Significance of p53 expression as a prognostic factor in oesophageal squamous cell carcinoma

The human antigen R as an actionable super-hub within the network of cancer cell persistency and plasticity

In this perspective article, a clinically inspired phenotype-driven experimental approach is put forward to address the challenge of the adaptive response of solid cancers to small-molecule targeted therapies. A list of conditions is derived, including an experimental quantitative assessment of cell plasticity and an information theory-based detection of in vivo dependencies, for the discovery of post-transcriptional druggable mechanisms capable of preventing at multiple levels the emergence of plastic dedifferentiated slow-proliferating cells. The approach is illustrated by the author's own work in the example case of the adaptive response of BRAFV600-melanoma to BRAF inhibition. A bench-to-bedside and back to bench effort leads to a therapeutic strategy in which the inhibition of the baseline activity of the interferon-γ-activated inhibitor of translation (GAIT) complex, incriminated in the expression insufficiency of the RNA-binding protein HuR in a minority of cells, results in the suppression of the plastic, intermittently slow-proliferating cells involved in the adaptive response. A similar approach is recommended for the validation of other classes of mechanisms that we seek to modulate to overcome this complex challenge of modern cancer therapy.

Comparative Analysis of Clinicopathological Characteristics, Survival Features, and Protein Expression Between Basaloid and Squamous Cell Carcinoma of the Esophagus

Background

Basaloid squamous cell carcinoma (BSCC) is a rare variant of squamous cell carcinoma (SCC) of the esophagus. This study aimed to assess the discrepancy in clinicopathological characteristics and protein expression between esophageal BSCC and typical esophageal SCC.

Study Design

We reviewed 40 cases of esophageal BSCC. As controls, 63 well-differentiated SCC (WSCC) patients, 70 moderately differentiated SCC (MSCC) patients, and 51 poorly differentiated SCC (PSCC) patients were selected. The clinicopathologic characteristics and immunoreactivity of Ki-67, p53, p63, and epidermal growth factor receptor (EGFR) were then evaluated in the BSCC and typical SCC patients.

Results

The 5-year survival rates for the BSCC patients were 27.5%. The prognostic outcomes of the BSCC group were similar to those of the PSCC and MSCC groups but worse than that of the WSCC group, with a significant difference (P=0.045). Ki-67 expression was significantly higher in the BSCC group than that in the WSCC group (P < 0.05). Meanwhile, there were no significant differences in the expression of the other molecular markers (p53, p63, and EGFR) between the typical SCC and BSCC groups (P > 0.05). The median survival time of esophageal the BSCC patients with low p53 expression was significantly longer than that of the patients with high p53 expression (P=0.026). Further, the median survival time of the esophageal BSCC patients with high p63 expression was significantly longer than that of the patients with low p63 expression (P=0.041). Meanwhile, Ki-67 and EGFR expressions were not correlated with OS in the BSCC group.

Conclusion

Esophageal BSCC has a more clinically virulent course. Notably, p53 and p63 expression are associated with prognosis in BSCC. These findings conject that evaluation of multiple cancer biomarkers might be a promising auxiliary diagnostic indicator in BSCC.

UGT2B17 and miR-224 contribute to hormone dependency trends in adenocarcinoma and squamous cell carcinoma of esophagus

Esophageal squamous cell carcinoma (ESCC) and esophageal adenocarcinoma (EA) are the two main subtypes of esophageal cancer. Genetics underpinnings of EA are substantially less understood than that of ESCC. A large-scale relation data analysis was conducted to explore the genes implicated with either EA or ESCC, or both. Each gene linked to ESCC but not EA was further explored in mega-analysis of six independently collected EA RNA expression datasets. A multiple linear regression (MLR) model was built to study the possible influence of sample size, population region, and study date on the gene expression data in EA. Finally, a functional pathway analysis was conducted to identify the possible linkage between EA and the genes identified as novel significant contributors. We have identified 276 genes associated with EA, 1088 with ESCC, with a significant (P<5.14e-143) overlap between these two gene groups (n=157). Mega-analysis showed that two ESCC-related genes, UGT2B17 and MIR224, were significantly associated with EA (P-value <1e-10), with multiple connecting pathways revealed by functional analysis. ESCC and EA share some common pathophysiological pathways. Further study of UGT2B17 and MIR224, which are differentially dysregulated in ESCC and EA tumors, is warranted. Enhanced expression of UGT2B17 and the lack of miR-224 signaling may contribute to the responsiveness of EA to the male sex steroids.

Microvessel density as a prognostic factor in esophageal squamous cell cancer patients: A meta-analysis

BACKGROUND

To date, literature has emerged that shows contradictory results about the prognostic role of microvessel density (MVD) in esophageal squamous cell cancer (ESCC). The aim of the study set out to evaluate the correlation between MVD and the prognosis of ESCC.

METHODS

Identified publications from various databases were obtained and reviewed. A meta-analysis was performed to evaluate the prognostic role of MVD among ESCC patients.

RESULTS

A total of 11 eligible studies containing 891 ESCC cases were included in the meta-analysis. The pooled hazard ratio for overall survival was 2.39 (95% confidence interval 1.92-2.96, P < .001). Heterogeneity among the studies was not significant, and publication bias was not found. Subgroup analyses were also performed on different issues, such as districts, antibodies, and median age.

CONCLUSION

High MVD is a prognostic factor among ESCC that indicated worse prognosis in these patients. More studies are needed, and through abundant evidence, the topic could be re-evaluated by then.

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.

p53 is an independent prognostic factor in operable esophageal squamous cell carcinoma: a large-scale study with a long follow-up

The p53 protein is involved in many biological functions in cancer, such as cell cycle arrest, DNA repair, apoptosis, senescence, DNA metabolism, angiogenesis, and cellular differentiation. However, the association between p53 expression and clinicopathological findings or prognosis in esophageal squamous cell carcinoma (ESCC) is controversial. We designed a large-scale study of 830 operable ESCC patients with a long follow-up to investigate the relationship between p53 expression and the clinicopathological characteristics and prognosis of patients. Immunohistochemistry was used to detect p53 protein expression. When the patients were divided into two groups, a positive expression group and a negative expression group, p53-positive expression positively correlated with a poorer differentiation level (P = 0.044). The overexpression of p53 was associated with a more advanced clinical stage (P = 0.015). A total of 775 patients were available for survival analysis. The median OS of 160 patients who had p53-positive expression and 486 patients who had p53-negative expression were 58.8 and 46.3 months, respectively (P = 0.021); the median PFS of the two groups were 39.6 and 27.5 months, respectively (P = 0.015). Lymph node metastasis, gender, differentiation, depth of invasion, and p53 protein expression were proven to have an influence on both OS and PFS in a univariate analysis. In the multivariate analysis, p53-positive expression maintained its independent prognostic impact on OS (P = 0.048) and PFS (P = 0.039), as did lymph node metastasis, differentiation, and depth of invasion. We identified that p53 protein-positive expression can serve as an independent, unfavorable prognosis biomarker in ESCC.

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.

Transglutaminase 3 as a prognostic biomarker in esophageal cancer revealed by proteomics

To develop a prognostic biomarker for esophageal squamous cell carcinoma (ESCC), we examined the proteomic profile of ESCC using two-dimensional difference gel electrophoresis (2D-DIGE), and identified proteins associated with prognosis by mass spectrometry. The prognostic performance of the identified proteins was examined by immunohistochemistry in additional cases. We identified 22 protein spots whose intensity was statistically different between ESCC cases with good (N = 9; survived more than 5 years without evidence of recurrence) and poor (N = 24; died within 2 years postsurgery) prognosis, within the patient group that had two or more lymph node metastases. Mass spectrometric protein identification resulted in 18 distinct gene products from the 22 protein spots. Transglutaminase 3 (TGM3) was inversely correlated with shorter patient survival. The prognostic performance of TGM3 was further examined by immunohistochemistry in 76 ESCC cases. The 5-year disease-specific survival rate was 64.5% and 32.1% for patients with TGM3-positive and TGM3-negative tumors, respectively (p = 0.0033). Univariate and multivariate analyses revealed that TGM3 expression was an independent prognostic factor among the clinicopathologic variables examined. It is noteworthy that the prognostic value of TGM3 was shown to be higher than those of the lymph node metastasis, intramural metastasis and vascular invasion status. These results establish TGM3 as a novel prognostic biomarker for ESCC for the first time. Examination of TGM3 expression may provide novel therapeutic strategies to prevent recurrence of ESCC.

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.

Combined expression of p53, cyclin D1 and epidermal growth factor receptor improves estimation of prognosis in curatively resected oral cancer

p53, cyclin D1 and epidermal growth factor receptor (EGFR) are molecular markers that regulate the cell cycle or cell growth and play important roles in tumor development and progression. In this study, we examined the impact of immunohistochemical expression of these markers on tumor progression in 140 oral cancers. p53, cyclin D1 and EGFR were expressed in 64 cases (46%), 54 cases (39%) and 54 cases (39%), respectively, but there was no inter-relationship between any two of these markers. In the association of these markers with clinicopathological features, EGFR expression alone was significantly associated with poor differentiation (P=0.0008) and invasive growth pattern (P=0.0003). Any of these markers, including EGFR, had no significant impact on survival. Coexpression of all these markers, however, was significantly associated with invasive growth pattern (P=0.0149) and shortened survival (P=0.0181), and was a significant and independent unfavorable prognostic factor (P=0.0002), along with tumor size (P=0.0040), nodal metastasis (P=0.0137) and growth pattern (P=0.0017) in a multivariate analysis. Simultaneous coexpression of these markers in oral cancers might prove to be a useful indicator for identification of low- or high-risk patients.

Mutational spectra of p53 in geographically localized esophageal squamous cell carcinoma groups in China

BACKGROUND

Esophageal carcinoma is a particularly interesting tumor because of the dramatic difference in its incidence and geographic distribution among populations of similar ethnic origin. Epidemiologic data have suggested that many environmental exposures may be associated with an increased risk of its formation.

METHODS

In this study, 92 samples of esophageal squamous cell carcinoma (ESCC) were collected from patients who resided in 2 geographic areas in China with different incidences of ESCC: Linxian and Zhejiang. Overexpression and mutations of the p53 tumor-suppressor gene were examined by using immunohistochemistry, single-strand conformation polymorphism analysis, and direct sequencing.

RESULTS

The rates of point mutation and overexpression of p53 in the ESCC specimens studied were 30.4% (29 of 92 specimens) and 51.1% (47 of 92 specimens), respectively. The overexpression of p53 was associated with tumor metastasis and with 5-year case fatality. Significant differences were found in the rates of overexpression and mutations in patients with clinical T2 tumors between the specimens from Linxian, which is a high-incidence geographic area, and the specimens from Zhejiang, which is a low-incidence area. Furthermore, different mutational spectra were found in the tumor samples from these two geographic areas: In tumor samples from Linxian, the most common substitution mutation was a transversion in exon 5, whereas the most common mutations in tumor samples from Zhejiang were transitions in exon 7.

CONCLUSIONS

The data suggest that the mutation and overexpression of p53 may play important roles in the development of ESCC. The changes in p53 may reflect environmental exposure to the different combinations of mutagenic factors and genetic instability demonstrated by the populations in Linxian and Zhejiang. The overexpression of p53 protein may have significance as a prognostic factor for patients with esophageal carcinoma.

Biological behavior of mucoepidermoid carcinoma of the esophagus

Mucoepidermoid carcinoma of the esophagus (MEC) is uncommon and has not been fully investigated. The biological behavior and clinical aspects of MEC were studied. The clinical features of eight patients with MEC were compared with 51 cases of squamous cell carcinoma of the esophagus (SCC). Proliferating cell nuclear antigen (PCNA), p53, and carcinoembryonic antigen (CEA) were stained in the resected specimens by immunohistochemistry. Seven out of 8 cases (87.5%) had stage III by TNM classification. Four cases died of widespread metastases and 2 cases died of local recurrence within 2 years after the surgery. Neither chemotherapy and radiotherapy were effective against MEC. Overall median survival periods were 10.8 months for MEC and 32.1 months for SCC (P<0.05). When patients in stage III alone were compared, MEC tended to have a worse prognosis than SCC (P=0.058). Immunohistochemical studies revealed that the positive rates of PCNA and CEA were significantly higher in MEC than in SCC (P<0.05), while there was no significant difference in p53 positive rate. Esophageal MEC had an aggressive biological nature and was resistant to adjuvant therapies. The poor prognosis of esophageal MEC may be caused by high proliferative and metastatic potential.

Cell-cycle regulators and the Ki-67 labeling index can predict the response to chemoradiotherapy and the survival of patients with locally advanced squamous cell carcinoma of the esophagus

BACKGROUND

We investigated whether aberrant p53 and p16 expression, the Ki-67 labeling index (LI), and int-2/cyclin D1 gene amplification predict the response to chemoradiotherapy (CRT) in patients with locally advanced esophageal squamous cell carcinoma (ESCC).

METHODS

p53 and p16 expression status, the Ki-67 LI, and int-2/cyclin D1 amplification were assessed by immunohistochemical staining and slot blot analysis in pretreatment endoscopic biopsy specimens of 41 patients with T4 or M1 Lym (distant lymph node metastasis) ESCC. All patients received a course of chemotherapy (5-fluorouracil and cisplatin) with radiotherapy.

RESULTS

The CRT therapeutic response rate was 71%, and resection after CRT was successful in 15 of the cases in which the CRT effect was significant. The cumulative survival rate after CRT in the p53-negative patients was significantly higher than in the p53-positive patients (P =.037). The mean Ki-67 LI in the CRT response cases was significantly higher than in the CRT no-response cases (P =.023). Multivariate regression analysis revealed high Ki-67 LI to be an independent variable linked to a pathologic complete response to CRT (P =.033). The cumulative survival rate after CRT in the group that was p53-negative and int-2/cyclin D1 amplification-positive was significantly higher than in the other groups (P =.008).

CONCLUSIONS

Evaluating predictive factors in pretreatment endoscopic biopsy specimens may allow selection of more suitable multimodal treatment for ESCC patients and improve their quality of life.

Multigene analysis of Rb pathway and apoptosis control in esophageal squamous cell carcinoma identifies patients with good prognosis

Deregulation of cell-cycle G(1)-restriction point control by disruption of Rb-pathway components is a frequent event in cancer. In concert with the inactivation of cell death pathways, such events not only contribute to tumor development but also determine the intrinsic and acquired resistance to cancer therapy and, ultimately, disease prognosis. We previously observed that the cyclin-dependent kinase inhibitor p16(INK4a) and the proapoptotic Bcl-2 homolog Bax are positive prognostic factors and identify patients with good prognosis in esophageal squamous cell carcinoma (SCC). In the present study, we therefore extend our analysis to additional genes controlling the G(1) restriction point and apoptosis, respectively. This retrospective analysis was performed in a cohort of 53 patients undergoing surgery for esophageal SCC with curative intent, i.e., R0 resection. Protein expression profiles of cyclin D1, p16(INK4a), Rb, p21(CIP/WAF-1), p53, Bax and Bcl-2 were analyzed by immunohistochemistry and compared to p53 mutational status, as determined by SSCP-PCR of exons 5-8. Loss of p16(INK4a), Rb, p21(CIP/WAF-1) or Bax and overexpression of cyclin D1 were associated individually with shorter overall survival, while Bcl-2 expression and p53 mutation were not of prognostic relevance. The longest survival was observed in a subgroup of patients whose tumors bore a combination of favorite genotypes, i.e., low cyclin D1 and high Rb, p21(CIP/WAF-1), p16(INK4a) and Bax protein expression. These results show that multigene analyses based on limited sets of functionally linked genes reliably identify patients with good vs. poor prognosis.

Cell cycle-regulated factors in esophageal cancer

Alterations of cell cycle-regulated genes play an important role in the process of carcinogenesis, and some of them are thought to be prognostic factors in esophageal cancer. The expressions of p53, p16, pRB and Cyclin D1 proteins were evaluated immunohistochemically in 144 patients who underwent curative esophagectomy without any adjuvant therapy before surgery. p53 overexpression was observed in 99 (69%) out of the 144 patients. No significant correlation was noted between p53 and any other gene expression. p16 expression was observed in 12 (8.3%) out of all cases. A negative correlation was recognized between p16 and Cyclin D1 expression (P=0.0004). pRB expression was observed in 130 (90.3%) out of all cases, whereas pRB expression was not observed in 11 out of the 12 patients with p16-positive tumors. A negative correlation was also found between p16 and pRB (P < 0.0001). A positive correlation was noted between pRB and Cyclin D1 expression (P=0.0009). The cumulative survival rate of patients without pRB expression was significantly lower than that of patients with positive expression (P=0.003). In the multivariate survival analysis, pRB expression was an independent prognostic factor. In 98% of all patients with esophageal cancer, impairment of the G1 checkpoint is due to a loss of function by p16, pRB or Cyclin D1, which showed a negative correlation in each factor. In addition, aberrant expression of pRB is useful as a prognostic factor in esophageal cancer.

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.

Bax and Bcl-X(L) expression are not related to prognosis in patients with advanced esophageal squamous cell carcinoma

Bax and Bcl-X(L) genes play an important role in the apoptotic pathway. These expressions were immunohistochemically investigated in 111 patients with advanced esophageal squamous cell carcinoma. The positive rates of p53, Bax, and Bcl-X(L) were 42.3, 38.7, and 46.8%, respectively. The expression of both Bax and Bcl-X(L) was not related to clinicopathological findings, including survival. Neither Bax nor Bcl-X(L) expression correlated with p53 overexpression. Five-year survival rate did not differ according to the co-expression pattern of Bax and Bcl-X(L). In 44 patients who underwent chemotherapy and/or radiation therapy after surgery, Bax and Bcl-X(L) expression was not related to patients' survival. Multiple apoptotic pathways may be associated with advanced esophageal squamous cell carcinoma.

Coexpression of vascular endothelial growth factor and p53 protein in squamous cell carcinoma of the esophagus

OBJECTIVE

p53 plays a role in tumor angiogenesis, and vascular endothelial growth factor (VEGF) plays a key role in tumor angiogenesis. The aim of the present study was to clarify how expression of p53 protein participates in angiogenesis, and whether the coexpression of VEGF and p53 protein has a significance for angiogenesis and the clinicopathological features in esophageal squamous cell carcinoma (SCC).

METHODS

Tissues samples were taken from 60 patients with esophageal SCC after surgery. The expression of VEGF and p53 protein in these SCC was examined immunohistochemically. Microvessel density (MVD) was determined by counting microvessels in tumor sections stained for Factor VIII-related antigen. Ki-67 labeling index (LI) was calculated, based on Ki-67 antigen immunostaining, as a proliferative marker. Apoptotic index (AI) was calculated, based on the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate biotin nick end labeling, to evaluate apoptosis.

RESULTS

VEGF expression was observed in 58.3%, and p53 protein expression was observed in 61.7% of the 60 patients. VEGF and p53 protein were significantly coexpressed in 26 (43.4%). Histological venous invasion (p < 0.01) and distant metastasis (p < 0.05) were significantly correlated with p53 protein expression. The two parameters were more frequently observed in the SCC with VEGF/p53 coexpression than in those without the coexpression. The MVD and Ki-67 LI were significantly higher (p < 0.01 and p < 0.001), and the AI was significantly lower (p < 0.001) in the SCC with p53 protein expression than in the SCC without it. The MVD and Ki-67 LI were higher, and the AI was lower in the SCC with VEGF/p53 coexpression than in those without the coexpression. The 5-yr survival rate in patients with the coexpression was poorer than in the other patients.

CONCLUSION

These results suggest that mutant p53 expression is associated with angiogenesis and distant metastasis in esophageal SCC, and that the coexpression of p53 and VEGF may play an important role in angiogenesis, and have important clinical significance.

Histopathological analysis of non-malignant and malignant epithelium in achalasia of the esophagus

We studied the premalignant nature of achalasia using anti-Ki-67 and anti-p53 monoclonal antibodies immunohistochemically. In this study, four patients with esophageal carcinoma and achalasia were investigated. Three tumors were pT4 (UICC pTNM) and one tumor was pT1. The majority of non-malignant esophageal epithelium showed esophagitis and/or dysplasia histologically. Esophageal epithelial cells in the lesions of esophagitis and/or dysplasia had a higher number of Ki-67-positive cells than normal epithelial cells. p53 protein was expressed in two tumors and it was not expressed in non-malignant epithelium. From these results, we found that esophageal epithelium in achalasia lesions is changed to varying degrees of esophagitis and/or dysplasia by stagnation of intake foods, and these abnormal epithelial cells showed a high proliferative state compared with the normal cells without the p53 gene mutation. We suggest that the distinct proliferative status is a cause of carcinogenesis.

Heterogeneous nuclear ribonucleoprotein B1 expressed in esophageal squamous cell carcinomas as a new biomarker for diagnosis

We recently reported that heterogeneous nuclear ribonucleoprotein (hnRNP) B1 was overexpressed in most human lung cancers, especially squamous cell carcinoma (SCC), as well as human oral SCC. To find the significance of hnRNP B1 in cancer diagnosis, we studied hnRNP B1 expression in 16 paraffinized sections of esophageal SCC, using immunohistochemical staining with anti-hnRNP B1 polyclonal antibody, raised in a rabbit. We compared the expression of hnRNP B1 in cancerous and noncancerous regions of the same specimen: enhanced expression was observed in 63% of cancerous regions (10 / 16), whereas none of the noncancerous regions showed enhanced expression. The enhanced expression of hnRNP B1 in cancerous regions was compared with that in noncancerous tissue in relation to histopathological grade: 83% for well differentiated (5 / 6), 83% for moderately differentiated (5 / 6) and 0% for poorly differentiated (0 / 4). Histologically, enhanced expression of hnRNP B1 was observed around cancer pearls, as well as in the cells of nests lacking keratinization in well and moderately differentiated SCC. Western blotting analysis revealed enhanced expression in three frozen specimens of moderately differentiated SCC. Using esophageal cancer cell lines, we further confirmed the decreased expression in poorly differentiated SCC cells, compared with other differentiation types. All our results support the significance of hnRNP B1 expression in esophageal SCC as a unique diagnostic marker with regard to association between expression level and histopathological grading.

Clinical application of malignancy potential grading as a prognostic factor of human esophageal cancers

BACKGROUND

Various biologic markers have been reported to be prognostic factors in human esophageal cancers. In the current study, we established a new tumor-grading system representing the malignancy potential of cancer cells and compared it with the clinical-stage system.

METHODS

Tumor samples from 77 patients with squamous cell carcinoma of the esophagus were immunohistochemically evaluated for the expression of 10 molecules: the cell cycle-related molecules of cyclin D1, Rb, p16INK4, p27KIP1, and PCNA; the cell-cell adhesion molecules of E-cadherin, alpha-catenin, and beta-catenin; and the heat shock proteins of HSP27 and HSP70.

RESULTS

P27KIP1, beta-catenin, and HSP70 were selected for their high hazard ratio in multivariate analysis, and the number of their disordered molecules was used to define the malignancy grade (MG). Five-year survival rates were 83%, 54%, 17%, and 0% for MG1, MG2, MG3, and MG4. The gradation of survival curves was better for MGs than for clinical stages. MGs and clinical stages showed significant correlation; however, 55% of those in higher clinical stages (stage 3 or 4) had lower MG (MG1 or 2) and showed better prognosis than others in their group (stage 3 or 4 and MG3 or 4). The proportions of shorter survival span to cancer death patients (less than 1 year) were 0%, 33%, 75%, and 100% in MG1, 2, 3, and 4, but the clinical stage was not associated with the survival span.

CONCLUSIONS

The grading of malignancy potential is clinically useful, especially for selecting patients who may show good prognosis in the advanced clinical stage and for predicting short survival span. These predictions are not possible with the clinical-stage system, which is based on the anatomic spread of cancer cells.

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.

Biological evaluation of undifferentiated carcinoma of the esophagus

BACKGROUND

Patients with undifferentiated carcinoma of the esophagus (UEC) are rare and have a poor prognosis compared with those with differentiated squamous cell carcinomas (DECs). We compared clinicopathological and biological features of UEC and DEC, with emphasis on markers for epithelial cell origin, proliferation, and cell-cell adhesion.

METHODS

Seven patients with UEC were compared with 21 with DEC. Immunohistochemical studies were performed by using monoclonal antibodies to cytokeratin, epithelial membrane antigen, p53, p21WAF1/CIP1, Ki-67, E-cadherin, desmoglein-1, and thrombomodulin.

RESULTS

Patients with UEC had a poorer prognosis because of hematogenous metastasis at the time of presentation (mean survival, 6.5 +/- 6.2 vs. 35.5 +/- 28.9 months; P < .05). Immunohistochemical findings for cytokeratin and epithelial membrane antigen suggest that some UECs had epithelial origins. The following immunohistochemical profile of UEC was consistent with its highly malignant properties: (1) reduced or negative expression of cell-cell adhesion molecules such as E-cadherin, desmoglein-1, and thrombomodulin, (2) high positive rate for p53 and Ki-67, and (3) negative expression of p21WAF1/CIP1.

CONCLUSIONS

The immunohistochemical findings for UEC showed its high cell-proliferative activity and a high potential for metastasis. Clinical features of UEC were supported by the results of immunohistochemical findings.

Prognostic significance of biologic factors in squamous cell carcinoma of the esophagus

BACKGROUND

Esophageal carcinoma is one of the most lethal tumors. Therefore, it is important to identify prognostic factors for patients with this disease. The objective of this study was to clarify the relation between clinicopathologic and biologic factors in esophageal carcinoma and to determine the prognostic significance of different biologic factors.

METHODS

DNA ploidy pattern, Ki-67 labeling index (LI), and cyclin D1 and p53 protein expression were examined and detailed pathologic examinations were conducted on tumors from 53 patients (46 males and 7 females with a mean age of 66 years [range, 47-85 years]) with surgically resected esophageal squamous cell carcinoma and the prognostic value of these factors was evaluated.

RESULTS

Of the 53 esophagus carcinomas examined, 26 (49%) were classified as DNA diploid. The mean Ki-67 LI was 45 +/- 4. 9% (range, 10.5-86.1%). p53 expression was detected in 38 of the carcinomas (71.7%) and cyclin D1 expression was detected in 35 (66%). Various prognostic factors were examined using the Cox stepwise regression model, four of which were found to correlate with overall survival: tumor size (P = 0.0346), lymph node status (P = 0.0384), Ki-67 LI (P = 0.0161), and p53 expression (P = 0.001). Lower Ki-67 LI and a lower rate of p53 expression were detected in the long term survival group (> 3 years) compared with the short term survival group (P = 0.00045 and P = 0.0023, respectively).

CONCLUSIONS

The biologic factors of Ki-67 LI and p53 expression, as well as clinicopathologic factors, may be used as independent prognostic factors for patients with esophageal carcinoma. However, the results of the current study do not support cyclin D1 expression as a prognostic factor.

No prognostic significance of p53 expression in esophageal squamous cell carcinoma

BACKGROUND AND OBJECTIVES

It is generally accepted that the overexpression of p53 protein is associated with poor prognosis in breast, colorectal, and other types of cancer. However, the prognostic significance of p53 aberrations in esophageal squamous cell carcinoma has yet to be determined. We attempted to analyze the relationship between p53 expression and the clinicopathologic features of esophageal squamous cell carcinoma by reviewing the medical records of a large patient population. Our study of esophageal squamous cell carcinoma involves the largest patient population to date.

METHODS

p53 expression in formalin-fixed, paraffin-embedded samples of 239 patients with primary esophageal squamous cell carcinoma (TNM stage I:79 cases, stage II: 82 cases, stage III: 78 cases), who underwent esophageal resection without additional treatment, were analyzed by immunohistochemical staining using a polyclonal antibody, RSP53. The relationships between p53 immunoreactivity and prognostic factors were determined by the chi(2) test, and the prognostic impact of p53 protein expression was analyzed by univariate and multivariate survival analyses.

RESULTS

In 115 (48.1%) of 239 esophageal tumors, nuclear immunoreactivity for the p53 protein was detected. The expression of the p53 protein did not correlate with sex, age, histological grading, lymph node metastasis, vascular invasion, or TNM stage. Similarly, p53 expression did not correlate with prognosis in univariate and multivariate survival analysis.

CONCLUSIONS

The expression of the p53 gene product had no impact on the prognosis of esophageal squamous cell carcinoma.

p53 and cyclin A protein expression in squamous carcinoma of the oesophagus

The aim of this study was to explore the relationship between p53 and cyclin A immunostaining in squamous carcinomas of the oesophagus. It has been shown that both these proteins are overexpressed in poorly differentiated endometrial carcinomas. Fifty oesophagectomy specimens were analysed for p53 and cyclin A immunoexpression. This was correlated with patient age and gender and tumor stage and grade. Forty-two percent of cases were p53 positive, while 94% of the squamous cancers expressed cyclin A protein. Neither protein showed any statistically significant correlation with clinicopathological parameters. This study has demonstrated that only 42% of oesophageal squamous carcinomas from South Africa express p53 protein, while the vast majority (94%) express cyclin A protein. Neither of these proteins showed any relationship to each other or any clinical feature or the tumor grade or stage.

Immunoreactivity of p53, Ki-67, and Bcl-2 in oncocytic adenomas and carcinomas of the thyroid gland

To analyze relevant factors of neoplastic transformation in oncocytic neoplasms of the thyroid, expression of p53, Ki-67, and bcl-2 has been studied in oncocytic carcinomas (n = 17) and compared with results obtained in oncocytic adenomas (n = 20). P53 protein accumulation was found immunohistochemically in 75% of the oncocytic adenomas (15 of 20) and 88% of the oncocytic carcinomas (15 of 17). Eight of 17 of the carcinomas (47%), but only 3 of the 20 adenomas (15%), showed nuclear p53 accumulation in more than 10% of the cells, mostly in a focal pattern. Ki-67 expression also differed significantly between adenomas and carcinomas. The median of Ki-67-positive cells was 12/10 high-power fields (HPF) for adenomas and 76/10 HPF for carcinomas (P < .001). Furthermore, metastatic carcinomas had a significantly higher Ki-67 positivity than nonmetastasized carcinomas (164/10 HPF v 42/10 HPF, P < .05). Bcl-2 immunohistochemistry showed a constantly positive reaction in normal thyroid tissue. In contrast, bcl-2 protein was not detected in most of the adenomas (70%) and carcinomas (76%). In conclusion, p53 protein and Ki-67 is more prevalent in oncocytic carcinomas than in oncocytic adenomas of the thyroid, indicating that these factors may be involved in the progression of oncocytic neoplasms in the thyroid. In contrast, loss of bcl-2 appears to be an early event in the formation of oncocytic neoplasms of the thyroid. Its importance for malignant transformation is, however, unclear.

The clinicopathological significance of p21 and p53 expression in esophageal squamous cell carcinoma: an analysis of 153 patients

OBJECTIVE

The p21 gene is thought to play a central role in tumor suppression. The aim of this study was to examine the clinicopathological role of p21 and p53 in esophageal squamous cell carcinomas.

METHODS

The expression of p21 and p53 proteins in 153 Chinese patients (131 men, 22 women) with resected esophageal squamous cell carcinomas was investigated by the immunohistochemical method. Correlation between p21 and p53 expression and clinicopathological features was examined.

RESULTS

The expression of p21 and p53 was detected in 70% and 64% of the tumors, respectively. The staining of p21 and p53 was also found in squamous carcinoma in situ, dysplasia, and nontumor epithelium. p21 expression was often weak in the suprabasal cells and found in better differentiated tumors. There was no significant correlation between the expression of p21 and the abnormal accumulation of p53. The prognosis of the patients depended on the size, stage, and p21 expression of the lesion. In stage III lesions with tumor diameter < or = 7.5 cm (n = 93), patients with loss of p21 expression had better survival. The survival rates of patients were worse if they had expression of both p21 and p53.

CONCLUSIONS

Thus, p21 and p53 had prognostic value for esophageal squamous cell carcinomas. Loss of p21 expression was shown without p53 alternations, indicating that other mechanisms are also involved in turning off the gene. The pattern of p21 and p53 expression predicts an aggressive clinical course of esophageal squamous cell carcinomas.

p21Waf1/Cip1 expression is a prognostic marker in curatively resected esophageal squamous cell carcinoma, but not p27Kip1, p53, or Rb

BACKGROUND

p21Waf1/Cip1 (p21), p27Kip1 (p27), p53, and Rb play critical roles in cell cycle regulation and may influence the clinical behavior of tumors. We examined whether their expression is useful to predict survival of patients with esophageal squamous cell carcinoma (ESC).

METHODS

Expression of p21, p27, p53, and Rb was studied by the immunohistochemical method in specimens from 62 patients with curatively resected ESC tumors and scored by a computerized image analysis system.

RESULTS

The median expression scores of p21, p27, p53, and Rb (14, 12, 27, and 50, respectively) were used as cut-off points to define low and high expression groups for each protein. The 5-year survival rate for the high p21 expression group was 68%; that for the low expression group was 31% (P = .0062). p27, p53, and Rb were not correlated with overall survival. When patients were categorized into four groups based on p21 expression level and lymph node involvement (pN), the survival curves were significantly different (P = .0017). Thus, patients without lymph node involvement but with low p21 expression had survival similar to that of patients with lymph node involvement and high p21 expression. Multivariate analysis showed that age (P = .0102), lymph node involvement (P = .0076), and p21 (P = .0276) were independent prognostic factors.

CONCLUSIONS

Expression of p21 is an independent prognostic factor in curatively resected ESC. Definition of new subgroups of patients based on p21 expression may help to enhance the stratification of stage.

Evaluation of malignancy and the prognosis of esophageal cancer based on an immunohistochemical study (p53, E-cadherin, epidermal growth factor receptor)

The subjects in this study consisted of 40 preoperative untreated esophageal squamous cell carcinoma patients. While p53 did not significantly correlate with the clinicopathological factors, E-cadherin significantly correlated with lymphatic invasion, vascular invasion, the depth of invasion, the degree of lymph node metastasis, the histological stage, and the number of lymph node metastases. Epidermal growth factor receptor (EGFR) significantly correlated with age, the depth of invasion, and the number of lymph node metastases. The 5-year cumulative survival rate was 45.7% in the p53-positive cases and 61.9% in the p53-negative cases, with no significant difference, and 87.8% in the E-cadherin-positive cases and 19.1% in the -negative cases, and the difference was significant. The prognosis was significantly poor in EGFR-positive subjects: the 5-year survival rate was 38.6% in EGFR-positive cases and 68% in -negative cases. The 5-year survival rate in E-cadherin-negative, EGFR-positive cases was 0%, while it was 91.7% in the reverse pattern, and this difference was significant. These findings suggest that both E-cadherin and EGFR are important prognostic factors, and a more precise prognosis can thus be obtained by combining them. Such a combined technique may be very useful as an indicator for grading the biological malignancy of esophageal cancer.

Prognostic significance of heat shock proteins 27 and 70 in patients with squamous cell carcinoma of the esophagus

BACKGROUND

Heat shock proteins (HSPs) first were defined as proteins induced by heat shock and other environmental and pathophysiologic stresses and are implicated in protein-protein interactions such as folding, translocation, and prevention of inappropriate protein aggregation. Many of their functions suggest that they play important roles in cancer.

METHODS

Immunohistochemical study for HSP 27 and HSP 70 was performed on buffered formalin fixed, paraffin embedded sections of 102 esophageal squamous cell carcinoma specimens using monoclonal anti-HSP 27 antibody and anti-HSP 70 antibody.

RESULTS

Normal squamous cells expressed both HSP 27 and HSP 70 with the exception of the basal layer. In cancerous tissue, expression of HSP 27 was evaluated as positive (+) (39 cases; 38%), reduced (+/-) (53 cases; 52%), or negative (-) (10 cases; 10%) and expression of HSP 70 was evaluated as (+) (14 cases; 14%), (+/-) (57 cases; 56%), or (-) (31 cases; 30%). There was a strong correlation between the expression of HSP 27 and HSP 70 (P < 0.0001). When compared with clinicopathologic features, expression of both HSP 27 and HSP 70 correlated negatively with lymph node metastases (P < 0.05), but not with depth of invasion or histologic grade. The reduction of the HSPs was associated significantly with poor postoperative survival (P < 0.0001). In addition, multivariate analysis revealed that HSP 27 (-) was the strongest prognostic factor among the clinicopathologic features.

CONCLUSIONS

This study suggests that the expression of HSP 27 and HSP 70 frequently is reduced in patients with esophageal squamous cell carcinoma and therefore should be considered an independent prognostic factor of this disease.

Prognostic significance of heat shock proteins 27 and 70 in patients with squamous cell carcinoma of the esophagus

BACKGROUND

Heat shock proteins (HSPs) first were defined as proteins induced by heat shock and other environmental and pathophysiologic stresses and are implicated in protein-protein interactions such as folding, translocation, and prevention of inappropriate protein aggregation. Many of their functions suggest that they play important roles in cancer.

METHODS

Immunohistochemical study for HSP 27 and HSP 70 was performed on buffered formalin fixed, paraffin embedded sections of 102 esophageal squamous cell carcinoma specimens using monoclonal anti-HSP 27 antibody and anti-HSP 70 antibody.

RESULTS

Normal squamous cells expressed both HSP 27 and HSP 70 with the exception of the basal layer. In cancerous tissue, expression of HSP 27 was evaluated as positive (+) (39 cases; 38%), reduced (+/-) (53 cases; 52%), or negative (-) (10 cases; 10%) and expression of HSP 70 was evaluated as (+) (14 cases; 14%), (+/-) (57 cases; 56%), or (-) (31 cases; 30%). There was a strong correlation between the expression of HSP 27 and HSP 70 (P < 0.0001). When compared with clinicopathologic features, expression of both HSP 27 and HSP 70 correlated negatively with lymph node metastases (P < 0.05), but not with depth of invasion or histologic grade. The reduction of the HSPs was associated significantly with poor postoperative survival (P < 0.0001). In addition, multivariate analysis revealed that HSP 27 (-) was the strongest prognostic factor among the clinicopathologic features.

CONCLUSIONS

This study suggests that the expression of HSP 27 and HSP 70 frequently is reduced in patients with esophageal squamous cell carcinoma and therefore should be considered an independent prognostic factor of this disease.

Prognostic value of p53 protein expression for patients with gastric cancer--a multivariate analysis

Mutations in the p53 gene, one of the most common genetic alterations in human cancer, are implicated in tumorigenesis and tumour progression. Although p53 protein expression appears to be correlated to prognosis in patients with malignancy, its prognostic role in gastric cancer has remained controversial. We examined the clinical significance of p53 overexpression in 427 patients with gastric cancer, using multivariate analysis. Tumour sections of gastric cancer tissues from these 427 Japanese patients were stained immunohistochemically with monoclonal antibody PAb1801. The presence of p53 expression was statistically compared with clinicopathological features and post-operative survival, using univariate and multivariate analyses. p53 expression was detected in 38.6% (165 out of 427) of these gastric cancers and immunoreactivity was not observed in normal mucosa adjacent to the tumour. A higher rate of p53 detection was observed among large tumours and in those with a prominent depth of invasion, lymphatic and vascular invasion and lymph node involvement. Prognosis was significantly worse for patients with p53-positive-staining tumours. The 5-year survival rate was 62.5% for patients with p53-negative tumours and 43.3% for those with positive malignancies. p53 expression was a significant prognostic factor for node-positive gastric cancers in subjects undergoing treatment with curative resection, as assessed by Cox regression analysis. Thus, the expression of p53 was closely related to the potential for tumour advance and a poorer post-operative prognosis for patients with gastric cancer.

p53 alterations in oesophageal cancer: association with clinicopathological features, risk factors, and survival

AIM

To characterise the spectrum of p53 alterations (gene mutations and protein accumulation) in a consecutive series of surgically resected oesophageal cancers, and to evaluate associations with clinicopathological findings (age, sex, tumour histology, grade, and stage), potential risk factors (alcohol, tobacco, hot beverage consumption, history of gastrooesophageal reflux disease and antacid use), and survival.

METHODS

The case series comprised 61 sequentially accrued patients with primary oesophageal carcinomas. Genomic DNA was extracted from banked (frozen) tumours and matched normal mucosal tissue; p53 mutations (exons 4-10) were studied by means of polymerase chain reaction (PCR)/single strand conformation polymorphism (SSCP) analysis and DNA sequencing. Immunohistochemistry (DO7, CM1) was used to assess cell nuclear p53 protein accumulation. Risk factor data, overall and disease free survival were measured prospectively, and analysis was carried out at the univariate level using Kaplan-Meier survival curves with log rank tests, and in multivariate analysis using Cox's proportional hazards models (parsimonious and fully adjusted).

RESULTS

p53 mutations were found in 59% (36 of 61) and p53 protein accumulation was detected in 39% (24 of 61) of oesophageal cancers. Eighty eight per cent (23 of 26) of poorly differentiated tumours had p53 alterations compared with 57% (20 of 35) of moderate/well differentiated tumours (odds ratio (OR) = 5.575; p = 0.013). p53 mutations increased significantly with increasing consumption of hot beverages (measured by the average temperature of beverage, number consumed daily, and an index made by multiplying the two variables together) using both univariate (OR = 18.6; p = 0.0025) and multivariate (OR = 24.5; p = 0.0025) analysis. p53 alterations were associated with reduced disease free and overall survival (p = 0.051, log rank), with a univariate (unadjusted) hazard ratio (HR) of 2.241 (95% confidence limits (CL) = 0.973, 5.159; p = 0.058) for overall survival. By multivariate analysis adjusted for other relevant variables, the HR for tumours with p53 alterations was estimated at 2.913 (95% CL = 1.069, 7.936; p = 0.036) for overall survival.

CONCLUSIONS

This study reports novel p53 mutations (exon 10), and an association between increasing consumption of hot beverages as a risk factor for p53 mediated oesophageal cancer. p53 is a potentially useful prognostic marker in this disease.

Extraction and analysis of diagnostically useful proteins from formalin-fixed, paraffin-embedded tissue sections

We describe and discuss a method of protein extraction for Western blot analysis from formalin-fixed, paraffin-embedded tissue sections. From 5-mm2 50-micron-thick tissue sections, an abundance of proteins could be extracted by incubating the sections in lysis buffer containing 2% sodium dodecyl sulfate (SDS) at 100C for 20 min followed by incubation at 60C for 2 hr. Extracts yielded discernible protein bands ranging from 10 kD to 120 kD as identified by SDS-polyacrylamide gel electrophoresis (PAGE). Western blot analysis successfully detected membrane-bound protein such as E-cadherin, cytosolic protein such as beta-catenin, and nuclear proteins including proliferating cell nuclear antigen (PCNA), mutant-type p53, cyclin D1, cyclin E, and cyclin-dependent kinases (CDKs). With this technique, we could examine cyclin D1 and CDK2 expression in small adenomas compared with cancer tissues and normal mucosa. The simple method of protein extraction described here should make it possible to use large-scale archives of formalin-fixed, paraffin-embedded samples for Western blot analysis, and its application could lead to detailed analysis of protein expression. This new technique should yield valuable information for molecular biology.

Cyclin D1 overexpression related to retinoblastoma protein expression as a prognostic marker in human oesophageal squamous cell carcinoma

The relationship between aberrant expression of cyclin D1 and retinoblastoma (RB) protein and clinicopathological factors was investigated in 80 patients with oesophageal SCC using immunohistochemical analyses. Heterogeneous staining of cancer cell nuclei with antibody to cyclin D1 was found in 31.3% of patients (25 out of 80 patients). Nuclear staining of cancer cells with anti-RB antibody was homogeneous in 10.0% (8 out of 80 patients) and heterogeneous in 58.8% (47 out of 80 patients). Among cases with homogeneous staining for RB protein, 75% (six out of eight patients) exhibited simultaneous positivity for cyclin D1 (P < 0.05). No significant relationship was found between cyclin D1 or RB protein expression and various clinicopathological parameters. The prognosis of patients with cyclin D1-positive tumours was significantly poorer than that of the other patients (P < 0.01). In addition, when patients with cyclin D1-positive and -negative tumours were stratified according to presence or absence of lymph node metastasis and RB status, the cumulative survival rates in the cyclin D1-positive groups were significantly lower for patients without lymph node metastasis (P < 0.01) and for patients whose tumours were positive for RB (P< 0.0001). These findings suggest the possibility that cyclin D1 positivity is a useful prognostic marker related to lymph node metastasis and RB protein expression in human oesophageal SCC, in addition to clinicopathological factors.

High Prevalence of p53 Gene Mutation in Esophageal Cancer

Tissue samples from 24 patients with esophageal cancer were studied to determine the incidence and clinical implications of alterations of the p53 gene. Allelic deletion of chromosome 17p and mutation of the p53 gene were determined by Southern blot analysis and polymerase chain reaction single-stranded conformation polymorphism. Nucleotide sequence analysis was performed using the direct sequencing method when abnormalities were detected. Eighteen of the 24 cases of esophageal cancer showed either gene deletions or mutations of the p53 gene. Among 15 tumors with p53 gene deletion or mutation, 13 point mutations and 2 frame shifts were identified. The clinical data were also analyzed in relation to genetic alteration of the p53 gene. These results indicate that allelic deletion of 17p 13 and mutation of the p53 gene are frequent and may occur simultaneously in esophageal cancer cells. Such changes might be an important step in the development of esophageal cancer. However, the presence of a p53 gene mutation was not significantly associated with tumor stage, nodal stage, age, or smoking. There was no evidence to suggest that p53 gene mutation could be a prognostic factor in esophageal cancer patients.

P53 gene product and EGF-receptor are highly expressed in placental site trophoblastic tumor

Immunohistochemical analysis of curettage material from a placental site trophoblastic tumor (PSTT) revealed a high expression of p53 gene products, of epidermal growth factor receptor (EGF-R) and of Ki-67 (MIB-1) proliferation associated antigen. bcl-2 was not expressed. These results show that in PSTT inactivation/dysregulation of p53 and upregulation of EGF-R and MiB-1 occurs, indicating that these factors are probably involved in tumor genesis and propagation of PSTT. The prognostic significance of the molecular genetic data, however, remains to be established.

Prevalence and predictive value of p53 mutation in patients with oesophageal squamous cell carcinomas: a prospective clinico-pathological study and survival analysis of 70 patients

The tissues from 70 Chinese patients with oesophageal squamous cell carcinoma were prospectively collected to study for the pattern of p53 mutations and its relationship with clinico-pathological features and prognosis using immunohistochemistry, polymerase chain reaction-single strand conformational polymorphism (PCR-SSCP) analysis and DNA sequencing. p53 over-expression and p53 mutations were detected in 73% and 44% of the patients. These p53 aberrations had no relationship with the patient age, sex, smoking/drinking habits and tumor site, size or stage. The p53 over-expression was more intense in moderately/poorly-differentiated squamous cell carcinomas. Thirty-three p53 mutations were noted in 31 patients; 18.2% in exon 5, 15.2% in exon 6, 33.3% in exon 7 and 33.3% in exon 8. Mutations were primarily point mutations and common in codons 248, 273 and 285. There were 46% transversions, 36% transitions and 18% frameshift. The survival of the patients depended mainly on the extent of resection. In patients with stage III oesophageal cancer, the median survival of those with p53 mutations was 6.8 months whereas those without was 12.5 months. The results were of clinical importance although the value did not reach statistical significance. Thus, there was a definite role of p53 mutations in the pathogenesis of oesophageal squamous cell carcinomas. p53 mutations were not synonymous with p53 over-expression. The distribution of p53 mutations in oesophageal cancers suggested that the etiologic contribution might be complex and probably involve different exogenous and endogenous exposures. p53 mutations also appear to play a role in predicting the survival of patients with stage III oesophageal squamous cell carcinomas.

p53 protein accumulation and p53 gene mutation in esophageal carcinoma. A molecular and immunohistochemical study with clinicopathologic correlations

BACKGROUND

p53 gene mutation and p53 protein accumulation are common in human cancer. However, their clinical significance is controversial and p53 accumulation may not correlate with gene mutation. The current study investigates the occurrence of p53 alterations in esophageal carcinoma, the correlation between the analyses at the gene and protein level, and their prognostic significance.

METHODS

A series of 74 esophageal carcinomas (46 squamous cell carcinomas, 21 Barrett's adenocarcinomas, and 7 undifferentiated carcinomas) was studied by single strand conformation polymorphism (SSCP) analysis and immunohistochemistry (IHC) to detect p53 mutation and accumulation, respectively.

RESULTS

p53 mutations in exons 5-8 were detected in 53% of the carcinomas whereas p53 accumulation was observed in 57% of cases. Comparing SSCP and IHC, there were 27 discordant cases (38%). Overall, only 20 tumors (27%) did not display p53 mutation and/or p53 accumulation. No associations were found between p53 aberrations and clinicopathologic parameters, including patients age and gender tumor type, stage, and grade. p53 protein accumulation and p53 gene mutation were not related to patient survival by univariate or multivariate analysis in esophageal carcinomas.

CONCLUSIONS

p53 aberrations are very common in esophageal carcinomas. However, p53 gene mutation and p53 protein accumulation have a significant discordance, suggesting that p53 function may be inactivated by mechanisms other than mutation. p53 aberrations do not independently predict prognosis in esophageal tumors.

Comparative p53 mutational analysis of multiple primary cancers of the upper aerodigestive tract

BACKGROUND

Tumors arising in the upper aerodigestive tract (UAT) are often associated with predisposing factors that place the patient at risk for development of multiple synchronous or metachronous tumors. The aim of this study was to evaluate p53 as a susceptibility gene in UAT malignancy.

METHODS

Seventeen patients with 41 separate primary tumors involving esophagus (n = 15), larynx (n = 14), pharynx (n = 6), lung (n = 2), mouth (n = 2), and tongue (n = 2) were analyzed for the presence and specific genotype of p53 point mutation. Immunohistochemical staining of p53 and topographic genotyping consisting of polymerase chain reaction amplification and direct sequencing of p53 exons to 5 to 8 were performed.

RESULTS

Eleven tumors were metachronous (6 months to 11 years), and 11 were synchronous. We found p53 point mutations in 19 (46.3%) of 41 tumors in exons 8 (n = 11), 7 (n = 4), 5 (n = 3), and 6 (n = 1). Tumors possessed either wild-type p53 or a single type of point mutation. Metastases displayed the identical genotype of its primary tumor in all cases. Most importantly, p53 genotype was found to be completely discordant between separate primary tumors for the same patient.

CONCLUSIONS

Complete discordance in p53 genotype between separate primary UAT cancers strongly indicates that p53 is not functioning as a susceptibility gene in this setting.

Genetic alterations in esophageal cancer and their relevance to etiology and pathogenesis: a review

Cancer of the esophagus exists in 2 main forms with different etiological and pathological characteristics-squamous cell carcinoma (SCC) and adenocarcinoma (ADC). This review focuses on the occurrence of genetic alterations in SSC and ADC of the esophagus and on their possible implications for the elucidation of the etiology and pathogenesis of these cancers. The most common alterations found in esophageal cancers include allelic losses at chromosomes 3p, 5q, 9p, 9q, 13q, 17p, 17q and 18q, as well as mutations of p53 (mostly missense), Rb (deletions), cyclin DI (amplifications) and c-myc (amplifications). The sequence of occurrence of these alterations with respect to histopathological tumor progression is discussed. Our findings underscore the different etiology and pathogenesis of SCC vs. ADC and suggest that the genetic alterations observed may represent molecular fingerprints of critical risk involved in the development of these 2 cancers.

p53 overexpression in head and neck squamous cell carcinoma: review of the literature

As a tumour suppressor gene, the inactivation of p53 induces the development of numerous human cancers. Mutations of p53 have been implicated in the pathogenesis of head and neck squamous cell carcinoma (HN-SCC) at a high incidence. In premalignant lesions and in situ carcinomas, p53 overexpression is not exclusively restricted to neoplastic cells, but frequently affects the normal appearing keratinocytes adjacent to p53 positive neoplasms or present in dysplastic areas. These results suggest that as contributors to the early phases of HN-SCC development, p53 alterations may be excellent biomarkers that indicate the predisposition of a particular oral cavity premalignant lesion toward malignancy. In most cases, the p53 overexpression status of a tumour metastasis is identical to that of a primary tumour, indicating that a p53 mutation precedes metastatic spread. In patients with multiple primary tumours, multiple foci of p53 overexpression are observed in epithelia distant from the tumour. So the expression of p53 in normal epithelium would indicate an increased risk for transformation to second or third primary cancers. Distinct p53 mutations in different primary tumours of the same patient indicate that these cancers arise as independent events; these results support the existence of multifocal polyclonal processes. Regardless of the aforementioned results that support p53 as a valid tumour biomarker, most studies have shown no relationship between the expression of p53 and clinical and histopathological parameters. The role played by p53 mutations in the progression and vital prognosis of HN-SCC has not yet been demonstrated.

p53 accumulation in colorectal cancer with hepatic metastasis

The prevalence of immunoreactive p53 and argyrophilic nucleolar organizer region (AgNOR) numbers were compared between colorectal cancers with (n=44) and without (n=51) hepatic metastasis for at least 5 years. At the same time, the distribution of p53-positive cells in primary, metastatic, and xenografted tumors from the same individuals were studied. Overall, p53 positivity was found more frequently in the cases with hepatic metastasis than in non-metastatic controls, regardless of the distribution pattern (P<0.05), whereas AgNOR counts were not different between the two groups. Significant heterogeneity in the distribution of p53 immunoreactivity was noted in both the primary and metastatic lesions. The intratumor distribution patterns of p53 immunoreactive cells in the primary (n=33), metastatic (n=33), and xenografted (n=7) tumors of the same individuals were consistent in the majority of cases. There were a few cases in which the p53 immunoreactive cells were more dominant in the metastatic tumor cells. Our observations suggest that p53 accumulation in colorectal cancer is associated with increased risk for hepatic metastasis, while cell proliferation as represented by AgNOR numbers is not. In addition, heterogeneity of abnormal p53 accumulation in the tumor is maintained during the course of metastasis and even after implantation in nude mouse. p53-Immunoreactive cells in the population of colorectal cancer cells do not necessarily have higher metastasizing potential.

Acceleration of proliferative activity of esophageal squamous cell carcinoma with invasion beyond the mucosa: immunohistochemical analysis of Ki-67 and p53 antigen in relation to histopathologic findings

BACKGROUND

The authors observed patients with superficial esophageal squamous cell carcinoma (s-ESC). Those with cancer invasion beyond the muscularis mucosae (SM-carcinoma) had an extremely poor prognosis, compared with those with intramucosal carcinoma (M-carcinoma). Therefore, we surveyed cell proliferative activities in relation to pathologic findings of the s-ESC.

METHODS

p53 protein expression and Ki-67 labeling index (LI) were surveyed with detailed pathologic examinations of 75 s-ESC lesions from 70 patients who underwent esophagectomy. The results were compared by statistical analysis using the chi-square test and unpaired Student's t-test.

RESULTS

p53 protein expression was observed in 57.3% of the patients with s-ESC. The frequency and intensity of its accumulation correlated with the depth of cancer invasion and was markedly elevated in invasion beyond the muscularis mucosae. The LI of Ki-67 positive nuclei was also increased with cancer invasion. The values in the intraepithelial carcinoma and in carcinoma with invasion to the muscularis mucosae were 48.5 +/- 13.7% [mean +/- standard deviation (SD)] and 66.6 +/- 12.9%, respectively, and the difference is significant, P < 0.01. In the SM-carcinomas, the LIs of Ki-67, with or without lymph node metastasis, were 73.5 +/- 10.0% and 64.4 +/- 11.3%, respectively, and the former was higher than the latter with a significant difference, P < 0.05.

CONCLUSIONS

Cancer cell proliferative activities were markedly accelerated in s-ESC cases with cancer invasion beyond the muscularis mucosae and lymph nodal involvement, which was associated with a poorer prognosis of the SM-carcinoma compared with the M-carcinoma, and must be one of the important indices to decide the indication of local resection for s-ESC.

Overexpression of p53 protein in squamous cell carcinoma of buccal mucosa and tongue in Taiwan: an immunohistochemical and clinicopathological study

Sixty squamous cell carcinomas of tongue and buccal mucosa were examined for expression of p53 protein by using an immunohistochemical technique improved by an antigen retrieval method. Twenty-seven (45%) tumors demonstrated strongly positive staining. Thirteen of p53-positive tumors (48%) also exhibited overexpression of p53 in immediately adjoining hyperplastic or pre-malignant epithelium. All 22 metastatic lymph nodes and 18 local recurrent lesions (except two) had an identical p53 immunophenotype to their corresponding primary sites. Mitotic indices were significantly higher in p53-positive tumors (P < 0.01); however, no association of PCNA scores with p53 expression was found (P > 0.1). There was no correlation between p53 overexpression and tumor grade, size and staging, vascular invasion, lymph node metastasis, and early local recurrence. Overexpression of p53 was found to be relatively higher, although not statistically significant, in nonsmokers than in heavy smokers (66.7% vs. 42.9%), and in nonbetel-quid chewers than in heavy chewers (62.5% vs. 34.2%). These data are consistent with the hypothesis that inactivation of p53 protein may occur in the early phases of oral tumorigenesis. It may not be a useful prognostic marker but could possibly be used for risk assessment and surveillance of local recurrence.