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Keywords:

  • chemotherapy;
  • survival;
  • COX-2

Abstract

  1. Top of page
  2. Abstract
  3. Material and methods
  4. Results
  5. Discussion
  6. Conclusion
  7. Acknowledgements
  8. References

Based on our previous demonstration that elevated cyclooxygenase-2 (COX-2) expression is a prognostic factor for reduced survival in patients with adenocarcinoma of the esophagus, the aim of our study was to analyze the role of COX-2 expression in esophageal squamous cell carcinoma. We analyzed COX-2 protein expression from 117 consecutive patients by immunohistochemistry using a COX-2 specific monoclonal antibody. Eighty-one patients had not received any therapy before surgery whereas 36 patients received neoadjuvant chemotherapy as part of a randomized controlled trial. In the patients who received no chemotherapy, COX-2 expression was low in 75% and high in 25% of the specimens. In this patient group, high COX-2 expression associated with distal location of the tumor (p = 0.02), but did not correlate with any other clinicopathological parameter tested, including overall survival. In the patient group who received neoadjuvant chemotherapy, postoperative COX-2 expression was low in 69% and high in 31%. Interestingly, in this patient group low COX-2 expression correlated with development of distant metastases (p = 0.03) and to reduced overall survival (p = 0.02). Our results show that the prognostic significance of COX-2 depends on the histological type of esophageal carcinoma and preoperative treatment of the patient. In conclusion, COX-2 is not a prognostic marker in squamous cell carcinoma of the esophagus, but low COX-2 expression is associated with poor prognosis in the neoadjuvant-treated patients. © 2005 Wiley-Liss, Inc.

Four of five epidemiological studies have indicated that the use of nonsteroid anti-inflammatory drugs (NSAID) is associated with reduced risk of esophageal cancer.1, 2, 3, 4, 5, 6 The best-known target of NSAID is the cyclooxygenase (COX) enzyme and it is primarily the inducible COX-2 isoenzyme that has been linked to human carcinogenesis.7, 8, 9, 10, 11 Genetic deletion of COX-2 leads to reduced polyp burden in mouse models of familial adenomatous polyposis (FAP),12, 13 and selective COX-2 inhibitors were shown to reduce polyp burden in patients with FAP.14, 15 Furthermore, we showed recently that expression of COX-2 is an independent factor of poor prognosis in patients with adenocarcinoma of the esophagus.16

Elevated COX-2 expression has been associated with resistance to treatment and to reduced overall survival for patients who received (neo-) adjuvant chemo- or radiotherapy.17, 18, 19, 20 Experimental models have demonstrated that selective COX-2 inhibitors can enhance the efficacy of radiotherapy or chemotherapy.21, 22, 23, 24, 25, 26, 27 For patients with squamous cell carcinoma of the esophagus, neoadjuvant radiotherapy alone seems to have no role in the treatment,28 although for neoadjuvant chemoradiotherapy an improvement in locoregional control has been demonstrated.29 In this context, it would be desirable to identify subgroups of patients who might benefit from (neo-) adjuvant therapy. The aim of our study was to assess the expression of COX-2 by immunohistochemistry in patients with esophageal squamous cell carcinomas. The analysis was done in patients who underwent potentially curative resection with or without neoadjuvant chemotherapy, and the results were correlated with clinicopathological parameters and overall survival.

Material and methods

  1. Top of page
  2. Abstract
  3. Material and methods
  4. Results
  5. Discussion
  6. Conclusion
  7. Acknowledgements
  8. References

Patients

Between January 1 1993 and December 31 2000, 504 patients underwent esophageal resection with proximal gastrectomy for an esophageal malignancy with curative intent, i.e., locally resectable disease without distant metastases. The data from these patients were prospectively collected in a database. The pathology reports of all patients were reviewed to identify 138 patients diagnosed with a squamous cell carcinoma of the esophagus. Thirteen tumors with adenosquamous characteristics were excluded during review of the slides, and another 8 patients were excluded during immunohistochemical analyses due to non-representative archival slides compared to the original tumor. Thus, 117 patients remained for further analysis. In 71 patients resection was carried out by a transhiatal approach without thoracotomy and extended lymph-node dissection. Forty-six patients underwent esophagectomy through a right-sided thoracotomy followed by a laparotomy in combination with 2-field lymph node dissection. Patients were followed until death or December 2003, ensuring a minimal potential follow-up of 3 years. The median actual follow-up was 33.0 months (range = 7 days to 8.5 years), which includes those 4 patients who died in the hospital within 30 days after the surgery. The patients were seen on a regular basis for 5 years in the outpatient clinic. For the first 2 years they were seen at 3–4-month intervals, afterward at 6-month intervals. For the present study, patients or their family practitioners were contacted by phone to assess their current status when they had been discharged by the surgeon after 5 years. None of the patients were lost to follow-up.

Neoadjuvant treatment

Thirty-six patients received chemotherapy preoperatively as part of a randomized controlled trial30: cisplatin (CddP; 80 mg/m2 i.v. Day 1) and etoposide (E; 100 mg i.v. Day 1+2; 200 mg/m2 orally Day 3+5). After 2 cycles of chemotherapy, a clinical response was evaluated based on clinical findings (e.g., decrease of dysphagia) and repeated endoscopy and CT-scanning. Patients with tumor response received another 2 cycles followed by surgery, whereas non-responding patients underwent surgery after the second cycle. No adjuvant treatment was administered postoperatively. Presence of necrosis was evaluated from H&E-stained samples.

Immunohistochemistry and scoring

Formalin-fixed and paraffin-embedded specimens representing the deepest tumor infiltration were sectioned (5 μm), deparaffinized, microwaved and immunostained using a COX-2 specific mouse anti-human monoclonal antibody (160112, Cayman Chemical Co., Ann Arbor, MI) in a dilution of 1:200 (2.5 μg/ml) as described previously.16, 31 Every 20th sample of the trial series was a known colon adenocarcinoma specimen, in which stromal cells at an area of ulceration were scored 3, cancer cells from 2–3 and adjacent nonneoplastic epithelium 1 (for scoring criteria see below). This procedure confirmed that there was no significant intra- and interassay variability of the staining intensity, and helped us to score the trial specimens. Specificity of the antibody was confirmed as described previously.16 COX-2 immunohistochemical staining was scored independently and in a blinded manner by 2 investigators (A.S. and C.J.B.) without knowledge of the status of the patients. The following scoring criteria of the tumor cells were agreed upon before the analysis: 0, no staining; 1, weak diffuse cytoplasmic staining (may contain stronger intensity in less than 10% of the cancer cells); 2, moderate to strong granular cytoplasmic staining in 10–90% of the cancer cells; 3, >90% of the tumor cells stained with strong intensity. Scores 0 and 1 were categorized as “COX-2 low” and scores 2 and 3 as “COX-2 high” for the statistical analyses (see below). The allocation of tumors to the “COX-2 low” vs. the “COX-2 high” category by the 2 investigators was similar (93% of the specimens were categorized identically). In cases of disagreement (n = 9) the slides were re-evaluated by a group of investigators (A.S., C.J.B. and G.J.A.O.) using a multiheaded microscope. Immunohistochemistry of p53 was carried out using an established procedure,32 and staining for p53 was considered weakly positive if 0–50% of the tumor cells were immunopositive and strongly positive if 50–100% of the tumor cells were immunopositive.

Statistical analysis

The associations between factors were analyzed using Student's t-test (continuous data) and χ2 test (categorical data). Overall survival was estimated according to the Kaplan-Meier method and compared using the log-rank test. The Cox proportional hazard model was used to examine the role of COX-2 expression and clinicopathological parameters as prognostic factors. Variables with multiple categories were recoded into dichotomous variables by combining categories with comparable prognosis (differentiation grade: well vs. moderate and poor; radicality of resection: microscopically radical [R0] vs. microscopically nonradical [R1] and macroscopically nonradical [R2]; tumor stage: Stage I and IIa vs. IIb, III and IV). p-Values of 0.05 or below were considered statistically significant. All statistical analyses were carried out using the Statistical Software Package version 11.0 (SPSS Inc., Chicago, IL).

Results

  1. Top of page
  2. Abstract
  3. Material and methods
  4. Results
  5. Discussion
  6. Conclusion
  7. Acknowledgements
  8. References

Patients

In the patient group who did not receive neoadjuvant chemotherapy, there were 45 males (55.6%) and 36 females (44.4%), with a median age of 60 years (range = 33–79 years). For the 36 patients who received neoadjuvant chemotherapy the age and gender distribution was similar (19 males, 52.8%; 17 females, 47.2%; median age = 59 years, range = 38–78 years).

COX-2 protein expression in esophageal squamous cell carcinoma

Expression of COX-2 protein was evaluated in the 117 esophageal squamous cell carcinoma specimens using immunohistochemistry. COX-2 expression was localized mainly in the neoplastic cells, whereas nonneoplastic squamous epithelium was consistently negative or only weakly positive. Immunoreactivity in the cancer cells was relatively heterogeneous, however, when compared to the esophageal adenocarcinoma specimens analyzed previously.16 Among the 81 patients who did not receive neoadjuvant chemotherapy, immunoreactivity was negative in 34 (42.0%), weakly positive in 27 (33.3%), moderately positive in 19 (23.5%) and strongly positive in one (1.2%) of the specimens. Of 36 patients who received neoadjuvant treatment, no immunoreactivity was observed in 14 (38.9%), weak in 11 (30.6%), moderate in 11 (30.6%) and strong in none of the samples. There was no statistically significant difference in COX-2 expression between the groups with or without neoadjuvant chemotherapy (p = 0.8).

Correlation between COX-2 expression and clinicopathological parameters

In the patient group who did not receive neoadjuvant treatment, COX-2 expression was associated with the location of the tumor with a higher COX-2 expression in distal tumors (p = 0.02). For the other clinicopathological parameters no correlation with COX-2 expression was demonstrated (Table I). In the group of 36 patients who received neoadjuvant chemotherapy, high COX-2 expression was associated with the distal location of the tumor (p = 0.03), with male gender (p = 0.02), and with response to neoadjuvant chemotherapy (p = 0.04). Furthermore, a significant association was found between low COX-2 expression and the development of distant metastases (p = 0.03), with all of the eight distant metastases developing in the COX-2 low group. Although 13 of 16 locoregional recurrences developed in the COX-2 low group, this was not statistically significant (p = 0.1). For all other parameters, there existed no significant association with COX-2 expression (Table II). Notably, there were no statistically significant differences in the clinicopathological parameters between esophageal squamous cell carcinoma patients with or without chemotherapy treatment.

Table I. Correlation of Clinicopathological Parameters and COX-2 Expression of 81 Patients with A Squamous Cell Carcinoma of The Esophagus (Patients Did Not Receive Chemotherapy Before Operation)
Patient characteristics COX-2 expressionp-value
Low (n = 61)n (%)High (n = 20)n (%)
  • a

    T1, tumor limited to the submucosa; T2, tumor infiltrates muscularis propria, but not adventitia; T3, tumor infiltrates adventitia; T4, tumor infiltrates adjacent structures.

  • b

    N0: no lymph node metastases, N1, lymph node metastases present.

  • c

    I, T1N0M0; IIa, T2-3N0M0; IIb, T1-2N1M0; III, T3N1M0, T4anyNM0; IV, anyTanyNM1.

  • d

    THE, transhiatal esophagectomy; TTE, transthoracic esophagectomy.

  • e

    R0, microscopically radical; R1, microscopically nonradical; R2, macroscopically nonradical.

Age (mean ± SD)Years60.5 ± 10.560.5 ± 9.51.0
GenderMale (45)34 (56)11 (55)1.0
Female (36)27 (44)9 (45) 
Tumor characteristics
Tumor locationDistal (29)17 (28)12 (60)0.02
Middle (35)28 (46)7 (35) 
Proximal (17)16 (26)1 (5) 
Depth of invasionaT1 (15)13 (21)2 (10)0.07
T2 (5)4 (7)1 (5) 
T3 (59)44 (72)15 (75) 
T4 (2)0 (0)2 (10) 
Lymph node involvementbN0 (41)33 (54)8 (40)0.3
N1 (40)28 (46)12 (60) 
Distant metastasisM0 (65)49 (80)16 (80)1.0
M1 (16)12 (20)4 (20) 
Differentiation gradeWell (3)2 (3)1 (5)0.5
Moderate (34)28 (46)6 (30) 
Poor (44)31 (51)13 (65) 
Tumor stagecI (12)10 (16)2 (10)0.5
IIa (24)19 (31)5 (25) 
IIb (4)4 (7)0 (0) 
III (25)16 (26)9 (45) 
IV (16)12 (20)4 (20) 
Operation typedTHE (52)38 (62)14 (70)0.5
TTE (29)23 (38)6 (30) 
Radicality of resectioneR0 (56)45 (74)11 (55)0.2
R1 (17)12 (20)5 (25) 
R2 (8)4 (7)4 (20) 
Clinical outcome
Locoregional recurrenceNo (47)38 (62)9 (45)0.2
Yes (34)23 (38)11 (55) 
Distant metastasesM0 (54)42 (69)12 (60)0.5
M1 (27)19 (31)8 (40) 
Table II. Correlation of Clinicopathological Findings and COX-2 Expression of 36 Patients with A Squamous Cell Carcinoma of The Esophagus (Patients Received Chemotherapy Before Operation)
Patient characteristics COX-2 expressionp-value
Low (n = 25)n (%)High (n = 11)n (%)
  • a

    T1, tumor limited to the submucosa; T2, tumor infiltrates muscularis propria, but not adventitia; T3, tumor infiltrates adventitia; T4, tumor infiltrates adjacent structures.

  • b

    N0, no lymph node metastases; N1, lymph node metastases present.

  • c

    I, T1N0M0; IIa, T2-3N0M0; IIb, T1-2N1M0; III, T3N1M0, T4anyNM0; IV, anyTanyNM1.

  • d

    THE, transhiatal esophagectomy; TTE, transthoracic esophagectomy.

  • e

    R0, microscopically radical; R1, microscopically nonradical; R2, macroscopically nonradical.

Age (mean ± SD)Years58.2 ± 8.960.1 ± 12.70.6
GenderMale (19)10 (40)9 (82)0.02
Female (17)15 (60)2 (18) 
Tumor characteristics
Tumor locationDistal (12)6 (24)6 (55)0.03
Middle (21)18 (72)3 (27) 
Upper (3)1 (4)2 (18) 
Depth of invasionaT1 (2)1 (4)1 (9)0.7
T2 (5)3 (12)2 (18) 
T3 (27)19 (76)8 (73) 
T4 (2)2 (8)0 (0) 
Lymph node involvementbN0 (17)12 (48)5 (45)0.9
N1 (19)13 (52)6 (55) 
Distant metastasisM0 (30)21 (84)9 (82)0.9
M1 (6)4 (16)2 (18) 
Differentiation gradeWell (4)2 (8)2 (18)0.2
Moderate (14)12 (48)2 (18) 
Poor (18)11 (44)7 (64) 
Tumor stagecI (1)0 (0)1 (9)0.7
IIa (15)11 (44)4 (36) 
IIb (3)2 (8)1 (9) 
III (11)8 (32)3 (27) 
IV (6)4 (16)2 (18) 
Operation typedTHE (19)12 (48)7 (64)0.4
TTE (17)13 (52)4 (36) 
Radicality of resectioneR0 (28)19 (76)9 (82)0.6
R1 (6)4 (16)2 (18) 
R2 (2)2 (8)0 (0) 
Response to neoadjuvant treatmentNo (25)20 (80)5 (45)0.04
Yes (11)5 (20)6 (55) 
Tumor necrosisAbsent (20)13 (52)7 (64)0.5
Present (16)12 (48)4 (36) 
p53 expressionNegative (12)8 (32)4 (36)0.8
Positive (24)17 (68)7 (64) 
Clinical outcome
Locoregional recurrenceNo (20)12 (48)8 (73)0.2
Yes (16)13 (52)3 (27) 
Distant metastasesM0 (28)17 (68)11 (100)0.03
M1 (8)8 (32)0 (0) 

Association of COX-2 expression with overall survival

COX-2 expression did not associate with overall survival in the patient group who did not receive neoadjuvant treatment (p = 0.4). The 5-year survival was 32.0% (95% confidence interval [CI] = 20.0–43.9) in the COX-2 low group and 36.0% (95% CI = 13.9–58.1) in the COX-2 high group. In the 36 patients who received neoadjuvant chemotherapy, a significant association was found between low COX-2 expression and reduced overall survival (p = 0.02). The 5-year survival was 19.4% (95% CI = 2.9–35.9) in the COX-2 low group and 72.7% (95% CI = 46.4–98.9) in the COX-2 high group. Kaplan-Meier curves for patient survival are depicted in Figure 1. There was no difference, however, in overall survival between the combined therapy group and the surgery alone group (p = 0.5).

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Figure 1. Kaplan-Meier curves of patients with a squamous cell carcinoma of the esophagus. (a) In the group of patients (n = 81), who did not receive chemotherapy before operation, there were 61 patients with cyclooxygenase-2 (COX-2) low (scores = 0–1) expression and 20 with COX-2 high (scores = 2–3) expression. No significant difference was observed between the 2 groups (p = 0.4, log-rank test). (b) In the group of patients (n = 36), who received neoadjuvant chemotherapy, there were 25 patients with COX-2 low expression and 11 with COX-2 high expression. A statistically significant difference was observed between the 2 groups (p = 0.02, log-rank test).

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Univariate and multivariate analysis

To evaluate the role of COX-2 as an independent prognostic factor in the group of neoadjuvant treated patients a multivariate analysis was carried out. In the univariate Cox regression analysis, a significant prognostic effect was found for tumor stage, radicality of resection and low COX-2 expression. The impact of low COX-2 expression on decreased overall survival persisted after adjustment for the other possibly confounding variables in the multivariate analysis (Table III).

Table III. Univariate and Multivariate Analysis of Prognostic Factors in The 36 Patients with A Squamous Cell Carcinoma of The Esophagus Who Received Neoadjuvant Chemotherapy
VariableUnivariateaMultivariatea
RR95% CIp-valueRR95% CIp-value
  • a

    RR, relative risk; CI, confidence interval.

Differentiation grade2.00.9–4.80.11.60.7–3.70.2
High tumor stage2.61.0–6.70.042.40.9–6.80.08
Nonradical resection2.01.0–4.40.051.70.8–3.50.2
Response to treatment1.90.6–5.60.091.20.4–3.90.7
Low COX-2 expression5.81.3–24.80.027.51.6–35.30.01

Presence of necrosis and p53 expression in the neoadjuvant treated group

It has been shown previously that COX-2 expression can associate with tumor necrosis and p53 immunopositivity.33, 34, 35, 36, 37 To address this issue, COX-2 expression was re-analyzed and correlated to presence of necrosis and p53 immunopositivity. Tumoral necrosis was demonstrated in 16 (44.4%) samples derived from the 36 patients with neoadjuvant treatment. Although necrosis did not significantly correlate with COX-2 expression (p = 0.5) or overall survival (p = 0.4), there was an association between the presence of necrosis and clinical response to the neoadjuvant chemotherapy (p = 0.03). High expression of p53 protein was detected in 24 of the 36 samples (66.7%). There was no association between high COX-2 expression and p53 expression (p = 0.8), nor was there any correlation between p53 expression and tumor response to chemotherapy (p = 0.7) or overall survival (p = 0.8). It seems that COX-2 expression is independent of necrotic processes and loss of p53 function in this material.

Discussion

  1. Top of page
  2. Abstract
  3. Material and methods
  4. Results
  5. Discussion
  6. Conclusion
  7. Acknowledgements
  8. References

Our results show that COX-2 expression does not associate with survival of esophageal squamous cell carcinoma patients who were treated with surgery alone. These data are in line with previous publications,37, 38 and one study demonstrated a significant correlation between low expression of COX-2 and advanced tumor stage and presence of distant metastases.39 Similarly to our study, a heterogenic intratumoral staining pattern of COX-2 was found38 with a significantly higher expression in tumors located in the distal esophagus than in more proximal areas.37 The value of our series is that it originated from the same cohort of patients from which COX-2 has been analyzed previously from esophageal and gastric cardia adenocarcinomas using identical staining protocol and scoring criteria. In previous studies we found COX-2 expression to be an independent prognostic variable for reduced overall survival in esophageal adenocarcinoma,16 but it did not show any prognostic value in adenocarcinoma of the gastric cardia.40 The prognostic significance of COX-2 is apparently distinct in different histological types and locations of digestive tract carcinomas.

In esophageal squamous carcinoma patients who received neoadjuvant chemotherapy, low COX-2 expression associated with the development of distant metastases and it was an independent prognostic variable for poor outcome. This was an unexpected result, which was investigated further. Because we have shown previously that COX-2 expression is associated with necrotic areas in lung and bladder carcinomas33, 34 and COX-2 is induced in an experimental necrosis model,41 we correlated the presence of necrosis and COX-2 expression. Although COX-2 expression associated with the clinical response to chemotherapy, it did not correlate with histologically detectable necrosis. We also investigated a possible correlation between p53 overexpression as an indicator of mutation of p53 gene and elevated COX-2 expression, because there seems to be a direct link between a defective p53 pathway and induction of COX-2 expression in esophageal squamous cell carcinomas37, 42 as well as in other cancers.35, 36, 43 The COX-2 gene has been shown to be induced in p53 defective cells and downregulated by wild-type p53.44, 45 We found no association between p53 immunoreactivity and COX-2 expression. We were unable to correlate COX-2 expression to other markers that might be related to the response to treatment.

Several in vitro studies and one in vivo study show that radiation and chemotherapeutic agents can enhance expression of COX-2.46, 47, 48, 49, 50 Although the frequency of COX-2 expression did not differ between non-treated and neoadjuvant treated patients, we cannot exclude the possibility that COX-2 expression was induced by the chemotherapy. If this was the case, it could be hypothesized that COX-2 signals a favorable response to the neoadjuvant treatment. Ferrandina et al.51 demonstrated that in locally advanced cervical cancer patients receiving neoadjuvant chemotherapy, COX-2 expression increased progressively from responders to partial responders to non-responders and COX-2 positivity was a prognostic variable of shorter overall survival. Kulke et al.52 reported recently that in esophageal squamous cell carcinoma patients low pretreatment COX-2 expression correlated with response to neoadjuvant chemoradiation, but no correlation was found between pretreatment COX-2 expression and survival of the patients. We cannot directly compare these results to our data because in both studies the biopsy specimens were obtained before neoadjuvant treatment and in our study the samples were obtained from surgical resection material after the chemotherapy. We decided not to include an analysis of the preoperative biopsy specimens because the COX-2 staining pattern was relatively heterogeneous in the histological tumor samples, and it was assumed that staining results of preoperative biopsies might only reflect sampling artifacts.

Conclusion

  1. Top of page
  2. Abstract
  3. Material and methods
  4. Results
  5. Discussion
  6. Conclusion
  7. Acknowledgements
  8. References

Our study demonstrates that low COX-2 expression is associated with poor prognosis in patients with esophageal squamous cell carcinomas who received neoadjuvant chemotherapy. For patients who did not receive neoadjuvant therapy, COX-2 expression was not associated with overall survival. This is in contrast to a previous study in which we demonstrated that elevated COX-2 expression is an independent prognostic variable for reduced overall survival in patients with esophageal adenocarcinoma. Our results suggest that the prognostic significance of COX-2 depends on the histologic type of esophageal carcinoma and on the treatment applied. In addition, COX-2 may serve as a possible marker for favorable response to neoadjuvant treatment.

Acknowledgements

  1. Top of page
  2. Abstract
  3. Material and methods
  4. Results
  5. Discussion
  6. Conclusion
  7. Acknowledgements
  8. References

We thank Ms. E. Laitinen and Ms. P. Peltokangas from the Helsinki University Central Hospital and E. Caspers, F. Morsink and A. Musler from the AMC Department of Pathology for excellent technical assistance.

References

  1. Top of page
  2. Abstract
  3. Material and methods
  4. Results
  5. Discussion
  6. Conclusion
  7. Acknowledgements
  8. References
  • 1
    Thun MJ, Namboodiri MM, Calle EE, Flanders WD, Heath CWJr. Aspirin use and risk of fatal cancer. Cancer Res 1993; 53: 13227.
  • 2
    Funkhouser EM, Sharp GB. Aspirin and reduced risk of esophageal carcinoma. Cancer 1995; 76: 11169.
  • 3
    Farrow DC, Vaughan TL, Hansten PD, Stanford JL, Risch HA, Gammon MD, Chow WH, Dubrow R, Ahsan H, Mayne ST, Schoenberg JB, West AB, et al. Use of aspirin and other nonsteroidal anti-inflammatory drugs and risk of esophageal and gastric cancer. Cancer Epidemiol Biomarkers Prev 1998; 7: 97102.
  • 4
    Coogan PF, Rosenberg L, Palmer JR, Strom BL, Zauber AG, Stolley PD, Shapiro S. Nonsteroidal anti-inflammatory drugs and risk of digestive cancers at sites other than the large bowel. Cancer Epidemiol Biomarkers Prev 2000; 1: 11923.
  • 5
    Langman MJS, Cheng KK, Gilman EA, Lancashire RJ. Effect of anti-inflammatory drugs on overall risk of common cancer: Case control study in general practice research database. Br Med J 2000; 320: 16426.
  • 6
    Raj A, Jankowski J. Acid suppression and chemoprevention in Barrett's oesophagus. Dig Dis 2004; 22: 17180.
  • 7
    Taketo MM. Cyclooxygenase-2 inhibitors in tumorigenesis (Part II). J Natl Cancer Inst 1998; 90: 160920.
  • 8
    Dannenberg AJ, Altorki NK, Boyle JO, Dang C, Howe LR, Weksler BB, Subbaramaiah K. Cyclo-oxygenase 2: a pharmacological target for the prevention of cancer. Lancet Oncol 2001; 2: 54451.
  • 9
    Dubois RN, Gupta RA. Colorectal cancer prevention and treatment by inhibition of cyclooxygenase-2. Nat Rev Cancer 2001; 1: 1121.
  • 10
    Van Rees BP, Ristimäki A. Cyclooxygenase-2 in carcinogenesis of the gastrointestinal tract. Scand J Gastroenterol 2001; 36: 897903.
  • 11
    Buskens CJ, Ristimäki A, Offerhaus GJ, Richel DJ, van Lanschot JJ. Role of cyclooxygenase-2 in the development and treatment of oesophageal adenocarcinoma. Scand J Gastroenterol Suppl 2003; 239: 8793.
  • 12
    Oshima M, Dinchuk JE, Kargman SL, Oshima H, Hancock B, Kwong E, Trzaskos JM, Evans JF, Taketo MM. Suppression of intestinal polyposis in Apc delta716 knockout mice by inhibition of cyclooxygenase 2 (COX-2). Cell 1996; 87: 8039.
  • 13
    Chulada PC, Thompson MB, Mahler JF, Doyle CM, Gaul BW, Lee C, Tiano HF, Morham SG, Smithies O, Langenbach R. Genetic disruption of Ptgs-1,as well as Ptgs-2, reduces intestinal tumorigenesis in Min mice. Cancer Res 2000; 60: 47058.
  • 14
    Steinbach G, Lynch PM, Phillips RK, Wallace MH, Hawk E, Gordon GB, Wakabayashi N, Saunders B, Shen Y, Fujimura T, Su LK, Levin B. The effect of celecoxib, a cyclooxygenase-2 inhibitor, in familial adenomatous polyposis. N Engl J Med 2000; 342: 194652.
  • 15
    Higuchi T, Iwama T, Yoshinaga K, Toyooka M, Taketo MM, Sugihara K. A randomized, double-blind, placebo-controlled trial of the effects of rofecoxib, a selective cyclooxygenase-2 inhibitor, on rectal polyps in familial adenomatous polyposis patients. Clin Cancer Res 2003; 9: 475660.
  • 16
    Buskens CJ, Van Rees BP, Sivula A, Reitsma JB, Haglund C, Bosma PJ, Offerhaus GJ, Van Lanschot JJ, Ristimäki A. Prognostic significance of elevated cyclooxygenase 2 expression in patients with adenocarcinoma of the esophagus. Gastroenterology 2002; 122: 18007.
  • 17
    Gaffney DK, Holden J, Davis M, Zempolich K, Murphy KJ, Dodson M. Elevated cyclooxygenase-2 expression correlates with diminished survival in carcinoma of the cervix treated with radiotherapy. Int J Radiat Oncol Biol Phys 2001; 49: 12137.
  • 18
    Ferrandina G, Lauriola L, Zannoni GF, Fagotti A, Fanfani F, Legge F, Maggiano N, Gessi M, Mancuso S, Ranelletti FO, Scambia G. Increased cyclooxygenase-2 (COX-2) expression is associated with chemotherapy resistance and outcome in ovarian cancer patients. Ann Oncol 2002; 13: 120511.
  • 19
    Kim YB, Kim GE, Cho NH, Pyo HR, Shim SJ, Chang SK, Park HC, Suh CO, Park TK, Kim BS. Overexpression of cyclooxygenase-2 is associated with a poor prognosis in patients with squamous cell carcinoma of the uterine cervix treated with radiation and concurrent chemotherapy. Cancer 2002; 95: 5319.
  • 20
    Wulfing C, Eltze E, von Struensee D, Wulfing P, Hertle L, Piechota H. Cyclooxygenase-2 expression in bladder cancer: correlation with poor outcome after chemotherapy. Eur Urol 2004; 45: 4652.
  • 21
    Milas L, Kishi K, Hunter N, Mason K, Masferrer JL, Tofilon PJ. Enhancement of tumour response to gamma-radiation by an inhibitor of cyclooxygenase-2 enzyme. J Natl Cancer Inst 1999; 91: 15014.
  • 22
    Kishi K, Petersen S, Petersen C, Hunter N, Mason K, Masferrer JL, Tofilon PJ, Milas L. Preferential enhancement of tumour radio response by a cyclooxygenase-2 inhibitor. Cancer Res 2000; 60: 132631.
  • 23
    Pyo H, Choy H, Amorino GP, Kim JS, Cao Q, Hercules SK, DuBois RN. A selective cyclooxygenase-2 inhibitor, NS-398, enhances the effect of radiation in vitro and in vivo preferentially on the cells that express cyclooxygenase-2. Clin Cancer Res 2001; 7: 29983005.
  • 24
    Hida T, Kozaki K, Ito H, Miyaishi O, Tatematsu Y, Suzuki T, Matsuo K, Sugiura T, Ogawa M, Takahashi T, Takahashi T. Significant growth inhibition of human lung cancer cells both in vitro and in vivo by the combined use of a selective cyclooxygenase 2 inhibitor, JTE-522, and conventional anticancer agents. Clin Cancer Res 2002; 8: 24437.
  • 25
    Trifan OC, Durham WF, Salazar VS, Horton J, Levine BD, Zweifel BS, Davis TW, Masferrer JL. Cyclooxygenase-2 inhibition with celecoxib enhances antitumor efficacy and reduces diarrhea side effect of CPT-11. Cancer Res 2002; 62: 577884.
  • 26
    Hida T, Kozaki K, Muramatsu H, Masuda A, Shimizu S, Mitsudomi T, Sugiura T, Ogawa M, Takahashi T. Cyclooxygenase-2 inhibitor induces apoptosis and enhances cytotoxicity of various anticancer agents in non-small cell lung cancer cell lines. Clin Cancer Res 2000; 6: 200611.
  • 27
    Petersen C, Petersen S, Milas L, Lang FF, Tofilon PJ. Enhancement of intrinsic tumour cell radiosensitivity induced by a selective cyclooxygenase-2 inhibitor. Clin Cancer Res 2000; 6: 251320.
  • 28
    Enzinger PC, Mayer RJ. Esophageal cancer. N Engl J Med 2003; 349: 224152.
  • 29
    Liao Z, Zhang Z, Jin J, Ajani JA, Swisher SG, Stevens CW, Ho L, Smythe R, Vaporciyan AA, Putnam JBJr, Walsh GL, Roth JA, et al. Esophagectomy after concurrent chemoradiotherapy improves locoregional control in clinical stage II or III esophageal cancer patients. Int J Radiat Oncol Biol Phys 2004; 60: 148493.
  • 30
    Kok TC, Van Lanschot JJB, Siersema PD, Van Overhagen H, Tilanus HW. Neoadjuvant chemotherapy in operable esophageal squamous cell cancer: final report of a phase III multicenter randomized controlled trial. Abstract J Clin Oncol 1997; 16: 277a.
  • 31
    Saukkonen K, Nieminen O, van Rees B, Vilkki S, Härkönen M, Juhola M, Mecklin JP, Sipponen P, Ristimäki A. Expression of cyclooxygenase-2 in dysplasia of the stomach and in intestinal-type gastric adenocarcinoma. Clin Cancer Res 2001; 7: 192331.
  • 32
    Lundin J, Nordling S, von Boguslawsky K, Roberts PJ, Haglund C. Prognostic value of immunohistochemical expression of p53 in patients with pancreatic cancer. Oncology 1996; 53: 10411.
  • 33
    Wolff H, Saukkonen K, Anttila S, Karjalainen A, Vainio H, Ristimäki A. Expression of cyclooxygenase-2 in human lung carcinoma. Cancer Res 1998; 58: 49975001.
  • 34
    Ristimäki A, Nieminen O, Saukkonen K, Hotakainen K, Nordling S, Haglund C. Expression of cyclooxygenase-2 in human transitional cell carcinoma of the urinary bladder. Am J Pathol 2001; 158: 84953.
  • 35
    Ristimäki A, Sivula A, Lundin J, Lundin M, Salminen T, Haglund C, Joensuu H, Isola J. Prognostic significance of elevated cyclooxygenase-2 expression in breast cancer. Cancer Res 2002; 62: 6325.
  • 36
    Erkinheimo TL, Lassus H, Finne P, van Rees BP, Leminen A, Ylikorkala O, Haglund C, Butzow R, Ristimäki A. Elevated cyclooxygenase-2 expression is associated with altered expression of p53 and SMAD4,amplification of HER-2/neu, and poor outcome in serous ovarian carcinoma. Clin Cancer Res 2004; 10: 53845.
  • 37
    Kawabe A, Shimada Y, Uchida S, Maeda M, Sato F, Itami A, Imamura M. Expression of cyclooxygenase-2 is associated with carcinogenesis of the lower part of thoracic esophageal squamous cell carcinoma and p53 expression. Oncology 2002; 62: 4654.
  • 38
    Shamma A, Yamamoto H, Doki Y, Okami J, Kondo M, Fujiwara Y, Yano M, Inoue M, Matsuura N, Shiozaki H, Monden M. Up-regulation of cyclooxygenase-2 in squamous carcinogenesis of the esophagus. Clin Cancer Res 2000; 6: 122938.
  • 39
    Kuo KT, Chow KC, Wu YC, Lin CS, Wang HW, Li WY, Wang LS. Clinicopathologic significance of cyclooxygenase-2 overexpression in esophageal squamous cell carcinoma. Ann Thorac Surg 2003; 76: 90914.
  • 40
    Buskens CJ, Sivula A, van Rees BP, Haglund C, Offerhaus GJA, van Lanschot JJB, Ristimäki A Comparison of cyclooxygense-2 expression in adenocarcinomas of the gastric cardia and distal oesophagus. Gut 2003; 52: 167883.
  • 41
    Bizik J, Kankuri E, Ristimäki A, Taieb A, Vapaatalo H, Lubitz W, Vaheri A. Cell-cell contacts trigger programmed necrosis and induce cyclooxygenase-2 expression. Cell Death Differ 2004; 11: 18395.
  • 42
    Biramijamal F, Allameh A, Mirbod P, Groene HJ, Koomagi R, Hollstein M. Unusual profile and high prevalence of p53 mutations in esophageal squamous cell carcinomas from northern Iran. Cancer Res 2001; 61: 311923.
  • 43
    Leung WK, To KF, Ng YP, Lee TL, Lau JY, Chan FK, Ng EK, Chung SC, Sung JJ. Association between cyclo-oxygenase-2 overexpression and missense p53 mutations in gastric cancer. Br J Cancer 2001; 84: 3359.
  • 44
    Subbaramaiah K, Altorki N, Chung WJ, Mestre JR, Sampat A, Dannenberg AJ. Inhibition of cyclooxygenase-2 gene expression by p53. J Biol Chem 1999; 274: 109115.
  • 45
    Gallo O, Schiavone N, Papucci L, Sardi I, Magnelli L, Franchi A, Masini E, Capaccioli S. Down-regulation of nitric oxide synthase-2 and cyclooxygenase-2 pathways by p53 in squamous cell carcinoma. Am J Pathol 2003; 163: 72332.
  • 46
    Steinauer KK, Gibbs I, Ning S, French JN, Armstrong J, Knox SJ. Radiation induces upregulation of cyclooxygenase-2 (COX-2) protein in PC-3 cells. Int J Radiat Oncol Biol Phys 2000; 48: 3258.
  • 47
    Subbaramaiah K, Hart JC, Norton L, Dannenberg AJ, Subbaramaiah K. Microtubule-interfering agents stimulate the transcription of cyclooxygenase-2. Evidence for involvement of ERK1/2 AND p38 mitogen-activated protein kinase pathways. J Biol Chem 2000; 275: 1483845.
  • 48
    Subbaramaiah K, Marmo TP, Dixon DA, Dannenberg AJ. Regulation of cyclooxgenase-2 mRNA stability by taxanes: evidence for involvement of p38, MAPKAPK-2, and HuR. J Biol Chem 2003; 278: 3763747.
  • 49
    Davis TW, O'Neal JM, Pagel MD, Zweifel BS, Mehta PP, Heuvelman DM, Masferrer JL. Synergy between celecoxib and radiotherapy results from inhibition of cyclooxygenase-2-derived prostaglandin E2, a survival factor for tumour and associated vasculature. Cancer Res 2004; 64: 27985.
  • 50
    Tessner TG, Muhale F, Schloemann S, Cohn SM, Morrison AR, Stenson WF. Ionizing radiation up-regulates cyclooxygenase-2 in I407 cells through p38 mitogen-activated protein kinase. Carcinogenesis 2004; 25: 3745.
  • 51
    Ferrandina G, Lauriola L, Distefano MG, Zannoni GF, Gessi M, Legge F, Maggiano N, Mancuso S, Capelli A, Scambia G, Ranelletti FO. Increased cyclooxygenase-2 expression is associated with chemotherapy resistance and poor survival in cervical cancer patients. J Clin Oncol 2002; 20: 97381.
  • 52
    Kulke MH, Odze RD, Mueller JD, Wang H, Redston M, Bertagnolli MM. Prognostic significance of vascular endothelial growth factor and cyclooxygenase 2 expression in patients receiving preoperative chemoradiation for esophageal cancer. J Thorac Cardiovasc Surg 2004; 127: 157986.