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

p53 protein expression in esophageal squamous cell papillomas: a study of 36 lesions

BACKGROUND AND METHODS

In the present study 36 esophageal squamous cell papillomas (ESCP), uncommon benign neoplasms of the esophagus, were investigated retrospectively for p53 immunoreactivity by using the monoclonal antibody PAb 1801. Two ESCPs had previously been found to be human papillomavirus (HPV) type-6-positive.

RESULTS

Only very occasional epithelial cells were stained in two cases, and in three ESCPs p53 staining was restricted to the basal epithelial cells. Both HPV-positive ESCPs remained p53-negative.

CONCLUSION

We speculate that these findings are the result of immunohistochemical detection of the stabilized wild-type p53 protein rather then mutated p53 protein.

The relationship of p53 expression to the prognosis of 418 patients with gastric carcinoma

BACKGROUND

Mutations of the p53 gene belong to the most common genetic alterations in human cancer that have been implicated in tumorigenesis and tumor progression. Although p53 expression appears to be correlated with prognosis in patients with breast cancer and some other types of cancer, its prognostic role in gastric cancer is still uncertain. In the present study, therefore, the prognostic impact of p53 expression was evaluated in 418 patients with curatively resected gastric carcinomas without residual tumor (RO-resection).

METHODS

Tumor sections of 418 RO-resected gastric carcinomas were stained with the monoclonal antibody DO-1 after microwave processing. p53 expression was statistically compared with clinico-pathologic features and postoperative survival.

RESULTS

p53 expression was detected in 57.5% of all tumors, with strong inter- and intratumor heterogeneity. No immunoreactivity was observed in the normal mucosa adjacent to the tumor. Statistically, no significant correlation between p53 overexpression and depth of invasion, lymph node involvement, or grade of tumor differentiation was detected. The correlations with blood vessel invasion (P = 0.049) and lymphatic vessel invasion (P = 0.047) were of marginal significance. Survival analysis revealed no significant impact of p53 expression on survival, the 5-year survival rates were 40.6% +/- 7.8% for patients with p53 positive tumors and 49.2% +/- 8.9% for patients with p53 negative tumors (P = 0.43). Furthermore, no correlation with survival was found when four different levels of p53 expression were analyzed (P = 0.51). p53 expression had no influence on survival, in either the lymph node positive or negative groups.

CONCLUSIONS

The data suggest that the immunohistochemical detection of p53 expression is at present not a predictor of outcome of patients with gastric cancer or to identify subgroups of patients who may be at higher risk.

Expression of p53 in oesophageal squamous cell carcinoma in Hong Kong Chinese

We studied p53 overexpression in a series of 99 primary oesophageal squamous cell carcinomas (28 well-differentiated, 42 moderately-differentiated and 29 poorly-differentiated squamous cell carcinomas) from Chinese patients using the p53 protein specific mouse monoclonal antibody DO-7 on paraffin sections. The p53 protein was detected in 30% (30 cases) of the tumours. A significantly higher positive rate was noted in the poorly-differentiated tumours (11% for the well-differentiated, 31% for the moderately-differentiated and 48% for the poorly-differentiated tumours). In addition, strong positive p53 staining was identified only in the less differentiated tumour cells in the periphery of the tumour cell nests in all the cases and the expression was weaker in the better differentiated foci. The central keratinizing areas and the immediately adjacent tumour cells were always negative for p53. The adjacent normal oesophageal mucosa was all negative for p53 protein but the non-invasive dysplastic epithelium next to the tumours could also be strongly positive for p53 protein (four out of 14 cases in which the dysplastic epithelium adjacent to the tumour was adequately sampled). In two out of these four cases, the dysplastic epithelium showed staining for p53; even the adjacent invasive tumour was negative for p53. It is concluded that there is a strong relationship between p53 overexpression and tumour cell differentiation in oesophageal squamous carcinoma and overexpression of p53 can occur in non-invasive tumour cells.

Expression of the p53 protein in malignant melanomas as a prognostic indicator

It is currently widely accepted that the tumour suppressor gene p53 is critically involved in the proliferation and differentiation of tumour cells including melanoma cells. In the present study, we examined 60 cases of primary melanoma to compare the expression of p53 protein with conventional prognostic markers for melanoma such as clinical and histological parameters. No correlation was found between the p53 protein and clinical factors except for the presence of a metastatic node and development to clinical stage II. However, the expression of p53 protein was significantly associated with tumour thickness over 1.5 mm, levels IV and V of invasion, the presence of ulceration, and high mitotic rate for 5-year survival rate. Although many questions still remain to be answered, our results and those of others for various other malignant tumours, implicate p53 in malignant transformation of pigment cells. Indeed, it could be a new marker for an unfavourable prognosis of malignant melanoma, even though the gene mutation in this highly lethal tumour has yet to be established.

p53 expression and cell proliferation in squamous cell carcinomas of the head and neck

BACKGROUND

In squamous cell carcinoma of the head and neck (SCCHN), overexpression of the p53 protein has been found in 34-80% of the tumors studied. No data are available regarding p53 expression versus tumor cell proliferation and prognosis for this tumor type.

METHODS

p53 protein levels were studied by immunohistochemical staining of 33 primary SCCHN using 3 antibodies (DO7, PAb 1801, and CM1) that react with different epitopes of the p53 protein. The cellular expression of p53 was compared with in vivo incorporation of the thymidine analog iododeoxyuridine (IdUrd) and expression of proliferating cell nuclear antigen (PCNA).

RESULTS

Twenty-one tumors (64%) had a positive nuclear staining for p53 with the monoclonal antibody DO7, which reacts with a denaturation-resistant epitope in wild-type and mutant p53. PAb 1801 and CM1 reacted with 19 and 20 tumors, respectively, all of which were DO7-positive. No correlation was found between incorporation of IdUrd and p53 expression or between PCNA and p53 expression. The data indicate that intracellular accumulation of the p53 protein was related to tumor stage and localization of the tumor. No indication of a clinical or prognostic significance of p53 expression in SCCHN was found.

CONCLUSIONS

No association between p53 deregulation and tumor cell proliferation was found.

High prevalence of p53 protein overexpression in patients with esophageal cancer in Linxian, China and its relationship to progression and prognosis

BACKGROUND

Linxian is the highest endemic area of esophageal squamous cell carcinoma (ESCC) in China and one of the highest incidence areas in the world. The relationship of p53 protein accumulation to geographic variation, pathologic findings, and prognosis has not been investigated extensively.

METHODS

Formalin fixed, paraffin embedded ESCC tissues from 100 patients who underwent esophagectomy between 1973 and 1983 were immunostained by using monoclonal antibody pAB1801.

RESULTS

p53 overexpression was observed in 41 (87.2%) of 47 tumors of patients in Linxian and in 16 (64%) of 25 additional patients outside Linxian. Its prevalence in the noncancerous epithelium (11/72, 15.3%) and carcinoma in situ (1/7, 14.3%) was lower than that in invasive lesions (64/93, 68.8%). Its immunostaining intensity increased with the depth of cancer invasion. Of 30 primary carcinomas with lymph node metastasis, 29 (96.7%) were positive. However, only 36 (51.4%) of 70 primary lesions without metastasis were positive, and a higher intensity was noticed in the metastases. There was a lower expression rate in tumors of patients surviving more than 10 years (25/52, 48.1%) than in those surviving less than 3 years (40/48, 83.3%). Overall and nonadvanced or metastasis-free cumulative survival rates were both significantly different in patients with and without p53 protein overexpression.

CONCLUSIONS

There is a higher expression rate of p53 protein in ESCC in tumors of patients from Linxian than in those from the surrounding area. The accumulation of p53 protein is related to the invasiveness and capability for metastases of cancer cells and appears to be a useful prognostic factor for patients with ESCC.

Differential diagnosis of keratoacanthomas and squamous cell carcinomas: diagnostic value of DNA image cytometry and p53 expression

DNA-cytometry and immunohistochemistry with the anti-p53 antibody DO-1 was performed in 24 keratoacanthomas (KA) and 21 squamous cell carcinomas (SCC) (13 well-differentiated, 8 moderately differentiated) to establish the possible value of these methods for the differential diagnosis of both epithelial tumors. Aneuploidy was detected in 1 (4%) KA and 12 (57%) SCC (p < 0.05). In the latter tumors, histologic grade was associated with an abnormal DNA-content. Six (46%) well and 6 (75%) moderately differentiated SCC were shown to be aneuploid. Over-expression of p53 protein was found in 16 (76%) SCC and 14 (66%) KA (p > 0.05; not significant). However, quantification of p53 expression by evaluating both the intensity of immunostaining and the number of cells with over-expression by means of an immunoreactivity score (IRS) showed significant differences (p < 0.05). There was no correlation of p53 over-expression and aneuploidy in the tumors examined. The analysis of ploidy and immunostaining with anti-p53 antibodies may give useful additional information regarding the differential diagnosis of SCC and KA, if only aneuploidy or a high IRS are considered.

Overexpression of the p53 tumor suppressor gene product in esophageal and gastric carcinomas

PURPOSE

p53 protein has been reported as frequently overexpressed in esophageal and gastric carcinomas. However, the correlation between p53 protein expression and clinico-pathological features of the tumors is debated in this heterogeneous group of cancers. The aim of this study was to establish the prevalence of p53 protein overexpression in a series of resected esophageal squamous carcinomas (n = 78), adenocarcinomas developed on Barrett's esophagus (n = 20), adenocarcinomas of the cardia (n = 36), and adenocarcinomas of the antrum (n = 30), and to correlate this expression with the clinico-pathological and flow-cytometric characteristics of the tumors.

METHODS

Immunohistochemical staining was performed on frozen sections with a monoclonal antibody directed against wild type and mutated p53 protein (Pab 1801). An adjacent frozen specimen was used for flow cytometric determination of the DNA-ploidy and S phase fraction.

RESULTS

p53 protein nuclear expression was detected in 76% of esophageal squamous carcinomas, in 75% of adenocarcinomas developed in Barretts esophagus, in 56% of adenocarcinomas of the cardia, and in 27% of adenocarcinomas of the antrum. Only the number of positive adenocarcinomas of the antrum was significantly lower when compared to the other three types of tumors (p = 0.001). No significant correlation was observed between p53 protein expression and most of the clinico-pathological and flow-cytometric parameters (sex, age, tobacco smoking, chronic alcohol consumption, size of the tumor, grade of differentiation, depth of infiltration, presence of lymph node metastases, UICC stage, DNA-ploidy, S phase fraction). p53 protein expression was more frequent in Lauren's intestinal adenocarcinomas (67%) when compared to the diffuse type tumors (24%) (p = 0.002).

CONCLUSIONS

Our results confirm that overexpression of p53 protein is a common feature of esophageal and gastric carcinomas. The high prevalence of p53 protein overexpression found in cardiac adenocarcinoma when compared to antral adenocarcinoma reinforces the hypothesis of distinct carcinogenetic mechanisms in these two cancers. In particular the lack of correlation between p53 expression and tumor stage suggests that p53 protein overexpression is an early event in these tumors.

p53 protein expression and prognosis in squamous cell carcinoma of the esophagus

BACKGROUND

The p53 gene product is known to regulate cell growth and proliferation. Whereas the wild-type p53 protein suppresses cell growth, the mutated p53 protein acts as an oncogene. Mutations in the p53 gene usually result in p53 protein stabilization and accumulation; so that the gene product can be detected by immunohistochemistry. Recently, the immunohistochemical detection of the p53 protein was associated with prognosis in breast, colorectal, and other types of cancer. However, its prognostic role in esophageal cancer remains to be elucidated.

METHODS

p53 expression in formalin fixed, paraffin embedded samples of 204 patients with primary squamous cell carcinoma of the esophagus, who underwent esophageal resection, were analyzed immunohistochemically with DO-1, a monoclonal antibody that detects wild-type and mutant forms of p53. The relationship between p53 immunoreactivity and prognostic factors was determined by the Chi-square test, and the prognostic impact of p53 protein expression was analyzed using univariate and multivariate survival analyses.

RESULTS

In 137 of 204 tumors (67.2%), nuclear immunoreactivity for the p53 protein was detected. There was no correlation with sex, age, pathologic tumor (pT) category, pathologic lymph node (pN) category, metastasis (M) category, residual cancer (R) category, histologic grade, or preoperative radiation therapy. In contrast to clinicopathologic parameters, p53 expression was not correlated with prognosis in univariate and multivariate survival analyses.

CONCLUSIONS

The p53 protein can be detected by immunohistochemistry in a high percentage of squamous cell carcinomas of the esophagus. However, the overexpression of the p53 gene product has no impact on the prognosis.