Cadherin switching in oral squamous cell carcinoma: A clinicopathological study

Background and aim

Oral squamous cell carcinoma (OSCC) is one of the most common malignancies worldwide as it represents the sixth most common cancer. Numerous molecular mechanisms have been explained to regulate OSCC progression, including epithelial-mesenchymal transition (EMT). Cadherin switching is the pivotal process that controls EMT in which E-cadherin reduces while N-cadherin elevates. This work aimed to clarify the role of cadherin switching in OSCC.

Material and methods

Thirty paraffin-embedded tissue blocks of OSCC including six cases with lymph node metastasis were subjected to immunohistochemical staining using antibodies against E&N-cadherins. Cell cultures were performed using OSCC cell lines (SCC-15/SCC-25) from the human tongue. F-12K medium (Kaighn's Modification of Ham's F12 Medium) was added as EMT inducing media. E&N-cadherin mRNA gene expression levels were detected by real time-polymerase chain reaction (RT-PCR).

Results

Cadherin switching through N-cadherin elevation and E-cadherin reduction was evaluated at the histopathologic level in primary and metastatic OSCC as well as at the genetic level within OSCC cell culture. Cadherin switching showed a significant correlation between E&N-cadherins at different histopathological grades of OSCC and in metastatic OSCC. Moreover, the level of mRNA gene expression of E&N-cadherins in human 15 SCC and 25 SCC cell lines with EMT-inducing media exhibited a significant correlation.

Conclusions

Cadherin switching is a crucial event in the EMT process. It may be used as a significant tool in the study of OSCC progression. Cadherin switching plays a significant role in the invasion and metastasis of OSCC.

An association of epidermal growth factor receptor mutation subtypes with prognostic prediction and site-specific recurrence in advanced stage lung cancer patients

BACKGROUND

Concerning the different clinical behavior of epidermal growth factor receptor (EGFR) subtypes in advanced-stage lung cancer patients, the current study aimed to evaluate the clinical, pathological, and prognostic significance of EGFR mutation subtypes, and treatment response in patients with advanced-stage lung cancer.

METHODS AND RESULTS

A retrospective study enrolled a total of 346 patients with advanced-stage lung cancer tested for EGFR mutation. EGFR mutation was analyzed by amplification refractory mutation system-polymerase chain reaction (ARMS-PCR). Statistical analysis was performed using SPSS version 20.0. EGFR mutation was evident in 38% of patients with the highest prevalence of exon 19 deletions. A higher incidence of 19-deletions and 20-insertions were observed in young patients, while a higher incidence of L858R was noted in old age patients. Patients with de-novo T790M failed to improve their OS by any of the treatment modalities. Patients with de-novo T790M mutation have a higher risk of developing lung, liver, and multiple site metastases while patients with L858R mutation have a higher risk of developing brain metastasis. Additionally, patients with 19 deletion mutation did not improve their OS after receiving conventional chemotherapy hence, they demonstrate better survival only after EGFR-TKIs. Multivariate survival analysis predicted chemotherapy as an independent predictor of OS.

CONCLUSION

Besides clinicopathological and prognostic consequences of EGFR mutation and mutation subtypes, patients harboring TKI sensitive, or insensitive mutations reveal different secondary disease development and hence should be treated accordingly for better survival. Current findings may provide the basis for a better treatment strategy.

Metabolic tumor parameters complement clinicopathological factors in prognosticating advanced stage Hodgkin Lymphoma

Objectives

Advanced Hodgkin Lymphoma has a higher probability of relapse and recurrence. Classical clinicopathological parameters including the International Prognostic Score (IPS) have not been reliable in predicting prognosis or tailoring treatment. Since FDG PET/CT is the standard of care in staging Hodgkin Lymphoma, this study attempted to evaluate the clinical utility of baseline metabolic tumor parameters in a cohort of advanced Hodgkin lymphoma (stage III and IV).

Methods

Histology-proven advanced Hodgkin Patients presenting to our institute between 2012-2016 and treated with chemo-radiotherapy (ABVD / AEVD) were followed up till 2019. Quantitative PET/CT and clinicopathological parameters were used to estimate the Event Free Survival (EFS) in 100 patients. Kaplan-Meier method with log-rank test was used to compare the survival times of prognostic factors.

Results

At a median follow-up of 48.83 months (IQR:33.31-63.05 months), the five-year-EFS was 81%. Of the 100 patients, 16 had relapsed (16%) and none died at the last follow-up. On Univariate analysis, among non-PET parameters bulky disease (P=0.03) and B-symptoms (P=0.04) were significant while among PET/CT parameters SUV_max (p=0.001), SUV_mean (P=0.002), WBMTV2.5 (P<0.001), WBMTV41% (P<0.001), WBTLG2.5 (P<0.001) and WBTLG41% (P <0.001) predicted poorer EFS. 5-year EFS for patients with low WBMTV2.5 [<1038.3 cm3] was 89% and 35% for patients with high WBMTV2.5 [≥1038.3 cm3] (p <0.001). In a multivariate model, only WBMTV2.5 (P=0.03) independently predicted poorer EFS.

Conclusion

PET-based metabolic parameter (WBMTV2.5) was able to prognosticate and complement the classical clinical prognostic factors in advanced Hodgkin Lymphoma. This parameter could have a surrogate value for prognosticating advanced Hodgkin lymphoma. Better prognostication at baseline translates to tailored or risk-modified treatment and hence higher survival.

TP73-AS1 as a predictor of clinicopathological parameters and prognosis in human malignancies: a meta and bioinformatics analysis

Background

Long non-coding RNA P73 antisense RNA 1 T (non-protein coding), also known as Lnc RNA TP73-AS1, is dysregulated in various tumors but the correlation between its expression and clinicopathological parameters and/or prognoses in cancer patients is inconclusive. Here, we performed a meta-analysis to evaluate the prognostic value of Lnc RNA TP73-AS1 for malignancies.

Methods

We systematically searched four online databases including PubMed, the Web of Science, Embase, and the Cochrane Library for eligible articles published up to June 29/2020. Odds ratios (ORs) and Pooled hazard ratios (HRs) with 95% confidence intervals (95% CIs) were used to assess the association of TP73-AS1 expression with prognostic and clinicopathological parameters. We further validated TP73-AS1 expression in various malignancies and its potential prognostic value using the GEPIA online database. We predicted potential biological processes and relevant signal mechanisms through the public databases.

Results

A total of 26 studies examining 14 cancers were analyzed to evaluate the relationship between TP73-AS1 expression, clinicopathological features and prognostic indicators. The results indicated that TP73-AS1 expression markedly correlates with TNM stage (OR = 3.27,95% CI:2.43–4.39, P < 0.00001), tumor size (OR = 3.00, 95%CI:2.08–4.35, P < 0.00001), lymph node metastasis (OR = 2.77, 95%CI:1.42–5.38,P < 0.00001) and distant metastasis (OR = 4.50,95%CI:2.

62–7.73,P < 0.00001). No correlation with age (OR = 1.12,95%CI:0.77–1.64, P > 0.05), gender (OR = 1.08, 95%CI:0.84–1.38, P > 0.05) or differentiation (OR = 1.39, 95%CI:0.71–2.70, P = 0.340) was observed. TP73-AS1 overexpression was a biomarker of poor Overall survival(OS)(HR = 1.85,95%CI:1.53–2.22, P < 0.00001) and Disease-Free-Survival (DFS) (HR = 1.57,95%CI:1.03–2.42, P < 0.05). Dysregulated TP73-AS1 expression and its prognostic value in various cancers was validated based on The Cancer Genome Atlas (TCGA). Further biological function predictions indicated that TP73-AS1 was involved in pro-oncogenic signaling.

Conclusions

The upregulation of Lnc RNA TP73-AS1 was related to detrimental clinicopathological parameters and can be considered an indicator of poor prognosis for cancer malignancies.

The status of HER2 in colorectal carcinoma and the relation of HER2 with prognostic parameters and MSI

BACKGROUND

Colorectal cancer (CRC) is the third most commonly occurring cancer in men and the second most common cancer in women. Despite advances in surgical techniques and chemotherapeutic regimens, CRC continues to be one of the main causes of cancer-related deaths in the world.

AIMS

The aim of the study was to evaluate the immunohistochemical expression of human epidermal growth factor receptor 2 (HER2) and the relationship between HER2, clinicopathological parameters, and microsatellite instability (MSI).

MATERIALS AND METHODS

Two hundred and forty resected CRCs at our institution between 2016 and 2019 were included in the study. Tumors were re-evaluated and classified according to the World Health Organization. Tissue macroarray techniques were used to generate tissue samples. HER2 antibody was performed using the automated system.

RESULTS

HER2 antibody was score 3 positive in only 5 cases. Score 2 was observed in 13 cases, score 1 in 27, score 0 in 195. All of the HER2-positive cases were metastatic. All of them were tubular adenocarcinoma. HER2 positive cases were well and moderately differentiated. Four of the HER2 positive cases were T3 stage, and one was T4.

CONCLUSION

A total of 2.1% of CRCs were positive for HER2 antibody. There was a positive correlation between HER2 and distant metastasis. There was no significant relationship between MSI, other prognostic parameters, and HER2.

Roles of hydroxyacyl-CoA dehydrogenase trifunctional multienzyme complex subunit alpha, a lipid metabolism enzyme, in Wilms tumor patients

Objectives

Wilms tumor is a common pediatric malignant tumor that accounts for approximately 95% of kidney tumors in children. The role of lipid metabolism in tumors has attracted increased attention in recent years. We examined the role of hydroxyacyl-CoA dehydrogenase trifunctional multienzyme complex subunit alpha (HADHA), a lipid metabolism enzyme, in the pathogenesis of Wilms tumor.

Materials and Methods

In a previous study, we screened Wilms tumors and adjacent normal tissues for differentially expressed proteins by mass spectrometry and verified the results by western blot analysis. The Oncomine database and quantitative reverse transcription-polymerase chain reaction were used to verify the expression of HADHA at the genetic level. Immunohistochemistry and immunofluorescence were also used to validate the differential expression of the HADHA protein. The relationship between histopathological typing, clinical pathology, and HADHA expression was analyzed in 65 paraffin-embedded specimens from pediatric Wilms tumor patients. Kaplan-Meier survival curves were used to analyze the relationship between the expression of HADHA and patient prognosis.

Results

HADHA was expressed at low levels in Wilms tumor tissue compared with the corresponding normal tissue. The expression of HADHA was closely associated with histopathological typing (P = 0.030). The prognostic analysis of 65 children with Wilms tumor showed that high expression of HADHA was closely associated with poor prognosis (P = 0.046).

Conclusions

HADHA expression is downregulated in Wilms tumor tissues, but high expression in tumor tissues is associated with clinical stage and the prognosis of children with this tumor.

Human glutathione peroxidase codon 198 variant increases nasopharyngeal carcinoma risk and progression

PURPOSE

Glutathione peroxidase 1 (GPx-1) is a selenium-dependent detoxifying enzyme involved in the protection of cells against oxidative damage. Some genetic association studies reported significant associations between GPx-1 Pro198Leu variant and carcinogenesis across different populations; however, the impact of this variant on nasopharyngeal carcinoma (NPC) has not been explored. Therefore, the present study was planned to evaluate the potential involvement of the GPx-1 Pro198Leu variant and plasma GPx activity in the risk of developing NPC in a Tunisian population.

METHODS

The GPx-1 Pro198Leu genotype was determined in 327 NPC patients and 150 healthy controls by the RFLP-PCR analysis. The correlation between the GPx-1 variant and the clinicopathological parameters was examined. GPx activity was assessed in the plasma of 119 NPC patients and 58 healthy control subjects and according to GPx-1 genotypes and clinicopathological characteristics of NPC patients.

RESULTS

A significant association was found between GPx-1 Pro198Leu variant and NPC risk in a Tunisian population. The allelic frequencies of Pro and Leu alleles were 32% versus 68% and 41% versus 59% in NPC cases and controls, respectively. Thus, the minor 198 Leu allele increased significantly in NPC patients and appeared as a potential risk factor for NPC occurrence (OR = 1.48, CI 95% = 1.14-1.91, p = 0.002). The plasma GPx activity was significantly higher in NPC patients than in controls (p = 0.03). According to the clinicopathological characteristics of NPC patients, GPx activity decreased significantly in patients with lymph node metastasis (p = 0.004).

CONCLUSION

This is the first study showing a strong association between GPx-1 Pro198Leu genetic variant and NPC risk. GPx-1 Pro198Leu variant increased the development of regional lymph node metastasis. Plasma GPx activity was higher in NPC patients. Thus, GPx-1 gene could be considered as a determinant factor influencing NPC risk and progression.

Prognostic value of changes in portal blood TXA2, VEGF, and CEA levels in patients with colorectal cancer after surgery

BACKGROUND

Colorectal cancer (CRC) is a malignant tumor with high morbidity and mortality worldwide, representing a major public health problem. It ranks the third among newly diagnosed cancers and is the fourth cause of cancer death. There is currently an urgent need to find effective indexes for predicting liver metastasis after CRC surgery. Early detection of CRC liver micrometastasis is helpful for effective intervention and comprehensive treatment, which will greatly improve the prognosis of patients.

AIM

To explore the prognostic value of changes in portal vein thromboxane A2 (TXA2), vascular endothelial growth factor (VEGF), and carcinoembryonic antigen (CEA) levels in patients with CRC after surgery.

METHODS

From May 2017 to November 2019, 112 CRC patients at our hospital were selected and divided into either an observation group (liver metastasis, n = 21) or a control group (no liver metastasis, n = 91) according to whether there were liver metastases 6 mo after surgery. The clinical data and the levels of TXA2, VEGF, and CEA in portal vein blood were compared between the two groups, and the influencing factors of liver metastasis in patients with CRC were analyzed. The correlation between the levels of portal venous blood indicators and clinicopathological parameters, their predictive value for postoperative liver metastasis in patients with CRC, and their correlation with the prognosis were evaluated.

RESULTS

The levels of TXA2, VEGF, and CEA in portal vein blood were significantly higher in the observation group than in the control group (P < 0.05). Age, lesion size, histological grade, T stage, regional lymph node metastasis, vascular tumor thrombosis, surgical methods, adjuvant chemotherapy, and portal vein blood TXA2, VEGF, and CEA levels were all influential factors for postoperative liver metastasis in CRC patients (P < 0.05). Portal vein blood TXA2, VEGF, and CEA levels in patients with liver metastases after CRC were positively correlated with age, lesion size, T stage, regional lymph node metastasis, and tumor thrombus, and negatively correlated with histological grade (P < 0.05). The AUC of combined detection of TXA2, VEGF, and CEA in the prediction of postoperative liver metastasis in CRC patients was the largest (0.929). There was no statistically significant difference in the postoperative survival rate of patients with high levels of TXA2, VEGF, and CEA in portal vein blood and those with low levels (P > 0.05).

CONCLUSION

The high expression of TXA2, VEGF, and CEA in portal vein blood may be involved in the process of liver metastasis after CRC. The combined detection of the above indicators can provide data support for clinical prediction of liver metastasis and prognosis in patients with CRC after surgery.

Associations of individual and joint expressions of ERCC6 and ERCC8 with clinicopathological parameters and prognosis of gastric cancer

Background

Excision repair cross-complementing group 6 and 8 (ERCC6 and ERCC8) have been implicated in ailments such as genetic diseases and cancers. However, the relationship between individual and joint expressions of ERCC6/ERCC8 and clinicopathological parameters as well as prognosis of gastric cancer (GC) still remains unclear.

Methods

In this study, protein expressions of ERCC6, ERCC8 and ERCC6-ERCC8 were detected by immunohistochemistry (IHC) in 109 paired GC and para-cancerous normal tissue samples. The mRNA expression was detected in 36 pairs of tissue samples. IHC results and RNA-seq data extracted from The Cancer Genome Atlas (TCGA) were used to explore the clinical value of ERCC6 and ERCC8 expression in GC. We further conducted protein-protein interaction analysis, Gene Ontology, Kyoto Encyclopedia of Genes and Genomes, gene set enrichment analysis, and gene-gene interaction analysis to explore the function and regulation networks of ERCC6 and ERCC8 in GC.

Results

Individual and joint ERCC6/ERCC8 expression were significantly higher in adjacent normal mucosa compared with GC tissues. ERCC6 mRNA expression showed no difference in GC and paired tissues, while ERCC8 mRNA was significantly decreased in GC tissues. Protein expression of ERCC6, ERCC8, double negative ERCC6-ERCC8 and double positive ERCC6-ERCC8 and overexpressed ERCC6 mRNA were related to better clinicopathologic parameters, while overexpressed ERCC8 mRNA suggested worse parameters. Univariate survival analysis indicated that the OS was longer when ERCC6 protein expression and ERCC8 mRNA expression increased, and double negative ERCC6-ERCC8 expression was associated with a short OS. Bioinformatics analyses showed ERCC6 and ERCC8 were associated with nucleotide excision repair (NER) pathway, and six and ten gene sets were figured out to be related with ERCC6 and ERCC8, respectively. KEGG pathway showed that ERCC6/ERCC8 related gene sets were mainly involved in the regulation of PI3K/AKT/mTOR pathway. Direct physical interactions were found between ERCC6 and ERCC8.

Conclusions

Individual and joint expressions of ERCC6/ERCC8 were associated with clinical features of GC. Protein expression of ERCC6, ERCC6-ERCC8, and mRNA expression of ERCC8 were related to prognosis of GC. ERCC6 and ERCC8 primarily function in the NER pathway, and may regulate GC progression through the regulation of PI3K/AKT/mTOR pathway.

EIF5A expression and its role as a potential diagnostic biomarker in hepatocellular carcinoma

Introduction and objectives: Eukaryotic translation initiation factor 5A (EIF5A) is a member of the identified eIF family and played an important role in cell proliferation. There are few studies about the correlation between EIF5A and hepatocellular carcinoma (HCC).

Materials and methods: We evaluated the expression of the EIF5A in human HCC cell lines and tissues by western blot analysis. Immunohistochemistry analysis of EIF5A was performed on a tissue microarray including 10 normal liver samples and 90 pathological section of HCC. Receiver operating characteristic (ROC) was introduced to obtain an optimal cut-off score for EIF5A positive expression.

Results: Western blot results showed that EIF5A was highly expressed in HCC cell lines and tissues. Based on ROC curve analysis, 1/10 (10.0%) of normal hepatic tissues and 67/90 (74.4%) of HCC tissues were tested positive for EIF5A expression, which indicated that EIF5A were significantly up-regulated in HCC tissues compared with normal liver tissues (χ²=17.177, P<0.001). Furthermore, expression of EIF5A was significantly correlated with histological grade (P=0.048), clinical stage (P=0.003) and pT stage (P=0.003) but not correlated with sex (P=0.617) and age (P=0.831).

Conclusions: In our study, we demonstrated the expression of EIF5A is closely correlated with HCC. In consideration of its relationship with clinicopathological parameters including histological grade, clinical stage and pT stage of HCC, EIF5A could be a potential biomarker.

LncRNA H19 rs4929984 Variant is Associated with Coronary Artery Disease Susceptibility in Han Chinese Female Population

Long non-coding RNAs (lncRNAs) have been reported to play an important role in cardiovascular diseases. The present study aimed to investigate the levels of lncRNA H19 in patients with coronary artery disease (CAD) and the genetic association of lncRNA H19 rs217727 and rs4929984 polymorphisms with CAD susceptibility. We detected an upregulated expression of lncRNA H19 in the peripheral blood of CAD patients compared with healthy controls, and the area under the receiver operating characteristic curve of lncRNA H19 for CAD diagnosis was 0.918. In addition, rs4929984 was associated with the susceptibility of Han Chinese females to CAD, as shown in the additive and dominant models, and the significant association remained after adjusting for age and Bonferroni correction. The A allele carriers of rs4929984 were correlated with females' susceptibility to CAD compared with the C allele, and the A-G haplotype of rs4929984-rs217727 was associated with females' susceptibility to CAD. Furthermore, rs217727 and rs4929984 were associated with the levels of clinicopathological parameters of CAD cases. We suggest that lncRNA H19 has a potential to be a diagnostic biomarker for CAD; rs4929984 polymorphism is associated with females' susceptibility to CAD in the Han Chinese population, and lncRNA H19 variants may influence lipid metabolism, inflammation, and coagulation function of CAD patients.

Factors associated with chemotherapy benefit in breast cancer patients with midrange Oncotype DX breast recurrence scores

Chemotherapy for patients with hormone receptor-positive, human epidermal growth factor receptor 2 (HER2)-negative, node-negative breast cancer, and with midrange Oncotype DX breast recurrence scores (RS) still needs to be further individualized. To improve the treatment decision making, we aimed to develop a method that provides a single score based on multiple factors associated with chemotherapy benefit. We analyzed Surveillance, Epidemiology, and End Results registry data from 31,731 patients with hormone receptor-positive, HER2-negative, node-negative breast cancer and midrange RS characterized by sociodemographic (age and marital status) and clinicopathologic (tumor size, histologic grade, progesterone receptor status, broad histological classification, lesion laterality, and lesion overlap) features and stratified by RS ranges. For the entire sample and for each characteristic, overall survival was compared between patients who underwent chemotherapy and those who did not (or status unknown) within each RS stratum. There was no any association between chemotherapy and survival for patients with RS = 11-15. However, for patients with RS = 16-25, a chemotherapy benefit was associated with tumor size, histologic grade, progesterone receptor status, histological type, and lesion laterality. In addition, overlapping lesion of breast and married at diagnosis might provide additional predictive information of chemotherapy benefit when RS = 21-25. A simple and effective algorithm was designed by combining these factors to output a novel and personalized chemotherapy benefit score to effectively identify patients with RS = 16-25 who would most likely benefit from chemotherapy, which might facilitate improved treatment by providing individualized recommendations.

Lymph node metastasis in suprasternal space in pathological node-positive papillary thyroid carcinoma

BACKGROUND

The objective of the current study was to investigate the clinical significance of the suprasternal space lymph node (SSLN) in pathological node-positive (pN+) papillary thyroid carcinoma (PTC) patients.

METHOD

One hundred and forty patients with pN + PTC who underwent neck dissection were enrolled into this study. SSLN was resected and used as a specimen to investigate the relationship of SSLN with several clinicopathological parameters.

RESULTS

The metastasis rate of SSLN was 20.7%. On univariate analysis, we found that SSLN metastasis was significantly associated with primary cancer site (inferior portion), strap muscle invasion, level III metastasis, Level IV metastasis and lymph node metastasis between sternocleidomastoid and sternohyoid muscles. On multivariate analysis, primary cancer site (inferior portion), strap muscle invasion, Level IV metastasis and lymph node metastasis between sternocleidomastoid and sternohyoid muscles were independent risk factors for SSLN metastasis of PTC.

CONCLUSION

For pN + PTC patients, special attention should be paid to the issue of SSLN metastasis.

Aberrant expression of N-glycolyl GM3 ganglioside is associated with the aggressive biological behavior of human sarcomas

BACKGROUND

The aberrant expression of N-glycolyl GM3 ganglioside (NeuGcGM3) in patients with sarcomas was reevaluated by assessing the relation of this molecule with some clinicopathological features and overall survival (OS) of patients.

METHODS

Fifty formalin-fixed and paraffin-embedded specimens from patients diagnosed with sarcomas were included. For the evaluation of NeuGcGM3, the 14F7 monoclonal antibody followed by a peroxidase avidin-biotin system was used. Clinicopathological features were obtained from patient records. Survival rates were estimated by the Kaplan-Meier method and compared with the log-rank test. For multivariate analyses, the Cox regression model was used to identify independent prognostic factors for OS.

RESULTS

The majority of samples had high levels of NeuGcGM3 expression (66.0%) that showed statistical correlation with age (p = 0.014), TNM stage (p = 0.022), histological grade (p = 0.013) and proliferation rates (p = 0.012). In addition, a tendency for association with tumor depth (p = 0.070) was evidenced. In univariate survival analysis, TNM stage (p = 0.000), occurrence of metastasis (p = 0.000) and expression of NeuGcGM3 (p = 0.034) were significant prognostic factors for OS, while a tendency for association was evidenced for histological grade (p = 0.091). Among these variables, only the presence of metastasis (p = 0.001) was an independent prognostic factor on multivariate analysis.

CONCLUSIONS

The present research suggests the evaluation of NeuGcGM3 expression as a complementary prognostic factor in sarcoma, although our results need to be validated in a larger series and prospective studies. Moreover, our results could support the use of this molecule as a target for immunotherapy.

PD-L1 expression and its clinicopathological correlation in advanced esophageal squamous cell carcinoma in a Chinese population

Background

Programmed death ligand 1 (PD-L1) is a ligand for the inhibitory programmed cell death protein 1 (PD-1), which are targeted by several anti-PD-1 and PD-L1 drugs for a variety of human cancers. However, only a few studies have evaluated PD-L1 expression in esophageal squamous cell carcinoma (ESCC) with a large Chinese cohort. Our present study is to evaluate the association of PD-L1 expression with clinicopathological features on ESCC.

Methods

Using tissue microarray and immunohistochemistry, PD-L1 expression on tumor cells and tumor-infiltrating immune cells was studied in 378 advanced ESCC patients without neoadjuvant chemoradiotherapy. Its correlation with clinicopathological parameters was analyzed.

Results

PD-L1 was expressed on 29.9% (113/378) ESCC tumor cells and 40.2% (152/378) tumor-infiltrating immune cells. PD-L1 expression in tumor cells was significantly correlated with age, degree of differentiation, T stage, N stage and metachronous hematogenous metastasis, and PD-L1 expression in tumor-infiltrating immune cells was significantly associated with N stage (P < 0.05). Patients with PD-L1 expression in tumor cells had poor disease-free survival (Hazard ratio [HR] = 1.436, P = 0.009). There was a positive association between tumor cells and tumor-infiltrating immune cells for PD-L1 expression (r = 0.16, P = 0.002). However, PD-L1 expression in tumor-infiltrating immune cells was not significantly correlated with disease-free survival and overall survival.

Conclusions

PD-L1 expression in tumor cells and tumor infiltrating immune cells is not only an indicator for immunotherapy, but also significantly related with age, differentiation, stage, metastasis and disease free survival.

Clinicopathological parameters predicting recurrence of pT1N0 esophageal squamous cell carcinoma

AIM

To identify the clinicopathological characteristics of pT1N0 esophageal squamous cell carcinoma (ESCC) that are associated with tumor recurrence.

METHODS

We reviewed 216 pT1N0 thoracic ESCC cases who underwent esophagectomy and thoracoabdominal two-field lymphadenectomy without preoperative chemoradiotherapy. After excluding those cases with clinical follow-up recorded fewer than 3 mo and those who died within 3 mo of surgery, we included 199 cases in the current analysis. Overall survival and recurrence-free survival were assessed by the Kaplan-Meier method, and clinicopathological characteristics associated with any recurrence or distant recurrence were evaluated using univariate and multivariate Cox proportional hazards models. Early recurrence (≤ 24 mo) and correlated parameters were assessed using univariate and multivariate logistic regression models.

RESULTS

Forty-seven (24%) patients had a recurrence at 3 to 178 (median, 33) mo. The 5-year recurrence-free survival rate was 80.7%. None of 13 asymptomatic cases had a recurrence. Preoperative clinical symptoms, upper thoracic location, ulcerative or intraluminal mass macroscopic tumor type, tumor invasion depth level, basaloid histology, angiolymphatic invasion, tumor thickness, submucosal invasion thickness, diameter of the largest single tongue of invasion, and complete negative aberrant p53 expression were significantly related to tumor recurrence and/or recurrence-free survival. Upper thoracic tumor location, angiolymphatic invasion, and submucosal invasion thickness were independent predictors of tumor recurrence (Hazard ratios = 3.26, 3.42, and 2.06, P < 0.001, P < 0.001, and P = 0.002, respectively), and a nomogram for predicting recurrence-free survival with these three predictors was constructed. Upper thoracic tumor location and angiolymphatic invasion were independent predictors of distant recurrence. Upper thoracic tumor location, angiolymphatic invasion, submucosal invasion thickness, and diameter of the largest single tongue of invasion were independent predictors of early recurrence.

CONCLUSION

These results should be useful for designing optimal individual follow-up and therapy for patients with T1N0 ESCC.

Clinical and prognostic value of chaperonin containing T-complex 1 subunit 3 in hepatocellular carcinoma: A Study based on microarray and RNA-sequencing with 4272 cases

Liver cancer is one of the few tumors with a steadily increasing morbidity and mortality; hepatocellular carcinoma (HCC) is the most common type of primary liver cancer. We combined the expression profiles of Chaperonin Containing T-complex 1 Subunit 3 (CCT3) in HCC tissues based on microarray and RNA-sequencing data. The CCT3 expression levels were extracted and examined based on 421 samples from The Cancer Genome Atlas (TCGA) (HCC, n = 371; non-HCC, n = 50) and 3851 samples from 31 microarray or RNA-sequencing datasets (HCC, n = 1975; non-tumor = 1876). We used a variety of meta-analytic methods, including SMD forest maps, sensitivity analysis, subgroup analysis and sROC curves, to confirm the final results. Meanwhile, database-derived immunohistochemistry data was used for validation. We also further explained the potential mechanism of CCT3 in HCC through signal pathway analyses and PPI network construction with the CCT3 co-expressed genes. The mRNA and protein expression of CCT3 in HCC tissues were higher than in non-HCC tissues. The expression of CCT3 differed between groups when grouped according to clinicopathological parameters, such as race, family history, and histological grade. The results of standardised mean difference (SMD) forest map and summary receiver operating characteristic (sROC) curve revealed that CCT3 was highly expressed in HCC tissues and had a high ability to distinguish between cancer tissues and non-cancer tissues. The main form of CCT3 gene alteration in HCC was mRNA up-regulation and amplification (23%), and the most common mutation type was missense. The mRNA expression of CCT3 in HCC was negatively correlated with DNA methylation. According to the Kyoto Encyclopedia of Genes and Genomes pathway analysis, CCT3 can influence HCC occurrence and development through cell cycle and DNA replication pathways. In summary, this study carries out the staging and prognostic analysis of HCC. It suggests that CCT3 might play an important part in the tumorigenesis and progression of HCC and may have a certain prognostic value in HCC. Moreover, CCT3 might represent a promising biomarker for HCC.

Clinicopathological and prognostic significance of C/EBP homologous protein (CHOP) in advanced gastric cancer

BACKGROUND

Few studies have reported the clinical and prognostic significance of C/EBP homologous protein (CHOP) in advanced gastric cancer (GC). Therefore, the present study investigated the expression of CHOP in advanced GC patients to determine its potential prognostic role.

METHODS

The levels of CHOP in 95 patients with advanced GC and adjacent non-cancerous tissues were evaluated by qRT-PCR, western blot and immunohistochemistry. Furthermore, the association of CHOP expression with clinicopathological parameters and prognosis of advanced GC patients was analyzed.

RESULTS

The levels of CHOP were down-regulated in advanced GC compared with non-cancerous tissues (P<0.01). In addition, high CHOP expression more frequently occurred in advanced GC tissues with depth of invasion of T_1-2 (P < 0.01), lower clinical stage (TNM Ⅰ-Ⅱ stage) (P<0.05) and without lymph node metastasis (P<0.05). No significant difference was observed between the expression of CHOP and age, gender, tumor size, lesion site and differentiation (P>0.05). The Kaplan-Meier survival analyses showed that the overall survival rate of advanced GC patients with positive CHOP expression was significantly higher than that of patients with negative CHOP expression (P<0.01). Univariate and multivariate Cox proportional hazards models revealed that low CHOP expression (OR = 0.314, 95%CI: 0.176～0.794, P = 0.003) was an independent factor for poor overall survival in advanced GC patients.

CONCLUSION

Low expression of CHOP predicts the poor prognosis of advanced GC patients, and CHOP may be a prognostic biomarker for patients with advanced GC.

Positive Correlation between Matrix Metalloproteinases and Epithelial-to-Mesenchymal Transition and its Association with Clinical Outcome in Bladder Cancer Patients

Involvement of matrix metalloproteinases (MMPs) in the pathogenesis of urothelial carcinoma elects them to be sensitive marker for clinical and prognostic implications. MMPs regulate tumor growth and invasion by inducing epithelial-to-mesenchymal transition (EMT) which is characterized by the complex reprogramming of epithelial cells and ultimately bring about major changes in the structural organization of bladder urothelium. The present study has been undertaken to evaluate the clinical relevance of MMPs in two distinct types of bladder cancer disease. Expression analysis of MMPs namely MMP-2, MMP-7, MMP-9 and EMT markers including epithelial marker, E-cadherin; mesenchymal markers, N-cadherin and Vimentin; and EMT-activating transcriptional factors (EMT-ATFs), Snail, Slug, Twist and Zeb was done in 64 cases of bladder tumor tissues [{Non-muscle invasive bladder cancer (NMIBC): 35 cases} and {Muscle invasive bladder cancer (MIBC): 29 cases}] by real-time quantitative polymerase chain reaction (RT-qPCR). Immunohistochemistry (IHC) staining was done in matched bladder tumor tissues to evaluate the protein expression and localization of E-cadherin, N-cadherin, Vimentin, Snail, and Slug. Our data showed overexpression of MMP-2, MMP-7 and MMP-9 at transcriptome level in 32.8%, 25% and 37.5% bladder tumor cases respectively. These tumor tissues were examined for higher expression of mesenchymal markers (N-cadherin and Vimentin) at mRNA and protein level and exhibited statistical association with tumor stage and tumor grade (p = 0.02, p = 0.04, Mann-Whitney test). Significant statistical correlation in tumor tissues with overexpressed MMPs has also been observed between gain of transcriptional factors and weak expression of E-cadherin with tumor stage, grade, gender, presence of hematuria and smoking history of the patients. Gene expression patterns of EMT markers in bladder tumors with overexpressed MMPs and their significant association with clinical profile validate the important role of MMPs in the pathogenesis of urothelial carcinoma of bladder (UCB). Increased expression of specific MMPs may affect several downstream EMT programs and thus may improve its diagnostic and prognostic utility in clinical setting.

Expression of PRR11 protein in gastric cancer: Correlation with disease progression and prognosis

AIM

To detect the expression of PRR11 in gastric cancer (GC) and to analyze its relationship with GC progression and prognosis.

METHODS

Expression of PRR11 in 436 GC samples was detected by immunohistochemistry (IHC), and Western blot was used to compare PRR11 expression between GC samples and normal gastric mucosal samples. The correlation of PRR11 expression with clinicopathological parameters was analyzed.

RESULTS

Western blot analysis showed that the expression of PRR11 in GC samples was obviously higher than that in normal gastric mucosal samples. IHC results showed that PRR11 was specifically expressed in GC and located in the cytoplasm and membrane; PRR11 was overexpressed in 182 (41.8%) of GC samples, but none or weak expression was detected in the normal gastric mucosa. PRR11 overexpression was correlated significantly with clinicopathologic features such as tumor differentiation (P < 0.01), tumor invasion (P = 0.03), TNM stage (P < 0.01), lymph node metastasis (P < 0.01), and distant metastasis (P < 0.01).

CONCLUSION

PRR11 is overexpressed in GC, which is associated with the occurrence, progression, and prognosis of GC. These data indicate that PRR11 can be used as an important biomarker to estimate the progression and prognosis of GC.

Impact of clinicopathological parameters on survival after multiorgan resection among patients with T4 gastric carcinoma: a systematic review and meta-analysis

BACKGROUND

The prognostic factors which can improve the overall survival (OS) of patients with T4 gastric carcinoma (GC) are still controversial: a meta-analysis was conducted to analyze the impact of clinicopathological parameters on survival after MOR among patients with T4 GC.

METHODS

A systematic search was performed. Odd risks (ORs) of patients with T4 GC were used to calculate the relationship between clinicopathological parameters and OS.

RESULTS

Nine studies involving 941 patients with T4 GC were identified. Well-moderate differentiation led to increased 1-, 3-, 5-year OS with an OR of 2.63, 1.58 and 1.45. Borrmann type I-II led to increased 1-, 3-year OS with an OR of 1.67 and 2.08. No lymph node metastasis led to increased 1-, 3-, 5-year OS with an OR of 7.16, 3.18 and 3.71. Total gastrectomy led to increased 1-, 3-year OS with an OR of 2.01 and 1.79. ≥2 Organs resected led to increased 1-, 3-year OS with an OR of 2.19 and 2.19. TNM stage II-III led to increased 1-, 3-year OS with an OR of 3.68 and 5.75. Curative resection led to increased 1-, 3-, 5-year OS with an OR of 4.46, 5.80 and 5.98.

CONCLUSION

Well-moderate differentiation, Borrmann type I-II, no lymph node metastasis, total gastrectomy, ≥2 organs resected, TNM stage II-III and curative resection were positive prognostic factors for OS of patients with T4 GC.

Relationship between TRAF6 and deterioration of HCC: an immunohistochemical and in vitro study

Objective

To explore the relationship between tumor necrosis factor receptor-associated factor 6 (TRAF6) and the clinicopathological features in HCC as well as its biological function.

Methods

Totally, 412 liver tissues were collected, including 171 hepatocellular carcinoma (HCC) and their corresponding non-tumor tissues, 37 cirrhosis and 33 normal liver tissues. The expression of TRAF6 was assessed by immunohistochemistry. Then, analysis of the correlations between TRAF6 expression and clinicopathological parameters in HCC was conducted. Furtherer, in vitro experiments on HepG2 and Hep3B cells were performed to validate the biological function of TRAF6 on HCC cells. TRAF6 siRNA was transfected into HepG2 and Hep3B cell lines and TRAF6 expression was evaluated with RT-qPCR and western blot. The assays of cell viability, proliferation, apoptosis and caspase-3/7 activity were carried out to investigate the effects of TRAF6 on HCC cells with RNA interference. Cell viability was assessed with Cell Titer-Blue kit. Cell proliferation was tested with MTS kit. Cell apoptosis was checked through morphologic detection with fluorescence microscope, as well as caspase-3/7 activity was measured with fluorogenic substrate detection.

Results

The positive expression rate of TRAF6 protein was 49.7 % in HCC, significantly higher than that of normal liver (12.1 %), cirrhosis (21.6 %) and adjacent non-cancerous tissues (36.3 %, all P < 0.05). Upregulated TRAF6 was detected in groups with metastasis (Z = −2.058, P = 0.04) and with low micro-vessel density (MVD) expression (Z = −2.813, P = 0.005). Spearman correlation analysis further showed that the expression of TRAF6 was positively correlated with distant metastasis (r = 0.158, P = 0.039) and negatively associated with MVD (r = −0.249, P = 0.004). Besides, knock-down of TRAF6 mRNA in HCC cell lines HepG2 and Hep3B both resulted in cell viability and proliferation inhibition, also cell apoptosis induction and caspase-3/7 activity activation.

Conclusions

TRAF6 may contribute to metastasis and deterioration of the HCC via influencing cell growth and apoptosis. Thus, TRAF6 might become a predictive and therapeutic biomarker for HCC.

Clinicopathological and prognostic significance of GPX2 protein expression in esophageal squamous cell carcinoma

BACKGROUND

Chaoshan region, a littoral area of Guangdong province in southern China, has a high incidence of esophageal squamous cell carcinoma (ESCC). At present, the prognosis of ESCC is still very poor, therefore, there is urgent need to seek valuable molecular biomarker for prognostic evaluation to guide clinical treatment. GPX2, a selenoprotein, was exclusively expressed in gastrointestinal tract and has an anti-oxidative damage and anti-tumour effect in the progress of tumourigenesis.

METHODS

We collected 161 ESCC patients samples, among which 83 patients were followed up. We employed immunochemistry analysis, western blotting and quantitative real-time PCR for measuring the expression of GPX2 within ESCC samples. We analysed the relationship between the expression of GPX2 and clinicopathological parameters of 161 patients with ESCC by Chi-square or Fisher's exact test. The survival analysis of GPX2 expression within ESCC tissues was evaluated by the Kaplan-Meier method and Cox-regression.

RESULTS

A significant higher expression level of GPX2 was detected in tumour tissues compared to that in non-tumour tissues (P < 0.001). Moreover, GPX2 expression has statistically significant difference in the tumour histological grade of ESCC (P < 0.001), while there was no statistically significant difference in age, sex, tumour size, tumour location, gross morphology and clinical TNM stages (P > 0.05). Meanwhile, the expression of GPX2 protein was obviously down-regulated within poorly differentiated ESCC. Last, survival analysis revealed that tumour histological grade and clinical TNM stages, both of the clinical pathological parameters of ESCC, were associated with the prognosis of patients with ESCC (respectively, P = 0.009, HR (95 % CI) = 1.885 (1.212 ~ 2.932); P = 0.007, HR (95 % CI) = 2.046 (1.318 ~ 3.177)). More importantly, loss expression of GPX2 protein predicted poor prognosis in patients with ESCC (P < 0.001, HR (95 % CI) = 5.700 (2.337 ~ 13.907)).

CONCLUSIONS

Collectively, these results suggested that the expression of GPX2 was significantly up-regulated within ESCC tumour tissues. GPX2 might be an important predictor for the prognosis of ESCC and a potential target for intervention and treatment of ESCC.

Clinical significance of expression of miR-638 in gastric carcinoma

AIM: To investigate the expression of miR-638 in gastric carcinoma and to analyze its clinical significance.

METHODS: Total RNA was extracted from 31 pairs of gastric carcinoma tissues and normal tissues. The expression levels of miR-638 were detected by quantitative real-time polymerase chain reaction (qRT-PCR). The relationship between miR-638 expression and clinicopathological parameters of gastric carcinoma was analyzed.

RESULTS: miR-638 was lowly expressed in 27 (87.10%) cases of gastric carcinoma, and highly expressed in 4 (12.90%) cases. The expression level of miR-638 was significantly lower in gastric carcinoma tissues than in normal tissues (P < 0.01). miR-638 expression in gastric carcinoma was significantly associated with the depth of tumor invasion (P < 0.05), but was not associated with sex, age, degree of differentiation, TNM stage, or lymph node metastasis (P > 0.05).

CONCLUSION: The expression of miR-638 is lower than in normal tissues in gastric carcinoma, which may be associated with the carcinogenesis and development of gastric carcinoma.

Clinical significance of expression of receptor-type tyrosine-protein phosphatase N2 and proliferation cell nuclear antigen in hepatocellular carcinoma

AIM: To explore the correlation of receptor-type tyrosine-protein phosphatase N2 (PTPRN2) and proliferation cell nuclear antigen (Ki-67) expression with clinical parameters in hepatocellular carcinoma (HCC).

METHODS: We collected 186 HCC specimens from patients treated at the First Affiliated Hospital of Zhengzhou University, 180 tumor adjacent normal liver tissues, and 138 non-neoplastic distant tissues. The expression of PTPRN2 and Ki-67 proteins was examined by immunohistochemistry in the above tissues.

RESULTS: The positive expression rates of PTPRN2 and Ki-67 were 55.9% and 49.5%, respectively. The positive expression of PTPRN2 was correlated with serum AFP level, tumor size, TNM stage, and histopathological differentiation (P < 0.05). The expression of Ki-67 was correlated with lymph node metastasis, TNM stage, and histopathological differentiation (P < 0.05). There was no significant correlation between PTPRN2 and Ki-67 expression (r = -0.161, P > 0.05).

CONCLUSION: The high expression of PTPRN2 and Ki-67 is closely associated with HCC development, but there is no significant correlation between them.

Evaluation of cannabinoid CB1 and CB2 receptors expression in mobile tongue squamous cell carcinoma: associations with clinicopathological parameters and patients' survival

Cannabinoid receptors (CB1R and CB2R) constitute essential members of the endocannabinoid system (ECS) which participates in many different functions indispensable to homeostatic regulation in several tissues, exerting also antitumorigenic effects. The present study aimed to assess the clinical significance of CB1R and CB2R protein expression in mobile tongue squamous cell carcinoma (SCC). CB1R and CB2R expression was assessed immunohistochemically on 28 mobile tongue SCC tissue samples and was analyzed in relation with clinicopathological characteristics and overall and disease-free patients' survival. CB1R, CB2R, and concomitant CB1R/CB2R expression was significantly increased in older compared to younger mobile tongue SCC patients (p = 0.0243, p = 0.0079, and p = 0.0366, respectively). Enhanced CB2R and concomitant CB1R/CB2R expression was significantly more frequently observed in female compared to male mobile tongue SCC patients (p = 0.0025 and p = 0.0016, respectively). Elevated CB2R expression was significantly more frequently observed in mobile tongue SCC patients presenting well-defined tumor shape compared to those with diffuse (p = 0.0430). Mobile tongue SCC patients presenting enhanced CB1R, CB2R, or concomitant CB1R/CB2R expression showed significantly longer overall (log-rank test, p = 0.004, p = 0.011, p = 0.018, respectively) and disease-free (log-rank test, p = 0.003, p = 0.007, p = 0.027, respectively) survival times compared to those with low expression. In multivariate analysis, CB1R was identified as an independent prognostic factor for disease-free patients' survival (Cox-regression analysis, p = 0.032). The present study provides evidence that CB1R and CB2R may play a role in the pathophysiological aspects of the mobile tongue SCC and even each molecule may constitute a potential target for the development of novel anti-cancer drugs for this type of malignancy.

Clinical Significance of EphB4 and EphB6 Expression in Human Malignant and Benign Thyroid Lesions

Ephrin receptors (Ephs) are frequently overexpressed in a wide variety of human malignant tumors, being associated with tumor growth, invasion, angiogenesis and metastasis. The present study aimed to evaluate the clinical significance of EphB4 and EphB6 protein expression in human malignant and benign thyroid lesions. EphB4 and EphB6 protein expression was assessed immunohistochemically on paraffin-embedded thyroid tissues obtained from 127 patients with benign (n = 71) and malignant (n = 56) thyroid lesions. Enhanced EphB4 and EphB6 expression was more frequently observed in malignant compared to benign thyroid lesions (p = 0.0508 and p = 0.0006, respectively). EphB4 and EphB6 expression also provided a distinct discrimination between papillary carcinoma and hyperplastic nodules (p = 0.0302 and p = 0.0013, respectively). In malignant thyroid lesions, enhanced EphB4 expression was significantly associated with larger tumor size (p = 0.0366). Enhanced EphB6 expression was significantly associated with larger tumor size (p = 0.0366), the presence of lymph node metastases (p = 0.0023), the presence of capsular (p = 0.0038), lymphatic (p = 0.0053) and vascular invasion (p = 0.0018) and increased risk of recurrence rate (p = 0.0038). The present study supported evidence that EphB4 and mainly EphB6 may participate in the malignant thyroid transformation, reinforcing their utility as useful biomarkers and possible therapeutic targets in this type of neoplasia.

Prognostic significance of preoperative fibrinogen in patients with colon cancer

AIM: To investigate the prognostic significance of preoperative fibrinogen levels in colon cancer patients.

METHODS: A total of 255 colon cancer patients treated at the Affiliated Tumor Hospital of Xinjiang Medical University from June 1^st 2005 to June 1^st 2008 were enrolled in the study. All patients received radical surgery as their primary treatment method. Preoperative fibrinogen was detected by the Clauss method, and all patients were followed up after surgery. Preoperative fibrinogen measurements were correlated with a number of clinicopathological parameters using the Student t test and analysis of variance. Survival analyses were performed by the Kaplan-Meier method and Cox regression modeling to measure 5-year disease-free survival (DFS) and overall survival (OS).

RESULTS: The mean preoperative fibrinogen concentration of all colon cancer patients was 3.17 ± 0.88 g/L. Statistically significant differences were found between preoperative fibrinogen levels and the clinicopathological parameters of age, smoking status, tumor size, tumor location, tumor-node-metastasis (TNM) stage, modified Glasgow prognostic scores (mGPS), white blood cell (WBC) count, neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR), and carcinoembryonic antigen (CEA) levels. Univariate survival analysis showed that TNM stage, tumor cell differentiation grade, vascular invasion, mGPS score, preoperative fibrinogen, WBC, NLR, PLR and CEA all correlated with both OS and DFS. Alpha-fetoprotein (AFP) and body mass index correlated only with OS. Kaplan-Meier analysis revealed that both OS and DFS of the total cohort, as well as of the stage II and III patients, were higher in the hypofibrinogen group compared to the hyperfibrinogen group (all P < 0.05). In contrast, there was no significant difference between OS and DFS in stage I patients with low or high fibrinogen levels. Cox regression analysis indicated preoperative fibrinogen levels, TNM stage, mGPS score, CEA, and AFP levels correlated with both OS and DFS.

CONCLUSION: Preoperative fibrinogen levels can serve as an independent prognostic marker to evaluate patient response to colon cancer treatment.

Detection of k-ras gene mutations in Chinese patients with colorectal cancer

AIM: To investigate k-ras gene mutations and to analyze their clinical significance in Chinese patients with colorectal cancer.

METHODS: A total of 280 surgical specimens taken from patients with colorectal cancer who were treated at Fuzhou General Hospital of Nanjing Military Command between January 2008 and December 2009 and had complete clinical data were used in the study. Six k-ras gene mutations at codon 12 (35G>A, 35G>T, 35G>C, 34G>A, 34G>T, 34G>C) and one at codon 13 (38G>A) were detected by real-time fluorescence quantitative PCR (qPCR) and direct sequencing. A comparison of results obtained by the two methods was then performed.

RESULTS: The overall positive rate of k-ras gene mutations obtained by direct sequencing was 33.57% (94/280), and the positive rate of mutations at codon 12 [4.29% (12/280) for 35G>A, 0.36% (1/280) for 35G>T, 0.36% (1/280) for 35G>C, 2.86% (8/280) for 34G>A, 3.57% (10/280) for 34G>T, and 0.36% (1/280) for 34G>C] was 14.64% (41/280) and 7.5% (21/280) at codon 13. Of 94 patients who were demonstrated to have k-ras gene mutations by direct sequencing, 91 were confirmed by qPCR [sensitivity, 96.8% (91/94)]. Meanwhile, of 186 patients who were demonstrated to have no k-ras gene mutation by direct sequencing, 184 were confirmed by qPCR [specificity, 98.9% (184/186)]. The matching rate between the two methods was 98.2%. K-ras gene mutations were significantly associated with sex and age (both P < 0.05), but not with tumor site, differentiation, depth of invasion, TNM stage, lymph node metastasis, or distant metastasis (all P > 0.05).

CONCLUSION: A high proportion of k-ras gene mutations (33.57%) were detected in Chinese patients with colorectal cancer. qPCR may be an accurate, rapid and simple method for detection of k-ras gene mutations in patients with colorectal cancer. There was no significant correlation between k-ras gene mutations and biological behavior of colorectal cancer, though a higher rate of gene mutations were detected in female patients older than 60 years.