Comparing short-term outcomes of robot-assisted and conventional laparoscopic total mesorectal excision surgery for rectal cancer in elderly patients.

BACKGROUND: Da Vinci Robotics-assisted total mesorectal excision (TME) surgery for rectal cancer is becoming more widely used. There is no strong evidence that robotic-assisted surgery and laparoscopic surgery have similar outcomes in elderly patients with TME for rectal cancer. AIM: To determine the improved oncological outcomes and short-term efficacy of robot-assisted surgery in elderly patients undergoing TME surgery. METHODS: A retrospective study of the clinical pathology and follow-up of elderly patients who underwent TME surgery at the Department of Gastrointestinal Oncology at the Affiliated Hospital of Nanjing University of Chinese Medicine was conducted from March 2020 through September 2023. The patients were divided into a robot-assisted group (the R-TME group) and a laparoscopic group (the L-TME group), and the short-term efficacy of the two groups was compared. RESULTS: There were 45 elderly patients (≥ 60 years) in the R-TME group and 50 elderly patients (≥ 60 years) in the L-TME group. There were no differences in demographics, conversion rates, or postoperative complication rates. The L-TME group had a longer surgical time than the R-TME group [145 (125, 187.5) vs 180 (148.75, 206.25) min, P = 0.005), and the first postoperative meal time in the L-TME group was longer than that in the R-TME (4 vs 3 d, P = 0.048). Among the sex and body mass index (BMI) subgroups, the R-TME group had better outcomes than did the L-TME group in terms of operation time (P = 0.042) and intraoperative assessment of bleeding (P = 0.042). In the high BMI group, catheter removal occurred earlier in the R-TME group than in the L-TME group (3 vs 4 d, P = 0.001), and autonomous voiding function was restored. CONCLUSION: The curative effect and short-term efficacy of robot-assisted TME surgery for elderly patients with rectal cancer are similar to those of laparoscopic TME surgery; however, robotic-assisted surgery has better short-term outcomes for individuals with risk factors such as obesity and pelvic stenosis. Optimizing the learning curve can shorten the operation time, reduce the recovery time of gastrointestinal function, and improve the prognosis.

Helicobacter pylori infection is associated with the co-occurrence of bacteria in the oral cavity and the gastric mucosa.

BACKGROUND: Pathogens capable of impacting gastrointestinal tract tumor development are located in the oral cavity, but whether these oral bacteria are able to colonize the gastric mucosa in gastric cancer (GC) patients and whether Helicobacter pylori infection can influence this process remains to be established. METHODS: Microbial 16S rDNA deep sequencing was conducted to characterize bacteria present in paired gastric mucosa and tongue coating samples in 27 patients with superficial gastritis (SG) and 11 GC patients. RESULTS: While the overall composition of the gastric mucosa and tongue coating microbiomes differed substantially, certain bacteria were present in both of these communities. The co-occurrence of bacteria between the tongue coating and gastric mucosa differed significantly between SG and GC patients. Of the 15 most abundant shared oral bacteria genera (the core shared oral bacteria), which were associated with differences in microbiota composition between these tongue coating and gastric mucosa, three were enriched in the gastric mucosa of GC patients relative to SG patients, whereas, 12 were depleted in GC patient samples. Furthermore, the prevalence and relative abundance of these core shared oral bacteria in the gastric mucosa were also linked to H. pylori infection status, and the core shared oral bacteria were also associated with the overall composition of the gastric mucosal microbiome. CONCLUSIONS: Helicobacter pylori infections are linked to the co-occurrence of bacteria in the oral microbiome and the gastric mucosal microbiome. Ectopic colonization of oral microbes may be a primary driver of H. pylori-induced gastric microbial dysbiosis in patients with GC.

A Comparison of Tumor-Associated and Non-Tumor-Associated Gastric Microbiota in Gastric Cancer Patients.

BACKGROUND: How gastric cancer (GC) incidence is associated with changes in the gastric microbiome has not been firmly established. The present study therefore aims to investigate the microbial communities present within the gastric mucosa of patients with superficial gastritis (SG) or GC. METHODS: Paired tumor and paracancerous samples of the gastric mucosa were collected from 18 patients being surgically treated for GC and from 32 patients with SG being treated via gastroscopy. The gastric microbiome in these samples was then profiled via 16S rRNA sequencing, with a linear discriminant analysis effect size (LEfSe) approach used to identify and compare different bacteria, and with PICRUSt used for predictive functional analyses. RESULTS: GC patients exhibited a distinct gastric microbiota profile from that observed in SG patients. These changes were evident in both tumor and paracancerous tissues from GC patients. Specifically, we found that 6 bacterial genera were specifically enriched in GC tissue samples relative to SG samples, while 18 genera were depleted in these same samples. Based on the differential abundance of these bacteria, we were able to calculate microbial dysbiosis index (MDI) values, which were significantly higher in GC patients than in SG patients. In addition, MDI values were negatively correlated with gastric Shannon index and were positively correlated with relative Helicobacter spp. abundance. Importantly, these MDI values were readily able to discriminate between GC and SG patient samples. Functional analysis suggested that GC patients were more likely to harbor a nitrosating microbial community. CONCLUSIONS: GC patients exhibited a gastric microbiome profile distinct from that observed in SG patients, with these differences being evident in both tumor and paracancerous tissues. Differences in the relative abundance of Helicobacter spp. may be the primary driver of gastric dysbiosis in GC patients.

Identification of RING-box 2 as a potential target for combating colorectal cancer growth and metastasis.

Development of cancer metastasis is a key contributor to mortality in patients with colorectal cancer. High expression of RING-box 2 (RBX2) in cancer cells is known to play a key role in tumor progression. However, the role of RBX2 in colorectal cancer progression is not well elucidated. In this study, we silenced RBX2 via CRISPR/Cas9 in two colorectal cancer cell lines, HCT116 and SW480. RBX2 knockout attenuated proliferation, colony formation and enhanced sensitivity of colorectal cancer cells to paclitaxel treatment. Invasive property of HCT116 and SW480 cells was also attenuated by RBX2 silencing. We confirmed that increased RBX2 correlated with higher tumor cells growth and metastasis abilities by ectopic expression of RBX2 in HCT116 and SW480 cells. In vivo studies suggested that knockout of RBX2 inhibited xenografts growth and metastasis to lung tissue, whereas ectopic expression of RBX2 promoted these cellular functions. Mechanically, RBX2 induced gastric cancer cell growth and metastasis by activating mammalian target of rapamycin/S6 kinase 1 (mTOR/S6K1). Treatment of everolimus, the specific mTOR inhibitor, significantly attenuated RBX2-mediated cell proliferation and mobility in vitro. Taken together, these results revealed a novel role of RBX2 in colorectal cancer cell growth and metastasis via the mTOR pathway and suggested RBX2 may serve as a therapeutic target in colorectal cancer.

FOXQ1 promotes cancer metastasis by PI3K/AKT signaling regulation in colorectal carcinoma.

Colorectal cancer is one of the major health problems, with invade surrounding tissues, and migrate to distant organs being the most critical concern, thus identified metastasis associated hallmarks and more efficacious treatment are urgently needed. It found that forkhead box q1 (FOXQ1) is aberrant expression in variety of human cancers and FOXQ1 is involved in oncogenic pathways. However, the role of FOXQ1 has been unexplored in colorectal cancer metastasis to date. Here, expression of FOXQ1 was higher in colorectal cancer tissue samples and cancer cell lines than in normal colorectal tissue and cell lines. Further research suggested that FOXQ1 positively regulated cell proliferation in colorectal cancer and down-regulation of CDK6, extracellular regulated protein kinases 1/2 (ERK1/2) and mammalian target of rapamycin (mTOR). In corresponding to this result, over-expression of FOXQ1 significantly promoted colorectal cancer growth in vivo. Moreover, down regulation of FOXQ1 expression in colorectal carcinoma cell HCT116 and LOVO strikingly inhibits tumor growth in vivo. Finally, FOXQ1-dependent inhibition of colorectal cancer cell migration and invasion and down-regulation of focal adhesion kinase (FAK), phosphatidyl inositol 3-kinase (PI3K) phosphorylation, AKT (v-akt murine thymoma viral oncogene) phosphorylation and matrix metalloproteinase-2/9 (MMP-2/9) expression. These integrated efforts have identified FOXQ1 as a tumor promoter and might provide promising approaches for colorectal cancer metastasis treatment.

Shenmai injection enhances the cytotoxicity of chemotherapeutic drugs against colorectal cancers via improving their subcellular distribution.

Shenmai injection (SMI) is a Chinese patent-protected injection, which was mainly made of Red Ginseng and Radix Ophiopogonis and widely used for treating coronary heart disease and tumors by boosting Qi and nourishing Yin. In this study we examined whether SMI could produce direct synergetic effects on the cytoxicity of adriamycin (ADR) and paclitaxel (PTX) in colorectal cancers in vivo and in vitro, and explored the underlying pharmacokinetic mechanisms. BALB/c nude mice with LoVo colon cancer xenografts were intraperitoneally injected with ADR (2 mg·kg-1·3d-1) or PTX (7.5 mg·kg-1·3d-1) with or without SMI (0.01 mL·g-1·d-1) for 13 d. Co-administration of SMI significantly enhanced the chemotherapeutic efficacy of ADR and PTX, whereas administration of SMI alone at the given dosage did not produce visible anti-cancer effects, The chemosensitizing action of SMI was associated with increased concentrations of ADR and PTX in the plasma and tumors. In Caco-2 and LoVo cells in vitro, co-treatment with SMI (2 µL/mL) significantly enhanced the cytotoxicity of ADR and PTX, and resulted in some favorable pharmacokinetic changes in the subcellular distribution of ADR and PTX. In addition, SMI-induced intracellular accumulation of ADR was closely correlated with the increased expression levels of P-glycoprotein in 4 colon cancer cell lines (r2=+0.8558). SMI enhances the anti-cancer effects of ADR and PTX in colon cancers in vivo and in vitro by improving the subcellular distributions of ADR and PTX.

Identification of HRAS as cancer-promoting gene in gastric carcinoma cell aggressiveness.

Gastric carcinoma is one of the most lethal malignancies of cancers and its prognosis remains dismal due to the paucity of effective therapeutic targets. Herein, we showed that HRAS is markedly up-regulated in gastric carcinoma. Prognostic analysis indicated that HRAS expression might be a prognostic indicator for the survival of patients with gastric carcinoma. Ectopic expression of HRAS in gastric carcinoma cells accelerated proliferation, migration, invasion, angiogenesis, and clone formation ability of gastric carcinoma cells in vitro. Furthermore, HRAS over-expressing significantly promoted the tumorigenicity of gastric carcinoma cells in vivo whereas silencing endogenous HRAS caused opposite outcomes. Moreover, we demonstrated that HRAS enhanced gastric carcinoma aggressiveness by activating VEGFA/PI3K/AKT pathway and Raf-1 signaling. Together, our results provide new evidence that HRAS overexpression promotes the progression of gastric carcinoma and might represent a novel therapeutic target for its treatment.

Regional Arterial Infusion Chemotherapy improves the Pathological Response rate for advanced gastric cancer with Short-term Neoadjuvant Chemotherapy.

To identify clinicopathologic and treatment variables that could predict pathologic tumor response to short-term neoadjuvant chemotherapy (NAC) for patients with locally advanced gastric cancer. A retrospective analysis was conducted of 178 patients who underwent short-term NAC with EOX regimen followed by surgery from January 2008 to December 2010. Neoadjuvant treatment response was evaluated using tumor regression grade. Relationships between pathologic tumor response and clinicopathological factors were evaluated using logistic regression analysis. The benefits of regional arterial infusion chemotherapy were investigated separately. The postoperative pathological response rate was 46.1% (82/178) and 4 patients (2.2%) had complete pathological remission. Pathological response was significantly associated with tumor differentiation (P = 0.008), abnormal a-fetoprotein levels (P = 0.01) and administration approach to chemotherapy (intravenous versus regional arterial infusion chemotherapy) (P = 0.018). Most bone marrow toxicities, vomiting, nausea, alopecia, and fatigue were acceptable. Grade 3/4 toxicities were not commonly observed. The 3-year overall survival (OS) and recurrence free survival (RFS) were 67.0% and 53.0%, respectively. Regional arterial infusion NAC group had significantly better median RFS (48.0 versus 34.0 months) than the intravenous NAC group (P = 0.049). In conclusion, regional arterial infusion NAC can improve the pathological response rate of advanced gastric cancer treated with EOX regimen.

Formononetin, a novel FGFR2 inhibitor, potently inhibits angiogenesis and tumor growth in preclinical models.

Most anti-angiogenic therapies currently being evaluated in clinical trials target vascular endothelial growth factor (VEGF) pathway, however, the tumor vasculature can acquire resistance to VEGF-targeted therapy by shifting to other angiogenesis mechanisms. Therefore, other potential therapeutic agents that block non-VEGF angiogenic pathways need to be evaluated. Here we identified formononetin as a novel agent with potential anti-angiogenic and anti-cancer activities. Formononetin demonstrated inhibition of endothelial cell proliferation, migration, and tube formation in response to basic fibroblast growth factor 2 (FGF2). In ex vivo and in vivo angiogenesis assays, formononetin suppressed FGF2-induced microvessel sprouting of rat aortic rings and angiogenesis. To understand the underlying molecular basis, we examined the effects of formononetin on different molecular components in treated endothelial cell, and found that formononetin suppressed FGF2-triggered activation of FGFR2 and protein kinase B (Akt) signaling. Moreover, formononetin directly inhibited proliferation and blocked the oncogenic signaling pathways in breast cancer cell. In vivo, using xenograft models of breast cancer, formononetin showed growth-inhibitory activity associated with inhibition of tumor angiogenesis. Moreover, formononetin enhanced the effect of VEGFR2 inhibitor sunitinib on tumor growth inhibition. Taken together, our results indicate that formononetin targets the FGFR2-mediated Akt signaling pathway, leading to the suppression of tumor growth and angiogenesis.

Cyclooxygenase-2 knockdown using retinoic acid chalcone (RAC), a promising therapeutic strategy for colon cancer.

Retinoic acid is an effective agent in the treatment of epithelial and hematological malignancies. The present study demonstrates that retinoic acid chalcone (RAC), an analogue of retinoic acid inhibits cell proliferation and induces apoptosis in HCT-15 and CT26.WT colon cancer cell lines. In HCT-15 cells the percentage of apoptotic cells increased from 32.4 ± 3, 45.0 ± 3 to 72.6 ± 5% respectively at 10, 15 and 20 µg/mL compared to 3.7% in control. Similarly in CT26.WT cells the percentage increased from 28.6 ± 3, 41.2 ± 3 to 65.4 ± 5% on treatment with 10, 15 and 20 µg/mL concentrations of RAC after 72 h compared to 2.9 ± 1% in control. Western blotting, fluorescence-activated cell sorting analysis and reverse transcription-PCR assays were used to investigate these effects. RAC inhibited the overexpression of COX-2, PGE2 and PGE2 receptor (EP1 and EP4) in the colon cancer cell lines. RAC mediated inhibition of cell growth and induction of apoptosis through COX-2 inhibition was also confirmed by treating the HCT-15 and CT26.WT colon cancer cells with COX-2 inhibitor, indomethacin and transfection of cells with COX-2 small interfering RNA. In nude mice with tumor xenografts, treatment with RAC-supplemented diet caused inhibition of COX-2, PGE2, and PGE2 receptors (EP1, EP3, and EP4) in tumors. Thus RAC can be a potential candidate for the treatment of colon cancer through the inhibition of COX-2 expression and subsequent inhibition of PGE2 and PGE2 receptors.

Prognosis after resection for hepatitis B virus-associated intrahepatic cholangiocarcinoma.

AIM: To investigate the prognostic factors after resection for hepatitis B virus (HBV)-associated intrahepatic cholangiocarcinoma (ICC) and to assess the impact of different extents of lymphadenectomy on patient survival. METHODS: A total of 85 patients with HBV-associated ICC who underwent curative resection from January 2005 to December 2006 were analyzed. The patients were classified into groups according to the extent of lymphadenectomy (no lymph node dissection, sampling lymph node dissection and regional lymph node dissection). Clinicopathological characteristics and survival were reviewed retrospectively. RESULTS: The cumulative 1-, 3-, and 5-year survival rates were found to be 60%, 18%, and 13%, respectively. Multivariate analysis revealed that liver cirrhosis (HR = 1.875, 95%CI: 1.197-3.278, P = 0.008) and multiple tumors (HR = 2.653, 95%CI: 1.562-4.508, P < 0.001) were independent prognostic factors for survival. Recurrence occurred in 70 patients. The 1-, 3-, and 5-year disease-free survival rates were 36%, 3% and 0%, respectively. Liver cirrhosis (HR = 1.919, P = 0.012), advanced TNM stage (stage III/IV) (HR = 2.027, P < 0.001), and vascular invasion (HR = 3.779, P = 0.02) were independent prognostic factors for disease-free survival. Patients with regional lymph node dissection demonstrated a similar survival rate to patients with sampling lymph node dissection. Lymphadenectomy did not significantly improve the survival rate of patients with negative lymph node status. CONCLUSION: The extent of lymphadenectomy does not seem to have influence on the survival of patients with HBV-associated ICC, and routine lymph node dissection is not recommended, particularly for those without lymph node metastasis.

Impact of occult hepatitis B virus infection on outcome after resection for non-B non-C hepatocellular carcinoma.

BACKGROUND: To investigate the clinicopathologic characteristics of patients with both hepatitis B virus-surface antigen and hepatitis C virus antibody negative hepatocellular carcinoma (non-B non-C HCC [NBNC-HCC]) and examine the impact of occult hepatitis B virus infection (OBI) on patients' survival. METHODS: All patients with OBI were identified from a database of patients with NBNC-HCC who underwent surgical resection between January 1, 2006, and December 31, 2008. Their clinicopathologic and survival characteristics were compared with NBNC-HCC patients without OBI. RESULTS: Out of the 86 NBNC-HCC patients, 59 patients (68.6%) with OBI. A higher prevalence of hepatitis B core antigen positive rate, low platelet count, portal hypertension, and liver cirrhosis were observed in NBNC-HCC patients with OBI. The 1- and 3-y recurrence free survival rates were 66% and 25% in OBI group and 89% and 70% in the no OBI group, respectively (P < 0.001). The 1-, 3-, and 5-y overall survival rates were 86%, 55%, and 51% in OBI group and 93%, 85%, and 66% in no OBI group, respectively (P = 0.112). Multivariate analysis revealed that OBI (hazard ratio [HR] = 2.122; 95% confidence interval [CI], 1.086-4.149; P = 0.028), liver cirrhosis (HR = 2.411; 95% CI, 1.337-4.345; P = 0.003), and vascular invasion (HR = 5.858; 95% CI, 2.799-12.261; P < 0.001) were independent poor prognostic factors for recurrence free survival of patients with NBNC-HCC. CONCLUSIONS: NBNC-HCC patients with OBI had a poorer prognosis. OBI can be a useful predictor for recurrence in patients with NBNC-HCC after surgery.

Insulin-like growth factor receptor-1 overexpression is associated with poor response of rectal cancers to radiotherapy.

AIM: To explore the potential correlation between insulin-like growth factor receptor-1 (IGF-1R) expression and rectal cancer radiosensitivity. METHODS: Eighty-seven rectal cancer patients (cTNM I-III) treated in our department between January 2011 and December 2012 were enrolled. All subjects were treated with preoperative radiotherapy and radical resection of rectal carcinoma. Immunohistochemistry and reverse transcription polymerase chain reaction (RT-PCR) were performed to detect IGF-1R expression in pre-treatment and postoperative colorectal cancer specimens. Radiosensitivity for rectal cancer specimens was evaluated by observing rectal carcinoma mass regression combined with fibrosis on HE staining, degree of necrosis and quantity of remaining tumor cells. The relative IGF-1R expression was evaluated for association with tumor radiosensitivity. RESULTS: Immunohistochemistry showed diffuse IGF-1R staining on rectal cancer cells with various degrees of signal density. IGF-1R expression was significantly correlated with cTNM staging (P = 0.012) while no significant association was observed with age, sex, tumor size and degree of differentiation (P = 0.424, 0.969, 0.604, 0.642). According to the Rectal Cancer Regression Grades (RCRG), there were 31 cases of RCRG1 (radiation sensitive), 28 cases of RCRG2 and 28 cases of RCRG3 (radiation resistance) in 87 rectal cancer subjects. IGF-1R protein hyper-expression was significantly correlated with a poor response to radiotherapy (P < 0.001, r = 0.401). RT-PCR results from pre-radiation biopsy specimens also showed that IGF-1R mRNA negative group exhibited a higher radiation sensitivity (P < 0.001, r = 0.497). Compared with the pre-radiation biopsy specimens, the paired post-operative specimens showed a significantly increased IGF-1R protein and mRNA expression in the residual cancer cells (P < 0.001, respectively). CONCLUSION: IGF-1R expression level may serve as a predictive biomarker for radiosensitivity of rectal cancer before preoperative radiotherapy.

Growth hormone protects colorectal cancer cells from radiation by improving the ability of DNA damage repair.

The present study aimed to examine the effects of recombinant human growth hormone (rhGH) on the sensitivity of a colorectal cancer cell line to radiotherapy, and to investigate its association with DNA damage and repair. Flow cytometry and immunofluorescence were employed to detect growth hormone receptor (GHR) expression in nine human colorectal cancer cell lines. A colony forming assay was performed to measure the colorectal cancer cell proliferation post­radiotherapy, as an indicator of radiotherapy sensitivity. The comet assay results were interpreted as an indicator of radiotherapy­induced DNA damage, and growth arrest and DNA damage 45 (GADD45) and apurinic/apyrimidinic endonuclease (APEN) protein expression were quantified with western blot analysis from the same cell lines. The results demonstrated that the colony­forming efficiency (CFE) was significantly increased in HCT­8 cells subject to radiotherapy and rhGH pretreatment compared with the cells treated with radiotherapy alone, in a dose­dependent manner (0­100 mg/l). This effect was enhanced under high doses of radiation (8 Gy; 52.1±2.9 vs. 21.0±2.7; P<0.001) and was ameliorated with GHR neutralizing antibody exposure. By contrast, rhGH pre­incubation did not change the colony formation rate in GHR(­) LOVO cells. rhGH intervention reduced the early HCT­8 cell DNA damage (21.53±2.88 vs. 36.56±3.93; P=0.003) as well as the following plateau phase, compared with cells treated with radiotherapy alone (5.5±0.42 vs. 9.07±0.84; P=0.012). rhGH upregulated GADD45 and APEN protein expression, which is associated with cellular stress responses and DNA damage repair (P=0.007). The results suggest that rhGH is able to protect colorectal cancer cells from radiation through the interaction with GHR, which is associated with the promotion of DNA damage repair activity.

[Expression of survivin in human gastric adenocarcinomas: correlation with proliferation and apoptosis].

OBJECTIVE: To investigate the expression and significance of survivin, ki-67 and apoptosis index in patients with advanced gastric adenocarcinoma. METHODS: Immunohistochemical SP method for survivin expression as well as cell proliferative index (ki-67) and apoptosis index (TUNEL) was conducted on 120 gastric adenocarcinomas. RESULTS: The survivin was detected in the cytoplasm of carcinoma cells in 59 (49.17%) of the 120 gastric adenocarcinomas, in 32 (64.00%) of the lymph node metastasis, and in 21 (17.50%) of the 120 basal layer in normal gastric mucosa, respectively. The mean proliferative index (ki-67) in primary tumors was 7.55%, which was significantly lower than the mean proliferative index of 8.34% observed in lymph node metastasis. The mean apoptosis index in primary tumors was 1.16%, which was significantly higher than the mean apoptosis index of 0.89% observed in lymph node metastasis. The frequency of survivin expression was significantly higher in lymph node metastasis than in primary gastric adenocarcinoma. Expression of survivin was significantly correlated with histological subtypes, the depth of invasion, or lymph node metastasis (P < 0.05). There was negative correlation between weighted survivin score and apoptosis index (P < 0.05), but no correlation with proliferative index. CONCLUSION: The high level expression of survivin might be a referenced indicator in evaluating differentiation of tumor and in predicting lymph nodes metastasis and estimating apoptosis index.

Significance of effector protease receptor-1 expression and its relationship with proliferation and apoptotic index in patients with primary advanced gastric adenocarcinoma.

AIM: To investigate the expression of effector protease receptor-1 (EPR-1), proliferative index ki-67 and apoptosis index in patients with primary advanced gastric adenocarcinoma and to clarify the significance of EPR-1 expression and its correlationship with the proliferation and apoptosis indexes. METHODS: Using immunohistochemical staining and terminal deoxynucleotidyl transferase mediated nick end labelling (TUNEL) technique, we determined the expression of EPR-1, proliferative index (Ki-67) and apoptotic index (AI) in 120 paraffin-embedded specimens of primary advanced gastric adenocarcinoma as well as lymph node metastasis and adjacent normal tissues. RESULTS: EPR-1 expression was distributed in the cytoplasm of normal gastric mycoderma, carcinoma cells and smooth muscle cells. The positive rate of EPR-1 expression in the primary gastric adenocarcinomas, invasion tumor node and lymph node metastasis was 65.83%, 55.29% and 68%, respectively. While the positive rate in normal gastric mycoderma and smooth muscle cells was 46.7% and 53.3%, respectively. The average positive rate of ki-67 in EPR-1-positive tumors was 7.00% which was significantly lower than that of 8.53% in EPR-1-negative tumors, but the average AI in EPR-1-positive tumors was 1.25%, which was significantly higher than that of 1.00% observed in EPR-1-negative tumors. On the other hand, the average positive labeling index for Ki-67 (ki-67) in EPR-1-positive lymph node metastasis was 7.65%, which was significantly lower than that of 9.44% observed in EPR-1-negative lymph node metastasis. However, the average AI in EPR-1-positive lymph node metastasis tumors was 0.99%, which was significantly higher than that of 0.67% observed in EPR-1-negative lymph node metastasis. CONCLUSION: The frequency of EPR-1 expression was significantly higher in primary gastric adenocarcinoma and in its lymph node metastasis than that in normal gastric mucosa. Expression of EPR-1 was significantly correlated with tumor histological subtypes and tumor differentiation. Weighted EPR-1 Score is positively correlated with apoptosis index, but is negatively related with proliferative index. Thus, Weighted EPR-1 Score and EPR-1 expression in gastric adenocarcinoma cells maybe a potential marker in clinical setting.