High cyclooxygenase-2 expression following neoadjuvant radiochemotherapy is associated with minor histopathologic response and poor prognosis in esophageal cancer

Towards Personalized Treatment Strategies for Esophageal Adenocarcinoma; A Review on the Molecular Characterization of Esophageal Adenocarcinoma and Current Research Efforts on Individualized Curative Treatment Regimens

Esophageal cancers confer a major health challenge and are highly aggressive malignancies with poor prognosis. Esophageal adenocarcinoma (EAC) is one of the two major histopathological subtypes of esophageal cancer. Despite advances in treatment modalities, the prognosis of patients with EAC remains poor, with a 5-year survival rate that rarely exceeds 30% in patients treated with curative intent. Chemoradiotherapy followed by resection is the treatment of choice for EAC patients, which are deemed to be curable. Current patient stratification and treatments are based on outcomes from clinical trials. Unfortunately, the molecular heterogeneity of EAC which determines the chemo- and radiosensitivity of these cancers are not taken into account. A more personalized approach in the treatment of EAC could improve patient outcomes. This review aims at summarizing literature on translational and clinical research in the field of EAC which could be of importance to develop personalized approaches. As suggested by the TCGA, expression data features molecular classifications by different platforms, including miRNA, genomic mutations and reverse-phase protein arrays. Here, we summarize literature on transcriptomic, data-driven approaches to identify distinct subtypes of EAC associated with molecular features. These novel classifications may determine the responsiveness to chemo(radio)therapy and help to identify novel molecular targets within cell signaling pathways. Moreover, we discuss the current clinical research efforts on tailored treatment regimens for patients with EAC taking into account the heterogeneous response to chemoradiotherapy. We summarize the evidence regarding active surveillance instead of immediate surgical resection after application of neoadjuvant chemo(radio)therapy in EAC. We consider that in future patients with complete response to chemo(radio)therapy, predicted by (transcriptomic) biomarkers, might benefit most from this approach. Finally, challenges to overcome for current findings to be implemented in clinical practice and move the field forward are being discussed.

Lipid droplet biogenesis and COX-2 pathway activation are triggered by Barrett's esophagus and adenocarcinoma, but not esophageal squamous cell carcinoma risk factors

Esophageal cancer (EC) is an aggressive disease, presenting two main histological subtypes: adenocarcinoma (EAC) and squamous cell carcinoma (ESCC). The two EC subtypes widely differ concerning virtually all factors. ESCC development is mainly associated with tobacco and alcohol abuse, whereas obesity and chronic gastroesophageal reflux disease (GERD) are important risk factors not only for EAC, but also for for Barrett’s esophagus (BE), an intestinal metaplasia that precedes EAC. Obesity triggers ectopic lipid droplets (LD) accumulation in non-adipose tissues. LD are organelles involved in cell metabolism, signaling, proliferation and production of inflammatory mediators. Therefore, the aim of this work was to investigate LD occurrence and role in EC. This study shows progressive LD levels increase along EAC development, in esophageal samples from non-obese through obese individuals, as well as BE, and EAC patients, whereas no significant changes were observed in ESCC samples, when compared to non-tumor samples. Additionally, in order to mimic BE and EAC risk factors exposure, a non-tumor esophageal cell line was incubated with oleic acid (OA) and acidified medium and/or deoxycholic acid (DCA), revealing a significant increment in LD amount as well as in COX-2 and CXCL-8 expression, and in IL-8 secretion. Further, COX-2 expression and LD amount presented a significant positive correlation and were detected co-localized in EAC, but not in ESCC, suggesting that LD may be the site for eicosanoid production in EAC. In conclusion, this study shows that obesity, and BE- and EAC-associated inflammatory stimuli result in a gradual increase of LD, that may be responsible for orchestrating inflammatory mediators’ production and/or action, thus contributing to BE and EAC genesis and progression.

The Role of VEGFA, COX2, HUR and CUGBP2 in Predicting the Response to Neoadjuvant Therapy in Rectal Cancer Patients

Background and objectives: The effectiveness of neoadjuvant therapy, which is commonly used for stage II-III rectal cancer (RC) treatment, is limited. Genes associated with the pathogenesis of RC could determine response to this treatment. Therefore, the aim of this study was to investigate the potential predictive value of VEGFA, COX2, HUR and CUGBP2 genes and the associations between post-treatment changes in gene expression and the efficacy of neoadjuvant therapy. Materials and Methods: Biopsies from RC and healthy rectal tissue of 28 RC patients were collected before neoadjuvant therapy and 6-8 weeks after neoadjuvant therapy. The expression levels of VEGFA, COX2, HUR, CUGBP2 genes were evaluated using a quantitative real-time polymerase chain reaction. Results: The results reveal a significantly higher expression of VEGFA, COX2 and HUR mRNA in RC tissue compared to healthy rectal tissue (p < 0.05), and elevated VEGFA gene expression in pre-treatment tissues was associated with a better response to neoadjuvant therapy based on T-stage downstaging (p < 0.05). The expression of VEGFA, HUR and CUGBP2 genes significantly decreased after neoadjuvant therapy (p < 0.05). Responders to treatment demonstrated a significantly stronger decrease of VEGFA and COX2 expression after neoadjuvant therapy than non-responders (p < 0.05). Conclusions: The findings of this study suggest that the pre-treatment VEGFA gene expression might have predictive value for the response to neoadjuvant therapy, while the post-treatment decrease in VEGFA and COX2 gene expression could indicate the effectiveness of neoadjuvant therapy in RC patients.

Modulation of aryl hydrocarbon receptor inhibits esophageal squamous cell carcinoma progression by repressing COX2/PGE2/STAT3 axis

Esophageal squamous cell carcinoma (ESCC) is one of the most common malignant tumors with poor prognosis. Aryl hydrocarbon receptor (AHR) is a ligand-dependent transcription factor and emerging evidence shows it is associated with tumor initiation and promotion. However, the relationship between AHR and ESCC is not clear and it is meaningful to explore whether AHR could be a therapeutic target. In the present study, immunohistochemistry was performed to determine AHR expression levels in ESCC tissues. Knockdown of AHR expression in ESCC cell lines genetically and modulation of AHR by 3, 3'-diindolylmethane (DIM) pharmacologically both in vitro and in vivo were utilized to examine the corresponding alterations in cell growth, migration and invasion. Our study indicated that AHR expression levels were elevated in ESCC and associated with poor prognosis. Both knockdown and modulation of AHR inhibited tumor progression through down-regulating expression levels of PCNA, Bcl-2, Cyclin D1, MMP1, MMP2, MMP9 and up-regulating expression levels of Bax, Cleaved-Caspase 3. Our findings also indicated that repressing COX2/PGE₂/STAT3 axis exerted inhibitory effects on ESCC both in vitro and in vivo assays. Taken together, AHR plays the key role in ESCC progression and targeting AHR as a therapeutic strategy with DIM is deserved for further exploration.

High PTGS2 expression in post-neoadjuvant chemotherapy-treated oesophageal adenocarcinoma is associated with improved survival: a population-based cohort study

AIMS

High prostaglandin endoperoxide synthase-2 (PTGS2) enzyme expression in oesophageal adenocarcinoma has been shown to independently predict poor prognosis; however, the evidence is inconsistent. The aim of this study was to investigated the association between PTGS2 expression and prognosis in patients with oesophageal adenocarcinoma.

METHODS AND RESULTS

A cohort of 135 patients with oesophageal adenocarcinoma who received neoadjuvant chemotherapy and surgery from 2004 to 2012 was identified in the Northern Ireland Cancer Centre. Tissue microarrays were created in the Northern Ireland Biobank, with triplicate cores being sampled from each tumour. Immunohistochemical PTGS2 expression was scored by two independent assessors, with intensity and proportion of tumour staining being used to calculate H-scores for each patient. Cox regression models were used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) for overall and cancer-specific survival, and recurrence-free survival by PTGS2 expression, with adjustment for potential confounders. Patients were followed up for a mean of 3.0 years (standard deviation 1.8 years). The PTGS2 expression cut-off value was determined from the median H-score of the cohort (270/300). High (n = 79), as compared with low (n = 56), PTGS2 expression was associated with improved cancer-specific survival (adjusted HR 0.56, 95% CI 0.33-0.94; P = 0.03). PTGS2 expression was not significantly associated with recurrence-free survival (adjusted HR 0.85, 95% CI 0.52-1.38; P = 0.51).

CONCLUSIONS

High PTGS2 expression in oesophageal adenocarcinoma tissue was associated with improved overall and cancer-specific survival, in contrast to previous evidence. As this is the first study of its kind to include patients who had undergone neoadjuvant chemotherapy, further studies are needed to clarify these associations.

Comparison of the prognosis of neoadjuvant chemoradiotherapy treatment with surgery alone in esophageal carcinoma: a meta-analysis

Background

Resection remains the best treatment for carcinoma of the esophagus in terms of local control, but local recurrence and distant metastasis remain an issue after surgery. Chemo-radiotherapy (CRT) followed by surgery was associated with significantly improved survival benefit, but the effectiveness of neoadjuvant therapy in patients with resectable esophageal carcinoma remains controversial. The aim of this study was to evaluate the effects of neoadjuvant chemoradiotherapy in resectable esophageal carcinoma compared to surgery alone (SA).

Methods

A search for publications that compared the efficacy of CRT with SA in resectable esophageal carcinoma was conducted. After a rigorous review of the quality, the data were extracted from eligible trials. The major outcomes measures were odds ratios (ORs). The ORs with their corresponding 95% confidence intervals were the principal measure of effects. For the meta-analysis, Revman 5.3 software was used to analyze the combined pooled ORs using fixed- or random-effects models according to the heterogeneity.

Results

Our findings revealed that, compared with SA, neoadjuvant CRT was associated with improved overall survival (OS) and progression-free survival times, but the 3- and 5-year OS did not show a statistical difference (P≥0.05). The adjuvant chemotherapy group did not show significant improvement on reference rate and metastasis rate compared with the control group.

Conclusion

CRT does significantly improve progression-free survival and OS in patients with esophageal cancer compared with SA. However, further assessment is still warranted on the role of CRT in future trials with well-selected patients.

Predictive biomarkers for response of esophageal cancer to chemo(radio)therapy: A systematic review and meta-analysis

BACKGROUND

Esophageal cancer remains a major public health issue worldwide. In clinical practice, chemo(radio)therapy is an important approach to patients with esophageal cancer. Only the part of patients who respond to chemo(radio)therapy achieve better long-term outcome. In this case, predictive biomarkers for response of esophageal cancer patients treated with chemo(radio)therapy are of importance. Meta-analysis of P53 for predicting esophageal cancer response has been reported before and is not included in our study. We performed a systematic review and meta-analysis to summarize and evaluate the biomarkers for predicting response to chemo(radio)therapy.

METHOD

PubMed, Web of Science and the Ovid databases were searched to identify eligible studies published in English before March 2017. The risk ratio (or relative risk, RR) was retrieved in articles regarding biomarkers for predicting response of esophageal cancer patients treated with neoadjuvant therapy or chemo(radio)therapy. Fixed and random effects models were used to undertake the meta-analysis as appropriate.

RESULT

Forty-six articles reporting 56 biomarkers correlated with the response were finally included. Meta-analyses were carried out when there was more than one study related to the reported biomarker. Results indicated that low expression of (or IHC-negative) COX2, miR-200c, ERCC1 and TS was individually associated with prediction of response. The RR was 1.64 (n = 202, 95% CI 1.22-2.19, P < 0.001), 1.96 (n = 162, 95% CI 1.36-2.83, P < 0.001), 2.55 (n = 206, 95% CI 1.80-3.62, P < 0.001) and 1.69 (n = 144, 95% CI 1.10-2.61, P = 0.02), respectively. High expression of (or IHC-positive) CDC25B and p16 was individually related to prediction of response. The RR was 0.62 (n = 159, 95% CI 0.43-0.89, P = 0.01) and 0.62 (n = 142, 95% CI 0.43-0.91, P = 0.01), respectively.

CONCLUSION

Low expression of (or IHC-negative) COX2, miR-200c, ERCC1 and TS, or high expression of (or IHC-positive) CDC25B and p16 are potential biomarkers for predicting the response of esophageal cancer patients treated with chemo(radio)therapy.

The prognostic value of cyclooxygenase-2 expression in patients with esophageal cancer: evidence from a meta-analysis

Published studies have investigated the prognostic role of cyclooxygenase-2 (COX-2) expression in patients with esophageal cancer (EC), but the result remains controversial. Thus, this meta-analysis was conducted to comprehensively evaluate the impact of COX-2 expression on the prognostic value in patients with EC. Relevant studies were identified from PubMed, EMBASE, and Web of Science databases. Studies that detected the COX-2 expression by immunohistochemistry and evaluated the relationship between COX-2 expression and overall survival (OS) or clinicopathological parameters were used in our analysis. The summary hazard ratios (HRs) or odds ratios were calculated to assess the risk or hazard association. A total of 25 studies, which included 2,465 patients, were included in our meta-analysis. Our analysis suggested that overexpression of COX-2 was associated with poor OS (HR =1.60, 95% CI =1.32–1.94, P<0.001). Subgroup analyses by race, percentage of high/positive COX-2 expression, histology type, treatment, and sample size all suggested significant association. Moreover, overexpression of COX-2 was significantly associated with depth of invasion, lymph node metastasis, distant metastasis, and TNM stage. This meta-analysis suggested that overexpression of COX-2 might serve as a prognostic biomarker for EC. Large well-designed prospective studies are needed to confirm our conclusion.

Expression of cyclooxygenase 2 in gastrointestinal stromal tumors

AIM: To investigate the correlation of cyclooxygenase 2 (COX2) protein and mRNA expression with clinicopathological characteristics and prognosis in gastrointestinal stromal tumors (GISTs).

METHODS: EnVision technique was used to detect COX2 protein expression in GISTs and in situ hybridization method was used to detect COX2 mRNA expression. The patients were followed for prognosis evaluation.

RESULTS: Of 74 cases of GISTs, positive expression of COX2 protein was observed in 62 (83.8%) cases and positive expression of COX2 mRNA was observed in 58 (78.4%). COX2 protein and mRNA expression between different risk groups was statistically significant (P < 0.05), with the highest positive expression in the high risk group. COX2 protein and mRNA expression had no significant correlation with gender, age, lesion location, histological type, or metastasis (P > 0.05). A total of 38 (51.4%) patients were followed; of 24 patients with strongly positive expression of COX2 protein, 5 had metastases and 2 died. No recurrence, metastasis or death was observed in cases with negative, weakly positive or moderately positive expression. Of 17 cases showing strongly positive expression of COX2 mRNA, 3 had metastases and 2 died. No recurrence, metastasis or death was found in all 6 cases with negative expression of COX2 mRNA. Metastasis was observed in a case with weekly positive expression and a case with moderately positive expression, with no recurrence or death.

CONCLUSION: Upregulation of COX2 protein and mRNA expression in GISTs suggests that COX2 is a possible indicator for GISTs risk stratification and might affect prognosis.

Overcoming paclitaxel resistance in uterine endometrial cancer using a COX-2 inhibitor

Cyclooxygenase (COX)-2 inhibitors have been reported to potentially modulate the resistance of cancer cells to chemotherapeutic drugs by affecting multidrug resistance 1 (MDR1) expression. In the present study, we investigated the association between COX-2 and MDR1 expression in endometrial cancers and evaluated the effects of the COX-2 inhibitor, etodolac, in combination with paclitaxel on paclitaxel-resistant endometrial cancer cells. The relationship between COX-2 and MDR1 mRNA expression was examined by quantitative PCR in 36 endometrial cancer specimens. The paclitaxel-resistant cell line OMC-2P was established from OMC-2 cells. Paclitaxel (1 µg/ml) with or without etodolac (10 µg/ml) was added to OMC-2 and OMC-2P cells, and COX-2 and MDR1 mRNA expression levels were examined. The concentration of prostaglandin E2 (PGE2) in the supernatant of each cell line was examined by enzyme-linked immunosorbent assay. The function of MDR1 was determined by intracellular accumulation of rhodamine 123 using flow cytometry, and the concentration of intracellular paclitaxel was determined by high-performance liquid chromatography. We found a positive relationship between COX-2 and MDR1 mRNA expression in endometrial cancer. Both COX-2 mRNA expression and PGE2 production were elevated in resistant OMC-2P cells when compared to non-resistant OMC-2 cells. Additionally, MDR1 mRNA expression was markedly upregulated in OMC-2P cells. In OMC-2 cells, COX-2 and MDR1 mRNA levels were significantly upregulated by paclitaxel treatment and downregulated by co-administration with etodolac. In OMC-2P cells, COX-2 mRNA expression was also significantly upregulated by paclitaxel treatment and tended to be downregulated by co-administration with etodolac. Moreover, co-administration of paclitaxel and etodolac suppressed the induction of MDR1 mRNA. Rhodamine 123 efflux was increased in OMC-2P cells when compared to the efflux in the OMC-2 cells and was increased in response to paclitaxel treatment. Co-administration of paclitaxel and etodolac in both cell lines resulted in decreased rhodamine 123 efflux. The actual concentration of intracellular paclitaxel in OMC-2P cells was significantly lower than that in OMC-2 cells treated with paclitaxel alone and was significantly increased after co-administration of paclitaxel and etodolac. These findings suggest that paclitaxel resistance may be associated with COX-2 and MDR1 expression in cancer cells. Co-administration of COX-2 inhibitors and paclitaxel may have a key role in modulating or overcoming paclitaxel resistance in endometrial cancers.

Barrett's esophagus: genetic and cell changes

The following includes commentaries on how genetic code of Barrett's esophagus (BE) patients, the mechanisms for GERD-induced esophageal expression of caudal homeobox, and the development of Barrett's metaplasia are increasingly better known, including the role of stromal genes in oncogenesis. Additional lessons have been learned in vitro models in nonneoplastic cell lines, yet there are limitations to what can be expected from BE-derived cell lines. Other topics discussed include clonal diversity in Barrett's esophagus; the application of peptide arrays to clinical samples of metaplastic mucosa; proliferation and apoptosis of Barrett's cell lines; tissue biomarkers for neoplasia; and transcription factors associated with BE.

Preoperative taxane-based chemotherapy and celecoxib for carcinoma of the esophagus and gastroesophageal junction: results of a phase 2 trial

PURPOSE

The primary objective of this study was to determine the rate of pathological response after preoperative celecoxib and concurrent taxane-based chemotherapy in patients with cancer of the esophagus and gastroesophageal junction.

METHODS

Thirty-nine patients were enrolled in this single-arm, phase II clinical trial. Patients were administered daily celecoxib in combination with two to three cycles of carboplatin and paclitaxel with preoperative intent. Levels of cyclooxygenase (COX)-2 expression in resected tumors were analyzed by immunohistochemistry and correlated with clinical outcome measures. Postoperatively, patients were administered daily celecoxib for 1 year or until documented tumor recurrence.

RESULTS

All patients received two to three cycles of chemotherapy plus celecoxib 800 mg/d. Toxicities were as expected. A major clinical response (complete response + partial response) was noted in 22 patients (56%); six patients (15%) had a complete clinical response. Thirty-seven patients underwent esophagectomy. Five patients had a major pathological response (12.8%). Four-year overall and disease-free survivals were 40.9% and 30.3%, respectively. Patients with tumors expressing COX-2 demonstrated a higher likelihood of a major clinical response response (62% versus 50%) and an improved overall survival, compared with patients with COX-2-negative tumors.

CONCLUSIONS

Preoperative celecoxib with concurrent chemotherapy demonstrated sufficient effect on pathologic response to warrant further study. Patients with tumors expressing COX-2 demonstrated trends toward improved response to preoperative therapy and improved overall survival compared with nonexpressors.

Roles of thymidylate synthase and dihydropyrimidine dehydrogenase expression in blood as predictors of response to multimodal therapy in esophageal cancer

BACKGROUND

Thymidylate synthetase (TS) and dihydropyrimidine dehydrogenase (DPD) RNA expression in peripheral blood was examined as a noninvasive molecular predictor of response to neoadjuvant radiochemotherapy in patients with locally advanced cancer of the esophagus.

METHODS

Blood samples were drawn from 29 patients with esophageal cancer (10 squamous cell carcinomas and 19 adenocarciomas) before neoadjuvant radiochemotherapy. After extraction of cellular tumor RNA from blood samples, quantitative expression analysis of TS and DPD was performed with quantitative real-time reverse-transcription polymerase chain reaction.

RESULTS

Twenty of 29 (68%) of patients had a minor histopathologic response, and 9 of 29 (32%) had a major response to neadjuvant radiochemotherapy. RNA expression in the blood of patients was detectable for TS in 86%, for DPD in 97%, and in 100% for β-actin. No significant associations were detected between TS and DPD expression levels and clinical variables of the patients. A high expression level for TS was associated with a minor response to neoadjuvant treatment (P = .046), while there was no significant association between DPD and response to therapy. Combined analysis of TS and DPD expression increased the specificity for the prediction of response to 100%. No major responder to therapy had high expression levels for both genes in their peripheral blood.

CONCLUSION

Quantitation of TS and DPD in peripheral blood may be a highly specific analysis to identify a subset of patients who do not respond to neoadjuvant radiochemotherapy and may therefore prevent expensive, noneffective, and potentially harmful therapies in a substantial number of patients with esophageal cancer.

Plasma levels of vascular endothelial growth factor during and after radiotherapy in combination with celecoxib in patients with advanced head and neck cancer

Celebrex and radiotherapy in advanced head and neck cancer. This phase I dose-escalation study seeks to determine the phase II recommended dose of cyclooxygenase type 2 (COX-2) inhibitor in patients with locally advanced squamous cell head and neck (H&N) cancer, treated with accelerated radiotherapy. Anti-vasculogenic effect of this treatment on serum vascular endothelial growth factor (VEGF) is examined. Patients were irradiated with curative intent (72Gy in 6weeks). Celecoxib was administered throughout the radiotherapy course. Serum VEGF level were tested during radiotherapy and in follow-up. Tumor specimens were stained to quantify the COX-2 expression. Thirty-two patients completed the treatment. The dose of celecoxib was escalated (200, 400 and 800mg bid, then de-escalated to 600mg bid). The acute toxicity related to the treatment in the first and second cohort did not reach grade III; in the third cohort three patients had grade III radiation toxicity and one had celecoxib-related toxicity. In the last fourth cohort the toxicity was acceptable. Significant VEGF level drop (p=0.011) was found between radiation day 1 and post-treatment visit. Significant decrease (p=0.022) of the VEGF level was shown in patients with high COX-2 expression in the tumor. Phase II recommended dose of celecoxib combined with accelerated radiotherapy in advanced H&N cancer was 600mg bid. A significant decrease of the post-treatment serum VEGF level compared to the initial level was noticed only in patients with high COX-2 expression in tumors.

Celecoxib antagonizes the cytotoxicity of cisplatin in human esophageal squamous cell carcinoma cells by reducing intracellular cisplatin accumulation

High cyclooxygenase 2 (COX-2) expression has been reported to be clinically associated with reduced cisplatin-based therapy efficacy in esophageal cancer. However, the benefit of including COX-2-selective inhibitors in therapeutic regimens remains uncertain. Thus, we sought to determine the effects of COX inhibitors on the cytotoxicity of cisplatin and to further explore the mechanism involved in human esophageal squamous cell carcinoma cells. Among the four tested COX inhibitors [celecoxib, 4-[5-(4-chlorophenyl)-3-(trifluoromethyl)-1H-pyrazol-1-yl]benzenesulfonamide (SC-236), nimesulide, and indomethacin], all of which substantially suppressed prostaglandin E(2) production to a similar extent; only the COX-2-selective inhibitors celecoxib and SC-236 antagonized cisplatin-induced cytotoxicity and apoptosis in both cisplatin-resistant cells and their wild-type counterparts. Knockdown of COX-2 by small interference RNA failed to mimic the antagonizing effects of celecoxib and SC-236, implying that their action is COX-2-independent. Further mechanistic analysis revealed that the antagonizing effect of celecoxib and SC-236 on cytotoxic action of cisplatin was associated with decreased whole-cell cisplatin accumulation and DNA platination. Reduced influx, accompanied by the reduction of protein level of copper transporter 1, accounts for decreased intracellular cisplatin accumulation. In addition, combined treatment did not elicit greater antitumor activity than cisplatin or celecoxib monotherapy in vivo in an esophageal cancer xenograft model. Collectively, these data demonstrate that celecoxib antagonizes the cytotoxicity of cisplatin by decreasing intracellular cisplatin and DNA platination. The combination treatment also shows no beneficial effect compared with cisplatin or celecoxib monotherapy in vivo. Therefore, current clinical trials with celecoxib in combination with cisplatin should be approached with caution.

Molecular response prediction in multimodality treatment for adenocarcinoma of the esophagus and esophagogastric junction

Cancers arising from the esophagus are becoming more common in the United States and Europe. In 2009, an estimate of 14,530 new cases will be diagnosed and more than 90% will die of their disease. Esophageal cancer is currently the most rapidly increasing cancer in the western world and is coinciding with a shift in histological type and primary tumor location. Despite recent improvements in the detection, surgical resection, and (radio-) chemotherapy, the overall survival (OS) of esophageal cancer remains relatively poor. It is becoming increasingly apparent that neoadjuvant chemoradiation followed by surgery may be beneficial in terms of increasing resectability and OS compared to surgery alone. Results from clinical trials are encouraging; however, they also demonstrated that only patients with major histopathological response (pCR) will benefit from neoadjuvant therapy. In addition, these therapies are expensive and the prognoses of patients who do not respond to trimodality treatment strategies appear to be inferior to that of patients who had surgery alone. Accordingly, the development of validated predictive molecular markers may not only be helpful in identifying EA patients who are more likely to respond, but they will also be critical in selecting more efficient treatment strategies with the means of a tailored, targeted, and effective therapy to the molecular profile of both the patient and their disease while minimizing and avoiding life-threatening toxicities.

Biomarkers in Barrett's oesophagus

Biomarkers are needed to screen multiple stages in the clinical pathway of Barrett's oesophagus patients; from disease diagnosis to risk stratification and predicting response to therapy. Routes to the identification of biomarkers have been recognized by known molecular features of the disease and more recently through transcriptomic, methylation and proteomic screening approaches. The majority of Barrett's oesophagus patients remain undiagnosed in the general population. In order to develop a tool to screen for Barrett's oesophagus in the primary care setting, minimally invasive sampling methods coupled with immunocytology-based biomarkers are currently being assessed. Biomarkers may also have utility in surveillance programmes by allowing endoscopic interval to be adjusted according to individual neoplastic risk. Many individual biomarkers have been proposed in this regard, but have frequently been assessed in studies of limited power, or have lacked sufficient sensitivity or specificity when assessed in wider population-based studies. Biomarker panels may provide a route forward. In this regard, a panel of methylation markers has shown promise in a multicentre, double-blind, validation study. Biomarkers are also being developed to improve detection of high-grade dysplasia and oesophageal adenocarcinoma, utilizing brush cytology combined with FISH (fluorescence in situ hybridization), and to assess therapeutic success and risk of complication during photodynamic therapy. Finally, we outline progress in identifying alternative sources of biomarkers for this condition.

Genetics in the pathogenesis of esophageal cancer: possible predictive and prognostic factors

INTRODUCTION

Esophageal adenocarcinoma is the most rapidly increasing cancer in Western countries. Like esophageal squamous-cell carcinoma, these tumors are often detected at an advanced stage, requiring a multimodal concept. Despite improvements in detection, surgical resection, and (neo-) adjuvant therapy, the overall survival of esophageal cancer remains lower than other solid tumors. In fact, just 30-40% of the patients with advanced esophageal cancer benefit from a neoadjuvant therapy. Therefore, predictive/prognostic markers are needed to allow tailored multimodality therapy with increased efficacy.

DISCUSSION

In recent years, there has been an exponential growth in our understanding of the cellular and molecular events associated with cell cycle regulation, programmed cell death, angiogenesis, and tumor growth. In this review, the classification of Hanahan and Weinberg is used concerning the six essential changes in carcinogenesis, i.e., the six hallmarks of cancer: (1) self-sufficiency in growth signals; (2) insensitivity to antigrowth signals; (3) avoidance of apoptosis; (4) limitless replicative potential; (5) sustained angiogenesis; and (6) tissue invasion and metastasis.

CONCLUSIONS

According to these six steps, this review provides an update of the most recent data about predictive/prognostic molecular markers in patients with esophageal cancer.

Quantitative analysis of survivin RNA expression in blood as a non-invasive predictor of response to neoadjuvant radiochemotherapy in esophageal cancer

BACKGROUND AND OBJECTIVES

Analysis of survivin RNA expression in peripheral blood as a non-invasive molecular predictor of response to neoadjuvant radiochemotherapy in patients with locally advanced cancer of the esophagus.

MATERIAL AND METHODS

Blood samples were drawn from 29 patients with esophageal cancer prior to neoadjuvant radiochemotherapy. After extraction of cellular tumor-RNA from blood samples, quantitative expression analysis of survivin was done by quantitative real-time RT-PCR.

RESULTS

Twenty of 29 (69%) of patients showed a minor histopathological response and 9 of 29 (31%) showed a major-response to neadjuvant radiochemotherapy. RNA expression in blood of patients was detectable for survivin in 27.6%, and in 100% for beta-actin. The mean survivin expression was not significantly different between minor- and major-responders. No significant associations were detected between survivin expression levels and patients clinical variables. A high expression level for survivin was significantly associated with a minor-response to neoadjuvant treatment (P = 0.042). Relative survivin expression levels above 0.15 were not associated with major histopathological response (sensitivity: 35%; specificity: 100%).

CONCLUSION

Minor-response to the applied therapy was significantly associated with a high survivin RNA expression level in patient's blood. Survivin appears to be a specific non-invasive predictor of response to neoadjuvant therapy in esophageal cancer.

Integration of targeted agents in the neo-adjuvant treatment of gastro-esophageal cancers

Pre- and peri-operative strategies are becoming standard for the management of localized gastro-esophageal cancer. For localized gastric/gastro-esophageal junction (GEJ) cancer there are conflicting data that a peri-operative approach with cisplatin-based chemotherapy improves survival, with the benefits seen in esophageal cancer likely less than a 5-10% incremental improvement. Further trends toward improvement in local control and survival, when combined chemotherapy and radiation therapy are given pre-operatively, are suggested by recent phase III trials. In fit patients, a significant survival benefit with pre-operative chemoradiation is seen in those patients who achieve a pathologic complete response. In esophageal/GEJ cancer, definitive chemoradiation is now considered in medically inoperable patients. In squamous cell carcinoma of the esophagus, surgery after primary chemoradiation is not clearly associated with an improved overall survival, however, local control may be better. In localized gastric/GEJ cancer, the integration of bevacizumab with pre-operative chemotherapy is being explored in large randomized studies, and with chemoradiotherapy in pilot trials. The addition of anti-epidermal growth factor receptor and anti-human epidermal growth factor receptor-2 antibody treatment to pre-operative chemoradiation continues to be explored. Early results show the integration of targeted therapy is feasible. Metabolic imaging can predict early response to pre-operative chemotherapy and biomarkers may further predict response to pre-operative chemo-targeted therapy. A multimodality approach to localized gastro-esophageal cancer has resulted in better outcomes. For T3 or node-positive disease, surgery alone is no longer considered appropriate and neo-adjuvant therapy is recommended. The future of neo-adjuvant strategies in this disease will involve the individualization of therapy with the integration of molecular signatures, targeted therapy, metabolic imaging and predictive biomarkers.

Effects of neoadjuvant radiochemotherapy on pathological staging and prognosis for locally advanced esophageal squamous cell carcinoma

The role of neoadjuvant therapy in the treatment of locally advanced esophageal carcinoma still remains controversial. The aim of this study was to evaluate the effects of neoadjuvant radiochemotherapy on pathological staging and prognosis in the patients with locally advanced esophageal squamous cell carcinoma. Between January 1991 and December 2000, 473 patients with advanced esophageal carcinoma diagnosed by endoscopic biopsy underwent surgical resection in our center. With informed consent, they were randomized into four groups: neoadjuvant chemotherapy, neoadjuvant radiotherapy, neoadjuvant radiochemotherapy, and surgery alone (control group). The preoperative computed tomography staging criteria were the following: Stage I, the tumor limited to the esophageal lumen or the thickness of the esophageal wall varied between 3-5 mm; Stage II, the thickness exceeds 5 mm but no invasion to the mediastinum or distant metastasis; Stage III, the tumor invades adjacent mediastinal structure; and Stage IV, there is distant metastasis. The tumor resection rate, pathological stage, treatment-related complication, and survival among groups were compared. The radical resection rate for the patients in radiotherapy and radiochemotherapy groups was increased in comparison with the control group (P < 0.05). Their pathological stage after esophagectomy was regressed significantly than that of the control group (50.85%, 55.08% vs. 0%, P < 0.05). The adjuvant chemotherapy group did show significant improvement on resection rate and pathological staging compared with the control group. The treatment-related complication in the three neoadjuvant groups had no significant difference from that of the control group (P > 0.05). The 3-year survival rate of radiotherapy and radiochemotherapy groups were significantly higher than that of the control group (69.49%, 73.73% vs. 53.38%, P < 0.05). The 5-year survival rate of radiochemotherapy group was higher than that of the radiotherapy group although did not show a statistical difference (P > 0.05). Rational application of neoadjuvant radiochemotherapy seems to provide a modest benefit in radical resection and survival in patients with locally advanced esophageal carcinoma.

Pharmacokinetics and pharmacogenomics in esophageal cancer chemoradiotherapy

Esophageal cancer is one of the most lethal malignancies. Surgical resection of the tumor from the primary site has been the standard treatment, especially for localized squamous cell carcinoma, but considerable clinical efforts during the last decade have resulted in novel courses of treatment. These options include chemoradiotherapy, consisting of a continuous infusion of 5-fluorouracil (5-FU), cisplatin (CDDP), and concurrent radiation. Given the substantial inter- and/or intra-individual variation in clinical outcome, future improvements will likely require the incorporation of a novel anticancer drug, pharmacokinetically guided administration of CDDP or 5-FU, and identification of potential responders by patient genetic profiling prior to treatment. In this review, the latest information on incidence, risk factors, biomarkers, therapeutic strategies, and the pharmacokinetically guided or genotype-guided administration of CDDP and 5-FU is summarized for future individualization of esophageal cancer treatment.

HIF-1alpha protein expression is associated with the environmental inflammatory reaction in Barrett's metaplasia

The oxygen-regulated transcription factor subunit hypoxia inducible factor-1alpha (HIF-1alpha) is involved in angiogenesis, energy metabolism, cell survival, and inflammation. We examined the protein expression of HIF-1alpha within the progression of Barrett's sequence as well as the type and degree of the environmental inflammatory reaction. Squamous epithelium (SE), metaplastic, low- and high-grade dysplastic lesions, and tumor tissue of 57 resection specimens from patients with Barrett's adenocarcinoma were immunohistochemically analyzed. Active and chronic inflammatory reactions were classified according to the Updated Sydney System. HIF-1alpha protein expression increased significantly from SE to Barrett's metaplasia (BM) (P < 0.0001). From metaplasia through low- and high-grade dysplasia to cancer, no further increase could be detected. Active and chronic inflammation were also significantly different between SE and BM (P < 0.0001) but not during further progression in the sequence. HIF-1alpha protein expression did not correlate with histopathologic parameters or survival. HIF-1alpha protein expression pattern resembles the active and chronic environmental inflammatory reaction. All were significantly increased in metaplasia compared to SE without further change in tumor development. HIF-1alpha protein expression appears to be associated with inflammatory processes in the development of BM.

GNAS1 T393C polymorphism is associated with histopathological response to neoadjuvant radiochemotherapy in esophageal cancer

Recent studies have shown an association between the GNAS1 T393C polymorphism and clinical outcome for various solid tumors. In this study, we genotyped 51 patients from an observational trial on cisplatin/5-FU-based neoadjuvant radiochemotherapy of locally advanced esophageal cancer (cT2-4, Nx, M0) and genotyping was correlated with histomorphological tumor regression. The C-allele frequency in esophageal cancer patients was 0.49. Pearson's chi(2)-test showed a significant (P<0.05) association between tumor regression grades and T393C genotypes. Overall, 63% of the patients in the T-allele group (TT+CT) were minor responders with more than 10% residual vital tumor cells in resection specimens, whereas T(-) genotypes (CC) showed a major histopathological response with less than 10% residual vital tumor cells in 80%. The results support the role of the T393C polymorphism as a predictive molecular marker for tumor response to cisplatin/5-FU-based radiochemotherapy in esophageal cancer.

Death-associated protein kinase (DAPK) promoter methylation and response to neoadjuvant radiochemotherapy in esophageal cancer

BACKGROUND

Multiple studies have shown that promoter methylation of tumor suppressor genes underlies esophageal carcinogenesis. Hypothetically, methylation resulting in tumor suppressor gene inactivation might result in tumors that are unresponsive to chemotherapy and radiation. Accordingly, our aim was to investigate if aberrant methylation of the apoptosis-related gene Death-Associated Protein Kinase (DAPK) could be used as a predictor of response to neoadjuvant therapy in locally advanced cancer of the esophagus.

METHODS

Tumor and normal esophageal tissues were obtained from 50 patients with locally advanced cancer of the esophagus prior to neoadjuvant radiochemotherapy. DAPK methylation analysis was performed on all samples by methylation-specific real-time polymerase chain reaction (PCR).

RESULTS

Seventeen (34%) patients showed a major and 33 (66%) a minor histomorphological response to neoadjuvant therapy. DAPK methylation was detectable in normal esophageal tissues with a frequency of 10% and in tumor tissue with a frequency of 78%. The median methylation level for DAPK was 2.7 x 10(-3) in tumor compared with 0.1 x 10(-3) in normal tissues (p < 0.001). DAPK methylation was not associated with response to neoadjuvant therapy or prognosis after esophagectomy.

CONCLUSION

Aberrant DAPK methylation in tumor tissues is significantly higher compared with matching normal esophageal tissues, suggesting a fundamental role of this epigenetic alteration in the pathogenesis of this disease. The level of DAPK methylation in pretreatment biopsies of patients with locally advanced cancer of the esophagus is no marker for the prediction of histomorphological regression or prognosis following neoadjuvant chemoradiation in this disease.

Polymorphism Arg290Arg in esophageal-cancer-related gene 1 (ECRG1) is a prognostic factor for survival in esophageal cancer

BACKGROUND

Esophageal cancer is one of the most frequent cancers worldwide and is associated with poor outcome. Besides clinicopathological data, few prognostic molecular markers exist. Esophageal-cancer-related gene1 (ECRG1) short tandem repeats are associated with higher risk for developing esophageal squamous cell carcinoma. The aim of the present study was to evaluate the impact of DNA polymorphisms in the coding region of ECRG1 in esophageal carcinoma.

METHODS

Genomic DNA of 107 patients with esophageal cancer that underwent complete surgical resection between 1997 and 2005 was extracted. DNA was analyzed for ECRG1 polymorphisms Arg290Arg, Arg290Gln, and Gln290Gln by PCR and gel electrophoresis. Polymorphisms were correlated with survival data by the Kaplan-Meier method, multivariate Cox regression analysis, and odds ratio were determined. For all variables, cross tables were generated, followed by calculation of the p value by using the chi-square test/Fisher-exact test.

RESULTS

Follow-up data of 102 patients with esophageal cancer were available after complete surgical resection for a median follow-up time of 24.3 months. Polymorphism Arg290Arg was found in 47 patients (46.1%), Arg290Gln in 48 patients (47.0%), and Gln290Gln in seven cases (6.9%). Arg290Arg polymorphism was significantly associated with reduced overall survival (p = 0.01) and tumor-free survival (p = 0.01) by the log-rank test. Multivariate regression analysis by Cox revealed polymorphism Arg290Arg to be a significant prognostic factor for survival (p = 0.012).

CONCLUSIONS

Polymorphism Arg290Arg in ECRG1 is associated with poor clinical outcome after complete surgical resection in patients with esophageal cancer.

ERCC1 RNA expression in peripheral blood predicts minor histopathological response to neoadjuvant radio-chemotherapy in patients with locally advanced cancer of the esophagus

OBJECTIVE

The aim of this study was to determine the gene is spelled excision repair cross-complementing gene 1 (ERCC1) RNA-expression in peripheral blood as a non-invasive molecular predictor of response to neoadjuvant radio-chemotherapy in patients with locally advanced cancer of the esophagus.

BACKGROUND

Only patients with locally advanced cancer of the esophagus with a major histopathological response to neoadjuvant radio-chemotherapy benefit from this treatment. No non-invasive molecular marker exists that can reliably predict response to neoadjuvant therapy in this disease. To improve the treatment of patients with cancer of the esophagus, molecular predictors of response are desperately needed.

METHODS

Blood samples were drawn from 29 patients with esophageal cancer prior to neoadjuvant radio-chemotherapy. After extraction of cellular tumor-RNA from blood samples, quantitative expression analysis of ERCC1 was done by real-time reverse transcription polymerase chain reaction.

RESULTS

Nineteen (65.5%) patients showed a minor and ten (34.5%) a major histopathological response to neoadjuvant therapy. ERCC1 expression in blood of patients was detectable in 82.8%. The median ERCC1 expression was 0.62 (minimum 0.00, maximum 2.48) in minor responders and 0.24 (minimum 0.00, maximum 0.45) in major responders (p = 0.004). No significant associations were detectable between ERCC1 levels and patients' clinical variables. Relative ERCC1 levels above 0.452 were not associated with major histopathological response (sensitivity, 68.4; specificity, 100%), and 13 of 19 patients with minor response could be unequivocally identified.

CONCLUSION

Minor responders to the applied therapy show a significant higher ERCC1 expression level in their blood compared to major responders. ERCC1 appears to be a highly specific non-invasive predictor of response to neoadjuvant therapy in esophageal cancer.

Locally advanced esophageal adenocarcinoma: current standards and molecular predictors of outcome

Despite decades of effort to improve outcomes, esophageal cancer remains a highly fatal disease. The optimal approach to cure is still debated globally, although a consensus favoring trimodality therapy has emerged in the USA. In this review, after providing a brief update on current standards of therapy in locally advanced esophageal cancer, we focus on one area in which the field is headed: the identification of molecular outcome markers, with the ultimate goal of individualizing therapy according to pretreatment profiles. We attempt to clarify the somewhat unwieldy body of literature in this area, with a focus on adenocarcinoma, keeping the clinician and clinical researcher particularly in mind.

Failure in downregulation of intratumoral survivin expression following neoadjuvant chemoradiation in esophageal cancer

Introduction: Neoadjuvant multimodality treatment is frequently applied to improve the poor prognosis associated with locally advanced esophageal cancer. However, only patients with a major histopathologic response to neoadjuvant therapy will have a significant survival benefit. Predictive markers to allow individualization of multimodality treatment could be very helpful. We aimed to examine the association of survivin protein expression, an inhibitor of apoptosis, with histopathologic response to neoadjuvant chemoradiation and prognosis in patients with esophageal cancer. Patients & methods: A total of 59 patients with esophageal cancer (clinical tumor stage 2–4, Nx, M0) received neoadjuvant chemoradiation followed by transthoracic en bloc esophagectomy. Histomorphologic regression was defined as major response when resected specimens contained less than 10% vital tumor cells. Intratumoral survivin expression was determined by immunohistochemistry in pretherapeutic biopsies and post-therapeutic resection specimens and correlated with clinicopathologic parameters. Results: The pretherapeutic intratumoral survivin protein expression was not associated with any clinicopathologic factor. Survivin protein expression decreased significantly during neoadjuvant therapy, showing lower levels in post-therapeutic tumor samples (p < 0.01). Elevated postoperative survivin levels were significantly associated with a higher pathologic tumor stage after neoadjuvant therapy (ypT) category (p < 0.01), a poorer histopathologic response (p < 0.01) and a shorter overall survival (p < 0.028). Conclusion: Intratumoral survivin protein expression was significantly downregulated during neoadjuvant therapy of esophageal cancers. Elevated survivin levels after preoperative therapy were significantly associated with a minor histopathologic response and prognosis. Therefore, failure in downregulation of intratumoral survivin expression following neoadjuvant chemoradiation in esophageal cancer needs therapeutic strategies to reduce survivin expression or block survivin-mediated pathways to increase the histopathologic response rate and prognosis.

Potential role of NF-kappaB in esophageal adenocarcinoma: as an emerging molecular target

Esophageal adenocarcinoma is increasing in incidence and arises in a background of reflux induced inflammation, metaplasia, and dysplasia. The proinflammatory transcription factor nuclear factor-kappa B (NF-kappaB) has a central role in inflammation and tumorigenesis. Because a role for NF-kappaB has been implicated in the pathogenesis of esophageal cancer, this transcription factor has been the focus of the current research of this devastating disease. NF-kappaB blocks apoptosis, mediates tumor cell proliferation, and induces resistance to chemotherapeutic drugs. Research efforts to improve the effect of chemotherapy have led to an improvement in patient survival but there is still a need for improvement, and NF-kappaB is a potential target for cancer drug development. In this review, we have attempted to highlight the possible role of NF-kappaB in esophageal adenocarcinoma and discuss the anticancer strategy with NF-kappaB as a promising molecular target in esophageal cancer therapy.

Selective cyclooxygenase-2 inhibition suppresses basic fibroblast growth factor expression in human esophageal adenocarcinoma

Inhibition of cyclooxygenase (COX)-2 is reported to suppress growth and induce apoptosis in human esophageal adenocarcinoma (EADC) cells, although the precise biologic mechanism is unclear. In this study we tested the hypothesis that the antitumor activity of COX-2 inhibitors may involve modulation of basic fibroblast growth factor (FGF-2), which is overexpressed in EADC. We evaluated the effects of NS-398, a selective COX-2 inhibitor, on FGF-2 expression and proliferation of EADC cell lines that express COX-2 and those that do not. We also correlated COX-2 and FGF-2 expression with clinico-pathologic findings and outcome in a well-characterized series of surgically resected EADC tissues. Seg-1 cells robustly expressed COX-2 and FGF-2, whereas Bic-1 cells expressed neither transcript. FGF-2 was reduced to undetectable levels in Seg-1 cells following NS-398 treatment, but increased within 4 h of drug removal. NS-398 significantly inhibited the growth of Seg-1 cells, and this effect was ameliorated by addition of exogenous FGF-2. In contrast, NS-398 had no effect on Bic-1 cell proliferation and FGF-2 alone had no effect on proliferation of either cell line. NS-398, or a neutralizing anti-FGF-2 antibody, induced apoptosis in Seg-1 cells, and these effects were inhibited by addition of exogenous FGF-2. COX-2 protein was strongly expressed in 46% (10/22) of EADCs, and was associated with a trend towards reduced disease-free survival. These findings indicate that the antitumor effects of COX-2 inhibition in EADC cells may be mediated via suppression of FGF-2, and that COX-2 may be a clinically relevant molecular marker in the management of human EADC.

Cyclooxygenase-2 expression as a predictor of para-aortic lymph node recurrence in uterine cervical cancer

PURPOSE

The overexpression of cyclooxygenase-2 (COX-2) is associated with a worse prognosis and the development of distant metastases in cervical cancer. This matched-pair analysis examined whether COX-2 expression is associated with para-aortic lymph node (PALN) recurrence in uterine cervical cancer treated with radiotherapy (RT).

METHODS AND MATERIALS

For this study, we matched 20 patients with PALN recurrence after definitive or postoperative RT by stage with 20 others who did not have PALN recurrence. Of the 20 patients with PALN recurrence, definitive or postoperative RT was performed in 11 and 9 patients, respectively. COX-2 expression was assessed immunohistochemically using a mouse monoclonal antibody on formalin-fixed paraffin-embedded tumor specimens taken before RT. A logistic regression model was used to predict for PALN recurrence.

RESULTS

COX-2 was expressed in 28 (70%) of the 40 patients. The staining intensity was as follows: weak in 19 (47%), moderate in 6 (15%), and strong in 3 (8%) patients. The patients with PALN recurrence had much greater expression of COX-2 (17 patients, 85%) than did the control group (11 patients, 55%; p = 0.04). Strong staining intensity of COX-2 was seen only in the PALN recurrence group. The statistically significant factors associated with PALN recurrence were positive pelvic lymph nodes (odds ratio, 7.61; 95% confidence interval, 1.55-37.37; p = 0.01) and COX-2 expression (odds ratio, 1.47; 95% confidence interval, 1.04-2.09; p = 0.03).

CONCLUSION

Our findings suggest that COX-2 overexpression in the initial tumor tissue might be associated with PALN recurrence after RT in cervical cancer patients.

Association of COX-2 expression with corresponding active and chronic inflammatory reactions in Barrett's metaplasia and progression to cancer

AIMS

Risk reduction for Barrett's cancer in individuals taking non-steroidal anti-inflammatory drugs has been reported. Cyclooxygenase (COX)-2, one of the inhibited enzymes, is putatively involved in Barrett's cancer pathogenesis. The aim of this study was to examine a possible association between COX-2 protein expression and the development and progression of the Barrett's metaplasia-dysplasia-carcinoma sequence and the type and degree of associated inflammatory reaction.

METHODS AND RESULTS

Squamous epithelium, metaplastic, low-grade, high-grade dysplastic lesions and tumour tissue of 49 resection specimens from patients with Barrett's adenocarcinoma were immunohistochemically analysed. Active and chronic inflammatory reactions were classified according to the Updated Sydney System. Within the Barrett's sequence, a significant progressive increase in COX-2 expression was identified (P < 0.0001). The most significant differences were detected between squamous epithelium and Barrett's metaplasia (P < 0.001) and from low- to high-grade dysplasia (P < 0.0001). Active and chronic inflammation were significantly different between squamous epithelium and Barrett's metaplasia (P < 0.0001), but not during further progression in the sequence.

CONCLUSIONS

Increasing COX-2 expression in Barrett's metaplasia is significantly associated with a change in the local inflammatory reaction, but not during further progression through dysplasia to cancer. This supports the potential of a chemoprevention strategy using COX-2 inhibitors independent of the extent and type of the inflammatory reaction in Barrett's oesophagus.

COX-2 expression predicts prostate-cancer outcome: analysis of data from the RTOG 92-02 trial

BACKGROUND

COX-2 is overexpressed in some cancers, including prostate cancer; however, little is known about the effect of COX-2 overexpression on outcome in radiation-treated patients with prostate cancer. We aimed to study COX-2 overexpression and outcome in a well-defined cohort of men who received treatment with short-term androgen deprivation (STAD) plus radiotherapy or long-term androgen deprivation (LTAD) plus radiotherapy.

METHODS

Men with prostate cancer who had participated in the Radiation Therapy Oncology Group (RTOG) 92-02 trial and for whom sufficient diagnostic tissue was available for immunohistochemical staining and image analysis of COX-2 expression were enrolled in this study. Patients in the 92-02 trial had been randomly assigned to treatment with STAD plus radiotherapy or LTAD plus radiotherapy. Multivariate analyses by Cox proportional hazards models were done to assess whether associations existed between COX-2 staining intensity and the RTOG 92-02 primary endpoints of biochemical failure (assessed by the American Society for Therapeutic Radiology and Oncology [ASTRO] and Phoenix criteria), local failure, distant metastasis, cause-specific mortality, overall mortality, and any failure.

FINDINGS

586 patients with sufficient diagnostic tissue for immunohistochemical staining and image analysis of COX-2 expression were included in this study. In the multivariate analyses, the intensity of COX-2 staining as a continuous covariate was an independent predictor of distant metastasis (hazard ratio [HR] 1.181 [95% CI 1.077-1.295], p=0.0004); biochemical failure by two definitions (ASTRO HR 1.073 [1.018-1.131], p=0.008; Phoenix HR 1.073 [1.014-1.134], p=0.014); and any failure (HR 1.068 [1.015-1.124], p=0.011). The higher the expression of COX-2, the greater the chance of failure. As a dichotomous covariate, COX-2 overexpression seemed to be most discriminating of outcome for those who received STAD compared with those who received LTAD.

INTERPRETATION

To our knowledge, this is the first study to establish an association of COX-2 expression with outcome in patients with prostate cancer who have had radiotherapy. Increasing COX-2 expression was significantly associated with biochemical failure, distant metastasis, and any failure. COX-2 inhibitors might improve patient response to radiotherapy in those treated with or without androgen deprivation. Our findings suggest that LTAD might overcome the effects of COX-2 overexpression. Therefore, COX-2 expression might be useful in selecting patients who need LTAD.

COX-2 mRNA expression is significantly increased in acid-exposed compared to nonexposed squamous epithelium in gastroesophageal reflux disease

BACKGROUND

Little is known about the role of cyclooxygenase (COX)-2 in gastroesophageal reflux disease (GERD) and the development of Barrett's metaplasia. The objectives of this study were to further analyze COX-2 mRNA expression in patients with GERD compared to Barrett's esophagus (BE) and Barrett's cancer (BC).

METHODS

Tissue samples from 110 patients with GERD (n = 43), BE (n = 20), and BC (n = 47) were obtained in routine upper GI endoscopy. Expression levels of COX-2 were measured by quantitative real-time reverse trancriptase polymerase chain reaction (RT-PCR). Also, 24-h pH monitoring was performed in all patients of the GERD study group and the DeMeester composite score was used to match COX-2 mRNA expression with the severity of acid exposure in the lower esophagus.

RESULTS

COX-2 mRNA is progressively upregulated within the metaplasia-dysplasia-adenocarcinoma (MDA) sequence (p = 0.001). COX-2 levels of the squamous epithelium in the distal esophagus from patients with GERD and a pathologic mean DeMeester score (>14.72) were significantly higher than in patients with normal DeMeester scores (p = 0.01).

CONCLUSION

In summary our findings suggest that alterations in COX-2 mRNA expression occur independently of endoscopic or histologic signs of GERD in the acid-exposed squamous epithelium of the distal esophagus. However, this early COX-2 increase in GERD is further upregulated within the MDA sequence for yet unknown reasons.

Cyclooxygenase 2 expression in rectal cancer is of prognostic significance in patients receiving preoperative radiotherapy

PURPOSE

To determine the effect of cyclooxygenase (COX)-2 expression on clinical behavior in irradiated and nonirradiated rectal carcinomas.

EXPERIMENTAL DESIGN

Tumor samples were collected from 1,231 patients of the Dutch TME trial, in which rectal cancer patients were treated with standardized surgery and randomized for preoperative short-term (5 x 5 Gy) radiotherapy or no preoperative radiotherapy. Tissue microarrays were constructed from primary tumor material, and COX-2 expression was assessed by immunohistochemistry. Tumor cell apoptosis was determined by M30 immunostaining.

RESULTS

A high level of COX-2 expression after radiotherapy was associated with low levels of tumor cell apoptosis (P=0.001). COX-2 expression had no significant effect on patient survival or tumor recurrence in nonirradiated tumors. However, in patients receiving preoperative radiotherapy, high level of COX-2 expression was associated with higher incidence of distant recurrences [P=0.003; hazard ratio (HR), 1.7; 95% confidence interval (95% CI), 1.2-2.5] and shorter disease-free survival (P=0.002; HR, 1.8; 95% CI, 1.2-2.5) and overall survival (P=0.009; HR, 1.5; 95% CI, 1.1-2.0), independent of patient age, tumor stage, tumor location, or the presence of tumor cells in the circumferential resection margin.

CONCLUSIONS

A high level of COX-2 expression after preoperative radiotherapy in resection specimens is associated with apoptosis resistance, high distant recurrence rates, and a poor prognosis in rectal cancer.

Mechanisms of resistance to cisplatin and carboplatin

While cisplatin and carboplatin are active versus most common cancers, epithelial malignancies are incurable when metastatic. Even if an initial response occurs, acquired resistance due to mutations and epigenetic events limits efficacy. Resistance may be due to excess of a resistance factor, to saturation of factors required for tumor cell killing, or to mutation or alteration of a factor required for tumor cell killing. Platinum resistance could arise from decreased tumor blood flow, extracellular conditions, reduced platinum uptake, increased efflux, intracellular detoxification by glutathione, etc., decreased binding (e.g., due to high intracellular pH), DNA repair, decreased mismatch repair, defective apoptosis, antiapoptotic factors, effects of several signaling pathways, or presence of quiescent non-cycling cells. In lung cancer, flattening of dose-response curves at higher doses suggests that efficacy is limited by exhaustion of something required for cell killing, and several clinical observations suggest epigenetic events may play a major role in resistance.

Cyclo-oxygenase-2 and its inhibition in cancer: is there a role?

Despite recent improvements in chemotherapy and radiation therapy in cancer management with the addition of biological agents, novel treatment approaches are needed to further benefit patients. Cyclo-oxygenase (COX)-2 inhibition represents one such possibility. COX-2 is an enzyme induced in pathological states such as inflammatory disorders and cancer, where it mediates production of prostanoids. The enzyme is commonly expressed in both premalignant lesions and malignant tumours of different types. A growing body of evidence suggests an association of COX-2 with tumour development, aggressive biological tumour behaviour, resistance to standard cancer treatment, and adverse patient outcome. COX-2 may be related to cancer development and propagation through multiple mechanisms, including stimulation of growth, migration, invasiveness, resistance to apoptosis, suppression of the immunosurveillance system, and enhancement of angiogenesis. Epidemiological data suggest that NSAIDs and selective COX-2 inhibitors might prevent the development of cancers, including colorectal, oesophageal and lung cancer. Preclinical investigations have demonstrated that inhibition of this enzyme with selective COX-2 inhibitors enhances tumour response to radiation and chemotherapeutic agents. These preclinical findings have been rapidly advanced to clinical oncology. Clinical trials of the combination of selective COX-2 inhibitors with radiotherapy, chemotherapy or both in patients with a number of cancers have been initiated, and preliminary results are encouraging. This review discusses the role of COX-2, its products (prostaglandins) and its inhibitors in tumour growth and treatment.

Adjuvant chemotherapy for non-small cell lung cancer

Cisplatin must be considered the treatment standard for lung cancer chemotherapy, whatever the disease setting, at least in the Western world. After the seminal meta-analysis published in 1995, 12 randomized clinical trials (RCTs) exploring the benefits of adjuvant cisplatin-based chemotherapy have been completed, published, or presented. Although all these RCTs differ in patient features, two common suggestions emerge when the stage is taken into account: a significant benefit for chemotherapy is demonstrated for stage II and IIIA patients and none of these trials showed any significant benefit for adjuvant chemotherapy in stage IB patients. Ten years after this meta-analysis, a further individual patient data-pooled analysis exploring the eventual benefits of adjuvant cisplatin-based chemotherapy after surgery for early stage non-small cell lung cancer in the more recent RCTs has been presented. The 5-year overall survival benefit in favor of cisplatin-based chemotherapy was 5.3% (48.8% versus 43.3%, p = 0.004), with a relative risk reduction of 11%. These results confirm those reported by previous meta-analyses performed according to a literature-based approach. Advances are emerging in the selection of those patients who are likely to benefit more from such treatment. In this respect, the customized therapy based on molecular/genetic patient and disease features constitutes a new avenue to pursue.

Cyclooxygenase-2 expression is related to prognosis in patients with esophageal squamous cell carcinoma

AIM

Esophageal carcinoma is one of the most aggressive malignancies. Many studies have examined various biological factors associated with the malignant potential of esophageal carcinoma. Cyclooxygenase (COX)-2 is overexpressed in various types of human malignancies, including esophageal carcinomas. Although some groups have described COX-2 expression in esophageal adenocarcinoma, few studies have reported COX-2 expression in esophageal squamous cell carcinoma (ESCC).

METHODS

We immunohistochemically investigated relationships between COX-2 overexpression in surgical specimens of primary tumors in 228 patients with ESCC. Relationships between COX-2 expression and clinicopathological factors, including prognosis, were analyzed. COX-2 expressions were classified into 4 criteria: Score 0, no staining; Score 1, <10% staining; Score 2, 10-90% staining; and Score 3, >90% staining.

RESULTS

Scores of COX-2 immunoreactivity in 228 patients were as follows: Score 0, 21 of 228; Score 1, 71of 228; Score 2, 117 of 228; and Score 3, 19 of 228, respectively. COX-2 expression was significantly correlated with depth of invasion and tumor stage (p=0.03 and p=0.04, respectively). The 5-year survival rate of patients decreased significantly with increased expression of COX-2 (p=0.005). Multivariate regression analysis indicated COX-2 expression as an independent prognostic factor for ESCC.

CONCLUSIONS

COX-2 overexpression was significantly correlated with depth of invasion, tumor stage and survival in ESCC. Evaluation of COX-2 expression should be useful for determining tumor properties, including prognosis, in patients with ESCC.

Cyclooxygenase-2 expression after preoperative chemoradiotherapy correlates with more frequent esophageal cancer recurrence

AIM: To investigate the relationship between cycloo-xygenase-2 (COX-2), and vascular endothelial growth factor (VEGF), and to determine the clinical significance of this relationship in esophageal cancer patients undergoing chemoradiotherapy (CRT).

METHODS: Immunohistochemical staining was used to evaluate COX-2 and VEGF expression in 40 patients with histologically-confirmed esophageal squamous carcinoma (ESCC) who were undergoing preoperative CRT.

RESULTS: Fourteen out of 40 ESCC patients showed a pathological complete response (CR) after CRT. COX-2 and VEGF protein expressions were observed in the cytoplasm of 17 and 13 tumors, respectively, with null expression in 9 and 13 tumors, respectively. COX-2 expression was strongly correlated with VEGF expression (P < 0.05). There were also significant associations between COX-2 expression, tumor recurrence, and lymph-node involvement (P = 0.0277 and P = 0.0095, respectively). COX-2 expression and VEGF expression had significant prognostic value for disease-free survival (log-rank test; P = 0.0073 and P = 0.0341, respectively), but not for overall survival, as assessed by univariate analysis.

CONCLUSION: Our results suggest that COX-2 expression correlates with VEGF expression and might be a useful prognostic factor for more frequent tumor recurrence in ESCC patients undergoing neoadjuvant CRT. These findings support the use of anti-angiogenic COX-2 inhibitors in the treatment of ESCC.

KG-135 Inhibits COX-2 Expression by Blocking the Activation of JNK and AP-1 in Phorbol Ester-Stimulated Human Breast Epithelial Cells

Ginsenosides, ingredients of ginseng, have a wide array of pharmacologic effects. Especially, ginsenosides Rk1, Rg3, and Rg5 derived from heat-processed ginseng have been shown to possess substantial anti-tumor-promoting effects. KG-135 is a formulated complex that contains several antitumorigenic ginsenosides, such as Rk1, Rg3, Rg5, Rk2, Rk3, Rs3, Rs4, Rs5, Rs6, Rs7, etc. The present article was aimed at evaluating the chemopreventive as well as anti-inflammatory effects of KG-135 in the human breast epithelial cell line (MCF-10A). One of the well-recognized molecular targets for chemoprevention is cyclooxygenase-2 (COX-2) that is abnormally upregulated in many premalignant and malignant tissues and cells. In this study, we found that KG-135 inhibited COX-2 expression in MCF-10A cells stimulated with a prototype tumor promotor 12-O-tetradecanoylphorbol-13-acetate (TPA). Since the transcription factor activator protein-1 (AP-1) plays a role in tumor promotion and is also known to regulate COX-2 induction, we attempted to determine the effect of KG-135 on TPA-induced activation of AP-1. Cotreatment with KG-135 resulted in a decrease in TPA-induced DNA binding of AP-1. In addition, KG-135 inhibited TPA-induced phosphorylation of c-Jun N-terminal kinases (JNK) that regulates COX-2 expression in MCF-10A cells. The JNK inhibitor SP600125 attenuated COX-2 expression in TPA-treated MCF-10A cells. Taken together, the above findings suggest that KG-135 inhibits TPA-induced COX-2 expression in MCF-10A cells by blocking the JNK/AP-1 signaling pathway.

Predictive and prognostic molecular markers in outcome of esophageal cancer

Despite improvements in detection, surgical resection and (neo-) adjuvant therapy, the overall survival in esophageal cancer remains lower than in other solid tumors. In fact, less than 20% of patients with advanced esophageal cancer benefit from a neoadjuvant therapy. Therefore predictive/prognostic markers are needed to allow tailored (radio-) chemotherapy with increased efficacy and decreased toxicity. Recently potential predictive/prognostic factors have been characterized by innovative molecular-based technologies. These factors include growth-factor receptors, enzymes of angiogenesis, tumor suppressor genes, cell cycle regulators, enzymes involved in the DNA repair system, in apoptosis and in the degradation of extracellular matrix. The results of these mostly retrospective studies are promising but prospective studies are needed to validate those markers in the multimodal therapy of esophageal cancer.

Cyclooxygenase-2 impairs treatment effects of radiotherapy for cervical cancer by inhibition of radiation-induced apoptosis

PURPOSE

Cyclooxygenase-2 (COX-2) plays a pivotal role in regulation of radiation-induced apoptosis. The aim of this study was to analyze the relationship between COX-2 expression and postradiotherapy outcomes of patients with cervical cancer.

METHODS AND MATERIALS

Biopsy specimens from 47 consecutive patients who had undergone definitive radiotherapy alone or radiotherapy combined with chemotherapy between October 2002 and November 2004 were investigated.

RESULTS

The COX-2 expression rate of the pretreatment samples was 46.1% +/- 21.0%, and the apoptotic index (AI) 1 week after start of radiotherapy was 2.1% +/- 0.9%. There was a significant negative correlation between the pretreatment COX-2 expression and the AI during radiotherapy (r = -0.52, p = 0.0002). Complete response rates were 59% for COX-2-positive patients compared with 80% for COX-2-negative patients (p = 0.12). The 2-year local control rate for COX-2-positive patients was 71.3%, whereas the corresponding rate for COX-2-negative patients was 96.0% (p = 0.06).

CONCLUSIONS

To the best of our knowledge, this is the first report to prove clinically that COX-2 can make cervical squamous cell carcinomas more refractory to radiotherapy by inhibition of radiation-induced apoptosis. Furthermore, expression of COX-2 may be a good indicator to predict local tumor control after radiotherapy. Although long-term results are ultimately needed, the combination therapy of radiotherapy with use of a COX-2 inhibitor could yield improved outcomes for patients with COX-2 expressing cervical cancer.