in comparison between lncRNA-GC1 and 3 traditional biomarkers (carcinoembryonic antigen [CEA], cancer antigen 72-4 [CA72-4], and CA19-9).

Main Outcomes and Measures

Assessment of diagnostic efficiency on the basis of area under curve (AUC), specificity, and sensitivity.

Results

Of the 826 patients included in the study, 508 were men (61.5%), and the median age of all patients was 60 years (range, 28-82 years). In the test phase, lncRNA-GC1 achieved better diagnostic performance than the standard biomarkers CEA, CA72-4, and CA19-9 (AUC = 0.9033) for distinguishing between the patients with GC and HDs. Additionally, exosomal lncRNA-GC1 levels were significantly higher in culture media from GC cells compared with those of normal gastric epithelial cells (t = 5.310; P = .002). In the verification phase, lncRNA-GC1 retained its diagnostic efficiency in discriminating patients with GC from those with gastric precancerous lesions as well from HDs. Moreover, lncRNA-GC1 exhibited a higher AUC compared with those of CEA, CA72-4, and CA19-9 for early detection of GC with sufficient specificity and sensitivity, especially for patients with GC with negative standard biomarkers. Moreover, the levels of circulating exosomal lncRNA-GC1 were significantly associated with GC from early to advanced stages (HD vs stage I, t = 20.98; P < .001; stage I vs stage II, t = 2.787; P = .006; stage II vs stage III, t = 4.471; P < .001; stage III vs stage IV, t = 1.023; P = .30), independent of pathological grading and Lauren classification (pathological grading: HD vs G1, t = 21.09; P < .001; G1 vs G2, t = 0.3718; P = .71; G2 vs G3, t = 0.3598; P = .72; Lauren classification: t = 24.81; P <.001). In the supplemental phase, the levels of circulating exosomal lncRNA-GC1 were consistent with those in GC tissues and cells and were higher compared with those in normal tissues and cells. Furthermore, the levels of circulating lncRNA-GC1 were unchanged after exosomes were treated with RNase and remained constant after prolonged exposure to room temperature or after repeated freezing and thawing (t = 1.443; P = .39). Total circulating lncRNA-GC1 was nearly all packaged within exosomes rather than a free form in plasma.

Conclusions and Relevence

Circulating exosomal lncRNA-GC1 may serve as a noninvasive biomarker for detecting early-stage GC and for monitoring disease progression. Combining circulating exosomal lncRNA-GC1 detection with endoscopy could improve the early diagnostic rate of GC.

MEF2A-mediated lncRNA HCP5 Inhibits Gastric Cancer Progression via MiR-106b-5p/p21 Axis

Background: Long non-coding RNAs (lncRNAs) are deemed to be relevant to the tumorigenesis and development of a variety of tumors, containing gastric cancer (GC). The purpose of our investigations is to explore the character of HCP5 in GC.

Methods: HCP5 expression was detected by quantitative real-time polymerase chain reaction (qRT-PCR) in 62 matched GC tissues and corresponding para-carcinoma tissues. In vitro and in vivo functional assays were subjected to verify the biological effects of HCP5 after alteration of HCP5. Chromatin immunoprecipitation assay (CHIP) assays were conducted to confirm that myocyte enhancer factor 2A (MEF2A) could bind to HCP5 promoter regions and thereby induce HCP5 expression. Analysis of the latent binding of miR-106b-5p to HCP5 and p21 was made by bioinformatics prediction and luciferase reporter assays.

Results: Significant downregulation of HCP5 was detected in GC tissues. Negative correlation was determined between HCP5 expression level and tumor size and overall survival in GC patients. HCP5 depletion had a facilitating impact on proliferation, migration and invasion of GC cells. Consistently, overexpression of HCP5 came into an opposite effect. Moreover, we demonstrated that MEF2A could combine with the promoter region of HCP5 and thereby induce HCP5 transcription. Luciferase reporter assays revealed that HCP5 could compete with miR-106b-5p as a competing endogenous RNA (ceRNA) and upregulated p21 expression in GC.

Conclusions: MEF2A-mediated HCP5 could exert an anti-tumor effect among the development of GC via miR-106b-5p/p21 axis, which provides a novel target for GC therapy.

Precision medicine in gastric cancer

Gastric cancer (GC) is a complex disease linked to a series of environmental factors and unhealthy lifestyle habits, and especially to genetic alterations. GC represents the second leading cause of cancer-related deaths worldwide. Its onset is subtle, and the majority of patients are diagnosed once the cancer is already advanced. In recent years, there have been innovations in the management of advanced GC including the introduction of new classifications based on its molecular characteristics. Thanks to new technologies such as next-generation sequencing and microarray, the Cancer Genome Atlas and Asian Cancer Research Group classifications have also paved the way for precision medicine in GC, making it possible to integrate diagnostic and therapeutic methods. Among the objectives of the subdivision of GC into subtypes is to select patients in whom molecular targeted drugs can achieve the best results; many lines of research have been initiated to this end. After phase III clinical trials, trastuzumab, anti-Erb-B2 receptor tyrosine kinase 2 (commonly known as ERBB2) and ramucirumab, anti-vascular endothelial growth factor receptor 2 (commonly known as VEGFR2) monoclonal antibodies, were approved and introduced into first- and second-line therapies for patients with advanced/metastatic GC. However, the heterogeneity of this neoplasia makes the practical application of such approaches difficult. Unfortunately, scientific progress has not been matched by progress in clinical practice in terms of significant improvements in prognosis. Survival continues to be low in contrast to the reduction in deaths from many common cancers such as colorectal, lung, breast, and prostate cancers. Although several target molecules have been identified on which targeted drugs can act and novel products have been introduced into experimental therapeutic protocols, the overall approach to treating advanced stage GC has not substantially changed. Currently, surgical resection with adjuvant or neoadjuvant radiotherapy and chemotherapy are the most effective treatments for this disease. Future research should not underestimate the heterogeneity of GC when developing diagnostic and therapeutic strategies aimed toward improving patient survival.

Introduction of plasmids into gastric cancer cells by endoscopic ultrasound

Short hairpin RNA of frizzled-2 (shRNA-Fz2) suppresses the cell proliferation of gastric cancer cells. Endoscopic ultrasound (EUS) is considered a suitable method for the introduction of therapeutic plasmids into cells, since the device enables the access and real-time monitoring of gastric cancer tissues. In the present study, plasmids were introduced into cells by sonoporation, as evidenced by the production of H₂O₂. The production of H₂O₂ was measured by absorbance of a potassium-starch solution irradiated with EUS. Luciferase activity was analyzed in the cells irradiated with EUS after the addition of a pMetLuc2-control in the media, and cell proliferation was analyzed using a 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium inner salt assay after irradiation with EUS following the addition of shRNA-Fz2. Absorbance levels corresponding to free radical levels were found to be higher in the cells irradiated with EUS. Luciferase activities were found to be significantly higher in the transfected cells (plasmid with Lipofectamine LTX) than in untreated cells and were furthermore found to be higher in MKN45 cells irradiated for 0.5 min than in cells not subjected to irradiation. Luciferase activity was also found to be higher in MKN74 cells irradiated for 2 min than in cells that were not irradiated. Although the cell proliferation of the MKN45 cells tended to be suppressed by irradiation with EUS, this was non-significant suppression, while the cell proliferation of MKN74 cells was found to be suppressed by irradiation with 12 MHz for 2 min (P<0.05). In conclusion, plasmids were introduced into cultured gastric cancer cells by irradiation with EUS due to sonoporation, as evidenced by the production of H₂O₂; however, the efficiency of the plasmid introduction was low compared with a traditional transfection approach.

Differences in the multimodal treatment of gastric cancer: East versus west

There has been a great deal of interest about varying treatment paradigms of gastric cancer in Eastern and Western countries. Differences in tumor biology, screening initiatives, surgical approach, extent of lymphadenectomy, and neoadjuvant versus adjuvant chemotherapy regimens have been studied and documented in the literature. The purpose of this review is to give an updated report on the current status and management differences in the treatment of gastric cancer between Eastern and Western countries.

Clinical significance and diagnostic value of serum CEA, CA19-9 and CA72-4 in patients with gastric cancer

AIMS

To evaluate the clinical significance of multiple serum tumor markers (TMs) in the diagnosis of gastric cancer (GC) and establish an accurate discriminant equation to identify the presence of GC.

RESULTS

The serum levels of CEA, CA19-9 and CA72-4 were higher in the GC group than in the control group (P < 0.005). The sensitivity of CEA, CA19-9 and CA72-4 in the diagnosis of GC was 20.1-27.6% individually and increased to 48.2% when they were considered in combination. By using the optimal cut-off value, the sensitivity of CEA, CA19-9 and CA72-4 for the diagnosis of GC was improved but remained unsatisfactory. In addition, we developed the equation Y = -2.185 - 0.015 X1 + 0.180 X2 + 1.226 X3 + 1.505 X4 + 2.749 X5 (X1 = Age, X2 = Sex, X3 =CEA, X4 = CA19-9 and X5 = CA72-4) to predict the presence of GC. This has better accuracy and diagnostic efficiency compared to the combination of TMs.

METHODS

Serum carcinoembryonic antigen (CEA), cancer antigen 19-9 (CA19-9)and cancer antigen 72-4 (CA72-4) levels were measured in a total of 2288 patients with GC and 1869 healthy volunteers or patients with benign gastric diseases. We established a diagnostic equation using a portion of the data (training set), and validate its accuracy using the other portion of the data (testing set) .

CONCLUSIONS

The diagnostic equation increases the accuracy rate for the diagnosis of GC and will be helpful in the clinic.

Plasma miR-940 may serve as a novel biomarker for gastric cancer

It was reported that circulating microRNAs could be applied as non-invasive biomarkers for cancer monitoring. The purpose of this study was to identify plasma miRNA that may serve as a novel biomarker for gastric cancer and to evaluate its clinical application. MicroRNA profiles were generated from plasma samples of 5 patients with gastric cancer (GC) versus 5 healthy controls (HC). MicroRNA-940 (miR-940) was one of the most downregulated miRNAs with fold change of 0.164. It was revealed that the expression of miR-940 was downregulated in both the initial set (N = 30, P < 0.0001) and the validation set (N = 80, P < 0.0001) of plasma samples of patients with gastric cancer. The sensitivity was obviously higher than the current biomarkers CEA and CA19-9 (81.25 % vs. 22.54 % and 15.71 %). MiR-940 was also significantly downregulated in gastric cancer tissue samples (N = 34, P = 0.0015), as well as in cancer cell lines (N = 7). Importantly, miR-940 was significantly highly expressed in stomach tissue samples than in other types of tissue samples including the liver, breast, thyroid, and lung. Moreover, there was a trend of lower expression of miR-940 from early to advanced stage of gastric cancer. Target prediction suggested that miR-940 regulated cell signaling including NF-κB and Wnt/β-catenin, as well as pathways of cell communication and adhesion. These pathways play critical roles in gastric cancer initiation and progression. It is the first report that miR-940 may mainly express in the stomach. Downregulation of plasma miR-940 may serve as a novel biomarker for detection of gastric cancer.

A tool to predict risk for gastric cancer in patients with peptic ulcer disease on the basis of a nationwide cohort

BACKGROUND & AIMS

Patients with gastric ulcers have significantly higher risk of gastric cancer, especially within 2 years after diagnosis. We used data from a national database to develop a personalized risk prediction model for patients with peptic ulcer diseases.

METHODS

We collected data from Taiwan's National Health Insurance Research Database on 278,898 patients admitted for the first time with a primary diagnosis of peptic ulcer disease. We used the data to develop a nomogram, which we validated by discrimination and calibration, and in a test cohort. Cumulative incidences of study subjects predicted by the nomogram were examined.

RESULTS

In total, 1269 subjects developed gastric cancer. Age, sex, peptic ulcer sites, peptic ulcer complications, Helicobacter pylori eradication, nonsteroidal anti-inflammatory drug use, and surveillance endoscopy were independent factors associated with risk of gastric cancer (all P < .001). The concordance index for the nomogram developed on the basis of these factors was 0.78. Study subjects were divided into quartiles of predicted risk scores; from lowest score quartile to highest, cumulative incidences at 1 year were 7.4/10,000 people, 14.2/10,000 people, 25.5/10,000 people, and 86.6/10,000 people. The cumulative incidences at 2 years were 9.3/10,000 people, 20.9/10,000 people, 38.0/10,000 people, and 135.7/10,000 people for the same quartiles of risk scores. The nomogram was validated in an independent cohort, and similar incidence values were determined.

CONCLUSIONS

We developed and validated a nomogram to predict risk for gastric cancer 1 and 2 years after diagnosis of peptic ulcer disease. The nomogram provides a prognostic tool that can be easily used for individuals and can help physicians explain risk levels to patients.

Is endoscopic ultrasonography still the modality of choice in preoperative staging of gastric cancer?

The treatment option for gastric cancer is usually based on preoperative staging by imaging modalities. Endoscopic ultrasonography (EUS) and computed tomography (CT) have been used as the diagnostic modality of choice in preoperative staging of gastric cancer. Magnetic resonance imaging (MRI) has been employed in several studies, and (¹⁸F) 2-Fluoro-2-deoxyglucose (FDG) positron emission tomography (PET) has emerged as a new promising imaging modality. The purpose of this article is to provide summarized information on preoperative staging using EUS, multi-detector row CT (MDCT), MRI and PET for gastric cancer. In T staging, both EUS and MDCT show high accuracy. MRI seemed to have better performance, but the number of MRI studies is limited. FDG-PET is not able to properly evaluate the depth of invasion. In N staging, the diagnostic accuracy of EUS, MDCT and MRI is not sufficient. In preoperative M staging, MDCT and FDG-PET showed similar diagnostic accuracies. FDG-PET/CT fusion could be expected to show better performance in the future. Physicians should keep in mind that each diagnostic modality has advantages and limitations and choose an appropriate diagnostic strategy tailored for each patient.

Lower serum folate is associated with development and invasiveness of gastric cancer

AIM: To evaluate the associations of serum folate level with development, invasiveness and patient survival of gastric cancer.

METHODS: In this nested case-control study, patients with newly diagnosed gastric cancer undergoing gastrectomy were enrolled, and patients receiving chemotherapy prior to surgery, with other concurrent malignancy, or of the aboriginal and alien populations were excluded. In total, 155 gastric cancer patients and 149 healthy controls were enrolled for determination of serum folate levels and their correlation with gastric cancer. Using the median value of serum folate computed among the overall population as the cutoff value, the associations between serum folate and gastric cancer in all cases and different age and gender subgroups were analyzed by multivariate logistic regression analysis. In the patient cohort of gastric cancer, receiver-operating characteristic analyses were performed to calculate the best cutoff values of serum folate, and the associations between serum folate levels and clinicopathological features were further analyzed by multivariate regression analysis. Survival analyses were conducted using the Cox proportional hazards model.

RESULTS: The mean serum folate level was significantly lower in gastric cancer patients than that in controls (3.71 ± 0.30 ng/mL vs 8.00 ± 0.54 ng/mL, P < 0.01), and folate levels were consistently lower in gastric cancer patients regardless of age and gender (all P < 0.01). Using the median serum folate value as the cutoff value, low serum folate was significantly associated with gastric cancer risk in the whole population (OR = 19.77, 95%CI: 10.54-37.06, P < 0.001) and all strata (age < 60 years OR = 17.39, 95%CI: 7.28-41.54, age ≥ 60 years (OR = 21.67, 95%CI: 8.27-56.80), males (OR = 17.95, 95%CI: 7.93-40.62), and females (OR = 20.95, 95%CI: 7.66-57.31); all P < 0.001. In the patient cohort of gastric cancer, the respective cutoff values showed that low serum folate levels were significantly associated with serosal invasion (OR = 2.54, 95%CI: 1.23-5.23), lymphatic invasion (OR = 2.23, 95%CI: 1.17-4.26), and liver metastasis (OR = 6.67, 95%CI: 1.28-34.91) of gastric cancer (all P < 0.05). Serum folate level below 1.90 ng/mL was associated with poor patient survival (HR = 1.84, 95%CI: 1.04-3.27, P < 0.05) in univariate analysis.

CONCLUSION: Lower serum folate levels were significantly associated with gastric cancer development and invasive phenotypes. The role of folate depletion in gastric cancer invasion warrants further study.

The Tumor Suppressor Roles of miR-433 and miR-127 in Gastric Cancer

The discovery of microRNAs (miRNAs) provides a new and powerful tool for studying the mechanism, diagnosis and treatment of human cancers. Currently, the methylation epigenetic silencing of miRNAs with tumor suppressor features by CpG island hypermethylation is emerging as a common hallmark of different tumors. Here we showed that miR-433 and miR-127 were significantly down-regulated in gastric cancer (GC) tissues compared with the adjacent normal regions in 86 paired samples. Moreover, the lower level of miR-433 and miR-127 was associated with pM or pTNM stage in clinical gastric cancer patients. The restored expression of miR-433 and miR-127 in GC cells upon 5-Aza-CdR and TSA treatment suggested the loss of miR-433 and miR-127 was at least partly regulated by epigenetic modification in GC. Furthermore, the ectopic expression of miR-433 and miR-127 in gastric cancer cell lines HGC-27 inhibits cell proliferation, cell cycle progression, cell migration and invasion by directly interacting with the mRNA encoding oncogenic factors KRAS and MAPK4 respectively. Taken together, our results showed that miR-433 and miR-127 might act as tumor suppressors in GC, and it may provide novel diagnostic and therapeutic options for human GC clinical operation in the near future.

Osteopontin promoter polymorphisms are associated with susceptibility to gastric cancer

GOALS

To evaluate the significance of osteopontin (OPN) genotypes in the susceptibility to gastric cancer.

BACKGROUND

The expression of OPN has been correlated with development, invasiveness, metastasis, and survival of gastric cancer, but the role of polymorphisms in the OPN promoter has not been investigated.

STUDY

We enrolled 146 gastric cancer patients and 128 controls. DNA was extracted from peripheral blood leucocytes. Single-nucleotide polymorphisms (SNPs) in the OPN promoter (-66, -156, -443, -616, -1748, and -1776) were analyzed by pyrosequencing and direct sequencing methods. Logistic regression analyses were used to evaluate the associations between SNPs and development of gastric cancer.

RESULTS

SNP -443 C/C and -616 T/T of the OPN promoter were significantly associated with gastric cancer [odds ratio (OR)=2.88; 95% confidence interval (CI), 1.16-7.12 and OR=1.95; 95% CI, 1.35-2.82, respectively]. Analysis of the combined effect of OPN promoter SNPs revealed that the combination of SNP -443 (T/C or C/C) and SNP -616 (T/T or T/G) had the most significant association with gastric cancer (OR=3.95; 95% CI, 1.58-9.90).

CONCLUSIONS

Our results suggest that polymorphisms in the OPN promoter are associated with the development of gastric cancer, and the combination of SNP -443 (T/C or C/C) and -616 (T/T or T/G) most significantly increases susceptibility to gastric cancer.