No prognostic significance of p53 expression in esophageal squamous cell carcinoma

The High Expression of p53 Is Predictive of Poor Survival Rather TP53 Mutation in Esophageal Squamous Cell Carcinoma

TP53 is a well-known tumor suppressor gene and one of the most common genetic alterations in human cancers. However, the role of p53 as a prognostic marker of esophageal squamous cell carcinoma (ESCC) is controversial in the association between TP53 alterations and clinical outcomes. To address this issue, we evaluated TP53 mutations, p53 protein expression, clinicopathological parameters, and survivals rates in a large scale of patients with ESCC. Two cohorts were included in this study: TP53 mutations were detected by next-generation sequencing in 316 ESCC patients, and p53 protein expression was tested by immunohistochemistry in 6,028 ESCC patients. Survival analysis was performed using the Kaplan-Meier curve and the Cox proportional hazards model. TP53 mutations were found in ESCC patients from 241 of 316 (76.3%), and the rate of positive expression of p53 protein was 59.1% in 6,028 ESCC patients (including 1819 with high expression of p53 protein), respectively. Most mutations were missense, which has a high expression of p53 protein. Compared with wild-typeTP53, TP53 gene mutations were not significantly associated with survival time (p=0.083). In multivariate analysis, the p53 protein expression was an independent prognostic factor for ESCC. The high-expression group of p53 protein has poor survival (p < 0.001) compared to low-expression group in patients with ESCC. The high expression of the p53 protein, not the TP53 mutation, is predictive of poor survival in patients with ESCC, and p53 protein expression might have the potential to be a prognosis biomarker and therapy target in ESCC.

Genetic and molecular bases of esophageal Cancer among Iranians: an update

Abstract

Background

Esophageal cancer is one of the leading causes of cancer related deaths among the Iranians. There is still a high ratio of mortality and low 5 years survival which are related to the late onset and diagnosis. Majority of patients refer for the treatment in advanced stages of tumor progression.

Main body

It is required to define an efficient local panel of diagnostic and prognostic markers for the Iranians. Indeed such efficient specific panel of markers will pave the way to decrease the mortality rate and increase the 5 years survival among the Iranian patients via the early diagnosis and targeted therapy.

Conclusion

in present review we have reported all of the molecular markers in different signaling pathways and cellular processes which have been assessed among the Iranian esophageal cancer patients until now.

Lymphovascular invasion as a poor prognostic indicator in thoracic esophageal carcinoma: a systematic review and meta-analysis

The ability to further stratify patients with esophageal carcinoma (EC) in the same stage into high-risk patients by the presence of lymphovascular invasion (LVI) may permit refinement of multi-modality therapy. However, the role of LVI in the prognosis of EC is not definite. A meta-analysis was conducted to investigate the relationship between LVI and EC prognosis. We searched PubMed, Embase, Web of Science, and Cochrane Library databases for studies on the association between LVI and prognosis of EC. Only studies with patient survival data related to LVI were included. The effect size for this analysis was the hazard ratio (HR) with 95% confidence intervals (CI) for overall survival (OS) and recurrence-free survival (RFS). Thirty-five studies with 9876 patients were included according to the defined inclusion and exclusion criteria. LVI was a poor indicator for the OS (HR = 1.64, 95% CI: 1.44-1.87, P < 0.001) and RFS (HR = 1.79, 95% CI: 1.38-2.34, P < 0.001). However, the heterogeneity was medium in OS (I2 = 61.2%, P < 0.001) and extreme in RFS (I2 = 77.5%, P < 0.001). In subgroup analysis, heterogeneity was originated from the staining method and proportion of early disease (stage (I + II)). We concluded that LVI was a poor prognostic indicator in patients with EC, especially in those studies with the IHC staining method and a high proportion of early disease (stage (I + II)).

Prognostic significance of p53 expression in patients with esophageal cancer: a meta-analysis

Background

The prognostic value of p53 protein expression in esophageal cancer has been evaluated, but the results remain inconclusive and no consensus has yet been achieved. This meta-analysis was conducted to quantitatively assess the prognostic significance of p53 expression in esophageal cancer.

Methods

Publications that assessed the clinical or prognostic significance of p53 expression in esophageal cancer and were published before July 1, 2015 were identified by searching the PubMed and EMBASE databases. A meta-analysis was performed to clarify the association between p53 expression and the clinical outcomes.

Results

A total of 36 publications met the criteria and included 4577 cases. Analysis of these data showed that p53 expression in esophageal cancer was significantly associated with poorer 5-year survival (RR = 1.30, 95 % CI: 1.11–1.51, P = 0.0008). Subgroup analyses according to histological type, continent of the patients, and cut-off value revealed the similar results. The results also indicated that p53 expression was highly associated with advanced TNM stages (I/II vs. III/IV, OR = 0.74, 95 % CI: 0.55–0.99, P = 0.04), lymph node metastasis (OR = 0.77, 95 % CI: 0.66–0.90, P = 0.001), and distant metastasis (OR = 0.46, 95 % CI: 0.26–0.80, P = 0.006). However, p53 expression in the included studies was not significantly associated with tumor size (≤ 5 cm vs. > 5 cm, OR = 1.13, 95 % CI: 0.92–1.40, P = 0.24), tumor location (upper + middle vs. lower, OR = 0.91, 95 % CI: 0.70–1.17, P = 0.45), grade of differentiation (well + moderate vs. poor, OR = 1.10, 95 % CI: 0.90–1.34, P = 0.35), and the depth of invasion (T1/T2 vs. T3/T4, OR = 0.86, 95 % CI: 0.71–1.03, P = 0.09).

Conclusions

This meta-analysis showed that p53 expression may be a useful biomarker for predicting poorer prognosis in patients with esophageal cancer.

Systematic review and meta-analysis of tumor biomarkers in predicting prognosis in esophageal cancer

BACKGROUND

Esophageal cancer (EC) is a frequently occurring cancer with poor prognosis despite combined therapeutic strategies. Many biomarkers have been proposed as predictors of adverse events. We sought to assess the prognostic value of biomarkers in predicting the overall survival of esophageal cancer and to help guide personalized cancer treatment to give patients the best chance at remission.

METHODS

We conducted a systematic review and meta-analysis of the published literature to summarize evidence for the discriminatory ability of prognostic biomarkers for esophageal cancer. Relevant literature was identified using the PubMed database on April 11, 2012, and conformed to the REMARK criteria. The primary endpoint was overall survival and data were synthesized with hazard ratios (HRs).

RESULTS

We included 109 studies, exploring 13 different biomarkers, which were subjected to quantitative meta-analysis. Promising markers that emerged for the prediction of overall survival in esophageal squamous cell cancer included VEGF (18 eligible studies, n=1476, HR=1.85, 95% CI, 1.55-2.21), cyclin D1 (12 eligible studies, n=1476, HR=1.82, 95% CI, 1.50-2.20), Ki-67 (3 eligible studies, n=308, HR=1.11, 95% CI, 0.70-1.78) and squamous cell carcinoma antigen (5 eligible studies, n=700, HR=1.28, 95% CI, 0.97-1.69); prognostic markers for esophageal adenocarcinoma included COX-2 (2 eligible studies, n=235, HR=3.06, 95% CI, 2.01-4.65) and HER-2 (3 eligible studies, n=291, HR=2.15, 95% CI, 1.39-3.33); prognostic markers for uncategorized ECs included p21 (9 eligible studies, n=858, HR=1.27, 95% CI, 0.75-2.16), p53 (31 eligible studies, n=2851, HR=1.34, 95% CI, 1.21-1.48), CRP (8 eligible studies, n=1382, HR=2.65, 95% CI, 1.64-4.27) and hemoglobin (5 eligible studies, n=544, HR=0.91, 95% CI, 0.83-1.00).

CONCLUSIONS

Although some modest bias cannot be excluded, this review supports the involvement of biomarkers to be associated with EC overall survival.

p53 immunohistochemical expression and patient prognosis in esophageal squamous cell carcinoma

It is generally accepted that overexpression of p53 protein is associated with poor prognosis in gastric, lung, and other types of cancer. However, the prognostic significance of p53 aberrations in esophageal cancer remains unclear. This is the largest study (n = 266) examining clinical and prognostic features of p53 immunohistochemical expression in esophageal squamous cell carcinoma. In 139 (52%) esophageal tumors, nuclear immunoreactivity for p53 protein was detected. p53 aberrant expression was not associated with sex, age, preoperative treatment, TNM stage, or histological grade. Furthermore, p53 expression did not correlate with disease-free survival (P = 0.73) or overall survival (P = 0.62). In addition, no significant modification effect by any of the covariates in the survival analysis was observed (all P > 0.15). In conclusion, our large-scale study demonstrates that p53 expression has no impact on the prognosis of esophageal squamous cell carcinoma.

PML protein as a prognostic molecular marker for patients with esophageal squamous cell carcinomas receiving primary surgery

BACKGROUND AND OBJECTIVES

We evaluated the clinicopathological associations and prognostic implications of promyelocytic leukemia gene (PML) expressions in patients with esophageal squamous cell carcinomas (ESCC) receiving primary surgery.

METHODS

Expression patterns of PML and tumor protein 53 (TP53) of 132 cases of ESCC were evaluated by immunohistochemistry and correlated with clinicopathological parameters. The Cox proportional hazards model was used to determine the prognostic influence of clinicopathological factors on progression-free survival (PFS) and overall survival (OS).

RESULTS

Forty-two cases (31.82%) were classified as lost expression of PML, 25 (18.94%) as focally positive, and 65 (49.24%) as diffusely expressed. Sixty-three cases (47.73%) were classified as over-expression of TP53. High expression of TP53 and down-regulation of PML were often found in advanced disease; and, in together with high pathological staging, grading, and positive margin, were associated with poor survival. However, only tumor differentiation (P = 0.016), distant metastasis (P = 0.001), and PML expression (P = 0.001) could act as independent prognostic factors for PFS, and LN metastasis (P = 0.004), TP53 (P = 0.006), and PML expression (P = 0.029) were identified as independent prognostic factors for OS in multivariate analysis.

CONCLUSIONS

Our study demonstrated PML protein as an independent prognostic marker for patients with ESCC receiving primary surgery.

Immunohistochemical evaluation for P53 and VEGF (Vascular Endothelial Growth Factor) is not prognostic for long term survival in end stage esophageal adenocarcinoma

OBJECTIVES

To correlate the expression of p53 protein and VEGF with the prognosis of patients submitted to curative resection to treat esophageal adenocarcinoma.

METHODS

Forty-six patients with esophageal adenocarcinoma, submitted to curative resection, were studied. The expressions of p53 protein and VEGF were assessed by immunohistochemistry in 52.2% and 47.8% of tumors, respectively.

RESULTS

P53 protein and VEGF expressions coincided in 26% of the cases, and no correlation between these expressions was observed. None of the clinicopathological factors showed a significant correlation with p53 protein or VEGF expressions. There was no significant association between p53 protein and VEGF expressions and long-term survival.

CONCLUSION

The expression of p53 protein and VEGF did not correlate with prognosis in esophageal adenocarcinoma patients submitted to curative resection.

Overexpression of SMYD2 relates to tumor cell proliferation and malignant outcome of esophageal squamous cell carcinoma

Although we have identified two putative targets, ATF3 and CENPF, for a frequently gained/amplified region around 1q32-q41 in esophageal squamous cell carcinoma (ESCC), it is possible that other amplification targets remain to be identified. In this study, we tested whether SET and MYND domain-containing protein 2 (SMYD2), located between those two genes and encoding a lysine methyltransferase for histone H3K36 and p53K370 that regulates transcription and inhibits transactivation activity, respectively, acts as a cancer-promoting gene through activation/overexpression in ESCC. Frequent overexpression of SMYD2 messenger RNA and protein was observed in KYSE150 cells with remarkable amplification at 1q32-41.1 and other ESCC cell lines (11/43 lines, 25.6%). Overexpression of SMYD2 protein was frequently detected in primary tumor samples of ESCC (117/153 cases, 76.5%) as well and significantly correlated with gender, venous invasion, the pT category in the tumor-lymph node-metastases classification and status of recurrence. Patients with SMYD2-overexpressing tumors had a worse overall rate of survival than those with non-expressing tumors, and SMYD2 positivity was independently associated with a worse outcome in the multivariate analysis. Knockdown of SMYD2 expression inhibited and ectopic overexpression of SMYD2 promoted the proliferation of ESCC cells in a TP53 mutation-independent but SMYD2 expression-dependent manner. These findings suggest that SMYD2 plays an important role in tumor cell proliferation through its activation/overexpression and highlight its usefulness as a prognosticator and potential therapeutic target in ESCC.

Posttranslational phosphorylation of mutant p53 protein in tumor development

p53 has been called the "cellular gatekeeper" and the "genome guard," because in response to exposure to DNA-damaging agents, it induces cell-cycle arrest in G1 or apoptosis and also directly affects DNA replication. Multiple mechanisms regulate p53 activity and posttranslational modification, including multisite phosphorylation of wild-type p53, in particular. Normal functions of wild-type p53 are abrogated by mutation of this gene, and oncogenic studies have revealed that p53 mutation is among the most common genetic alteration in human cancers. It is generally accepted that mutant p53 protein may not only lose the tumor suppressor functions of wild-type p53 but also acquire additional tumorigenetic roles, including dominant-negative effects and gain of function. Although many studies have revealed such aberrant functions of mutant p53, less is known about the posttranslational phosphorylation status of mutant p53 and novel biological functions of phosphorylation in carcinogenesis.

Cancer of the Gastroesophageal Junction: Combined Modality Therapy

Esophageal cancer, an uncommon, but highly virulent malignancy in the United States, will be responsible for nearly 14,000 deaths in the year 2005. The prognosis for patients who have adenocarcinoma of the distal esophagus and gastroesophageal junction and who are treated with the standard approaches of surgery or combined chemoradiation therapy is poor. Recent clinical trials have evaluated the use of preoperative chemotherapy followed by surgery, combined concurrent preoperative chemoradiotherapy followed by surgery, or definitive chemoradiotherapy alone without surgery. This article focuses on recent advances in the use of combined modality therapy in adenocarcinoma of the esophagus and gastroesophageal junction.

Cancer of the gastroesophageal junction: Current therapy options

Active chemotherapy agents in metastatic adenocarcinoma of the esophagus include taxanes (docetaxel or paclitaxel), 5-fluorouracil, irinotecan, platinum drugs (including cisplatin, oxaliplatin, and carboplatin), and anthracyclines. Conventional chemotherapy combines infusional 5-fluorouracil with cisplatin. The addition of a third drug to this backbone results in greater toxicity and only marginal improvements in outcome. Alternative and potentially better-tolerated chemotherapy involves two-drug regimens, combining 5-fluorouracil with a taxane or irinotecan, or combining a platinum drug with irinotecan or a taxane. Although preoperative chemotherapy improves survival compared with surgery alone, the addition of radiation therapy to chemotherapy preoperatively improves rates of curative resection, reduces local tumor recurrence, and achieves a significant rate of pathologic complete response. Combined preoperative chemotherapy and concurrent radiotherapy is the preferred preoperative strategy for locally advanced adenocarcinoma of the esophagus. Survival is improved with postoperative chemotherapy and radiotherapy if none has been delivered preoperatively.

Expression of p53R2 is related to prognosis in patients with esophageal squamous cell carcinoma

PURPOSE

The p53 gene and its family are important factors for carcinogenesis, prognosis, and chemoresistance in esophageal squamous cell carcinoma. A recently identified ribonucleotide reductase, p53R2, is regulated by p53 for supplying nucleotides to repair damaged DNA. In the present study, we analyzed the expression and clinicopathologic significance of p53 and p53R2 in esophageal squamous cell carcinoma.

EXPERIMENTAL DESIGN

We immunohistochemically investigated the relationship between p53 and p53R2 expressions in surgical specimens of primary tumors in 222 patients with esophageal squamous cell carcinoma.

RESULTS

The positive expression rate of p53 was 47.1% and that of p53R2 was 61.7%. Positive p53R2 expression was significantly correlated with depth of invasion, lymph node metastasis, stage, and poor prognosis. In the p53-negative group, the 5-year survival rate was better in patients with negative p53R2 expression than in those with positive p53R2 expression. Multivariate analysis indicated that the negative expression of both p53 and p53R2 was an independent prognostic factor along with tumor depth nodal metastasis and stage.

CONCLUSIONS

We showed that positive p53R2 expression was related to tumor development and that alteration of p53R2 expression in p53-negative tumors was closely related to prognosis. Evaluation of the expressions of p53 and p53R2 proteins should be useful for determining the tumor properties, including prognosis, in patients with esophageal squamous cell carcinoma.

Targeted therapies for esophageal cancer

Esophageal cancer is a highly aggressive neoplasm. In 2005, 14,520 Americans will be diagnosed with esophageal cancer, and more than 90% will die of their disease. On a global basis, cancer of the esophagus is the sixth leading cause of cancer death worldwide. In fact, gastric and esophageal cancers together accounted for nearly 1.3 million new cases and 980,000 deaths worldwide in 2000-more than lung, breast, or colorectal cancer. Although esophageal squamous cell carcinoma cases have steadily declined, the incidence of gastroesophageal junction adenocarcinoma has increased 4%-10% per year among U.S. men since 1976, more rapidly than for any other cancer type, and parallels rises in population trends in obesity and reflux disease. With advances in surgical techniques and treatment, the prognosis of esophageal cancer has slowly improved over the past three decades. However, the 5-year overall survival rate (14%) remains poor, even in comparison with the dismal survival rates (4%) from the 1970s. The underlying reasons for this disappointingly low survival rate are multifold: (a) ineffective screening tools and guidelines; (b) cancer detection at an advanced stage, with over 50% of patients with unresectable disease or distant metastasis at presentation; (c) high risk for recurrent disease after esophagectomy or definitive chemoradiotherapy; (d) unreliable noninvasive tools to measure complete response to chemoradiotherapy; and (e) limited survival achieved with palliative chemotherapy alone for patients with metastatic or unresectable disease. Clearly, additional strategies are needed to detect esophageal cancer earlier and to improve our systemic treatment options. Over the past decade, the field of drug development has been transformed with the identification of and ability to direct treatment at specific molecular targets. This review focuses on novel targeted treatments in development for esophageal squamous cell carcinoma and distal esophageal and gastroesophageal junction adenocarcinoma.

The associations of p53 overexpression with p53 codon 72 genetic polymorphism in esophageal cancer

Variations in p53 codon 72 have been identified as significant predisposing factors for various cancers, but molecular mechanisms remain unclear. We investigated associations of p53 overexpression with codon 72 variants and other factors with esophageal cancer. Status of p53 overexpression was determined by immunohistochemical staining. Codon 72 polymorphisms and mutation of p53 was identified by PCR-RFLP and direct sequencing from exons 4 to 9, respectively. We evaluated 126 patients who underwent esophagectomy in the National Taiwan University Hospital, and found that the status of p53 overexpression was significantly influenced by presence of codon 72 polymorphisms. After adjustment for other possible confounders, the incidence of p53 overexpression was significantly decreased in patients with Pro/Pro genotype with an odds ratio (OR) of 0.21 (95% CI: 0.067-0.64) (p = 0.0065) compared with incidence in patients with Arg/Arg genotype. The incidence of p53 overexpression was additively increased with environmental exposure to cigarette smoke, alcohol, and areca quid. When compared with individuals exposed to only one of these environmental risk factors, patients who had exposure to two or three risk factors had ORs of 6.11 (95% CI: 1.80-20.75) and 6.22 (95% CI: 1.81-21.34) for p53 overexpression, respectively. Elderly patients (age >70 years) were also more likely to have p53 overexpression, with an OR of 5.63 (95% CI: 1.53-20.64) compared with overexpression among patients aged less than 55 years. Forty-one patients received further evaluation of p53 mutation. There was also a higher incidence of, but without reaching a statistical significance, p53 mutation in patients with p53 overexpression (OR[95% CI]: 2.18 [0.52-9.6]) and codon 72 Arg/Arg genotype (OR [95% CI] of 0.8 [0.13-4.2], comparing genotypes of Pro/Pro and Arg/Pro with Arg/Arg). Our data provide the first observations that the presence of p53 codon 72 variants can be a significant factor influencing p53 overexpression in esophageal cancer, with overexpression also influenced by combined or prolonged environmental exposures.

Expression of p53 protein in esophageal squamous cell carcinoma: relation to hypoxia-inducible factor-1alpha, angiogenesis and apoptosis

OBJECTIVES

Hypoxia-inducible factor (HIF)-1 is important in the control of transcription of several genes related to angiogenesis. We have previously reported that expression of HIF-1alpha correlates with venous invasion and clinical outcome in esophageal squamous cell carcinoma. p53 has been reported to interact with HIF-1alpha and induce ubiquitin-mediated proteosomal degradation of HIF-1alpha. The purpose of this study was to clarify whether the expression of p53 is associated with that of HIF-1alpha.

METHODS

Expression of p53, HIF-1alpha and vascular endothelial growth factor (VEGF) was examined in 81 archival surgical specimens of human esophageal squamous cell carcinoma tissue. CD34 and single-stranded DNA were used to evaluate angiogenesis and apoptosis.

RESULTS

Forty-seven of the 81 (58.0%) tumor specimens showed high levels of nuclear p53 immunoreactivity. Overexpression of p53 was observed in the early clinical stage of tumor development. Expression of p53 was not correlated with HIF-1alpha or VEGF expression, angiogenesis or apoptosis in esophageal carcinoma.

CONCLUSIONS

These results suggest that mutations in p53 play a role in carcinogenesis but not in the progression of esophageal squamous cell carcinoma. HIF-1alpha may not only be regulated by p53 but also by other factors.

Prognostic significance of serine 392 phosphorylation in overexpressed p53 protein in human esophageal squamous cell carcinoma

OBJECTIVE

Posttranscriptional modification involving phosphorylation of wild-type p53 has been considered to play a role in the stabilization of p53. Little is known, however, about the role of phosphorylation of mutant p53 overexpressed in tumors. The aim of this study is to determine the phosphorylation state of p53 in tumors and its contribution to tumor development.

METHODS

Using immunohistochemical techniques, we examined the phosphorylation of Ser392 and 15 sites in p53 overexpressed in 137 esophageal squamous cell carcinomas (ESCCs). The relationships between the phosphorylation and the expression of cell cycle regulators, Ki-67 labeling index (LI), apoptotic index, clinicopathological factors, and patient prognosis were tested statistically.

RESULTS

Of the 137 samples examined, staining for Ser392 phosphospecific p53 antibody was detected in 53 (38.7%) cases, corresponding to 58.9% of 90 p53-positive cases, whereas only 3 (2.2%) were positive for Ser15 phosphospecific p53 antibody. A significant correlation was identified between Ser392 phosphorylation and high levels of Ki-67 LI (p = 0.0271), lymphatic invasion (p = 0.0246), and poorer prognosis for patients with stage II and III advanced tumors (p = 0.0136). Using multivariate analysis, Ser392 phosphorylation was recognized as an independent prognostic factor (p = 0.0136).

CONCLUSIONS

These findings suggest that p53 protein overexpressed in ESCCs is frequently phosphorylated at Ser392, and that the Ser392 phosphorylation might contribute to tumor progression of ESCCs.

Prognostic value of p53 protein expression and vascular endothelial growth factor expression in resected squamous cell carcinoma of the esophagus

The most common genetic alterations found in a wide variety of cancers are p53 tumor suppressor gene mutations. p53 appears to be a nuclear transcription factor that plays a role in the control of cell proliferation, apoptosis, and the maintenance of genetic stability. Angiogenesis is a critical process in solid tumor growth and metastasis. Vascular endothelial growth factor (VEGF), a recently identified growth factor with significant angiogenic properties, may be a major tumor angiogenesis regulator. Few studies have investigated the association between p53 and VEGF expressions and prognosis in esophageal carcinoma. Forty-seven specimens resected from patients with stage II and III squamous cell carcinoma (SCC) of the esophagus were studied using immunohistochemical staining. VEGF and p53 expressions were observed in 40% and 53% of the tumors, respectively. The p53 and VEGF staining statuses were coincident in only 21% of the tumors, and no significant correlation was found between p53 and VEGF statuses. No clinicopathologic factors were significantly correlated with p53 or VEGF expression. No significant association between p53 and VEGF expressions and poor prognosis was found. In conclusion, p53 and VEGF were not correlated with prognosis in patients with stage II and III SCC of the esophagus.

Association between inducible nitric oxide synthase expression and p53 status in human esophageal squamous cell carcinoma

Nitric oxide (NO) produced by the NO synthase (NOS), a family of enzymes such as inducible NOS (iNOS), has been suggested to play an important role in tumor bioloty. We immunohistochemically examined iNOS and p53 protein expression in 105 patients with esophageal squamous cell carcinoma (ESCC). Direct sequence analysis for the p53 gene was performed in 51 of 105 tumors. In total, 56 of 105 (53.3%) tumors exhibited intracytoplasmic staining for anti-iNOS antibody, including 17 (16.2%) cases of homogeneous and intense immunostaining (++) and 39 (37.1%) of heterogeneous staining (+). Of 62 p53 protein-positive tumors, 40 (63.5%) were positive for iNOS, and of 43 p53 protein-negative tumors, 27 (62.8%) were negative for iNOS. Of 34 iNOS-positive tumors, 23 (67.6%) carried a p53 gene mutation, and of 17 iNOS-negative tumors, 12 (70.6%) had wild-type p53 gene. There was a significant relationship between iNOS immunoreactivity and p53 protein overexpression (p = 0.0058) as well as p53 mutation frequency (p = 0.0163). No association was found between iNOS immunoreactivity and p53 mutation type, any clinicopathological factor and patient prognosis. Our in vivo findings suggest that iNOS activity might be associated with p53 alteration and contribute to tumorigenesis in ESCC.

Prognostic value of cyclin B1 in patients with esophageal squamous cell carcinoma

BACKGROUND

It has been reported that p53 regulates the G2-M checkpoint transition through cyclin B1, and it has been suggested that p53 plays an important role in the development and progression of various malignancies. The objective of the current study was to clarify the role of the cell cycle regulators, cyclin B1 and p53, in patients with esophageal squamous cell carcinoma (ESCC).

METHODS

Tissue samples from 71 patients with ESCC were included in the current study. Expression levels of cyclin B1 and p53 in samples of normal squamous epithelium, dysplasia, and tumor cells from patients with ESCC were analyzed by immunohistochemistry.

RESULTS

Several cells in the basement layer of normal epithelium expressed cyclin B1. The number of cyclin B1 positive cells tended to increase as the degree of dysplasia increased from low grade to high grade. More than 20% of tumor cells were cyclin B1 positive in 38 patients (49.3%). Several clinicopathologic parameters, including macroscopic configuration (P < 0.01), pathologic tumor status (P < 0.05), pathologic lymph node status (P < 0.001), pathologic metastatic status (P < 0.01), tumor stage (P < 0.0001), and invasion of lymphatic vessels (P < 0.05), were correlated with the overexpression of cyclin B1. Elevated expression levels of cyclin B1 also were correlated with a poor prognosis in patients with ESCC in univariate analysis (P < 0.0001) and multivariate analysis (P = 0.0135). In contrast, p53 expression exhibited no significant correlation with the level of cyclin B1 expression and was not associated with prognostic parameters in patients with ESCC.

CONCLUSIONS

These findings suggest that cyclin B1 is involved in the pathogenesis of carcinoma of the esophagus and that elevated levels of cyclin B1 expression, but not p53 expression, may indicate a poor prognosis for patients with ESCC.

Evaluation of an indicator for lymph node metastasis of esophageal squamous cell carcinoma invading the submucosal layer

Lymph node metastasis is a major prognostic factor for esophageal squamous cell carcinoma (ESCC). In recent years, endoscopic mucosal resection (EMR) has been developed with excellent results for the treatment of the superficial ESCC. To make the EMR treatment successful, it is important to establish a good indicator to identify ESCC patients at a high risk of lymph node metastasis. In this study, we examined clinicopathological and immunohistochemical factors to investigate the factors involved in lymph node metastasis of ESCC invading to the submucosal layer (sm-ESCC). Surgical specimens from 84 sm-ESCC patients were examined. Among 84 sm-ESCC patients, 33 (39.3%) had lymph node metastases. Clinicopathologically, tumor depth, lymphatic invasion and blood vessel invasion showed significant correlations with lymph node metastasis by univariate analysis. Tumor depth and lymphatic invasion showed significant correlations by multivariate analysis of these factors. Immunohistochemically, P53 accumulation was observed in 45 cases (53.6%), cyclin D1 overexpression in 25 (29.8%), and pRB in 65 (77.4%). P53 accumulation, cyclin D1 overexpression and MIB-1 Labeling Index were significantly associated with lymph node metastasis by univariate analysis, and P53 accumulation showed a significant correlation with lymph node metastasis by multivariate analysis. Among tumor depth, lymphatic invasion and P53 accumulation, tumor depth and lymphatic invasion were significantly correlated with lymph node metastasis (P = 0.0023 and P = 0.0092, respectively) by multivariate analysis. These data suggest that tumor depth and lymphatic invasion can be considered as good indicators for lymph node metastasis among patients with sm-ESCC. In addition, P53 accumulation could be helpful to identify the patients who need additional treatment after EMR.

Expression of p53 protein related to smoking and alcoholic beverage drinking habits in patients with esophageal cancers

In esophageal squamous cell carcinoma (SCC), we used immunohistochemical analysis to further elucidate the correlation of p53 protein expression with clinicopathological factors, as well as with risk factors, such as tobacco smoking, alcohol consumption and a family history of cancer, using odds ratios (ORs). The expression of p53 protein was demonstrated in 55.1% of 89 esophageal SCC cases examined by immunohistochemistry. The expression of p53 protein did not correlate with gender, age, histological grading, lymph node metastasis, or TNM stage. The prevalence of p53 expression was significantly higher in patients with multiple primary esophageal cancers (P<0.05). p53 expression did not correlate with prognosis in univariate survival analysis. The esophageal SCC in either smokers or alcohol users was 4.67-5.83 times more likely to express p53 protein, while the likelihood of p53 expression in patients who use both tobacco and alcohol was more than 14.0 times. However, a significant association was not found between p53 expression and a family history of cancer, this having an OR as low as 1.85. The expression of p53 protein did not correlate with clinicopathological factors and prognosis in univariate and multivariate survival analyses. In contrast, tobacco smoking and alcohol consumption were shown to be strongly associated with p53 mutations in esophageal carcinogenesis.

p53 expression in squamous dysplasia associated with carcinoma of the oesophagus: evidence for field carcinogenesis

Squamous epithelial dysplasia is often observed multifocally in the cancerous oesophagus and is presumably considered to be a pre-cancerous lesion. A mutation of the p53 tumour suppressor gene is commonly identified in oesophageal cancer and dysplasia. p53 mutations can be anticipated immunohistochemically. In order to confirm the biological and clinical significance of p53 expressions in oesophageal field carcinogenesis, immunostaining for p53 in cancerous and multifocal precancerous lesions from resected human oesophagus was systematically investigated, while paying special attention to the contiguity of these lesions. Lesions expressing p53 were detected in 46.5% (20 of 43 lesions) of the invasive carcinoma, and in 51.0% (46 of 90 lesions) of the carcinoma in situ, and in 51.4% (92 of 179 lesions) of the dysplasia. Next, the p53 expression in dysplasia was compared with that in carcinoma for the same case. 37 of 39 (94.8%) dysplasias contiguous to p53-positive carcinomas also expressed p53 (P<0.0001). On the other hand, the isolated dysplasias without contiguity to p53-positive carcinomas, only expressed p53 protein in 44.0% (11 of 25 lesions). No significant correlations were found between the p53 staining and either the clinicopathological features or prognosis. Discordant p53 alterations, such as those seen in cancerous and isolated precancerous lesions, may thus demonstrate further evidence for a multicentric or field carcinogenesis of the human oesophagus.

Detection of circulating anti-p53 antibodies in esophageal cancer patients

It has been reported that circulating anti-p53 antibodies (p53-Ab) in the serum are detected in some cancers. To investigate the usefulness of detecting p53-Ab, we measured the circulating p53-Ab in comparison with squamous cell carcinoma antigen (SCC-Ag) in patients with esophageal carcinoma. Serum specimens from 46 esophageal cancer patients (42 squamous cell carcinomas, 3 mucoepidermoid carcinomas and 1 basaloid squamous carcinoma) and 13 healthy subjects were studied. Serum p53-Ab was measured by an enzyme-linked immunosorbent assay. Surgically resected specimens from 43 patients were immunohistochemically stained for p53. Serum SCC-Ag was measured by a radioimmunoassay. The results were analyzed with the clinical data and outcome. Serum p53-Ab was detected in 13 (28%) of the 46 patients, but not in any of the healthy subjects. The positive rate was 0% (0/6) in stage I, 60% (3/5) in stage IIA, 30% (3/10) in stage IIB, 29% (7/24) in stage III and 0% (0/1) in stage IV. There was no difference in the outcome between the p53-Ab-positive and p53-Ab-negative patients. Immunohistochemically, 30 (70%) of the 43 specimens stained positively for p53. Serum p53-Ab was detected in 43% (13/30) of the patients with tumors which stained positively for p53. There was a close correlation between positivity for p53 immunostaining and positivity for p53-Ab (p<0.01). An elevated level of SCC-Ag was found in only 13%of the patients, and most patients positive for SCC-Ag already had advanced disease with lymph node metastasis and invasion to the adventitia. In conclusion, serum p53-Ab was detected in Japanese esophageal cancer patients at a frequency similar to that reported in Western countries. Serum p53-Ab may be a potentially useful molecular marker for detection and screening of esophageal cancer. Further studies of a large population may be required to elucidate the true diagnostic usefulness of measuring the serum p53-Ab.