Overexpression of p53 protein is an independent prognostic indicator in human endometrial carcinoma

p53 Immunohistochemical Staining and TP53 Gene Mutations in Endometrial Cancer: Does Null Pattern Correlate With Prognosis?

Whether immunohistochemistry (IHC) of p53 accurately reflects the TP53 mutational status of endometrial carcinoma (EC) has not yet been established. This study aimed to clarify the relationship between p53 IHC and TP53 mutations in EC and to examine whether p53 IHC can be a more convenient prognostic marker than TP53 mutation in EC. We performed p53 IHC staining of EC samples obtained via surgery and genetic analyses using next-generation sequencing. p53 IHC results showed that of the 101 cases, 71 (70%) were wild-type (WT), 12 (12%) were overexpression (OE), and 18 (18%) were in the null group. Missense mutations were found in 9 cases (47.4%) in OE, 2 (10.5%) in null, and 8 (42.1%) in the WT group. Truncating mutations were found in 1 case (8.3%) in OE, 6 (50%) in null, and 5 (41.7%) in the WT group. The 5-year progression-free survival was 0% in OE, 74.8% in null, and 79.0% in the WT group. In the prognosis for each type of TP53 mutation, the 5-year progression-free survival was missense (32.2%), truncating (65.6%), and WT (79.7%). These survival comparisons showed that the p53 IHC OE had the poorest prognosis. These results suggest that the p53 IHC OE is an independent poor prognostic factor for EC and can be used as a simple and rapid surrogate marker for TP53 mutations. Contrastingly, the complete absence of p53 IHC-the null staining pattern-may not accurately predict a TP53 mutation in EC, and it is necessary to be more careful in making the diagnosis of "abnormal."

Immunohistochemical Markers and TILs Evaluation for Endometrial Carcinoma

Objective: The molecular classification for endometrial cancer (EC) introduced by The Cancer Genome Atlas Research Network (TCGA) and the Proactive Molecular Risk Classifier for Endometrial Cancer (ProMisE) proved the existence of four molecular prognostic subtypes; however, both classifications require costly technology. We suggest a prognostic model for EC based on immunohistochemistry (IHC) and tumor-infiltrating lymphocytes (TILs). Study design: One hundred patients were included. We retrospectively investigated IHC prognostic parameters: mismatch repair (MMR)-deficient tumors, p53 mutation status, progesterone receptors (PgRs), and estrogen receptors (ERs). We further evaluated TILs. These parameters were related to the clinical and morphological features and to the outcome. Results: We classified tumors into three groups (IHC analysis): MMR-deficient, p53-mutated, p53 wild-type. MMR-deficient tumors had a good prognosis, p53 wild-type tumors an intermediate one, and p53-mutated tumors had the poorest outcomes. Disease-free (DFS) and overall survival (OS) were significantly better among PgR+ tumors (respectively p = 0.011 and p = 0.001) and PgR expression is an independent prognostic factor for a better DFS frommultivariate analysis (OR = 0.3; CI: 0.1–0.9; p = 0.03).No significant correlation was observed between DFS and TILs. However, among MMR-deficient tumors, the mean value of TILs was higher than among the other tumors(111 versus 71, p = 0.01) Conclusions: The prognostic model based on IHC markers could potentially be a valid and applicable alternative to the TCGA one. The PgR determination could represent an additional prognostic factor for EC.

A prediction model based on clinical and histological features for predicting recurrence in patients with stage I-II endometrial cancer after surgical treatment

OBJECTIVE

The study aimed to develop a prediction model combining clinical and histological features to predict recurrence in patients with stage I-II endometrial cancer (EC) after surgical treatment.

METHODS

A total of 746 stage I-II EC patients who had received primary surgical treatment at Taizhou People's Hospital between 2014 and 2018 were included and randomly divided as a Training cohort (n = 520) and a Validation cohort (n = 226) at a 7:3 ratio. Clinical features including age, body mass index, comorbidities, lymphadenectomy, and adjuvant treatment, and histological features including histologic type, myometrial invasion, cervical stromal invasion, and expression levels of Ki67, estrogen receptor (ER), progesterone receptor (PR), whey acidic protein 4-disulphide core domain 2 (WFDC2), and p53 were used to develop a prediction model for EC recurrence in the Training cohort using a multivariable Cox regression model. Model discrimination and calibration were further evaluated in the Validation cohort.

RESULTS

EC recurrence was observed in 60 (11.54%) patients in the Training cohort with a median length of follow-up of 39 months. Age, adjuvant treatment, histologic type, cervical stromal invasion, and expression levels of Ki67, ER, PR, and WFDC2 were factors significantly associated with EC recurrence based on univariable Cox regression analysis. After a model selection by AIC in a stepwise algorithm, the final model incorporated the above predictors showed a C-index of 0.85 and fair calibration in the Training cohort. In the Validation cohort, the model still showed good discrimination power (C-index 0.80) but moderate calibration.

CONCLUSIONS

The developed prediction model combining clinical and histological features can help to predict the EC recurrence in patients with stage I-II EC after surgical treatment.

Prognostic Biomarkers in Endometrial Cancer: A Systematic Review and Meta-Analysis

Endometrial cancer (EC) is the sixth most common cancer in women worldwide and its mortality is directly associated with the presence of poor prognostic factors driving tumor recurrence. Stratification systems are based on few molecular, and mostly clinical and pathological parameters, but these systems remain inaccurate. Therefore, identifying prognostic EC biomarkers is crucial for improving risk assessment pre- and postoperatively and to guide treatment decisions. This systematic review gathers all protein biomarkers associated with clinical prognostic factors of EC, recurrence and survival. Relevant studies were identified by searching the PubMed database from 1991 to February 2020. A total number of 398 studies matched our criteria, which compiled 255 proteins associated with the prognosis of EC. MUC16, ESR1, PGR, TP53, WFDC2, MKI67, ERBB2, L1CAM, CDH1, PTEN and MMR proteins are the most validated biomarkers. On the basis of our meta-analysis ESR1, TP53 and WFDC2 showed potential usefulness for predicting overall survival in EC. Limitations of the published studies in terms of appropriate study design, lack of high-throughput measurements, and statistical deficiencies are highlighted, and new approaches and perspectives for the identification and validation of clinically valuable EC prognostic biomarkers are discussed.

The Association and Significance of p53 in Gynecologic Cancers: The Potential of Targeted Therapy

Dysfunction of p53 is observed in the many malignant tumors. In cervical cancer, p53 is inactivated by degradation through the complex with human papilloma virus (HPV) oncoprotein E6 and E6-associated protein (E6AP), an E3 ubiquitin protein ligase. In endometrial cancer, overexpression of p53 in immunohistochemistry is a significant prognostic factor. A discrepancy between p53 overexpression and TP53 mutations is observed in endometrioid endometrial cancer, indicating that the accumulation of p53 protein can be explained by not only gene mutations but also dysregulation of the factors such as ERβ and MDM2. Furthermore, the double-positive expression of immunoreactive estrogen receptor (ER) β and p53 proteins is closely associated with the incidence of metastasis and/or recurrence. High-grade serous ovarian carcinoma (HGSC) arises from secretary cells in the fallopian tube. The secretary cell outgrowth (SCOUT) with TP53 mutations progresses to HGSC via the p53 signature, serous intraepithelial lesion (STIL), and serous intraepithelial carcinoma (STIC), indicating that TP53 mutation is associated with carcinogenesis of HGSC. Clinical application targeting p53 has been approved for some malignant tumors. Gene therapy by the adenovirus-mediated p53 gene transfer system is performed for head and neck cancer. A clinical phase III trial using MDM2/X inhibitors, idasanutlin (RG7388) combined with cytarabine, is being performed involving relapse/refractory acute myeloid leukemia patients. The use of adenoviruses as live vectors which encode wild-type p53 has given promising results in cervical cancer patients.

Validation of Molecular Typing for Endometrial Screening Test That Predicts Benign and Malignant Lesions

The aim of this study is to examine the immunocytochemical expression of p53, Ki-67, and CA125 in endometrial brush samples for endometrial cancer. Forty-four patients were recruited with liquid-based cytology preparations during a 5-month period. Both the histological and cytological samples were assessed by histology based on hematoxylin and eosin (H&E), and the expression of p53, CA125, and Ki-67 in endometrial cells was examined by immunocytochemistry. The percentage and intensity of endometrial cells were scored on a scale of 0-3. The final score was calculated by the addition of all partial scores, and then Probit model was used to predict the possibility for malignant lesions. The mean immunoreactivity score of the three immunocytochemical biomarkers (p53, CA125, and Ki-67) in the positive group (including atypical hyperplastic cells and malignant cells) was significantly higher than in the negative group (benign cells and non-atypical hyperplastic cells). The possibility value of the positive group was also significantly higher than the negative group (P < 0.05). The cutoff value of the possibility value was 0.754, the sensitivity and specificity of which were 86.4 and 95.5%. The assessment of p53, CA125, and Ki-67 combined with the prediction model is valuable for the detection of endometrial cancer and atypical hyperplasia in endometrial cytology.

Expression of p53 and PTEN in human primary endometrial carcinomas: Clinicopathological and immunohistochemical analysis and study of their concomitant expression

Endometrial carcinoma is a common malignancy of the female genital tract. Alterations in the expression levels of various oncogenes and tumor suppressor genes serve important roles in the carcinogenesis and biological behavior of endometrial carcinoma. The aim of the present study was to evaluate the combination and individual expression of p53 and phosphatase and tensin homolog (PTEN) protein in human endometrial carcinoma. In addition, the correlation of these proteins with clinicopathological parameters was also assessed. Retrospective immunohistochemical analysis of the expression of p53 and PTEN tumor suppressor proteins was conducted in 99 women with endometrial carcinoma. The overall rate of p53 and PTEN positivity was 89 and 77%, respectively, according to the sum of stain intensity and scores of immunopositive cells. The sum of p53 positivity correlated strongly with PTEN expression (ρ=0.256; P=0.044). The concomitant sum of p53 and PTEN expression was identified in 45% of patients with endometrial adenocarcinoma. Notably, the sum of the immunohistochemical expression of p53 was significantly correlated with patient age (P=0.037), histologic type (P=0.008), histologic grade (P=0.002) and fallopian and/or ovarian invasion (P=0.014). Furthermore, PTEN expression was associated with myometrial invasion (ρ=−0.377; P=0.002) and clinical stage (P=0.019). In addition, concomitant p53 and PTEN expression was correlated with patient age (P=0.008) and histologic differentiation (P=0.028). The findings indicated a correlation between the expression of p53 and PTEN in endometrial adenocarcinoma, which suggested an intrinsic association between expression levels of these tumor suppressor genes. The study also suggested that concomitant p53 and PTEN expression contributed in characterizing the tumor behavior of endometrial carcinoma. Taken together, the present study suggested the combined expression of p53 and PTEN in the development of high-grade endometrial carcinoma in older patients. In addition, the findings indicated activation of different molecular pathways in the tumor progression between low-grade and high-grade endometrial carcinomas.

Expression of p53, Bcl-2 and Bax in endometrial carcinoma, endometrial hyperplasia and normal endometrium: a histopathological study

Our objective was to examine the expression rates of p53, Bcl-2 and Bax in endometrial carcinoma, endometrial hyperplasia and normal endometrium. A total of 94 endometrial frozen sections (carcinoma 48, hyperplasia 21, normal tissue 25) were examined immunohistochemically in terms of the expression rates of p53, Bcl-2 and Bax. All of the specimens in the non-malignant groups were positive for Bax, whereas this rate was 85.4% in the group with malignant specimens (p = .03). Conversely, p53 was expressed only in the cancerous group (77.1%, p < .001). The Bcl-2 expression rate was 54.2% in the cancer group, 76.2% in the group with hyperplasia and 60% in the group containing normal tissue (p = .23). Comparing to the non-malignant specimens, the mean Bcl-2/Bax were significantly higher in the malignant group. In conclusion, Bax under-expression, p53 over-expression and a high Bcl-2 to Bax ratio might be associated with endometrial carcinoma. Bcl-2, however, plays no significant role in this regard. Impact statement What is already known on this subject? The p53, Bcl-2 and Bax are the three major genes that regulate apoptosis. Some studies have suggested that these genes may play a role in the pathogenesis of endometrial carcinoma. The available reports, however, are old and inconclusive. What do the results of this study add? Comparing immunohistochemically obtained p53, the Bcl-2 and Bax expression rates between normal endometrial tissue, endometrial specimens with endometrial hyperplasia and specimens with carcinoma showed that Bax under-expression, p53 over-expression and a high Bcl-2 to Bax ratio were associated with malignancy. Using an up-to-date technique to examine the three major regulators of apoptosis at the same time, in a rather large sample size of both normal and abnormal endometrial tissue specimens simultaneously, are the major advantages of the present work. What are the implications of these findings for clinical practice and/or further research? According to our findings, the status of p53, Bcl-2 and Bax expression in the endometrial tissue can be used for risk stratification of endometrial carcinoma for both screening and preventive purposes.

Modeling the Etiology of p53-mutated Cancer Cells

p53 gene mutations are among the most common alterations in cancer. In most cases, missense mutations in one TP53 allele are followed by loss-of-heterozygosity (LOH), so tumors express only mutant p53. TP53 mutations and LOH have been linked, in many cases, with poor therapy response and worse outcome. Despite this, remarkably little is known about how TP53 point mutations are acquired, how LOH occurs, or the cells involved. Nutlin-3a occupies the p53-binding site in MDM2 and blocks p53-MDM2 interaction, resulting in the stabilization and activation of p53 and subsequent growth arrest or apoptosis. We leveraged the powerful growth inhibitory activity of Nutlin-3a to select p53-mutated cells and examined how TP53 mutations arise and how the remaining wild-type allele is lost or inactivated. Mismatch repair (MMR)-deficient colorectal cancer cells formed heterozygote (p53 wild-type/mutant) colonies when cultured in low doses of Nutlin-3a, whereas MMR-corrected counterparts did not. Placing these heterozygotes in higher Nutlin-3a doses selected clones in which the remaining wild-type TP53 was silenced. Our data suggest silencing occurred through a novel mechanism that does not involve DNA methylation, histone methylation, or histone deacetylation. These data indicate MMR deficiency in colorectal cancer can give rise to initiating TP53 mutations and that TP53 silencing occurs via a copy-neutral mechanism. Moreover, the data highlight the use of MDM2 antagonists as tools to study mechanisms of TP53 mutation acquisition and wild-type allele loss or silencing in cells with defined genetic backgrounds.

ESMO-ESGO-ESTRO Consensus Conference on Endometrial Cancer: Diagnosis, Treatment and Follow-up

The first joint European Society for Medical Oncology (ESMO), European SocieTy for Radiotherapy & Oncology (ESTRO) and European Society of Gynaecological Oncology (ESGO) consensus conference on endometrial cancer was held on 11-13 December 2014 in Milan, Italy, and comprised a multidisciplinary panel of 40 leading experts in the management of endometrial cancer. Before the conference, the expert panel prepared three clinically-relevant questions about endometrial cancer relating to the following four areas: prevention and screening, surgery, adjuvant treatment and advanced and recurrent disease. All relevant scientific literature, as identified by the experts, was reviewed in advance. During the consensus conference, the panel developed recommendations for each specific question and a consensus was reached. Results of this consensus conference, together with a summary of evidence supporting each recommendation, are detailed in this article. All participants have approved this final article.

ESMO-ESGO-ESTRO Consensus Conference on Endometrial Cancer: diagnosis, treatment and follow-up

The first joint European Society for Medical Oncology (ESMO), European SocieTy for Radiotherapy & Oncology (ESTRO) and European Society of Gynaecological Oncology (ESGO) consensus conference on endometrial cancer was held on 11-13 December 2014 in Milan, Italy, and comprised a multidisciplinary panel of 40 leading experts in the management of endometrial cancer. Before the conference, the expert panel prepared three clinically relevant questions about endometrial cancer relating to the following four areas: prevention and screening, surgery, adjuvant treatment and advanced and recurrent disease. All relevant scientific literature, as identified by the experts, was reviewed in advance. During the consensus conference, the panel developed recommendations for each specific question and a consensus was reached. Results of this consensus conference, together with a summary of evidence supporting each recommendation, are detailed in this article. All participants have approved this final article.

Nuclear and cytoplasmic p53 suppress cell invasion by inhibiting respiratory complex-I activity via Bcl-2 family proteins

Although the p53 tumor suppressor/transcription factor often accumulates in the cytoplasm of healthy cells, limited information is available on the cytoplasmic function of p53. Here, we show that cytoplasmic p53 suppresses cell invasion by reducing mitochondrial reactive oxygen species (ROS) levels. Analysis revealed that this function is mediated by Bcl-2 family proteins: Cytoplasmic p53 binds Bcl-w, liberating Bax, which then binds ND5, a subunit of respiratory complex-I, thereby suppressing complex-I activity and thus ROS production. The G13289A mutation of ND5, identified in cancer patients, prevents Bax/ND5 interactions and promotes ROS production and cell invasion. We also showed that Bcl-XL and Bak can substitute for Bcl-w and Bax, respectively, regulating complex-I activity and supporting the cytoplasmic function of p53; nuclear p53 also suppresses complex-I activity by inducing Bax expression. Studies in animal models support the notion that p53 and Bcl-2 family proteins exhibit these functions in vivo. This study demonstrates a link between p53 and Bcl-2 proteins as regulators of ROS production and cellular invasiveness, and reveals complex-I, especially ND5, as their functional target.

Loss of Cdh1 and Trp53 in the uterus induces chronic inflammation with modification of tumor microenvironment

Type II endometrial carcinomas (ECs) are estrogen independent, poorly differentiated tumors that behave in an aggressive manner. As TP53 mutation and CDH1 inactivation occur in 80% of human endometrial type II carcinomas, we hypothesized that mouse uteri lacking both Trp53 and Cdh1 would exhibit a phenotype indicative of neoplastic transformation. Mice with conditional ablation of Cdh1 and Trp53 (Cdh1(d/d)Trp53(d/d)) clearly demonstrate architectural features characteristic of type II ECs, including focal areas of papillary differentiation, protruding cytoplasm into the lumen (hobnailing) and severe nuclear atypia at 6 months of age. Further, Cdh1(d/d)Trp53(d/d) tumors in 12-month-old mice were highly aggressive, and metastasized to nearby and distant organs within the peritoneal cavity, such as abdominal lymph nodes, mesentery and peri-intestinal adipose tissues, demonstrating that tumorigenesis in this model proceeds through the universally recognized morphological intermediates associated with type II endometrial neoplasia. We also observed abundant cell proliferation and complex angiogenesis in the uteri of Cdh1(d/d)Trp53(d/d) mice. Our microarray analysis found that most of the genes differentially regulated in the uteri of Cdh1(d/d)Trp53(d/d) mice were involved in inflammatory responses. CD163 and Arg1, markers for tumor-associated macrophages, were also detected and increased in the uteri of Cdh1(d/d)Trp53(d/d) mice, suggesting that an inflammatory tumor microenvironment with immune cell recruitment is augmenting tumor development in Cdh1(d/d)Trp53(d/d) uteri. Further, inflammatory mediators secreted from CDH1-negative, TP53 mutant endometrial cancer cells induced normal macrophages to express inflammatory-related genes through activation of nuclear factor-κB signaling. These results indicate that absence of CDH1 and TP53 in endometrial cells initiates chronic inflammation, promotes tumor microenvironment development following the recruitment of macrophages and promotes aggressive ECs.

Expression of p53 in imprint smears of endometrial carcinoma

The aims of this study were to determine the expression of p53 protein in endometrial adenocarcinomas (as a potential prognostic indicator before treatment) as well as normal endometrium in imprint smears and to correlate the results with clinicopathologic parameters of primary untreated endometrial cancer patients. Two hundred fifty five patients were evaluated with endometrial imprint cytology during a 29-month period. Endometrial samples freshly resected from women who underwent total abdominal hysterectomy were studied. One hundred twenty six patients had endometrial carcinoma and 129 cases were diagnosed as normal endometrium. The expression of p53 was assessed by immunocytochemistry. Positive staining was correlated with increased surgical-pathological stage, histological grade and lymph node metastases. High expression of p53 staining was significantly more frequent in histological type II than type I endometrial adenocarcinoma. High-grade endometrial carcinoma had higher proportions and stronger intensity compared with low-grade carcinoma. Negative immunostain for p53 protein was found in proliferative, secretory, and atrophic endometrium. Immunocytochemical findings from p53 stain, in addition to cytomorphologic features, appeared to be useful in the diagnosis and in the postoperative prognosis of endometrial carcinoma in endometrial cytology, especially if combined with other markers. High p53 expression correlates with morphologic features of aggressiveness and the expression pattern of p53 correspond to the expected cyclic/atrophic pattern in normal endometrium.

Biomarkers in endometrial cancer: Possible clinical applications (Review)

The number of cases of endometrial cancer has shown a tendency to increase in recent years. Endometrial cancer originates from the endometrium and is classified, based on the development mechanism, into types 1 and 2, which are responsive and non-responsive to estrogen, respectively, and have significantly different gene expression profiles. Studies of genes with abnormal expression in endometrial cancer have identified multiple oncogenes, tumor suppressors, mismatch repair genes, apoptosis-associated genes, levels of hormone receptors and DNA ploidy and aneuploidy as biomarkers of endometrial cancer. The use of these molecules and genes may facilitate accurate diagnosis and prognostic prediction and contribute to individualized treatment. Trials of drugs which target these biomarkers and searches for new biomarkers using cDNA microarrays and RT-qPCR are ongoing and it is likely that these findings can be translated to clinical use.

Selected immunohistochemical prognostic factors in endometrial cancer

OBJECTIVE

The objectives of this study were to assess the immunohistochemical expression of p53, bcl-2, c-erbB-2, Ki-67, estrogen (ER) and progesterone (PR) receptors, matrix metalloproteinase-7 and -26 (MMP-7 and MMP-26) in endometrial cancer patients and to assess the relation between steroid receptor positivity and other markers.

DESIGN

Experimental prospective study.

SETTING

Department of Obstetrics and Gynecology, Department of Genetics, Department of Pathology, Palacký University Medical School and University Hospital Olomouc.

METHODS

We studied 144 cases of primary untreated endometrial carcinoma in which the p53, bcl-2, c-erbB-2, Ki-67, ER, PR, MMP-7, and MMP-26 antigens were investigated with the use of immunohistochemical methods. We evaluated the correlations among immunohistochemical staining and the age, International Federation of Gynecology and Obstetrics stage, grading, depth of invasion, and metastatic spread to lymph nodes.

RESULTS

Mean age was 65.7 years (range, 34-90 years). p53, bcl-2, c-erbB-2, Ki-67, ER, and PR were positive in 35 (24.3%), 100 (69.4%), 41 (28.4%), 65 (45.1%), 115 (79.8%), and 127 (88.1%) cases, respectively. Matrix metalloproteinases were evaluated in a group of 70 patients, wherein MMP-7 was positive in 33 patients (47.1%) and MMP-26 was positive in 40 patients (57.1%). The expression of MMP-7 decreased with higher patient age. p53 and Ki-67 overexpression was found to be related to poor differentiation. Immunostaining for bcl-2 correlated with the positivity of steroid receptors status, whereas immunostaining for c-erbB-2 correlated inversely with ER-positive group of cases.

CONCLUSIONS

The overexpression of p53 and Ki-67 seems to indicate a more malignant phenotype, whereas bcl-2 expression in dependence of steroid receptor positivity could contribute to the identification of high-risk tumors.

Correlation of p53 and Ki-67 (MIB-1) expressions with clinicopathological features and prognosis of early stage cervical squamous cell carcinomas

AIM

To evaluate the prognostic significance of the expression of p53 and Ki-67, and their correlation with various clinicopathological factors in patients with squamous cell carcinoma of the uterine cervix treated by radical hysterectomy.

METHODS

Two hundred and thirty five patients diagnosed between 1987 and 2004 were investigated for p53 and Ki-67 expression by immunohistochemistry. The relationship of these proteins and other potential prognostic factors with recurrence-free survival (RFS) was evaluated.

RESULTS

The mean age of the patients was 43.9 years (range, 27-68). There were 28 cases with stage IA2 (11.9%) and 207 cases with stage IB1 (88.1%). The overall 5-year RFS was 91.1% (95% confidence interval [CI] 86.0, 94.4). p53 and Ki-67 expressions were seen in 33.6% and 81.3% of cases, respectively. p53 expression was significantly associated only with parametrial or marginal involvement (P = 0.005), while Ki-67 expression significantly correlated only with larger tumor (P = 0.011) and parametrial or marginal involvement (P = 0.024). There was significant correlation between the expression of p53 and Ki-67 (P = 0.021). In multivariate analysis, Ki-67 expression (hazard ratio for >or=3rd vs 1st tertile [>or=30% vs <20% expression] = 16.0, 95%CI 2.1-124.5; P = 0.0015) appeared to be an independent prognostic factor for RFS, while no prognostic significance of p53 expression was found.

CONCLUSION

Ki-67 expression is an independent prognostic parameter for RFS in patients with early stage squamous cell carcinoma of the uterine cervix. Ki-67 expression at or above the cut-off point of 30.0% had significantly poorer RFS.

Differential effects of novel tumour-derived p53 mutations on the transformation of NIH-3T3 cells

The p53 tumour suppressor gene is frequently mutated in human tumours and different tumour-derived mutations have varying effects on cells. The effect of a novel tumour-derived p53 mutation and two recently described mutations from South African breast cancer patients on the growth rate, colony formation, cell cycle arrest after irradiation and response to chemotherapeutic drugs was investigated. None of the p53 mutations had any significant effect on the inherent growth rate of the cells; however, contact inhibition of growth in two of the mutants was lost. These same two mutants formed colonies in soft agar, whereas the third mutant did not. All three of the mutants failed to show a G(1) cell cycle arrest after exposure to 7 Gy of [(60)Co] radiation, albeit to different degrees. Cells expressing the p53 mutants were either more sensitive to cisplatin and melphalan or more resistant than the untransfected cells, depending on the mutation. However, there was no difference in response to daunorubicin treatment. These results demonstrate that different p53 mutations exert varying biological effects on normal cells, with some altering checkpoint activation more effectively than others. The data also suggest that the nature of the p53 mutation influences the sensitivity to cytostatic drugs.

P53/MDM2 overexpression in metastatic endometrial cancer: correlation with clinicopathological features and patient outcome

Several studies have reported that p53/mdm2 distortions play a pivotal role in the development and progression of various human malignancies. However, the number of reports having evaluated simultaneously the components of the P53-pathway alterations in advanced-stage human endometrial carcinomas (EC) is low. In this study, we examined the expression of P53/MDM2 proteins in primary and metastatic ECs, and analyzed the clinicopathological characteristics as well as the survival outcome of patients in relation to P53/MDM2 overexpression. The study group comprised 36 patients with advanced EC, whose primary and metastatic tumor slides were sufficient for analysis. Immunohistochemical assessment was made by applying anti-human P53 and MDM2 antibodies and a highly sensitive EnVision(+)/HPR visualization system. Nuclear P53 overexpression was seen in 11 (31%) primary ECs and 12 (33%) metastatic tumors. There was a significant correlation between P53 overexpression (in primary cancers and metastatic tumors) and MDM2 overexpression in metastatic tumors. Nuclear MDM2 overexpression was noted in 42% (15/36) of primary carcinomas and in 47% (17/36) of metastatic tumors. A significant association existed between MDM2 overexpression and histological grading (G1 + G2 versus G3, P = 0.043). P53/MDM2 overexpression occurred simultaneously in 7 out of 36 (19%) primary ECs and in 9 out of 36 (25%) metastatic lesions. Concomitant overexpression of these proteins was reported in 7 out of 36 (19%) cases and tended to be higher in tumors showing VSI compared to neoplasms lacking vascular space invasion (P = 0.051). P53 overexpression, either in primary ECs (P < 0.0001) or metastatic lesions (P < 0.0001), was significantly associated with poor survival in univariate analysis. Moreover, the log-rank test demonstrated that simultaneous P53/MDM2 overexpression was also correlated with decreased length of survival. There was no correlation between MDM2 overexpression and patient survival. Multivariate Cox regression analysis revealed that only P53 overexpression is an independent predictor of survival. In conclusion, our data support the view that patients with P53 overexpression are significantly associated with an unfavorable outcome, whereas MDM2 overexpression is not related to decreased survival length in women operated on for advanced-stage EC.

The association between p53 expression, stage and histological features in endometrial cancer

OBJECTIVE

Alterations of the p53 gene have been widely suggested to be relevant to the development of endometrial carcinoma. However, contradictory results have been reported when immunohistochemical determination of p53 expression has been correlated with stage and histological features of the tumours.

STUDY DESIGN

Pathology findings were reviewed and p53 immunoperoxidase staining was performed in 240 cases of endometrial carcinoma.

RESULTS

Uterine papillary serous adenocarcinomas showed significantly higher p53 overexpression than uterine endometrioid adenocarcinomas (100.0% versus 61.0%, p<0.005). p53 overexpression was significantly higher in the secretory variant (85.7%) than in the typical endometrioid carcinoma (60.0%) (p<0.05). p53 expression did not differ between early (stage I) and advanced (stage II-IV) carcinomas. Likewise, no difference was observed in p53 expression among different architectural grades. The incidence of metastasis to lymph nodes was similar in p53 positive (13.7%) and in p53 negative tumours (12.5%).

CONCLUSION

In the present series, p53 immunostaining did not differ between cases with different FIGO stages or histologic characteristics of the tumours. No simple relationship exists between the immunohistochemical determination of p53 expression and the biological aggressiveness of endometrial carcinomas.

Association of p53 mutations and a codon 72 single nucleotide polymorphism with lower overall survival and responsiveness to adjuvant radiotherapy in endometrioid endometrial carcinomas

p53 Genetic alterations are associated with advanced stage and aggressive tumors in a variety of human malignancies. The aim of this study was to examine p53 for genetic alterations and to evaluate the association of these alterations with clinical outcome and response to adjuvant radiotherapy in endometrioid endometrial carcinomas. p53 mutations in exons 2-11 were assessed in 59 endometrioid carcinomas by polymerase chain reaction-single-strand conformational polymorphism and sequence analysis. Twelve mutations (20.3%) and nine polymorphisms were identified. Seven of the nine polymorphisms were codon 72 single nucleotide polymorphisms (SNP) with an Arg/Pro allelotype. Women harboring either a mutation or an Arg/Pro allelotype at codon 72 had a lower overall survival rate than women whose tumors lacked alterations in the p53 gene (P= 0.0029). Women were stratified based on p53 genetic alterations (p53 mutation or p53 codon 72 SNP) and whether or not they received adjuvant radiation therapy. Women with p53 genetic alterations who did not receive adjuvant radiotherapy had the lowest survival rate (P= 0.0005). Treated women with p53 genetic alterations and untreated women with no p53 alteration had similar rates of survival. Among women with p53 alterations, adjuvant radiotherapy substantially increased survival (P= 0.035). In multivariate analyses, the group of women with p53 genetic alterations who did not receive adjuvant radiation therapy had a 5.9-fold increased risk of death (95% confidence interval: 1.5-22.7) compared to women whose tumors lacked p53 alterations and did not receive adjuvant radiation therapy.

Functional analysis of p53 gene and the prognostic impact of dominant-negative p53 mutation in endometrial cancer

In addition to the loss of function, mutant p53 can possess a dominant-negative effect on wild-type p53 and may also exert gain-of-function activity. It is not clear whether the functional status of p53 mutation contributes to differences in outcome in endometrial cancer. We collected a total of 92 RNA samples of high quality from endometrial cancer tissues, and the samples were subjected to yeast functional assay and sequencing for p53 mutations. The detected mutant p53 genes were further investigated for their dominant-negative activity using a yeast-based transdominance assay. p53 mutation was found in 24 out of 92 (26.1%) tumors, of which 10 exhibited no dominant-negative activity (recessive mutation) and 14 showed dominant-negative activity. Dominant-negative p53 mutation was related to advanced stages (p = 0.01), nonendometrioid type tumors (p = 0.01) and grade 3 tumors (p = 0.04). The patients with dominant-negative mutation had significantly shorter survival than patients with no mutation (p < 0.0001) and those with a recessive mutation (p = 0.01) in the p53 gene. No difference in survival was found between the patients with tumors harboring a recessive p53 mutation and those with tumors harboring a wild-type p53. Multivariate analysis revealed that dominant-negative p53 mutation (p = 0.019), FIGO stage (p = 0.0037) and histologic subtype (p = 0.014) were independently related to patient survival. Dominant-negative p53 mutation was the most important prognostic factor for stage III/IV endometrial cancer (p = 0.0023). In conclusion, dominant-negative p53 mutation is often found in advanced stages and aggressive histologic subtypes of endometrial cancer and it is a strong predictor of survival of patients with advanced endometrial cancer. To elucidate further the role of p53 mutation in endometrial cancer, it is necessary to investigate gain-of-function activity involving dominant-negative p53 mutant proteins.

Intratumoral heterogeneous expression of p53 correlates with p53 mutation, Ki-67, and cyclin A expression in endometrioid-type endometrial adenocarcinomas

To further elucidate the significance of p53 mutation in endometrial carcinoma, we investigated it in endometrioid-type endometrial carcinomas showing intratumoral heterogeneous p53 expression. In addition, we also examined the correlation of p53 mutation and cyclin A expression, because we previously reported a topological correlation between the expression of p53 and cyclin A. The p53 mutation in exons 5-8 in 54 cases of endometrial carcinoma showing immunohistochemical expression of p53 was examined using microdissected tissue DNAs. Of the 54 p53-positive endometrial carcinomas, 23 (43%) had p53 mutation with a tendency in histologically higher grade tumors. Ten of the 54 showed a heterogeneous p53 expression, and in 9 of the 10 cases, p53 mutation was present only in p53-positive sites, which were often found in histologically less differentiated areas with elevated Ki-67 in the same tumor. Cyclin A expression was topologically observed in p53-positive areas; however, it was noted in both tumors with (12/23, 52%) and without (18/31, 58%) p53 mutation. These results suggest that p53 mutation is a late event and plays an important role in the acquisition of malignant potentials in endometrioid-type endometrial adenocarcinomas. Unexpectedly, accumulation of the p53 protein itself may be important in cyclin A overexpression.

Cyclooxygenase-2 and p53 Expressions in Endometrial Cancer

Cyclooxygenase-2 (COX-2) has been known to be related with various types of carcinoma, but we have insufficient knowledge about the association between COX-2 and endometrial cancer. Many have reported a close relationship between p53 expression and a poor prognosis in endometrial cancer, but it is unclear whether p53 is an independent prognostic factor. To clarify these uncertainties, we examined the expressions of COX-2 and p53 in endometrial cancer tissues. The study was carried on 152 endometrial cancer patients who had operation at Seoul National University Hospital. Paraffin-embedded tissue blocks were sectioned and immunostained using monoclonal anti-COX-2 and anti-p53 antibodies. Twenty-seven (17.8%) specimens stained as COX-2 positive. COX-2 positivity was more frequently observed in postmenopausal patients than in premenopausal patients (8.8% versus 25.0%; P = 0.009). However, COX-2 positivity did not show a statistically significant association with any other clinicopathologic characteristic (parity, body mass index, histotype, International Federation of Gynecology and Obstetrics stage, grade, lymph node metastasis, deep myometrial invasion, or p53 overexpression). Thirty-one (20.4%) specimens showed p53 overexpression and this was significantly correlated with an advanced stage (P = 0.001), poor differentiation (P &lt; 0.001), lymph node metastasis (P = 0.012), and deep myometrial invasion (P &lt; 0.001). Multivariate Cox regression analysis showed that advanced stage was an independent prognostic factor of survival, but p53 overexpression was not. COX-2 may be associated with endometrial cancer carcinogenesis during the postmenopausal period but not with tumor aggressiveness and p53 overexpression. The p53 overexpression was found to be strongly associated with endometrial cancer aggressiveness.

Interpretation of p53 Immunoreactivity in Endometrial Carcinoma: Establishing a Clinically Relevant Cut-Off Level

There is accumulating evidence that immunohistochemical staining for p53 can identify patients with endometrial carcinoma who have an adverse outcome, but the interpretation of existing data is complicated by differences between studies in the way that p53 immunohistochemistry results have been assessed. In this study, we sought to determine the appropriate cut-off level for stratification of patients with endometrial carcinoma into high- and low-risk groups, based on p53 immunohistochemical staining. A total of 200 cases of endometrial carcinoma treated by hysterectomy were retrieved from the archives of the Department of Pathology, Vancouver General Hospital, from the period 1983 to 1998. Follow-up information was available for all cases. Slides were reviewed and the diagnosis confirmed, tumors graded according to FIGO grading system, and tumor cell type assessed. A tissue microarray consisting of duplicate 0.6-mm cores of tumor was constructed and immunostained for p53. Immunoreactivity for p53 was scored by counting the number of positively stained tumor cell nuclei and expressing this as a percentage of the total number of tumor cell nuclei counted (p53 index). Kaplan-Meier survival curves were constructed and compared by calculation of log-rank statistic, and multivariate analysis was performed by Cox regression modeling. The distribution of p53 index results was bimodal, with most cases having a very low or very high p53 index. The peaks of the bimodal distribution were clearly separated using a p53 index of > or =50%. Immunoreactivity was a significant adverse prognostic indicator of disease-specific survival (p<0.0001 by univariate analysis). Patients with strongly p53 immunoreactive tumors (p53 index >or =50%) had a significantly worse outcome than patients with weakly immunoreactive (p53 index > or =5% and <50%) or p53-negative (p53 index <5%) tumors (p = 0.0001). There was no significant difference between the outcomes for patients in the latter two groups. By multivariate analysis, p53 overexpression was a significant prognostic indicator independent of patient age and tumor stage (p = 0.008) but was not independent when the analysis was extended to include FIGO grade and tumor cell type. p53 immunostaining was of prognostic significance in the subset of patients with endometrioid carcinomas (p = 0.02), but not in patients with clear cell or papillary serous carcinomas. Using a p53 index of > or =50% as a cut-off between positive and negative p53 staining, immunohistochemical staining for p53 is a prognostic indicator in patients with endometrial carcinoma of endometrioid type. p53 immunostaining was not found to be of prognostic significance independent of tumor cell type and grade.

Angiogenesis, p53, and bcl-2 expression as prognostic indicators in endometrial cancer: comparison with traditional clinicopathologic variables

We investigated the relation of expression of tumor-suppressor gene product p53, apoptosis-regulator gene product bcl-2, and CD34 (as a measure of microvessel density [MVD]) with traditional clinicopathologic prognostic variables in endometrial carcinoma (histologic type, grade, depth of myometrial invasion, angiolymphatic invasion, lymph node involvement). In specimens from 63 patients with endometrial carcinoma, the mean MVD (64.38+/-28.71 microvessels per 200x field) was not related to any clinicopathologic variables. Nuclear p53 expression was detected in 15 (23.8%) patients and was higher in nonendometrioid carcinomas (p<0.05) and in tumors with increasing histologic grade (p<0.001). Cytoplasmic bcl-2 staining was seen in 79.3% of the tumors. There was a negative correlation between bcl-2 expression and histologic type and tumor grade (p<0.05). In survival analysis, patient age, FIGO stage, high expression of p53, low expression of bcl-2, and high and intermediate MVD values were found to be the most significant prognostic indicators of survival (p<0.05). In multivariate regression analysis, FIGO stage and low bcl-2 expression were found to be the only independent indicators of prognosis (p<0.05).

Immunohistochemical expression of cyclin E in endometrial adenocarcinoma (endometrioid type) and its clinicopathological significance

PURPOSE

Cyclin E is known as a G1-S phase regulatory protein and its abnormal expression has been implicated in cellular proliferation. This study aimed to investigate the correlation of cyclin E expression with tumorigenesis of the endometrium, proliferative activity, and clinicopathological features of endometrial adenocarcinoma.

METHODS

Immunohistochemical staining for cyclin E in addition to cyclin-dependent kinase 2 (cdk2), Ki67, p27, and p53 was performed by the labeled streptavidin-biotin method on formalin-fixed, paraffin-embedded tissues of normal endometria (20 cases), endometrial hyperplasias (20 cases), and endometrial adenocarcinomas (endometrioid type) (127 cases). Positive staining was expressed as a labeling index (LI) based on percentages of positive nuclei in tumor cells.

RESULTS

Immunohistochemistry showed that the nuclei of the cells were positive for cyclin E. Both proliferative and secretory endometria, and endometrial hyperplasia regardless of type were negligible for cyclin E expression. The expression in normal endometrium and hyperplasia was significantly less than that in endometrial adenocarcinomas (P<0.0001). LIs of cyclin E in well-differentiated, moderately differentiated, and poorly differentiated endometrial adenocarcinomas were 31.5+/-33.3%, 37.8+/-31.9%, and 51.1+/-30.8%, respectively. Cyclin E expression increased significantly more in histological grades. The LI of cyclin E in carcinoma was positively correlated with that of cdk2, Ki67, and p53 but not with p27. The cyclin E expression was correlated with myometrial invasion and lymph-vascular space involvement, but not with FIGO stage, lymph node metastasis, coexisting endometrial hyperplasia, estrogen receptor, progesterone receptor, and menopause.

CONCLUSION

Cyclin E as a complex with cdk2 is associated with carcinogenesis and disease progression in endometrial adenocarcinoma, and might be a prognostic indicator of endometrial adenocarcinoma.

p53 expression in normal paraffin-embedded tissue using different antibodies and antigen retrieval buffer systems

AIMS

The study was undertaken to demonstrate wild-type p53 in normal paraffin-embedded tissues using two widely used antibodies, DO7 and 1801 and two different antigen retrieval buffer systems.

METHODS AND RESULTS

Formalin-fixed paraffin-embedded normal tissue samples were obtained from the archives of the John Radcliffe Hospital, Oxford. Antigen retrieval was performed by microwaving using two different buffer systems: (i) the commercially available Dako target retrieval solution (Cat. no. 1699) (pH 9.8-9.9), (ii) freshly prepared buffer consisting of 0.1 m EDTA with 0.1% Tween pH 6.0, and (iii) freshly prepared buffer consisting of 0.1 m EDTA with 0.1% Tween pH 8.0. Staining was performed with DO7 and 1801 antibodies using the Dako Envision kit (peroxidase/DAB). DO7 antibody elicited strong nuclear staining in the mucosal cells of the small and large intestine, lymphoid cells, decidua, neurones such as Purkinje cells of the cerebellum, glandular epithelial cells and stromal cells of the prostate, cardiac myocytes and bronchial epithelial cells. Cytoplasmic staining was noted in Purkinje cells, glandular epithelium of prostate, exocrine pancreas and renal tubular epithelium. The 1801 antibody did not produce staining in any of these tissues.

CONCLUSIONS

Our study demonstrates the presence of p53 in normal paraffin-embedded tissue with nuclear and/or cytoplasmic localization in some instances. In our view, DO7 appears to be better suited for such detection.

Molecular pathogenesis and prognostic factors in endometrial carcinoma

Endometrial carcinoma is today among the most common gynecologic malignancies in industrialized countries. In order to improve the treatment and follow-up of these patients, various prognostic factors have been extensively studied. Patient age, stage of disease, histologic type and histologic grade have been shown to influence survival significantly, and the prognostic impact of these traditional clinicopathologic variables is well established. In addition, parity, hormone receptor concentration in the tumor, DNA ploidy and morphometric nuclear grade have all been found to influence prognosis. Information about DNA ploidy has especially been used in the clinical situation to determine individualized treatment. The prognostic significance of markers for tumor cell proliferation, cell cycle regulation (p53, p21 and p16) and angiogenesis is discussed as well as the molecular basis of endometrial carcinoma. In conclusion, several prognostic markers have been identified. It is likely that the information derived from these tumor biomarkers will reduce the need for extensive surgical staging and adjuvant treatment in endometrial carcinoma.

Nuclear and cytoplasmic p53 expression in pharyngeal squamous cell carcinoma: prognostic implications

BACKGROUND

The role of p53 expression in human neoplasms is still controversial, and it has been associated with both favorable and unfavorable outcome of the patients. Also cytoplasmic expression of p53 protein has been reported to affect survival in some cancers. Furthermore, an association between p53 and beta-catenin expression has been demonstrated. We studied the expression of p53 in a large group of oropharyngeal and hypopharyngeal squamous cell carcinomas and its relation to catenin expression, histologic differentiation, clinical data, and prognosis.

METHODS

Primary tumors for analyses were obtained from 123 patients diagnosed with squamous cell carcinoma of the oropharynx or hypopharynx between 1975 and 1998 in Eastern Finland. Immunohistochemistry was used to evaluate the expression of p53 as well as alpha-, beta-, and gamma-catenins.

RESULTS

In the primary tumors (n = 123), the nuclear p53 expression index was low in 42 (34%), intermediate in 38 (31%), and high in 43 (35%) cases. Cytoplasmic p53 expression was present in 56 (46%) and absent in 67 (54%) tumors. In univariate analyses (Kaplan-Meier), hypopharyngeal primary site (p =.02), high T class (p <.0005), presence of distant metastases (p =.02), low Karnofsky performance index (p <.0005), high nuclear p53 expression index (p =.01), and positive cytoplasmic p53 expression (p =.04) predicted poorer overall survival (OS). In Cox proportional hazards model, only T class (p =.0005), Karnofsky performance index (p =.005), and nuclear beta-catenin expression (p =.038) predicted poorer OS.

CONCLUSION

Positive cytoplasmic p53 expression and nuclear p53 overexpression seem to relate to more aggressive features and unfavorable outcome in pharyngeal squamous cell carcinoma (PSCC). However, unlike more traditional variables, p53 expression is not an independent predictor of disease outcome in PSCC.

TP53 protein expression analysis by luminometric immunoassay in comparison with gene mutation status and prognostic factors in early stage endometrial cancer

Mutations in the TP53 tumor suppressor gene have been shown to significantly correlate with poor prognosis in endometrial cancer. In the present study we have evaluated a luminometric immunoassay (LIA) for quantitative estimation of TP53 protein expression in 65 cytosol preparations from endometrial cancer, previously analyzed for mutations in TP53 exons 4-10. LIA showed high (> or = 0.6 ng/mg protein) expression of TP53 protein in all eight tumors with missense mutation, but high protein levels were also detected in 15 tumors with normal TP53 sequence. All four tumors with nonsense or frameshift mutations had low or no TP53 protein expression. LIA was further evaluated in a retrospective study of 201 cytosol samples from endometrial cancer. TP53 overexpression (> = 0.6 ng/mg protein) was observed in 22% of the tumors and correlated with nonendometrioid histology types (P = 0.005), poorly differentiated tumors (P = 0.001), higher FIGO grade (P = 0.001), DNA nondiploidy (P = 0.002), and high S-phase fraction (P = 0.03). After a median follow-up time of 6.8 years (range 0.7-9.9 years), 22 (13%) progressions were observed in the 175 patients with early stage (I-II) disease. TP53 overexpression (P = 0.04), FIGO grade 3 vs. 1 + 2 (P = 0.01), higher age (P = 0.02), and DNA nondiploidy (P < 0.001) showed significant correlation to shorter progression-free survival in these patients. We conclude that TP53 protein analysis by LIA provides an incomplete correlation to mutation status and cannot substitute for mutation analysis in assessment of prognosis in endometrial carcinoma. In comparison to TP53 overexpression and higher FIGO grades, DNA nonploidy status seems to be a better prognostic indicator to define a subset of early stage endometrial cancer patients who may benefit by adjuvant chemotherapy/radiotherapy.

Markers of proliferative activity are predictors of patient outcome for low-grade endometrioid adenocarcinoma but not papillary serous carcinoma of endometrium

On the basis of pathogenesis, two types of endometrial cancer can be recognized. Type 1 endometrial carcinomas are relatively indolent tumors that develop after prolonged estrogen stimulation, on a background of endometrial hyperplasia. Type 2 endometrial carcinomas are aggressive tumors that are not associated with hyperplasia or estrogen excess. The aim of this study is to evaluate the prognostic significance of tumor proliferative activity in early-stage endometrial cancer by using mitotic index and immunostaining, comparing Type 1 (endometrioid) and Type 2 (papillary serous carcinoma) tumors. The mitotic index, MIB-1, and p53 immunostaining in 39 tumors from patients with low-grade Stage Ia or Ib endometrioid adenocarcinoma; as well as 23 tumors from patients with Stage I papillary serous carcinoma. In low-grade endometrioid adenocarcinoma, mitotic and MIB-1 indices were statistically significant independent prognostic indicators (P =.004 and P =.018, respectively), and both were strongly correlated with p53 expression (P =.01 and P =.006, respectively). The mean mitotic index was 5 mitoses/10 high-power fields, and mean MIB-1 index was 27.5%. There was no significant correlation between mitotic or MIB-1 indices and patient outcome or p53 expression in papillary serous carcinoma. The mean mitotic index was 31 mitoses/10 high-power fields, and mean MIB-1 index was 30.5% in these tumors. p53 expression and proliferative indices are strongly correlated in low-grade endometrioid adenocarcinoma. MIB-1 and mitotic indices are independent prognostic indicators in these tumors. Papillary serous carcinoma of endometrium is rapidly proliferative in tumors even at an early stage, and quantification of proliferative activity in these tumors does not allow prediction of patient outcome.

Relationship between p53 pathway and estrogen receptor status in endometrioid-type endometrial cancer

We analyzed the mechanism of estrogen receptor (ER) loss and status of the p53 pathway in 64 cases of endometrial cancer. 26.6% (17 of 64) of endometrial cancers lost ER. Methylation of the ER CpG island was significantly related to ER status (P = 0.0074). However, the methylation site of the ER CpG island differed between breast and endometrial cancers. The abnormal expression rate of p14ARF, MDM2, p53, and the p53 pathway were 7.8% (5 of 64), 32.8% (21 of 64), 25.0% (16 of 64) and 53.1% (34 of 64), respectively. There was no significant difference in the overexpression of MDM2 between p53-positive cases (43.8%: 7 of 16) and p53-negative cases (29.2%; 14 of 48) (P = 0.3595). Abnormal p53 was higher in grade 3 tumors (55.6%; 5 of 9) than in grade 1 and 2 tumors (20.0%; 11 of 55) (P = 0.0364). The abnormality of the p53 pathway was higher in grade 3 tumors (88.9%; 8 of 9) than in grade 1 and 2 tumors (47.3%; 26 of 55) (P = 0.0294). However, there was no significant difference in abnormal p53 pathway between ER-negative and ER-positive cases. In endometrial cancer, ER CpG island methylation was the important mechanism of ER loss. However, there was no significant relationship between the p53 pathway and ER status.

Nuclear DNA content, proliferative activity, and p53 expression related to clinical and histopathologic features in endometrial carcinoma

The purpose of this study was to evaluate the prognostic impact of image cytometry DNA ploidy, MIB-1, and p53 in relation to clinicopathologic variables in 376 consecutive patients with endometrial carcinoma stages I-IV. Following primary treatment 358 patients were considered tumor-free. Relapses and tumor-specific deaths of these patients were noted. Image cytometry DNA ploidy (n = 340) and expression of MIB-1 (n = 318) and p53 (n = 323) were studied. In univariate analysis, stage (P < 0.001), histopathologic subtype (P < 0.001), degree of differentiation (P < 0.001), HRT (P = 0.034), DNA ploidy (P < 0.001), and p53 (P < 0.001) were significant predictors of relapse. Patient age showed that the estimated mean risk of relapse increases with nearly 64% per decade in life (P 0.003), and the MIB-1 expression with 21% per 10-unit increment (P 0.004). In multivariate analysis, degree of differentiation, MIB-1, and p53 lost their prognostic capability. However, after stage and histopathologic subtype, image cytometry DNA ploidy was the strongest predictor of outcome and was of value in predicting the risk for relapse. The combination of DNA ploidy, MIB-1, and p53 expression was an even stronger predictor of relapse-free survival than the individual prognostic factors.

P53 overexpression predicts endometrial carcinoma recurrence better than HER-2/neu overexpression

OBJECTIVE

to investigate the prognostic value of p53 and HER-2/neu overexpression in endometrial cancer.

STUDY DESIGN

p53 and HER-2/neu immunostaining was performed in 114 paraffin-embedded specimens of endometrial cancer diagnosed and treated between 1990 and 1997. Nuclear p53 and membrane HER-2/neu immunostaining were used.

RESULTS

p53 and HER-2/neu overexpression was observed in 17 cases (14.9%) and in 19 cases (16.7%), respectively. In univariate analysis p53 (P<0.001) and HER-2/neu (P=0.018) overexpression had a positive correlation with a high risk of recurrence. In multivariate analysis, age (P<0.001), FIGO stage (P<0.001), differentiation (P=0.013), non-endometrioid subtypes (P<0.001) and p53 overexpression (P<0.001), but not HER-2/neu overexpression, were independent prognostic indicators of recurrence. Simultaneous p53 and HER-2/neu overexpression made worse the prognostic (P<0.001).

CONCLUSIONS

p53 overexpression was an independent predictor of recurrent disease in endometrial cancer. HER-2/neu overexpression had a more limited effect but enhance the effect of p53.

Immunohistochemical analysis of MIB-1 proliferative activity in human endometrial cancer. Correlation with clinicopathological parameters, patient outcome, retinoblastoma immunoreactivity and K-ras codon 12 point mutations

To test the prognostic utility of MIB-1 in human endometrial neoplasias, the proliferative activities of fifty-two endometrial carcinomas obtained from Polish women were assessed. We also investigated the relationship between the MIB-1 Proliferative Index and the well-known clinicopathological features of cancer (clinical stage, histological type, histological grade, depth of myometrial invasion), patient's age, overall survival, retinoblastoma immunostaining and K-ras codon 12 point mutations. The mean MIB-1 Proliferation Index was 43.8%, with a median of 36.0%. Due to the great intratumour heterogeneity of the immunoreaction, the Index ranged from 0% to 98%. A significant relationship was noted between MIB-1 expression and histological grading (p = 0.0004) and myometrial invasion of cancer (p = 0.01). Multivariate Cox regression demonstrated that the clinical stage was the only independent prognostic factor during follow-up (p = 0.025). There was a tendency towards a poorer outcome for women with a Proliferative Index of > 31% than for patients whose Index was < or = 31%; the difference, however, did not reach significance (p = 0.25; log-rank test). Interestingly, uterine cancers lacking retinoblastoma protein expression had a mean MIB-1 Proliferation Index that was nearly twice as high as in those neoplasias that stained positively for retinoblastoma (70.33% and 42.14%, respectively; p = 0.09; Mann-Whitney-U test). There were no significant differences between K-ras codon 12 point mutation-positive and -negative endometrial carcinomas regarding the proliferative activity of the cancer (mean Indexes 47.6% and 43.8%, respectively; p = 0.66, Mann-Whitney-U test). Our data support the view that MIB-1 proliferative activity was significantly increased with a decrease of the histological grading and with the myometrial invasion of human endometrial cancer.

Expression of transcription factor AP-2alpha predicts survival in epithelial ovarian cancer

The 52-kDa activator protein (AP)-2 is a DNA-binding transcription factor which has been reported to have growth inhibitory effects in cancer cell lines and in human tumours. In this study the expression of AP-2alpha was analysed in 303 epithelial ovarian carcinomas by immunohistochemistry (IHC) with a polyclonal AP-2alpha antibody and its mRNA status was determined by in situ hybridization (ISH) and reverse transcriptase-polymerase chain reaction (RT-PCR). The immunohistochemical expression of AP-2alpha was correlated with clinicopathological variables, p21/WAF1 protein expression and survival. In normal ovaries, epithelial cells expressed AP-2alpha protein only in the cytoplasm. In carcinomas nuclear AP-2alpha expression was observed in 28% of the cases although cytoplasmic expression was more common (51%). The expression of AP-2alpha varied according to the histological subtype and differentiation. AP-2alpha and p21/WAF1 expressions did not correlate with each other. Both in univariate (P = 0.002) and multivariate analyses (relative risks (RR) 1.6, 95% confidence interval (CI) 1.13-2.18, P= 0.007) the high cytoplasmic AP-2alpha expression favoured the overall survival. In contrast, the nuclear AP-2alpha expression combined with low cytoplasmic expression increased the risk of dying of ovarian cancer (RR = 2.10, 95% CI 1.13-3.83, P= 0.018). The shift in the expression pattern of AP-2alpha (nuclear vs cytoplasmic) in carcinomas points out to the possibility that this transcription factor may be used by oncogenes in certain histological subtypes. Based on the mRNA analyses, the incomplete expression and translation of AP-2alpha in ovarian cancer may be due to post-transcriptional regulation.

p53 as a significant prognostic marker in endometrial carcinoma

Although several studies have reported that p53 overexpression is associated with poor survival from endometrial cancer, this relationship might be confounded by a number of possible factors. The objective of this study was to examine the prognostic role of p53 overexpression in endometrial cancer when a panel of well-selected potential confounding factors were controlled. One hundred and twenty-five endometrial cancers were examined for p53 overexpression by immunohistochemistry (IHC). Demographic and clinical data, including age at diagnosis, race, residence, tumor grade, surgical stage, and other possible confounding factors for endometrial cancer such as diabetes, family history of cancer, hypertension, hormone replacement therapy (HRT), and obesity were collected from medical charts and pathologic reports. Survival status was determined at the end of follow-up. The Kaplan-Meier method was used to derive the survival curve, while the log-rank test was used to compare curves for two or more groups of patients. The proportional hazards regression model was used to obtain maximum likelihood estimates of relative risks (RR) and their 95% confidence intervals. Compared to the p53 nonaltered group, the presence of p53 overexpression in endometrial carcinoma was related to significantly decreased patient survival. High nuclear grade and high FIGO stage were associated with poor survival. No obvious association was found between survival and study site, race, age, and other potential risk factors of endometrial cancer. Only two variables (p53 and stage) were significantly associated with poor survival in the multivariate proportional hazards analysis. Overexpression of p53 was found to be the most significant predictor of specific survival. The relative risk for p53 overexpression was 7.46 (95% CI: 4.26-13.1) and for late stage was 4.35 (95% CI: 1.91-9.92). We conclude that p53 overexpression is the most important predictor for patient survival when a panel of well-selected potential confounding factors are taken into account. Patients with endometrial cancers who have p53 overexpression have a seven-fold higher risk of dying from disease compared to those without p53 overexpression. Whether detection of p53 alteration may serve as an indicator of high-risk patients for whom more aggressive adjuvant chemotherapy may be considered needs to be explored in the future.